| /* |
| * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| // no precompiled headers |
| #include "classfile/classLoader.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "code/icBuffer.hpp" |
| #include "code/vtableStubs.hpp" |
| #include "compiler/compileBroker.hpp" |
| #include "interpreter/interpreter.hpp" |
| #include "jvm_linux.h" |
| #include "memory/allocation.inline.hpp" |
| #include "memory/filemap.hpp" |
| #include "mutex_linux.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "os_share_linux.hpp" |
| #include "prims/jniFastGetField.hpp" |
| #include "prims/jvm.h" |
| #include "prims/jvm_misc.hpp" |
| #include "runtime/arguments.hpp" |
| #include "runtime/extendedPC.hpp" |
| #include "runtime/globals.hpp" |
| #include "runtime/interfaceSupport.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/objectMonitor.hpp" |
| #include "runtime/osThread.hpp" |
| #include "runtime/perfMemory.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "runtime/statSampler.hpp" |
| #include "runtime/stubRoutines.hpp" |
| #include "runtime/threadCritical.hpp" |
| #include "runtime/timer.hpp" |
| #include "services/attachListener.hpp" |
| #include "services/runtimeService.hpp" |
| #include "thread_linux.inline.hpp" |
| #include "utilities/decoder.hpp" |
| #include "utilities/defaultStream.hpp" |
| #include "utilities/events.hpp" |
| #include "utilities/growableArray.hpp" |
| #include "utilities/vmError.hpp" |
| #ifdef TARGET_ARCH_x86 |
| # include "assembler_x86.inline.hpp" |
| # include "nativeInst_x86.hpp" |
| #endif |
| #ifdef TARGET_ARCH_sparc |
| # include "assembler_sparc.inline.hpp" |
| # include "nativeInst_sparc.hpp" |
| #endif |
| #ifdef TARGET_ARCH_zero |
| # include "assembler_zero.inline.hpp" |
| # include "nativeInst_zero.hpp" |
| #endif |
| #ifdef TARGET_ARCH_arm |
| # include "assembler_arm.inline.hpp" |
| # include "nativeInst_arm.hpp" |
| #endif |
| #ifdef TARGET_ARCH_ppc |
| # include "assembler_ppc.inline.hpp" |
| # include "nativeInst_ppc.hpp" |
| #endif |
| |
| // put OS-includes here |
| # include <sys/types.h> |
| # include <sys/mman.h> |
| # include <sys/stat.h> |
| # include <sys/select.h> |
| # include <pthread.h> |
| # include <signal.h> |
| # include <errno.h> |
| # include <dlfcn.h> |
| # include <stdio.h> |
| # include <unistd.h> |
| # include <sys/resource.h> |
| # include <pthread.h> |
| # include <sys/stat.h> |
| # include <sys/time.h> |
| # include <sys/times.h> |
| # include <sys/utsname.h> |
| # include <sys/socket.h> |
| # include <sys/wait.h> |
| # include <pwd.h> |
| # include <poll.h> |
| # include <semaphore.h> |
| # include <fcntl.h> |
| # include <string.h> |
| # include <syscall.h> |
| # include <sys/sysinfo.h> |
| # include <gnu/libc-version.h> |
| # include <sys/ipc.h> |
| # include <sys/shm.h> |
| # include <link.h> |
| # include <stdint.h> |
| # include <inttypes.h> |
| # include <sys/ioctl.h> |
| |
| #define MAX_PATH (2 * K) |
| |
| // for timer info max values which include all bits |
| #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) |
| |
| #define LARGEPAGES_BIT (1 << 6) |
| //////////////////////////////////////////////////////////////////////////////// |
| // global variables |
| julong os::Linux::_physical_memory = 0; |
| |
| address os::Linux::_initial_thread_stack_bottom = NULL; |
| uintptr_t os::Linux::_initial_thread_stack_size = 0; |
| |
| int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; |
| int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; |
| Mutex* os::Linux::_createThread_lock = NULL; |
| pthread_t os::Linux::_main_thread; |
| int os::Linux::_page_size = -1; |
| bool os::Linux::_is_floating_stack = false; |
| bool os::Linux::_is_NPTL = false; |
| bool os::Linux::_supports_fast_thread_cpu_time = false; |
| const char * os::Linux::_glibc_version = NULL; |
| const char * os::Linux::_libpthread_version = NULL; |
| |
| static jlong initial_time_count=0; |
| |
| static int clock_tics_per_sec = 100; |
| |
| // For diagnostics to print a message once. see run_periodic_checks |
| static sigset_t check_signal_done; |
| static bool check_signals = true;; |
| |
| static pid_t _initial_pid = 0; |
| |
| /* Signal number used to suspend/resume a thread */ |
| |
| /* do not use any signal number less than SIGSEGV, see 4355769 */ |
| static int SR_signum = SIGUSR2; |
| sigset_t SR_sigset; |
| |
| /* Used to protect dlsym() calls */ |
| static pthread_mutex_t dl_mutex; |
| |
| #ifdef JAVASE_EMBEDDED |
| class MemNotifyThread: public Thread { |
| friend class VMStructs; |
| public: |
| virtual void run(); |
| |
| private: |
| static MemNotifyThread* _memnotify_thread; |
| int _fd; |
| |
| public: |
| |
| // Constructor |
| MemNotifyThread(int fd); |
| |
| // Tester |
| bool is_memnotify_thread() const { return true; } |
| |
| // Printing |
| char* name() const { return (char*)"Linux MemNotify Thread"; } |
| |
| // Returns the single instance of the MemNotifyThread |
| static MemNotifyThread* memnotify_thread() { return _memnotify_thread; } |
| |
| // Create and start the single instance of MemNotifyThread |
| static void start(); |
| }; |
| #endif // JAVASE_EMBEDDED |
| |
| // utility functions |
| |
| static int SR_initialize(); |
| static int SR_finalize(); |
| |
| julong os::available_memory() { |
| return Linux::available_memory(); |
| } |
| |
| julong os::Linux::available_memory() { |
| // values in struct sysinfo are "unsigned long" |
| struct sysinfo si; |
| sysinfo(&si); |
| |
| return (julong)si.freeram * si.mem_unit; |
| } |
| |
| julong os::physical_memory() { |
| return Linux::physical_memory(); |
| } |
| |
| julong os::allocatable_physical_memory(julong size) { |
| #ifdef _LP64 |
| return size; |
| #else |
| julong result = MIN2(size, (julong)3800*M); |
| if (!is_allocatable(result)) { |
| // See comments under solaris for alignment considerations |
| julong reasonable_size = (julong)2*G - 2 * os::vm_page_size(); |
| result = MIN2(size, reasonable_size); |
| } |
| return result; |
| #endif // _LP64 |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // environment support |
| |
| bool os::getenv(const char* name, char* buf, int len) { |
| const char* val = ::getenv(name); |
| if (val != NULL && strlen(val) < (size_t)len) { |
| strcpy(buf, val); |
| return true; |
| } |
| if (len > 0) buf[0] = 0; // return a null string |
| return false; |
| } |
| |
| |
| // Return true if user is running as root. |
| |
| bool os::have_special_privileges() { |
| static bool init = false; |
| static bool privileges = false; |
| if (!init) { |
| privileges = (getuid() != geteuid()) || (getgid() != getegid()); |
| init = true; |
| } |
| return privileges; |
| } |
| |
| |
| #ifndef SYS_gettid |
| // i386: 224, ia64: 1105, amd64: 186, sparc 143 |
| #ifdef __ia64__ |
| #define SYS_gettid 1105 |
| #elif __i386__ |
| #define SYS_gettid 224 |
| #elif __amd64__ |
| #define SYS_gettid 186 |
| #elif __sparc__ |
| #define SYS_gettid 143 |
| #else |
| #error define gettid for the arch |
| #endif |
| #endif |
| |
| // Cpu architecture string |
| #if defined(ZERO) |
| static char cpu_arch[] = ZERO_LIBARCH; |
| #elif defined(IA64) |
| static char cpu_arch[] = "ia64"; |
| #elif defined(IA32) |
| static char cpu_arch[] = "i386"; |
| #elif defined(AMD64) |
| static char cpu_arch[] = "amd64"; |
| #elif defined(ARM) |
| static char cpu_arch[] = "arm"; |
| #elif defined(PPC) |
| static char cpu_arch[] = "ppc"; |
| #elif defined(SPARC) |
| # ifdef _LP64 |
| static char cpu_arch[] = "sparcv9"; |
| # else |
| static char cpu_arch[] = "sparc"; |
| # endif |
| #else |
| #error Add appropriate cpu_arch setting |
| #endif |
| |
| |
| // pid_t gettid() |
| // |
| // Returns the kernel thread id of the currently running thread. Kernel |
| // thread id is used to access /proc. |
| // |
| // (Note that getpid() on LinuxThreads returns kernel thread id too; but |
| // on NPTL, it returns the same pid for all threads, as required by POSIX.) |
| // |
| pid_t os::Linux::gettid() { |
| int rslt = syscall(SYS_gettid); |
| if (rslt == -1) { |
| // old kernel, no NPTL support |
| return getpid(); |
| } else { |
| return (pid_t)rslt; |
| } |
| } |
| |
| // Most versions of linux have a bug where the number of processors are |
| // determined by looking at the /proc file system. In a chroot environment, |
| // the system call returns 1. This causes the VM to act as if it is |
| // a single processor and elide locking (see is_MP() call). |
| static bool unsafe_chroot_detected = false; |
| static const char *unstable_chroot_error = "/proc file system not found.\n" |
| "Java may be unstable running multithreaded in a chroot " |
| "environment on Linux when /proc filesystem is not mounted."; |
| |
| void os::Linux::initialize_system_info() { |
| set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); |
| if (processor_count() == 1) { |
| pid_t pid = os::Linux::gettid(); |
| char fname[32]; |
| jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); |
| FILE *fp = fopen(fname, "r"); |
| if (fp == NULL) { |
| unsafe_chroot_detected = true; |
| } else { |
| fclose(fp); |
| } |
| } |
| _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); |
| assert(processor_count() > 0, "linux error"); |
| } |
| |
| void os::init_system_properties_values() { |
| // char arch[12]; |
| // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); |
| |
| // The next steps are taken in the product version: |
| // |
| // Obtain the JAVA_HOME value from the location of libjvm[_g].so. |
| // This library should be located at: |
| // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm[_g].so. |
| // |
| // If "/jre/lib/" appears at the right place in the path, then we |
| // assume libjvm[_g].so is installed in a JDK and we use this path. |
| // |
| // Otherwise exit with message: "Could not create the Java virtual machine." |
| // |
| // The following extra steps are taken in the debugging version: |
| // |
| // If "/jre/lib/" does NOT appear at the right place in the path |
| // instead of exit check for $JAVA_HOME environment variable. |
| // |
| // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, |
| // then we append a fake suffix "hotspot/libjvm[_g].so" to this path so |
| // it looks like libjvm[_g].so is installed there |
| // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm[_g].so. |
| // |
| // Otherwise exit. |
| // |
| // Important note: if the location of libjvm.so changes this |
| // code needs to be changed accordingly. |
| |
| // The next few definitions allow the code to be verbatim: |
| #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal) |
| #define getenv(n) ::getenv(n) |
| |
| /* |
| * See ld(1): |
| * The linker uses the following search paths to locate required |
| * shared libraries: |
| * 1: ... |
| * ... |
| * 7: The default directories, normally /lib and /usr/lib. |
| */ |
| #if defined(AMD64) || defined(_LP64) && (defined(SPARC) || defined(PPC) || defined(S390)) |
| #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" |
| #else |
| #define DEFAULT_LIBPATH "/lib:/usr/lib" |
| #endif |
| |
| #define EXTENSIONS_DIR "/lib/ext" |
| #define ENDORSED_DIR "/lib/endorsed" |
| #define REG_DIR "/usr/java/packages" |
| |
| { |
| /* sysclasspath, java_home, dll_dir */ |
| { |
| char *home_path; |
| char *dll_path; |
| char *pslash; |
| char buf[MAXPATHLEN]; |
| os::jvm_path(buf, sizeof(buf)); |
| |
| // Found the full path to libjvm.so. |
| // Now cut the path to <java_home>/jre if we can. |
| *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ |
| pslash = strrchr(buf, '/'); |
| if (pslash != NULL) |
| *pslash = '\0'; /* get rid of /{client|server|hotspot} */ |
| dll_path = malloc(strlen(buf) + 1); |
| if (dll_path == NULL) |
| return; |
| strcpy(dll_path, buf); |
| Arguments::set_dll_dir(dll_path); |
| |
| if (pslash != NULL) { |
| pslash = strrchr(buf, '/'); |
| if (pslash != NULL) { |
| *pslash = '\0'; /* get rid of /<arch> */ |
| pslash = strrchr(buf, '/'); |
| if (pslash != NULL) |
| *pslash = '\0'; /* get rid of /lib */ |
| } |
| } |
| |
| home_path = malloc(strlen(buf) + 1); |
| if (home_path == NULL) |
| return; |
| strcpy(home_path, buf); |
| Arguments::set_java_home(home_path); |
| |
| if (!set_boot_path('/', ':')) |
| return; |
| } |
| |
| /* |
| * Where to look for native libraries |
| * |
| * Note: Due to a legacy implementation, most of the library path |
| * is set in the launcher. This was to accomodate linking restrictions |
| * on legacy Linux implementations (which are no longer supported). |
| * Eventually, all the library path setting will be done here. |
| * |
| * However, to prevent the proliferation of improperly built native |
| * libraries, the new path component /usr/java/packages is added here. |
| * Eventually, all the library path setting will be done here. |
| */ |
| { |
| char *ld_library_path; |
| |
| /* |
| * Construct the invariant part of ld_library_path. Note that the |
| * space for the colon and the trailing null are provided by the |
| * nulls included by the sizeof operator (so actually we allocate |
| * a byte more than necessary). |
| */ |
| ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + |
| strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); |
| sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); |
| |
| /* |
| * Get the user setting of LD_LIBRARY_PATH, and prepended it. It |
| * should always exist (until the legacy problem cited above is |
| * addressed). |
| */ |
| char *v = getenv("LD_LIBRARY_PATH"); |
| if (v != NULL) { |
| char *t = ld_library_path; |
| /* That's +1 for the colon and +1 for the trailing '\0' */ |
| ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); |
| sprintf(ld_library_path, "%s:%s", v, t); |
| } |
| Arguments::set_library_path(ld_library_path); |
| } |
| |
| /* |
| * Extensions directories. |
| * |
| * Note that the space for the colon and the trailing null are provided |
| * by the nulls included by the sizeof operator (so actually one byte more |
| * than necessary is allocated). |
| */ |
| { |
| char *buf = malloc(strlen(Arguments::get_java_home()) + |
| sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); |
| sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, |
| Arguments::get_java_home()); |
| Arguments::set_ext_dirs(buf); |
| } |
| |
| /* Endorsed standards default directory. */ |
| { |
| char * buf; |
| buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); |
| sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); |
| Arguments::set_endorsed_dirs(buf); |
| } |
| } |
| |
| #undef malloc |
| #undef getenv |
| #undef EXTENSIONS_DIR |
| #undef ENDORSED_DIR |
| |
| // Done |
| return; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // breakpoint support |
| |
| void os::breakpoint() { |
| BREAKPOINT; |
| } |
| |
| extern "C" void breakpoint() { |
| // use debugger to set breakpoint here |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // signal support |
| |
| debug_only(static bool signal_sets_initialized = false); |
| static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; |
| |
| bool os::Linux::is_sig_ignored(int sig) { |
| struct sigaction oact; |
| sigaction(sig, (struct sigaction*)NULL, &oact); |
| void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) |
| : CAST_FROM_FN_PTR(void*, oact.sa_handler); |
| if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) |
| return true; |
| else |
| return false; |
| } |
| |
| void os::Linux::signal_sets_init() { |
| // Should also have an assertion stating we are still single-threaded. |
| assert(!signal_sets_initialized, "Already initialized"); |
| // Fill in signals that are necessarily unblocked for all threads in |
| // the VM. Currently, we unblock the following signals: |
| // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden |
| // by -Xrs (=ReduceSignalUsage)); |
| // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all |
| // other threads. The "ReduceSignalUsage" boolean tells us not to alter |
| // the dispositions or masks wrt these signals. |
| // Programs embedding the VM that want to use the above signals for their |
| // own purposes must, at this time, use the "-Xrs" option to prevent |
| // interference with shutdown hooks and BREAK_SIGNAL thread dumping. |
| // (See bug 4345157, and other related bugs). |
| // In reality, though, unblocking these signals is really a nop, since |
| // these signals are not blocked by default. |
| sigemptyset(&unblocked_sigs); |
| sigemptyset(&allowdebug_blocked_sigs); |
| sigaddset(&unblocked_sigs, SIGILL); |
| sigaddset(&unblocked_sigs, SIGSEGV); |
| sigaddset(&unblocked_sigs, SIGBUS); |
| sigaddset(&unblocked_sigs, SIGFPE); |
| sigaddset(&unblocked_sigs, SR_signum); |
| |
| if (!ReduceSignalUsage) { |
| if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { |
| sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); |
| sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); |
| } |
| if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { |
| sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); |
| sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); |
| } |
| if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { |
| sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); |
| sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); |
| } |
| } |
| // Fill in signals that are blocked by all but the VM thread. |
| sigemptyset(&vm_sigs); |
| if (!ReduceSignalUsage) |
| sigaddset(&vm_sigs, BREAK_SIGNAL); |
| debug_only(signal_sets_initialized = true); |
| |
| } |
| |
| // These are signals that are unblocked while a thread is running Java. |
| // (For some reason, they get blocked by default.) |
| sigset_t* os::Linux::unblocked_signals() { |
| assert(signal_sets_initialized, "Not initialized"); |
| return &unblocked_sigs; |
| } |
| |
| // These are the signals that are blocked while a (non-VM) thread is |
| // running Java. Only the VM thread handles these signals. |
| sigset_t* os::Linux::vm_signals() { |
| assert(signal_sets_initialized, "Not initialized"); |
| return &vm_sigs; |
| } |
| |
| // These are signals that are blocked during cond_wait to allow debugger in |
| sigset_t* os::Linux::allowdebug_blocked_signals() { |
| assert(signal_sets_initialized, "Not initialized"); |
| return &allowdebug_blocked_sigs; |
| } |
| |
| void os::Linux::hotspot_sigmask(Thread* thread) { |
| |
| //Save caller's signal mask before setting VM signal mask |
| sigset_t caller_sigmask; |
| pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); |
| |
| OSThread* osthread = thread->osthread(); |
| osthread->set_caller_sigmask(caller_sigmask); |
| |
| pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); |
| |
| if (!ReduceSignalUsage) { |
| if (thread->is_VM_thread()) { |
| // Only the VM thread handles BREAK_SIGNAL ... |
| pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); |
| } else { |
| // ... all other threads block BREAK_SIGNAL |
| pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); |
| } |
| } |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // detecting pthread library |
| |
| void os::Linux::libpthread_init() { |
| // Save glibc and pthread version strings. Note that _CS_GNU_LIBC_VERSION |
| // and _CS_GNU_LIBPTHREAD_VERSION are supported in glibc >= 2.3.2. Use a |
| // generic name for earlier versions. |
| // Define macros here so we can build HotSpot on old systems. |
| # ifndef _CS_GNU_LIBC_VERSION |
| # define _CS_GNU_LIBC_VERSION 2 |
| # endif |
| # ifndef _CS_GNU_LIBPTHREAD_VERSION |
| # define _CS_GNU_LIBPTHREAD_VERSION 3 |
| # endif |
| |
| size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); |
| if (n > 0) { |
| char *str = (char *)malloc(n, mtInternal); |
| confstr(_CS_GNU_LIBC_VERSION, str, n); |
| os::Linux::set_glibc_version(str); |
| } else { |
| // _CS_GNU_LIBC_VERSION is not supported, try gnu_get_libc_version() |
| static char _gnu_libc_version[32]; |
| jio_snprintf(_gnu_libc_version, sizeof(_gnu_libc_version), |
| "glibc %s %s", gnu_get_libc_version(), gnu_get_libc_release()); |
| os::Linux::set_glibc_version(_gnu_libc_version); |
| } |
| |
| n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); |
| if (n > 0) { |
| char *str = (char *)malloc(n, mtInternal); |
| confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); |
| // Vanilla RH-9 (glibc 2.3.2) has a bug that confstr() always tells |
| // us "NPTL-0.29" even we are running with LinuxThreads. Check if this |
| // is the case. LinuxThreads has a hard limit on max number of threads. |
| // So sysconf(_SC_THREAD_THREADS_MAX) will return a positive value. |
| // On the other hand, NPTL does not have such a limit, sysconf() |
| // will return -1 and errno is not changed. Check if it is really NPTL. |
| if (strcmp(os::Linux::glibc_version(), "glibc 2.3.2") == 0 && |
| strstr(str, "NPTL") && |
| sysconf(_SC_THREAD_THREADS_MAX) > 0) { |
| free(str); |
| os::Linux::set_libpthread_version("linuxthreads"); |
| } else { |
| os::Linux::set_libpthread_version(str); |
| } |
| } else { |
| // glibc before 2.3.2 only has LinuxThreads. |
| os::Linux::set_libpthread_version("linuxthreads"); |
| } |
| |
| if (strstr(libpthread_version(), "NPTL")) { |
| os::Linux::set_is_NPTL(); |
| } else { |
| os::Linux::set_is_LinuxThreads(); |
| } |
| |
| // LinuxThreads have two flavors: floating-stack mode, which allows variable |
| // stack size; and fixed-stack mode. NPTL is always floating-stack. |
| if (os::Linux::is_NPTL() || os::Linux::supports_variable_stack_size()) { |
| os::Linux::set_is_floating_stack(); |
| } |
| } |
| |
| ///////////////////////////////////////////////////////////////////////////// |
| // thread stack |
| |
| // Force Linux kernel to expand current thread stack. If "bottom" is close |
| // to the stack guard, caller should block all signals. |
| // |
| // MAP_GROWSDOWN: |
| // A special mmap() flag that is used to implement thread stacks. It tells |
| // kernel that the memory region should extend downwards when needed. This |
| // allows early versions of LinuxThreads to only mmap the first few pages |
| // when creating a new thread. Linux kernel will automatically expand thread |
| // stack as needed (on page faults). |
| // |
| // However, because the memory region of a MAP_GROWSDOWN stack can grow on |
| // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN |
| // region, it's hard to tell if the fault is due to a legitimate stack |
| // access or because of reading/writing non-exist memory (e.g. buffer |
| // overrun). As a rule, if the fault happens below current stack pointer, |
| // Linux kernel does not expand stack, instead a SIGSEGV is sent to the |
| // application (see Linux kernel fault.c). |
| // |
| // This Linux feature can cause SIGSEGV when VM bangs thread stack for |
| // stack overflow detection. |
| // |
| // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do |
| // not use this flag. However, the stack of initial thread is not created |
| // by pthread, it is still MAP_GROWSDOWN. Also it's possible (though |
| // unlikely) that user code can create a thread with MAP_GROWSDOWN stack |
| // and then attach the thread to JVM. |
| // |
| // To get around the problem and allow stack banging on Linux, we need to |
| // manually expand thread stack after receiving the SIGSEGV. |
| // |
| // There are two ways to expand thread stack to address "bottom", we used |
| // both of them in JVM before 1.5: |
| // 1. adjust stack pointer first so that it is below "bottom", and then |
| // touch "bottom" |
| // 2. mmap() the page in question |
| // |
| // Now alternate signal stack is gone, it's harder to use 2. For instance, |
| // if current sp is already near the lower end of page 101, and we need to |
| // call mmap() to map page 100, it is possible that part of the mmap() frame |
| // will be placed in page 100. When page 100 is mapped, it is zero-filled. |
| // That will destroy the mmap() frame and cause VM to crash. |
| // |
| // The following code works by adjusting sp first, then accessing the "bottom" |
| // page to force a page fault. Linux kernel will then automatically expand the |
| // stack mapping. |
| // |
| // _expand_stack_to() assumes its frame size is less than page size, which |
| // should always be true if the function is not inlined. |
| |
| #if __GNUC__ < 3 // gcc 2.x does not support noinline attribute |
| #define NOINLINE |
| #else |
| #define NOINLINE __attribute__ ((noinline)) |
| #endif |
| |
| static void _expand_stack_to(address bottom) NOINLINE; |
| |
| static void _expand_stack_to(address bottom) { |
| address sp; |
| size_t size; |
| volatile char *p; |
| |
| // Adjust bottom to point to the largest address within the same page, it |
| // gives us a one-page buffer if alloca() allocates slightly more memory. |
| bottom = (address)align_size_down((uintptr_t)bottom, os::Linux::page_size()); |
| bottom += os::Linux::page_size() - 1; |
| |
| // sp might be slightly above current stack pointer; if that's the case, we |
| // will alloca() a little more space than necessary, which is OK. Don't use |
| // os::current_stack_pointer(), as its result can be slightly below current |
| // stack pointer, causing us to not alloca enough to reach "bottom". |
| sp = (address)&sp; |
| |
| if (sp > bottom) { |
| size = sp - bottom; |
| p = (volatile char *)alloca(size); |
| assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); |
| p[0] = '\0'; |
| } |
| } |
| |
| bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { |
| assert(t!=NULL, "just checking"); |
| assert(t->osthread()->expanding_stack(), "expand should be set"); |
| assert(t->stack_base() != NULL, "stack_base was not initialized"); |
| |
| if (addr < t->stack_base() && addr >= t->stack_yellow_zone_base()) { |
| sigset_t mask_all, old_sigset; |
| sigfillset(&mask_all); |
| pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); |
| _expand_stack_to(addr); |
| pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); |
| return true; |
| } |
| return false; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // create new thread |
| |
| static address highest_vm_reserved_address(); |
| |
| // check if it's safe to start a new thread |
| static bool _thread_safety_check(Thread* thread) { |
| if (os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack()) { |
| // Fixed stack LinuxThreads (SuSE Linux/x86, and some versions of Redhat) |
| // Heap is mmap'ed at lower end of memory space. Thread stacks are |
| // allocated (MAP_FIXED) from high address space. Every thread stack |
| // occupies a fixed size slot (usually 2Mbytes, but user can change |
| // it to other values if they rebuild LinuxThreads). |
| // |
| // Problem with MAP_FIXED is that mmap() can still succeed even part of |
| // the memory region has already been mmap'ed. That means if we have too |
| // many threads and/or very large heap, eventually thread stack will |
| // collide with heap. |
| // |
| // Here we try to prevent heap/stack collision by comparing current |
| // stack bottom with the highest address that has been mmap'ed by JVM |
| // plus a safety margin for memory maps created by native code. |
| // |
| // This feature can be disabled by setting ThreadSafetyMargin to 0 |
| // |
| if (ThreadSafetyMargin > 0) { |
| address stack_bottom = os::current_stack_base() - os::current_stack_size(); |
| |
| // not safe if our stack extends below the safety margin |
| return stack_bottom - ThreadSafetyMargin >= highest_vm_reserved_address(); |
| } else { |
| return true; |
| } |
| } else { |
| // Floating stack LinuxThreads or NPTL: |
| // Unlike fixed stack LinuxThreads, thread stacks are not MAP_FIXED. When |
| // there's not enough space left, pthread_create() will fail. If we come |
| // here, that means enough space has been reserved for stack. |
| return true; |
| } |
| } |
| |
| // Thread start routine for all newly created threads |
| static void *java_start(Thread *thread) { |
| // Try to randomize the cache line index of hot stack frames. |
| // This helps when threads of the same stack traces evict each other's |
| // cache lines. The threads can be either from the same JVM instance, or |
| // from different JVM instances. The benefit is especially true for |
| // processors with hyperthreading technology. |
| static int counter = 0; |
| int pid = os::current_process_id(); |
| alloca(((pid ^ counter++) & 7) * 128); |
| |
| ThreadLocalStorage::set_thread(thread); |
| |
| OSThread* osthread = thread->osthread(); |
| Monitor* sync = osthread->startThread_lock(); |
| |
| // non floating stack LinuxThreads needs extra check, see above |
| if (!_thread_safety_check(thread)) { |
| // notify parent thread |
| MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); |
| osthread->set_state(ZOMBIE); |
| sync->notify_all(); |
| return NULL; |
| } |
| |
| // thread_id is kernel thread id (similar to Solaris LWP id) |
| osthread->set_thread_id(os::Linux::gettid()); |
| |
| if (UseNUMA) { |
| int lgrp_id = os::numa_get_group_id(); |
| if (lgrp_id != -1) { |
| thread->set_lgrp_id(lgrp_id); |
| } |
| } |
| // initialize signal mask for this thread |
| os::Linux::hotspot_sigmask(thread); |
| |
| // initialize floating point control register |
| os::Linux::init_thread_fpu_state(); |
| |
| // handshaking with parent thread |
| { |
| MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); |
| |
| // notify parent thread |
| osthread->set_state(INITIALIZED); |
| sync->notify_all(); |
| |
| // wait until os::start_thread() |
| while (osthread->get_state() == INITIALIZED) { |
| sync->wait(Mutex::_no_safepoint_check_flag); |
| } |
| } |
| |
| // call one more level start routine |
| thread->run(); |
| |
| return 0; |
| } |
| |
| bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { |
| assert(thread->osthread() == NULL, "caller responsible"); |
| |
| // Allocate the OSThread object |
| OSThread* osthread = new OSThread(NULL, NULL); |
| if (osthread == NULL) { |
| return false; |
| } |
| |
| // set the correct thread state |
| osthread->set_thread_type(thr_type); |
| |
| // Initial state is ALLOCATED but not INITIALIZED |
| osthread->set_state(ALLOCATED); |
| |
| thread->set_osthread(osthread); |
| |
| // init thread attributes |
| pthread_attr_t attr; |
| pthread_attr_init(&attr); |
| pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); |
| |
| // stack size |
| if (os::Linux::supports_variable_stack_size()) { |
| // calculate stack size if it's not specified by caller |
| if (stack_size == 0) { |
| stack_size = os::Linux::default_stack_size(thr_type); |
| |
| switch (thr_type) { |
| case os::java_thread: |
| // Java threads use ThreadStackSize which default value can be |
| // changed with the flag -Xss |
| assert (JavaThread::stack_size_at_create() > 0, "this should be set"); |
| stack_size = JavaThread::stack_size_at_create(); |
| break; |
| case os::compiler_thread: |
| if (CompilerThreadStackSize > 0) { |
| stack_size = (size_t)(CompilerThreadStackSize * K); |
| break; |
| } // else fall through: |
| // use VMThreadStackSize if CompilerThreadStackSize is not defined |
| case os::vm_thread: |
| case os::pgc_thread: |
| case os::cgc_thread: |
| case os::watcher_thread: |
| if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); |
| break; |
| } |
| } |
| |
| stack_size = MAX2(stack_size, os::Linux::min_stack_allowed); |
| pthread_attr_setstacksize(&attr, stack_size); |
| } else { |
| // let pthread_create() pick the default value. |
| } |
| |
| // glibc guard page |
| pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); |
| |
| ThreadState state; |
| |
| { |
| // Serialize thread creation if we are running with fixed stack LinuxThreads |
| bool lock = os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack(); |
| if (lock) { |
| os::Linux::createThread_lock()->lock_without_safepoint_check(); |
| } |
| |
| pthread_t tid; |
| int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); |
| |
| pthread_attr_destroy(&attr); |
| |
| if (ret != 0) { |
| if (PrintMiscellaneous && (Verbose || WizardMode)) { |
| perror("pthread_create()"); |
| } |
| // Need to clean up stuff we've allocated so far |
| thread->set_osthread(NULL); |
| delete osthread; |
| if (lock) os::Linux::createThread_lock()->unlock(); |
| return false; |
| } |
| |
| // Store pthread info into the OSThread |
| osthread->set_pthread_id(tid); |
| |
| // Wait until child thread is either initialized or aborted |
| { |
| Monitor* sync_with_child = osthread->startThread_lock(); |
| MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); |
| while ((state = osthread->get_state()) == ALLOCATED) { |
| sync_with_child->wait(Mutex::_no_safepoint_check_flag); |
| } |
| } |
| |
| if (lock) { |
| os::Linux::createThread_lock()->unlock(); |
| } |
| } |
| |
| // Aborted due to thread limit being reached |
| if (state == ZOMBIE) { |
| thread->set_osthread(NULL); |
| delete osthread; |
| return false; |
| } |
| |
| // The thread is returned suspended (in state INITIALIZED), |
| // and is started higher up in the call chain |
| assert(state == INITIALIZED, "race condition"); |
| return true; |
| } |
| |
| ///////////////////////////////////////////////////////////////////////////// |
| // attach existing thread |
| |
| // bootstrap the main thread |
| bool os::create_main_thread(JavaThread* thread) { |
| assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); |
| return create_attached_thread(thread); |
| } |
| |
| bool os::create_attached_thread(JavaThread* thread) { |
| #ifdef ASSERT |
| thread->verify_not_published(); |
| #endif |
| |
| // Allocate the OSThread object |
| OSThread* osthread = new OSThread(NULL, NULL); |
| |
| if (osthread == NULL) { |
| return false; |
| } |
| |
| // Store pthread info into the OSThread |
| osthread->set_thread_id(os::Linux::gettid()); |
| osthread->set_pthread_id(::pthread_self()); |
| |
| // initialize floating point control register |
| os::Linux::init_thread_fpu_state(); |
| |
| // Initial thread state is RUNNABLE |
| osthread->set_state(RUNNABLE); |
| |
| thread->set_osthread(osthread); |
| |
| if (UseNUMA) { |
| int lgrp_id = os::numa_get_group_id(); |
| if (lgrp_id != -1) { |
| thread->set_lgrp_id(lgrp_id); |
| } |
| } |
| |
| if (os::Linux::is_initial_thread()) { |
| // If current thread is initial thread, its stack is mapped on demand, |
| // see notes about MAP_GROWSDOWN. Here we try to force kernel to map |
| // the entire stack region to avoid SEGV in stack banging. |
| // It is also useful to get around the heap-stack-gap problem on SuSE |
| // kernel (see 4821821 for details). We first expand stack to the top |
| // of yellow zone, then enable stack yellow zone (order is significant, |
| // enabling yellow zone first will crash JVM on SuSE Linux), so there |
| // is no gap between the last two virtual memory regions. |
| |
| JavaThread *jt = (JavaThread *)thread; |
| address addr = jt->stack_yellow_zone_base(); |
| assert(addr != NULL, "initialization problem?"); |
| assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); |
| |
| osthread->set_expanding_stack(); |
| os::Linux::manually_expand_stack(jt, addr); |
| osthread->clear_expanding_stack(); |
| } |
| |
| // initialize signal mask for this thread |
| // and save the caller's signal mask |
| os::Linux::hotspot_sigmask(thread); |
| |
| return true; |
| } |
| |
| void os::pd_start_thread(Thread* thread) { |
| OSThread * osthread = thread->osthread(); |
| assert(osthread->get_state() != INITIALIZED, "just checking"); |
| Monitor* sync_with_child = osthread->startThread_lock(); |
| MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); |
| sync_with_child->notify(); |
| } |
| |
| // Free Linux resources related to the OSThread |
| void os::free_thread(OSThread* osthread) { |
| assert(osthread != NULL, "osthread not set"); |
| |
| if (Thread::current()->osthread() == osthread) { |
| // Restore caller's signal mask |
| sigset_t sigmask = osthread->caller_sigmask(); |
| pthread_sigmask(SIG_SETMASK, &sigmask, NULL); |
| } |
| |
| delete osthread; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // thread local storage |
| |
| int os::allocate_thread_local_storage() { |
| pthread_key_t key; |
| int rslt = pthread_key_create(&key, NULL); |
| assert(rslt == 0, "cannot allocate thread local storage"); |
| return (int)key; |
| } |
| |
| // Note: This is currently not used by VM, as we don't destroy TLS key |
| // on VM exit. |
| void os::free_thread_local_storage(int index) { |
| int rslt = pthread_key_delete((pthread_key_t)index); |
| assert(rslt == 0, "invalid index"); |
| } |
| |
| void os::thread_local_storage_at_put(int index, void* value) { |
| int rslt = pthread_setspecific((pthread_key_t)index, value); |
| assert(rslt == 0, "pthread_setspecific failed"); |
| } |
| |
| extern "C" Thread* get_thread() { |
| return ThreadLocalStorage::thread(); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // initial thread |
| |
| // Check if current thread is the initial thread, similar to Solaris thr_main. |
| bool os::Linux::is_initial_thread(void) { |
| char dummy; |
| // If called before init complete, thread stack bottom will be null. |
| // Can be called if fatal error occurs before initialization. |
| if (initial_thread_stack_bottom() == NULL) return false; |
| assert(initial_thread_stack_bottom() != NULL && |
| initial_thread_stack_size() != 0, |
| "os::init did not locate initial thread's stack region"); |
| if ((address)&dummy >= initial_thread_stack_bottom() && |
| (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) |
| return true; |
| else return false; |
| } |
| |
| // Find the virtual memory area that contains addr |
| static bool find_vma(address addr, address* vma_low, address* vma_high) { |
| FILE *fp = fopen("/proc/self/maps", "r"); |
| if (fp) { |
| address low, high; |
| while (!feof(fp)) { |
| if (fscanf(fp, "%p-%p", &low, &high) == 2) { |
| if (low <= addr && addr < high) { |
| if (vma_low) *vma_low = low; |
| if (vma_high) *vma_high = high; |
| fclose (fp); |
| return true; |
| } |
| } |
| for (;;) { |
| int ch = fgetc(fp); |
| if (ch == EOF || ch == (int)'\n') break; |
| } |
| } |
| fclose(fp); |
| } |
| return false; |
| } |
| |
| // Locate initial thread stack. This special handling of initial thread stack |
| // is needed because pthread_getattr_np() on most (all?) Linux distros returns |
| // bogus value for initial thread. |
| void os::Linux::capture_initial_stack(size_t max_size) { |
| // stack size is the easy part, get it from RLIMIT_STACK |
| size_t stack_size; |
| struct rlimit rlim; |
| getrlimit(RLIMIT_STACK, &rlim); |
| stack_size = rlim.rlim_cur; |
| |
| // 6308388: a bug in ld.so will relocate its own .data section to the |
| // lower end of primordial stack; reduce ulimit -s value a little bit |
| // so we won't install guard page on ld.so's data section. |
| stack_size -= 2 * page_size(); |
| |
| // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat |
| // 7.1, in both cases we will get 2G in return value. |
| // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0, |
| // SuSE 7.2, Debian) can not handle alternate signal stack correctly |
| // for initial thread if its stack size exceeds 6M. Cap it at 2M, |
| // in case other parts in glibc still assumes 2M max stack size. |
| // FIXME: alt signal stack is gone, maybe we can relax this constraint? |
| #ifndef IA64 |
| if (stack_size > 2 * K * K) stack_size = 2 * K * K; |
| #else |
| // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small |
| if (stack_size > 4 * K * K) stack_size = 4 * K * K; |
| #endif |
| |
| // Try to figure out where the stack base (top) is. This is harder. |
| // |
| // When an application is started, glibc saves the initial stack pointer in |
| // a global variable "__libc_stack_end", which is then used by system |
| // libraries. __libc_stack_end should be pretty close to stack top. The |
| // variable is available since the very early days. However, because it is |
| // a private interface, it could disappear in the future. |
| // |
| // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar |
| // to __libc_stack_end, it is very close to stack top, but isn't the real |
| // stack top. Note that /proc may not exist if VM is running as a chroot |
| // program, so reading /proc/<pid>/stat could fail. Also the contents of |
| // /proc/<pid>/stat could change in the future (though unlikely). |
| // |
| // We try __libc_stack_end first. If that doesn't work, look for |
| // /proc/<pid>/stat. If neither of them works, we use current stack pointer |
| // as a hint, which should work well in most cases. |
| |
| uintptr_t stack_start; |
| |
| // try __libc_stack_end first |
| uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); |
| if (p && *p) { |
| stack_start = *p; |
| } else { |
| // see if we can get the start_stack field from /proc/self/stat |
| FILE *fp; |
| int pid; |
| char state; |
| int ppid; |
| int pgrp; |
| int session; |
| int nr; |
| int tpgrp; |
| unsigned long flags; |
| unsigned long minflt; |
| unsigned long cminflt; |
| unsigned long majflt; |
| unsigned long cmajflt; |
| unsigned long utime; |
| unsigned long stime; |
| long cutime; |
| long cstime; |
| long prio; |
| long nice; |
| long junk; |
| long it_real; |
| uintptr_t start; |
| uintptr_t vsize; |
| intptr_t rss; |
| uintptr_t rsslim; |
| uintptr_t scodes; |
| uintptr_t ecode; |
| int i; |
| |
| // Figure what the primordial thread stack base is. Code is inspired |
| // by email from Hans Boehm. /proc/self/stat begins with current pid, |
| // followed by command name surrounded by parentheses, state, etc. |
| char stat[2048]; |
| int statlen; |
| |
| fp = fopen("/proc/self/stat", "r"); |
| if (fp) { |
| statlen = fread(stat, 1, 2047, fp); |
| stat[statlen] = '\0'; |
| fclose(fp); |
| |
| // Skip pid and the command string. Note that we could be dealing with |
| // weird command names, e.g. user could decide to rename java launcher |
| // to "java 1.4.2 :)", then the stat file would look like |
| // 1234 (java 1.4.2 :)) R ... ... |
| // We don't really need to know the command string, just find the last |
| // occurrence of ")" and then start parsing from there. See bug 4726580. |
| char * s = strrchr(stat, ')'); |
| |
| i = 0; |
| if (s) { |
| // Skip blank chars |
| do s++; while (isspace(*s)); |
| |
| #define _UFM UINTX_FORMAT |
| #define _DFM INTX_FORMAT |
| |
| /* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 */ |
| /* 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 */ |
| i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, |
| &state, /* 3 %c */ |
| &ppid, /* 4 %d */ |
| &pgrp, /* 5 %d */ |
| &session, /* 6 %d */ |
| &nr, /* 7 %d */ |
| &tpgrp, /* 8 %d */ |
| &flags, /* 9 %lu */ |
| &minflt, /* 10 %lu */ |
| &cminflt, /* 11 %lu */ |
| &majflt, /* 12 %lu */ |
| &cmajflt, /* 13 %lu */ |
| &utime, /* 14 %lu */ |
| &stime, /* 15 %lu */ |
| &cutime, /* 16 %ld */ |
| &cstime, /* 17 %ld */ |
| &prio, /* 18 %ld */ |
| &nice, /* 19 %ld */ |
| &junk, /* 20 %ld */ |
| &it_real, /* 21 %ld */ |
| &start, /* 22 UINTX_FORMAT */ |
| &vsize, /* 23 UINTX_FORMAT */ |
| &rss, /* 24 INTX_FORMAT */ |
| &rsslim, /* 25 UINTX_FORMAT */ |
| &scodes, /* 26 UINTX_FORMAT */ |
| &ecode, /* 27 UINTX_FORMAT */ |
| &stack_start); /* 28 UINTX_FORMAT */ |
| } |
| |
| #undef _UFM |
| #undef _DFM |
| |
| if (i != 28 - 2) { |
| assert(false, "Bad conversion from /proc/self/stat"); |
| // product mode - assume we are the initial thread, good luck in the |
| // embedded case. |
| warning("Can't detect initial thread stack location - bad conversion"); |
| stack_start = (uintptr_t) &rlim; |
| } |
| } else { |
| // For some reason we can't open /proc/self/stat (for example, running on |
| // FreeBSD with a Linux emulator, or inside chroot), this should work for |
| // most cases, so don't abort: |
| warning("Can't detect initial thread stack location - no /proc/self/stat"); |
| stack_start = (uintptr_t) &rlim; |
| } |
| } |
| |
| // Now we have a pointer (stack_start) very close to the stack top, the |
| // next thing to do is to figure out the exact location of stack top. We |
| // can find out the virtual memory area that contains stack_start by |
| // reading /proc/self/maps, it should be the last vma in /proc/self/maps, |
| // and its upper limit is the real stack top. (again, this would fail if |
| // running inside chroot, because /proc may not exist.) |
| |
| uintptr_t stack_top; |
| address low, high; |
| if (find_vma((address)stack_start, &low, &high)) { |
| // success, "high" is the true stack top. (ignore "low", because initial |
| // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) |
| stack_top = (uintptr_t)high; |
| } else { |
| // failed, likely because /proc/self/maps does not exist |
| warning("Can't detect initial thread stack location - find_vma failed"); |
| // best effort: stack_start is normally within a few pages below the real |
| // stack top, use it as stack top, and reduce stack size so we won't put |
| // guard page outside stack. |
| stack_top = stack_start; |
| stack_size -= 16 * page_size(); |
| } |
| |
| // stack_top could be partially down the page so align it |
| stack_top = align_size_up(stack_top, page_size()); |
| |
| if (max_size && stack_size > max_size) { |
| _initial_thread_stack_size = max_size; |
| } else { |
| _initial_thread_stack_size = stack_size; |
| } |
| |
| _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size()); |
| _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // time support |
| |
| // Time since start-up in seconds to a fine granularity. |
| // Used by VMSelfDestructTimer and the MemProfiler. |
| double os::elapsedTime() { |
| |
| return (double)(os::elapsed_counter()) * 0.000001; |
| } |
| |
| jlong os::elapsed_counter() { |
| timeval time; |
| int status = gettimeofday(&time, NULL); |
| return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count; |
| } |
| |
| jlong os::elapsed_frequency() { |
| return (1000 * 1000); |
| } |
| |
| // For now, we say that linux does not support vtime. I have no idea |
| // whether it can actually be made to (DLD, 9/13/05). |
| |
| bool os::supports_vtime() { return false; } |
| bool os::enable_vtime() { return false; } |
| bool os::vtime_enabled() { return false; } |
| double os::elapsedVTime() { |
| // better than nothing, but not much |
| return elapsedTime(); |
| } |
| |
| jlong os::javaTimeMillis() { |
| timeval time; |
| int status = gettimeofday(&time, NULL); |
| assert(status != -1, "linux error"); |
| return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); |
| } |
| |
| #ifndef CLOCK_MONOTONIC |
| #define CLOCK_MONOTONIC (1) |
| #endif |
| |
| void os::Linux::clock_init() { |
| // we do dlopen's in this particular order due to bug in linux |
| // dynamical loader (see 6348968) leading to crash on exit |
| void* handle = dlopen("librt.so.1", RTLD_LAZY); |
| if (handle == NULL) { |
| handle = dlopen("librt.so", RTLD_LAZY); |
| } |
| |
| if (handle) { |
| int (*clock_getres_func)(clockid_t, struct timespec*) = |
| (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); |
| int (*clock_gettime_func)(clockid_t, struct timespec*) = |
| (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); |
| if (clock_getres_func && clock_gettime_func) { |
| // See if monotonic clock is supported by the kernel. Note that some |
| // early implementations simply return kernel jiffies (updated every |
| // 1/100 or 1/1000 second). It would be bad to use such a low res clock |
| // for nano time (though the monotonic property is still nice to have). |
| // It's fixed in newer kernels, however clock_getres() still returns |
| // 1/HZ. We check if clock_getres() works, but will ignore its reported |
| // resolution for now. Hopefully as people move to new kernels, this |
| // won't be a problem. |
| struct timespec res; |
| struct timespec tp; |
| if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && |
| clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { |
| // yes, monotonic clock is supported |
| _clock_gettime = clock_gettime_func; |
| } else { |
| // close librt if there is no monotonic clock |
| dlclose(handle); |
| } |
| } |
| } |
| } |
| |
| #ifndef SYS_clock_getres |
| |
| #if defined(IA32) || defined(AMD64) |
| #define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229) |
| #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) |
| #else |
| #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" |
| #define sys_clock_getres(x,y) -1 |
| #endif |
| |
| #else |
| #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) |
| #endif |
| |
| void os::Linux::fast_thread_clock_init() { |
| if (!UseLinuxPosixThreadCPUClocks) { |
| return; |
| } |
| clockid_t clockid; |
| struct timespec tp; |
| int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = |
| (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); |
| |
| // Switch to using fast clocks for thread cpu time if |
| // the sys_clock_getres() returns 0 error code. |
| // Note, that some kernels may support the current thread |
| // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks |
| // returned by the pthread_getcpuclockid(). |
| // If the fast Posix clocks are supported then the sys_clock_getres() |
| // must return at least tp.tv_sec == 0 which means a resolution |
| // better than 1 sec. This is extra check for reliability. |
| |
| if(pthread_getcpuclockid_func && |
| pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && |
| sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { |
| |
| _supports_fast_thread_cpu_time = true; |
| _pthread_getcpuclockid = pthread_getcpuclockid_func; |
| } |
| } |
| |
| jlong os::javaTimeNanos() { |
| if (Linux::supports_monotonic_clock()) { |
| struct timespec tp; |
| int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); |
| assert(status == 0, "gettime error"); |
| jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); |
| return result; |
| } else { |
| timeval time; |
| int status = gettimeofday(&time, NULL); |
| assert(status != -1, "linux error"); |
| jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); |
| return 1000 * usecs; |
| } |
| } |
| |
| void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { |
| if (Linux::supports_monotonic_clock()) { |
| info_ptr->max_value = ALL_64_BITS; |
| |
| // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past |
| info_ptr->may_skip_backward = false; // not subject to resetting or drifting |
| info_ptr->may_skip_forward = false; // not subject to resetting or drifting |
| } else { |
| // gettimeofday - based on time in seconds since the Epoch thus does not wrap |
| info_ptr->max_value = ALL_64_BITS; |
| |
| // gettimeofday is a real time clock so it skips |
| info_ptr->may_skip_backward = true; |
| info_ptr->may_skip_forward = true; |
| } |
| |
| info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time |
| } |
| |
| // Return the real, user, and system times in seconds from an |
| // arbitrary fixed point in the past. |
| bool os::getTimesSecs(double* process_real_time, |
| double* process_user_time, |
| double* process_system_time) { |
| struct tms ticks; |
| clock_t real_ticks = times(&ticks); |
| |
| if (real_ticks == (clock_t) (-1)) { |
| return false; |
| } else { |
| double ticks_per_second = (double) clock_tics_per_sec; |
| *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; |
| *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; |
| *process_real_time = ((double) real_ticks) / ticks_per_second; |
| |
| return true; |
| } |
| } |
| |
| |
| char * os::local_time_string(char *buf, size_t buflen) { |
| struct tm t; |
| time_t long_time; |
| time(&long_time); |
| localtime_r(&long_time, &t); |
| jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", |
| t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, |
| t.tm_hour, t.tm_min, t.tm_sec); |
| return buf; |
| } |
| |
| struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { |
| return localtime_r(clock, res); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // runtime exit support |
| |
| // Note: os::shutdown() might be called very early during initialization, or |
| // called from signal handler. Before adding something to os::shutdown(), make |
| // sure it is async-safe and can handle partially initialized VM. |
| void os::shutdown() { |
| |
| // allow PerfMemory to attempt cleanup of any persistent resources |
| perfMemory_exit(); |
| |
| // needs to remove object in file system |
| AttachListener::abort(); |
| |
| // flush buffered output, finish log files |
| ostream_abort(); |
| |
| // Check for abort hook |
| abort_hook_t abort_hook = Arguments::abort_hook(); |
| if (abort_hook != NULL) { |
| abort_hook(); |
| } |
| |
| } |
| |
| // Note: os::abort() might be called very early during initialization, or |
| // called from signal handler. Before adding something to os::abort(), make |
| // sure it is async-safe and can handle partially initialized VM. |
| void os::abort(bool dump_core) { |
| os::shutdown(); |
| if (dump_core) { |
| #ifndef PRODUCT |
| fdStream out(defaultStream::output_fd()); |
| out.print_raw("Current thread is "); |
| char buf[16]; |
| jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); |
| out.print_raw_cr(buf); |
| out.print_raw_cr("Dumping core ..."); |
| #endif |
| ::abort(); // dump core |
| } |
| |
| ::exit(1); |
| } |
| |
| // Die immediately, no exit hook, no abort hook, no cleanup. |
| void os::die() { |
| // _exit() on LinuxThreads only kills current thread |
| ::abort(); |
| } |
| |
| // unused on linux for now. |
| void os::set_error_file(const char *logfile) {} |
| |
| |
| // This method is a copy of JDK's sysGetLastErrorString |
| // from src/solaris/hpi/src/system_md.c |
| |
| size_t os::lasterror(char *buf, size_t len) { |
| |
| if (errno == 0) return 0; |
| |
| const char *s = ::strerror(errno); |
| size_t n = ::strlen(s); |
| if (n >= len) { |
| n = len - 1; |
| } |
| ::strncpy(buf, s, n); |
| buf[n] = '\0'; |
| return n; |
| } |
| |
| intx os::current_thread_id() { return (intx)pthread_self(); } |
| int os::current_process_id() { |
| |
| // Under the old linux thread library, linux gives each thread |
| // its own process id. Because of this each thread will return |
| // a different pid if this method were to return the result |
| // of getpid(2). Linux provides no api that returns the pid |
| // of the launcher thread for the vm. This implementation |
| // returns a unique pid, the pid of the launcher thread |
| // that starts the vm 'process'. |
| |
| // Under the NPTL, getpid() returns the same pid as the |
| // launcher thread rather than a unique pid per thread. |
| // Use gettid() if you want the old pre NPTL behaviour. |
| |
| // if you are looking for the result of a call to getpid() that |
| // returns a unique pid for the calling thread, then look at the |
| // OSThread::thread_id() method in osThread_linux.hpp file |
| |
| return (int)(_initial_pid ? _initial_pid : getpid()); |
| } |
| |
| // DLL functions |
| |
| const char* os::dll_file_extension() { return ".so"; } |
| |
| // This must be hard coded because it's the system's temporary |
| // directory not the java application's temp directory, ala java.io.tmpdir. |
| const char* os::get_temp_directory() { return "/tmp"; } |
| |
| static bool file_exists(const char* filename) { |
| struct stat statbuf; |
| if (filename == NULL || strlen(filename) == 0) { |
| return false; |
| } |
| return os::stat(filename, &statbuf) == 0; |
| } |
| |
| void os::dll_build_name(char* buffer, size_t buflen, |
| const char* pname, const char* fname) { |
| // Copied from libhpi |
| const size_t pnamelen = pname ? strlen(pname) : 0; |
| |
| // Quietly truncate on buffer overflow. Should be an error. |
| if (pnamelen + strlen(fname) + 10 > (size_t) buflen) { |
| *buffer = '\0'; |
| return; |
| } |
| |
| if (pnamelen == 0) { |
| snprintf(buffer, buflen, "lib%s.so", fname); |
| } else if (strchr(pname, *os::path_separator()) != NULL) { |
| int n; |
| char** pelements = split_path(pname, &n); |
| for (int i = 0 ; i < n ; i++) { |
| // Really shouldn't be NULL, but check can't hurt |
| if (pelements[i] == NULL || strlen(pelements[i]) == 0) { |
| continue; // skip the empty path values |
| } |
| snprintf(buffer, buflen, "%s/lib%s.so", pelements[i], fname); |
| if (file_exists(buffer)) { |
| break; |
| } |
| } |
| // release the storage |
| for (int i = 0 ; i < n ; i++) { |
| if (pelements[i] != NULL) { |
| FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); |
| } |
| } |
| if (pelements != NULL) { |
| FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); |
| } |
| } else { |
| snprintf(buffer, buflen, "%s/lib%s.so", pname, fname); |
| } |
| } |
| |
| const char* os::get_current_directory(char *buf, int buflen) { |
| return getcwd(buf, buflen); |
| } |
| |
| // check if addr is inside libjvm[_g].so |
| bool os::address_is_in_vm(address addr) { |
| static address libjvm_base_addr; |
| Dl_info dlinfo; |
| |
| if (libjvm_base_addr == NULL) { |
| dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo); |
| libjvm_base_addr = (address)dlinfo.dli_fbase; |
| assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); |
| } |
| |
| if (dladdr((void *)addr, &dlinfo)) { |
| if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; |
| } |
| |
| return false; |
| } |
| |
| bool os::dll_address_to_function_name(address addr, char *buf, |
| int buflen, int *offset) { |
| Dl_info dlinfo; |
| |
| if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { |
| if (buf != NULL) { |
| if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { |
| jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); |
| } |
| } |
| if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; |
| return true; |
| } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) { |
| if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), |
| buf, buflen, offset, dlinfo.dli_fname)) { |
| return true; |
| } |
| } |
| |
| if (buf != NULL) buf[0] = '\0'; |
| if (offset != NULL) *offset = -1; |
| return false; |
| } |
| |
| struct _address_to_library_name { |
| address addr; // input : memory address |
| size_t buflen; // size of fname |
| char* fname; // output: library name |
| address base; // library base addr |
| }; |
| |
| static int address_to_library_name_callback(struct dl_phdr_info *info, |
| size_t size, void *data) { |
| int i; |
| bool found = false; |
| address libbase = NULL; |
| struct _address_to_library_name * d = (struct _address_to_library_name *)data; |
| |
| // iterate through all loadable segments |
| for (i = 0; i < info->dlpi_phnum; i++) { |
| address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); |
| if (info->dlpi_phdr[i].p_type == PT_LOAD) { |
| // base address of a library is the lowest address of its loaded |
| // segments. |
| if (libbase == NULL || libbase > segbase) { |
| libbase = segbase; |
| } |
| // see if 'addr' is within current segment |
| if (segbase <= d->addr && |
| d->addr < segbase + info->dlpi_phdr[i].p_memsz) { |
| found = true; |
| } |
| } |
| } |
| |
| // dlpi_name is NULL or empty if the ELF file is executable, return 0 |
| // so dll_address_to_library_name() can fall through to use dladdr() which |
| // can figure out executable name from argv[0]. |
| if (found && info->dlpi_name && info->dlpi_name[0]) { |
| d->base = libbase; |
| if (d->fname) { |
| jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); |
| } |
| return 1; |
| } |
| return 0; |
| } |
| |
| bool os::dll_address_to_library_name(address addr, char* buf, |
| int buflen, int* offset) { |
| Dl_info dlinfo; |
| struct _address_to_library_name data; |
| |
| // There is a bug in old glibc dladdr() implementation that it could resolve |
| // to wrong library name if the .so file has a base address != NULL. Here |
| // we iterate through the program headers of all loaded libraries to find |
| // out which library 'addr' really belongs to. This workaround can be |
| // removed once the minimum requirement for glibc is moved to 2.3.x. |
| data.addr = addr; |
| data.fname = buf; |
| data.buflen = buflen; |
| data.base = NULL; |
| int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); |
| |
| if (rslt) { |
| // buf already contains library name |
| if (offset) *offset = addr - data.base; |
| return true; |
| } else if (dladdr((void*)addr, &dlinfo)){ |
| if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); |
| if (offset) *offset = addr - (address)dlinfo.dli_fbase; |
| return true; |
| } else { |
| if (buf) buf[0] = '\0'; |
| if (offset) *offset = -1; |
| return false; |
| } |
| } |
| |
| // Loads .dll/.so and |
| // in case of error it checks if .dll/.so was built for the |
| // same architecture as Hotspot is running on |
| |
| void * os::dll_load(const char *filename, char *ebuf, int ebuflen) |
| { |
| void * result= ::dlopen(filename, RTLD_LAZY); |
| if (result != NULL) { |
| // Successful loading |
| return result; |
| } |
| |
| Elf32_Ehdr elf_head; |
| |
| // Read system error message into ebuf |
| // It may or may not be overwritten below |
| ::strncpy(ebuf, ::dlerror(), ebuflen-1); |
| ebuf[ebuflen-1]='\0'; |
| int diag_msg_max_length=ebuflen-strlen(ebuf); |
| char* diag_msg_buf=ebuf+strlen(ebuf); |
| |
| if (diag_msg_max_length==0) { |
| // No more space in ebuf for additional diagnostics message |
| return NULL; |
| } |
| |
| |
| int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); |
| |
| if (file_descriptor < 0) { |
| // Can't open library, report dlerror() message |
| return NULL; |
| } |
| |
| bool failed_to_read_elf_head= |
| (sizeof(elf_head)!= |
| (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; |
| |
| ::close(file_descriptor); |
| if (failed_to_read_elf_head) { |
| // file i/o error - report dlerror() msg |
| return NULL; |
| } |
| |
| typedef struct { |
| Elf32_Half code; // Actual value as defined in elf.h |
| Elf32_Half compat_class; // Compatibility of archs at VM's sense |
| char elf_class; // 32 or 64 bit |
| char endianess; // MSB or LSB |
| char* name; // String representation |
| } arch_t; |
| |
| #ifndef EM_486 |
| #define EM_486 6 /* Intel 80486 */ |
| #endif |
| |
| static const arch_t arch_array[]={ |
| {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, |
| {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, |
| {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, |
| {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, |
| {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, |
| {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, |
| {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, |
| {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, |
| {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, |
| {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, |
| {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, |
| {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, |
| {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, |
| {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, |
| {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, |
| {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} |
| }; |
| |
| #if (defined IA32) |
| static Elf32_Half running_arch_code=EM_386; |
| #elif (defined AMD64) |
| static Elf32_Half running_arch_code=EM_X86_64; |
| #elif (defined IA64) |
| static Elf32_Half running_arch_code=EM_IA_64; |
| #elif (defined __sparc) && (defined _LP64) |
| static Elf32_Half running_arch_code=EM_SPARCV9; |
| #elif (defined __sparc) && (!defined _LP64) |
| static Elf32_Half running_arch_code=EM_SPARC; |
| #elif (defined __powerpc64__) |
| static Elf32_Half running_arch_code=EM_PPC64; |
| #elif (defined __powerpc__) |
| static Elf32_Half running_arch_code=EM_PPC; |
| #elif (defined ARM) |
| static Elf32_Half running_arch_code=EM_ARM; |
| #elif (defined S390) |
| static Elf32_Half running_arch_code=EM_S390; |
| #elif (defined ALPHA) |
| static Elf32_Half running_arch_code=EM_ALPHA; |
| #elif (defined MIPSEL) |
| static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; |
| #elif (defined PARISC) |
| static Elf32_Half running_arch_code=EM_PARISC; |
| #elif (defined MIPS) |
| static Elf32_Half running_arch_code=EM_MIPS; |
| #elif (defined M68K) |
| static Elf32_Half running_arch_code=EM_68K; |
| #else |
| #error Method os::dll_load requires that one of following is defined:\ |
| IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K |
| #endif |
| |
| // Identify compatability class for VM's architecture and library's architecture |
| // Obtain string descriptions for architectures |
| |
| arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; |
| int running_arch_index=-1; |
| |
| for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { |
| if (running_arch_code == arch_array[i].code) { |
| running_arch_index = i; |
| } |
| if (lib_arch.code == arch_array[i].code) { |
| lib_arch.compat_class = arch_array[i].compat_class; |
| lib_arch.name = arch_array[i].name; |
| } |
| } |
| |
| assert(running_arch_index != -1, |
| "Didn't find running architecture code (running_arch_code) in arch_array"); |
| if (running_arch_index == -1) { |
| // Even though running architecture detection failed |
| // we may still continue with reporting dlerror() message |
| return NULL; |
| } |
| |
| if (lib_arch.endianess != arch_array[running_arch_index].endianess) { |
| ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); |
| return NULL; |
| } |
| |
| #ifndef S390 |
| if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { |
| ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); |
| return NULL; |
| } |
| #endif // !S390 |
| |
| if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { |
| if ( lib_arch.name!=NULL ) { |
| ::snprintf(diag_msg_buf, diag_msg_max_length-1, |
| " (Possible cause: can't load %s-bit .so on a %s-bit platform)", |
| lib_arch.name, arch_array[running_arch_index].name); |
| } else { |
| ::snprintf(diag_msg_buf, diag_msg_max_length-1, |
| " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", |
| lib_arch.code, |
| arch_array[running_arch_index].name); |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * glibc-2.0 libdl is not MT safe. If you are building with any glibc, |
| * chances are you might want to run the generated bits against glibc-2.0 |
| * libdl.so, so always use locking for any version of glibc. |
| */ |
| void* os::dll_lookup(void* handle, const char* name) { |
| pthread_mutex_lock(&dl_mutex); |
| void* res = dlsym(handle, name); |
| pthread_mutex_unlock(&dl_mutex); |
| return res; |
| } |
| |
| |
| static bool _print_ascii_file(const char* filename, outputStream* st) { |
| int fd = ::open(filename, O_RDONLY); |
| if (fd == -1) { |
| return false; |
| } |
| |
| char buf[32]; |
| int bytes; |
| while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { |
| st->print_raw(buf, bytes); |
| } |
| |
| ::close(fd); |
| |
| return true; |
| } |
| |
| void os::print_dll_info(outputStream *st) { |
| st->print_cr("Dynamic libraries:"); |
| |
| char fname[32]; |
| pid_t pid = os::Linux::gettid(); |
| |
| jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); |
| |
| if (!_print_ascii_file(fname, st)) { |
| st->print("Can not get library information for pid = %d\n", pid); |
| } |
| } |
| |
| void os::print_os_info_brief(outputStream* st) { |
| os::Linux::print_distro_info(st); |
| |
| os::Posix::print_uname_info(st); |
| |
| os::Linux::print_libversion_info(st); |
| |
| } |
| |
| void os::print_os_info(outputStream* st) { |
| st->print("OS:"); |
| |
| os::Linux::print_distro_info(st); |
| |
| os::Posix::print_uname_info(st); |
| |
| // Print warning if unsafe chroot environment detected |
| if (unsafe_chroot_detected) { |
| st->print("WARNING!! "); |
| st->print_cr(unstable_chroot_error); |
| } |
| |
| os::Linux::print_libversion_info(st); |
| |
| os::Posix::print_rlimit_info(st); |
| |
| os::Posix::print_load_average(st); |
| |
| os::Linux::print_full_memory_info(st); |
| } |
| |
| // Try to identify popular distros. |
| // Most Linux distributions have /etc/XXX-release file, which contains |
| // the OS version string. Some have more than one /etc/XXX-release file |
| // (e.g. Mandrake has both /etc/mandrake-release and /etc/redhat-release.), |
| // so the order is important. |
| void os::Linux::print_distro_info(outputStream* st) { |
| if (!_print_ascii_file("/etc/mandrake-release", st) && |
| !_print_ascii_file("/etc/sun-release", st) && |
| !_print_ascii_file("/etc/redhat-release", st) && |
| !_print_ascii_file("/etc/SuSE-release", st) && |
| !_print_ascii_file("/etc/turbolinux-release", st) && |
| !_print_ascii_file("/etc/gentoo-release", st) && |
| !_print_ascii_file("/etc/debian_version", st) && |
| !_print_ascii_file("/etc/ltib-release", st) && |
| !_print_ascii_file("/etc/angstrom-version", st)) { |
| st->print("Linux"); |
| } |
| st->cr(); |
| } |
| |
| void os::Linux::print_libversion_info(outputStream* st) { |
| // libc, pthread |
| st->print("libc:"); |
| st->print(os::Linux::glibc_version()); st->print(" "); |
| st->print(os::Linux::libpthread_version()); st->print(" "); |
| if (os::Linux::is_LinuxThreads()) { |
| st->print("(%s stack)", os::Linux::is_floating_stack() ? "floating" : "fixed"); |
| } |
| st->cr(); |
| } |
| |
| void os::Linux::print_full_memory_info(outputStream* st) { |
| st->print("\n/proc/meminfo:\n"); |
| _print_ascii_file("/proc/meminfo", st); |
| st->cr(); |
| } |
| |
| void os::print_memory_info(outputStream* st) { |
| |
| st->print("Memory:"); |
| st->print(" %dk page", os::vm_page_size()>>10); |
| |
| // values in struct sysinfo are "unsigned long" |
| struct sysinfo si; |
| sysinfo(&si); |
| |
| st->print(", physical " UINT64_FORMAT "k", |
| os::physical_memory() >> 10); |
| st->print("(" UINT64_FORMAT "k free)", |
| os::available_memory() >> 10); |
| st->print(", swap " UINT64_FORMAT "k", |
| ((jlong)si.totalswap * si.mem_unit) >> 10); |
| st->print("(" UINT64_FORMAT "k free)", |
| ((jlong)si.freeswap * si.mem_unit) >> 10); |
| st->cr(); |
| } |
| |
| void os::pd_print_cpu_info(outputStream* st) { |
| st->print("\n/proc/cpuinfo:\n"); |
| if (!_print_ascii_file("/proc/cpuinfo", st)) { |
| st->print(" <Not Available>"); |
| } |
| st->cr(); |
| } |
| |
| // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific |
| // but they're the same for all the linux arch that we support |
| // and they're the same for solaris but there's no common place to put this. |
| const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR", |
| "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG", |
| "ILL_COPROC", "ILL_BADSTK" }; |
| |
| const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV", |
| "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES", |
| "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" }; |
| |
| const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" }; |
| |
| const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" }; |
| |
| void os::print_siginfo(outputStream* st, void* siginfo) { |
| st->print("siginfo:"); |
| |
| const int buflen = 100; |
| char buf[buflen]; |
| siginfo_t *si = (siginfo_t*)siginfo; |
| st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen)); |
| if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) { |
| st->print("si_errno=%s", buf); |
| } else { |
| st->print("si_errno=%d", si->si_errno); |
| } |
| const int c = si->si_code; |
| assert(c > 0, "unexpected si_code"); |
| switch (si->si_signo) { |
| case SIGILL: |
| st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]); |
| st->print(", si_addr=" PTR_FORMAT, si->si_addr); |
| break; |
| case SIGFPE: |
| st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]); |
| st->print(", si_addr=" PTR_FORMAT, si->si_addr); |
| break; |
| case SIGSEGV: |
| st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]); |
| st->print(", si_addr=" PTR_FORMAT, si->si_addr); |
| break; |
| case SIGBUS: |
| st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]); |
| st->print(", si_addr=" PTR_FORMAT, si->si_addr); |
| break; |
| default: |
| st->print(", si_code=%d", si->si_code); |
| // no si_addr |
| } |
| |
| if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && |
| UseSharedSpaces) { |
| FileMapInfo* mapinfo = FileMapInfo::current_info(); |
| if (mapinfo->is_in_shared_space(si->si_addr)) { |
| st->print("\n\nError accessing class data sharing archive." \ |
| " Mapped file inaccessible during execution, " \ |
| " possible disk/network problem."); |
| } |
| } |
| st->cr(); |
| } |
| |
| |
| static void print_signal_handler(outputStream* st, int sig, |
| char* buf, size_t buflen); |
| |
| void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { |
| st->print_cr("Signal Handlers:"); |
| print_signal_handler(st, SIGSEGV, buf, buflen); |
| print_signal_handler(st, SIGBUS , buf, buflen); |
| print_signal_handler(st, SIGFPE , buf, buflen); |
| print_signal_handler(st, SIGPIPE, buf, buflen); |
| print_signal_handler(st, SIGXFSZ, buf, buflen); |
| print_signal_handler(st, SIGILL , buf, buflen); |
| print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); |
| print_signal_handler(st, SR_signum, buf, buflen); |
| print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); |
| print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); |
| print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); |
| print_signal_handler(st, BREAK_SIGNAL, buf, buflen); |
| } |
| |
| static char saved_jvm_path[MAXPATHLEN] = {0}; |
| |
| // Find the full path to the current module, libjvm.so or libjvm_g.so |
| void os::jvm_path(char *buf, jint buflen) { |
| // Error checking. |
| if (buflen < MAXPATHLEN) { |
| assert(false, "must use a large-enough buffer"); |
| buf[0] = '\0'; |
| return; |
| } |
| // Lazy resolve the path to current module. |
| if (saved_jvm_path[0] != 0) { |
| strcpy(buf, saved_jvm_path); |
| return; |
| } |
| |
| char dli_fname[MAXPATHLEN]; |
| bool ret = dll_address_to_library_name( |
| CAST_FROM_FN_PTR(address, os::jvm_path), |
| dli_fname, sizeof(dli_fname), NULL); |
| assert(ret != 0, "cannot locate libjvm"); |
| char *rp = realpath(dli_fname, buf); |
| if (rp == NULL) |
| return; |
| |
| if (Arguments::created_by_gamma_launcher()) { |
| // Support for the gamma launcher. Typical value for buf is |
| // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so". If "/jre/lib/" appears at |
| // the right place in the string, then assume we are installed in a JDK and |
| // we're done. Otherwise, check for a JAVA_HOME environment variable and fix |
| // up the path so it looks like libjvm.so is installed there (append a |
| // fake suffix hotspot/libjvm.so). |
| const char *p = buf + strlen(buf) - 1; |
| for (int count = 0; p > buf && count < 5; ++count) { |
| for (--p; p > buf && *p != '/'; --p) |
| /* empty */ ; |
| } |
| |
| if (strncmp(p, "/jre/lib/", 9) != 0) { |
| // Look for JAVA_HOME in the environment. |
| char* java_home_var = ::getenv("JAVA_HOME"); |
| if (java_home_var != NULL && java_home_var[0] != 0) { |
| char* jrelib_p; |
| int len; |
| |
| // Check the current module name "libjvm.so" or "libjvm_g.so". |
| p = strrchr(buf, '/'); |
| assert(strstr(p, "/libjvm") == p, "invalid library name"); |
| p = strstr(p, "_g") ? "_g" : ""; |
| |
| rp = realpath(java_home_var, buf); |
| if (rp == NULL) |
| return; |
| |
| // determine if this is a legacy image or modules image |
| // modules image doesn't have "jre" subdirectory |
| len = strlen(buf); |
| jrelib_p = buf + len; |
| snprintf(jrelib_p, buflen-len, "/jre/lib/%s", cpu_arch); |
| if (0 != access(buf, F_OK)) { |
| snprintf(jrelib_p, buflen-len, "/lib/%s", cpu_arch); |
| } |
| |
| if (0 == access(buf, F_OK)) { |
| // Use current module name "libjvm[_g].so" instead of |
| // "libjvm"debug_only("_g")".so" since for fastdebug version |
| // we should have "libjvm.so" but debug_only("_g") adds "_g"! |
| len = strlen(buf); |
| snprintf(buf + len, buflen-len, "/hotspot/libjvm%s.so", p); |
| } else { |
| // Go back to path of .so |
| rp = realpath(dli_fname, buf); |
| if (rp == NULL) |
| return; |
| } |
| } |
| } |
| } |
| |
| strcpy(saved_jvm_path, buf); |
| } |
| |
| void os::print_jni_name_prefix_on(outputStream* st, int args_size) { |
| // no prefix required, not even "_" |
| } |
| |
| void os::print_jni_name_suffix_on(outputStream* st, int args_size) { |
| // no suffix required |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // sun.misc.Signal support |
| |
| static volatile jint sigint_count = 0; |
| |
| static void |
| UserHandler(int sig, void *siginfo, void *context) { |
| // 4511530 - sem_post is serialized and handled by the manager thread. When |
| // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We |
| // don't want to flood the manager thread with sem_post requests. |
| if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) |
| return; |
| |
| // Ctrl-C is pressed during error reporting, likely because the error |
| // handler fails to abort. Let VM die immediately. |
| if (sig == SIGINT && is_error_reported()) { |
| os::die(); |
| } |
| |
| os::signal_notify(sig); |
| } |
| |
| void* os::user_handler() { |
| return CAST_FROM_FN_PTR(void*, UserHandler); |
| } |
| |
| extern "C" { |
| typedef void (*sa_handler_t)(int); |
| typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); |
| } |
| |
| void* os::signal(int signal_number, void* handler) { |
| struct sigaction sigAct, oldSigAct; |
| |
| sigfillset(&(sigAct.sa_mask)); |
| sigAct.sa_flags = SA_RESTART|SA_SIGINFO; |
| sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); |
| |
| if (sigaction(signal_number, &sigAct, &oldSigAct)) { |
| // -1 means registration failed |
| return (void *)-1; |
| } |
| |
| return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); |
| } |
| |
| void os::signal_raise(int signal_number) { |
| ::raise(signal_number); |
| } |
| |
| /* |
| * The following code is moved from os.cpp for making this |
| * code platform specific, which it is by its very nature. |
| */ |
| |
| // Will be modified when max signal is changed to be dynamic |
| int os::sigexitnum_pd() { |
| return NSIG; |
| } |
| |
| // a counter for each possible signal value |
| static volatile jint pending_signals[NSIG+1] = { 0 }; |
| |
| // Linux(POSIX) specific hand shaking semaphore. |
| static sem_t sig_sem; |
| |
| void os::signal_init_pd() { |
| // Initialize signal structures |
| ::memset((void*)pending_signals, 0, sizeof(pending_signals)); |
| |
| // Initialize signal semaphore |
| ::sem_init(&sig_sem, 0, 0); |
| } |
| |
| void os::signal_notify(int sig) { |
| Atomic::inc(&pending_signals[sig]); |
| ::sem_post(&sig_sem); |
| } |
| |
| static int check_pending_signals(bool wait) { |
| Atomic::store(0, &sigint_count); |
| for (;;) { |
| for (int i = 0; i < NSIG + 1; i++) { |
| jint n = pending_signals[i]; |
| if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { |
| return i; |
| } |
| } |
| if (!wait) { |
| return -1; |
| } |
| JavaThread *thread = JavaThread::current(); |
| ThreadBlockInVM tbivm(thread); |
| |
| bool threadIsSuspended; |
| do { |
| thread->set_suspend_equivalent(); |
| // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() |
| ::sem_wait(&sig_sem); |
| |
| // were we externally suspended while we were waiting? |
| threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); |
| if (threadIsSuspended) { |
| // |
| // The semaphore has been incremented, but while we were waiting |
| // another thread suspended us. We don't want to continue running |
| // while suspended because that would surprise the thread that |
| // suspended us. |
| // |
| ::sem_post(&sig_sem); |
| |
| thread->java_suspend_self(); |
| } |
| } while (threadIsSuspended); |
| } |
| } |
| |
| int os::signal_lookup() { |
| return check_pending_signals(false); |
| } |
| |
| int os::signal_wait() { |
| return check_pending_signals(true); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // Virtual Memory |
| |
| int os::vm_page_size() { |
| // Seems redundant as all get out |
| assert(os::Linux::page_size() != -1, "must call os::init"); |
| return os::Linux::page_size(); |
| } |
| |
| // Solaris allocates memory by pages. |
| int os::vm_allocation_granularity() { |
| assert(os::Linux::page_size() != -1, "must call os::init"); |
| return os::Linux::page_size(); |
| } |
| |
| // Rationale behind this function: |
| // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable |
| // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get |
| // samples for JITted code. Here we create private executable mapping over the code cache |
| // and then we can use standard (well, almost, as mapping can change) way to provide |
| // info for the reporting script by storing timestamp and location of symbol |
| void linux_wrap_code(char* base, size_t size) { |
| static volatile jint cnt = 0; |
| |
| if (!UseOprofile) { |
| return; |
| } |
| |
| char buf[PATH_MAX+1]; |
| int num = Atomic::add(1, &cnt); |
| |
| snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", |
| os::get_temp_directory(), os::current_process_id(), num); |
| unlink(buf); |
| |
| int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); |
| |
| if (fd != -1) { |
| off_t rv = ::lseek(fd, size-2, SEEK_SET); |
| if (rv != (off_t)-1) { |
| if (::write(fd, "", 1) == 1) { |
| mmap(base, size, |
| PROT_READ|PROT_WRITE|PROT_EXEC, |
| MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); |
| } |
| } |
| ::close(fd); |
| unlink(buf); |
| } |
| } |
| |
| // NOTE: Linux kernel does not really reserve the pages for us. |
| // All it does is to check if there are enough free pages |
| // left at the time of mmap(). This could be a potential |
| // problem. |
| bool os::pd_commit_memory(char* addr, size_t size, bool exec) { |
| int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; |
| uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, |
| MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); |
| if (res != (uintptr_t) MAP_FAILED) { |
| if (UseNUMAInterleaving) { |
| numa_make_global(addr, size); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| // Define MAP_HUGETLB here so we can build HotSpot on old systems. |
| #ifndef MAP_HUGETLB |
| #define MAP_HUGETLB 0x40000 |
| #endif |
| |
| // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. |
| #ifndef MADV_HUGEPAGE |
| #define MADV_HUGEPAGE 14 |
| #endif |
| |
| bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, |
| bool exec) { |
| if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { |
| int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; |
| uintptr_t res = |
| (uintptr_t) ::mmap(addr, size, prot, |
| MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_HUGETLB, |
| -1, 0); |
| if (res != (uintptr_t) MAP_FAILED) { |
| if (UseNUMAInterleaving) { |
| numa_make_global(addr, size); |
| } |
| return true; |
| } |
| // Fall through and try to use small pages |
| } |
| |
| if (commit_memory(addr, size, exec)) { |
| realign_memory(addr, size, alignment_hint); |
| return true; |
| } |
| return false; |
| } |
| |
| void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { |
| if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { |
| // We don't check the return value: madvise(MADV_HUGEPAGE) may not |
| // be supported or the memory may already be backed by huge pages. |
| ::madvise(addr, bytes, MADV_HUGEPAGE); |
| } |
| } |
| |
| void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { |
| // This method works by doing an mmap over an existing mmaping and effectively discarding |
| // the existing pages. However it won't work for SHM-based large pages that cannot be |
| // uncommitted at all. We don't do anything in this case to avoid creating a segment with |
| // small pages on top of the SHM segment. This method always works for small pages, so we |
| // allow that in any case. |
| if (alignment_hint <= (size_t)os::vm_page_size() || !UseSHM) { |
| commit_memory(addr, bytes, alignment_hint, false); |
| } |
| } |
| |
| void os::numa_make_global(char *addr, size_t bytes) { |
| Linux::numa_interleave_memory(addr, bytes); |
| } |
| |
| void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { |
| Linux::numa_tonode_memory(addr, bytes, lgrp_hint); |
| } |
| |
| bool os::numa_topology_changed() { return false; } |
| |
| size_t os::numa_get_groups_num() { |
| int max_node = Linux::numa_max_node(); |
| return max_node > 0 ? max_node + 1 : 1; |
| } |
| |
| int os::numa_get_group_id() { |
| int cpu_id = Linux::sched_getcpu(); |
| if (cpu_id != -1) { |
| int lgrp_id = Linux::get_node_by_cpu(cpu_id); |
| if (lgrp_id != -1) { |
| return lgrp_id; |
| } |
| } |
| return 0; |
| } |
| |
| size_t os::numa_get_leaf_groups(int *ids, size_t size) { |
| for (size_t i = 0; i < size; i++) { |
| ids[i] = i; |
| } |
| return size; |
| } |
| |
| bool os::get_page_info(char *start, page_info* info) { |
| return false; |
| } |
| |
| char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { |
| return end; |
| } |
| |
| |
| int os::Linux::sched_getcpu_syscall(void) { |
| unsigned int cpu; |
| int retval = -1; |
| |
| #if defined(IA32) |
| # ifndef SYS_getcpu |
| # define SYS_getcpu 318 |
| # endif |
| retval = syscall(SYS_getcpu, &cpu, NULL, NULL); |
| #elif defined(AMD64) |
| // Unfortunately we have to bring all these macros here from vsyscall.h |
| // to be able to compile on old linuxes. |
| # define __NR_vgetcpu 2 |
| # define VSYSCALL_START (-10UL << 20) |
| # define VSYSCALL_SIZE 1024 |
| # define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) |
| typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); |
| vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); |
| retval = vgetcpu(&cpu, NULL, NULL); |
| #endif |
| |
| return (retval == -1) ? retval : cpu; |
| } |
| |
| // Something to do with the numa-aware allocator needs these symbols |
| extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } |
| extern "C" JNIEXPORT void numa_error(char *where) { } |
| extern "C" JNIEXPORT int fork1() { return fork(); } |
| |
| |
| // If we are running with libnuma version > 2, then we should |
| // be trying to use symbols with versions 1.1 |
| // If we are running with earlier version, which did not have symbol versions, |
| // we should use the base version. |
| void* os::Linux::libnuma_dlsym(void* handle, const char *name) { |
| void *f = dlvsym(handle, name, "libnuma_1.1"); |
| if (f == NULL) { |
| f = dlsym(handle, name); |
| } |
| return f; |
| } |
| |
| bool os::Linux::libnuma_init() { |
| // sched_getcpu() should be in libc. |
| set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, |
| dlsym(RTLD_DEFAULT, "sched_getcpu"))); |
| |
| // If it's not, try a direct syscall. |
| if (sched_getcpu() == -1) |
| set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, (void*)&sched_getcpu_syscall)); |
| |
| if (sched_getcpu() != -1) { // Does it work? |
| void *handle = dlopen("libnuma.so.1", RTLD_LAZY); |
| if (handle != NULL) { |
| set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, |
| libnuma_dlsym(handle, "numa_node_to_cpus"))); |
| set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, |
| libnuma_dlsym(handle, "numa_max_node"))); |
| set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, |
| libnuma_dlsym(handle, "numa_available"))); |
| set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, |
| libnuma_dlsym(handle, "numa_tonode_memory"))); |
| set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, |
| libnuma_dlsym(handle, "numa_interleave_memory"))); |
| |
| |
| if (numa_available() != -1) { |
| set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); |
| // Create a cpu -> node mapping |
| _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); |
| rebuild_cpu_to_node_map(); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. |
| // The table is later used in get_node_by_cpu(). |
| void os::Linux::rebuild_cpu_to_node_map() { |
| const size_t NCPUS = 32768; // Since the buffer size computation is very obscure |
| // in libnuma (possible values are starting from 16, |
| // and continuing up with every other power of 2, but less |
| // than the maximum number of CPUs supported by kernel), and |
| // is a subject to change (in libnuma version 2 the requirements |
| // are more reasonable) we'll just hardcode the number they use |
| // in the library. |
| const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; |
| |
| size_t cpu_num = os::active_processor_count(); |
| size_t cpu_map_size = NCPUS / BitsPerCLong; |
| size_t cpu_map_valid_size = |
| MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); |
| |
| cpu_to_node()->clear(); |
| cpu_to_node()->at_grow(cpu_num - 1); |
| size_t node_num = numa_get_groups_num(); |
| |
| unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); |
| for (size_t i = 0; i < node_num; i++) { |
| if (numa_node_to_cpus(i, cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { |
| for (size_t j = 0; j < cpu_map_valid_size; j++) { |
| if (cpu_map[j] != 0) { |
| for (size_t k = 0; k < BitsPerCLong; k++) { |
| if (cpu_map[j] & (1UL << k)) { |
| cpu_to_node()->at_put(j * BitsPerCLong + k, i); |
| } |
| } |
| } |
| } |
| } |
| } |
| FREE_C_HEAP_ARRAY(unsigned long, cpu_map, mtInternal); |
| } |
| |
| int os::Linux::get_node_by_cpu(int cpu_id) { |
| if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { |
| return cpu_to_node()->at(cpu_id); |
| } |
| return -1; |
| } |
| |
| GrowableArray<int>* os::Linux::_cpu_to_node; |
| os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; |
| os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; |
| os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; |
| os::Linux::numa_available_func_t os::Linux::_numa_available; |
| os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; |
| os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; |
| unsigned long* os::Linux::_numa_all_nodes; |
| |
| bool os::pd_uncommit_memory(char* addr, size_t size) { |
| uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, |
| MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); |
| return res != (uintptr_t) MAP_FAILED; |
| } |
| |
| // Linux uses a growable mapping for the stack, and if the mapping for |
| // the stack guard pages is not removed when we detach a thread the |
| // stack cannot grow beyond the pages where the stack guard was |
| // mapped. If at some point later in the process the stack expands to |
| // that point, the Linux kernel cannot expand the stack any further |
| // because the guard pages are in the way, and a segfault occurs. |
| // |
| // However, it's essential not to split the stack region by unmapping |
| // a region (leaving a hole) that's already part of the stack mapping, |
| // so if the stack mapping has already grown beyond the guard pages at |
| // the time we create them, we have to truncate the stack mapping. |
| // So, we need to know the extent of the stack mapping when |
| // create_stack_guard_pages() is called. |
| |
| // Find the bounds of the stack mapping. Return true for success. |
| // |
| // We only need this for stacks that are growable: at the time of |
| // writing thread stacks don't use growable mappings (i.e. those |
| // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this |
| // only applies to the main thread. |
| |
| static |
| bool get_stack_bounds(uintptr_t *bottom, uintptr_t *top) { |
| |
| char buf[128]; |
| int fd, sz; |
| |
| if ((fd = ::open("/proc/self/maps", O_RDONLY)) < 0) { |
| return false; |
| } |
| |
| const char kw[] = "[stack]"; |
| const int kwlen = sizeof(kw)-1; |
| |
| // Address part of /proc/self/maps couldn't be more than 128 bytes |
| while ((sz = os::get_line_chars(fd, buf, sizeof(buf))) > 0) { |
| if (sz > kwlen && ::memcmp(buf+sz-kwlen, kw, kwlen) == 0) { |
| // Extract addresses |
| if (sscanf(buf, "%" SCNxPTR "-%" SCNxPTR, bottom, top) == 2) { |
| uintptr_t sp = (uintptr_t) __builtin_frame_address(0); |
| if (sp >= *bottom && sp <= *top) { |
| ::close(fd); |
| return true; |
| } |
| } |
| } |
| } |
| |
| ::close(fd); |
| return false; |
| } |
| |
| |
| // If the (growable) stack mapping already extends beyond the point |
| // where we're going to put our guard pages, truncate the mapping at |
| // that point by munmap()ping it. This ensures that when we later |
| // munmap() the guard pages we don't leave a hole in the stack |
| // mapping. This only affects the main/initial thread, but guard |
| // against future OS changes |
| bool os::pd_create_stack_guard_pages(char* addr, size_t size) { |
| uintptr_t stack_extent, stack_base; |
| bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); |
| if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { |
| assert(os::Linux::is_initial_thread(), |
| "growable stack in non-initial thread"); |
| if (stack_extent < (uintptr_t)addr) |
| ::munmap((void*)stack_extent, (uintptr_t)addr - stack_extent); |
| } |
| |
| return os::commit_memory(addr, size); |
| } |
| |
| // If this is a growable mapping, remove the guard pages entirely by |
| // munmap()ping them. If not, just call uncommit_memory(). This only |
| // affects the main/initial thread, but guard against future OS changes |
| bool os::remove_stack_guard_pages(char* addr, size_t size) { |
| uintptr_t stack_extent, stack_base; |
| bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); |
| if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { |
| assert(os::Linux::is_initial_thread(), |
| "growable stack in non-initial thread"); |
| |
| return ::munmap(addr, size) == 0; |
| } |
| |
| return os::uncommit_memory(addr, size); |
| } |
| |
| static address _highest_vm_reserved_address = NULL; |
| |
| // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory |
| // at 'requested_addr'. If there are existing memory mappings at the same |
| // location, however, they will be overwritten. If 'fixed' is false, |
| // 'requested_addr' is only treated as a hint, the return value may or |
| // may not start from the requested address. Unlike Linux mmap(), this |
| // function returns NULL to indicate failure. |
| static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { |
| char * addr; |
| int flags; |
| |
| flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; |
| if (fixed) { |
| assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); |
| flags |= MAP_FIXED; |
| } |
| |
| // Map uncommitted pages PROT_READ and PROT_WRITE, change access |
| // to PROT_EXEC if executable when we commit the page. |
| addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE, |
| flags, -1, 0); |
| |
| if (addr != MAP_FAILED) { |
| // anon_mmap() should only get called during VM initialization, |
| // don't need lock (actually we can skip locking even it can be called |
| // from multiple threads, because _highest_vm_reserved_address is just a |
| // hint about the upper limit of non-stack memory regions.) |
| if ((address)addr + bytes > _highest_vm_reserved_address) { |
| _highest_vm_reserved_address = (address)addr + bytes; |
| } |
| } |
| |
| return addr == MAP_FAILED ? NULL : addr; |
| } |
| |
| // Don't update _highest_vm_reserved_address, because there might be memory |
| // regions above addr + size. If so, releasing a memory region only creates |
| // a hole in the address space, it doesn't help prevent heap-stack collision. |
| // |
| static int anon_munmap(char * addr, size_t size) { |
| return ::munmap(addr, size) == 0; |
| } |
| |
| char* os::pd_reserve_memory(size_t bytes, char* requested_addr, |
| size_t alignment_hint) { |
| return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); |
| } |
| |
| bool os::pd_release_memory(char* addr, size_t size) { |
| return anon_munmap(addr, size); |
| } |
| |
| static address highest_vm_reserved_address() { |
| return _highest_vm_reserved_address; |
| } |
| |
| static bool linux_mprotect(char* addr, size_t size, int prot) { |
| // Linux wants the mprotect address argument to be page aligned. |
| char* bottom = (char*)align_size_down((intptr_t)addr, os::Linux::page_size()); |
| |
| // According to SUSv3, mprotect() should only be used with mappings |
| // established by mmap(), and mmap() always maps whole pages. Unaligned |
| // 'addr' likely indicates problem in the VM (e.g. trying to change |
| // protection of malloc'ed or statically allocated memory). Check the |
| // caller if you hit this assert. |
| assert(addr == bottom, "sanity check"); |
| |
| size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); |
| return ::mprotect(bottom, size, prot) == 0; |
| } |
| |
| // Set protections specified |
| bool os::protect_memory(char* addr, size_t bytes, ProtType prot, |
| bool is_committed) { |
| unsigned int p = 0; |
| switch (prot) { |
| case MEM_PROT_NONE: p = PROT_NONE; break; |
| case MEM_PROT_READ: p = PROT_READ; break; |
| case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; |
| case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; |
| default: |
| ShouldNotReachHere(); |
| } |
| // is_committed is unused. |
| return linux_mprotect(addr, bytes, p); |
| } |
| |
| bool os::guard_memory(char* addr, size_t size) { |
| return linux_mprotect(addr, size, PROT_NONE); |
| } |
| |
| bool os::unguard_memory(char* addr, size_t size) { |
| return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); |
| } |
| |
| bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { |
| bool result = false; |
| void *p = mmap (NULL, page_size, PROT_READ|PROT_WRITE, |
| MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, |
| -1, 0); |
| |
| if (p != (void *) -1) { |
| // We don't know if this really is a huge page or not. |
| FILE *fp = fopen("/proc/self/maps", "r"); |
| if (fp) { |
| while (!feof(fp)) { |
| char chars[257]; |
| long x = 0; |
| if (fgets(chars, sizeof(chars), fp)) { |
| if (sscanf(chars, "%lx-%*x", &x) == 1 |
| && x == (long)p) { |
| if (strstr (chars, "hugepage")) { |
| result = true; |
| break; |
| } |
| } |
| } |
| } |
| fclose(fp); |
| } |
| munmap (p, page_size); |
| if (result) |
| return true; |
| } |
| |
| if (warn) { |
| warning("HugeTLBFS is not supported by the operating system."); |
| } |
| |
| return result; |
| } |
| |
| /* |
| * Set the coredump_filter bits to include largepages in core dump (bit 6) |
| * |
| * From the coredump_filter documentation: |
| * |
| * - (bit 0) anonymous private memory |
| * - (bit 1) anonymous shared memory |
| * - (bit 2) file-backed private memory |
| * - (bit 3) file-backed shared memory |
| * - (bit 4) ELF header pages in file-backed private memory areas (it is |
| * effective only if the bit 2 is cleared) |
| * - (bit 5) hugetlb private memory |
| * - (bit 6) hugetlb shared memory |
| */ |
| static void set_coredump_filter(void) { |
| FILE *f; |
| long cdm; |
| |
| if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { |
| return; |
| } |
| |
| if (fscanf(f, "%lx", &cdm) != 1) { |
| fclose(f); |
| return; |
| } |
| |
| rewind(f); |
| |
| if ((cdm & LARGEPAGES_BIT) == 0) { |
| cdm |= LARGEPAGES_BIT; |
| fprintf(f, "%#lx", cdm); |
| } |
| |
| fclose(f); |
| } |
| |
| // Large page support |
| |
| static size_t _large_page_size = 0; |
| |
| void os::large_page_init() { |
| if (!UseLargePages) { |
| UseHugeTLBFS = false; |
| UseSHM = false; |
| return; |
| } |
| |
| if (FLAG_IS_DEFAULT(UseHugeTLBFS) && FLAG_IS_DEFAULT(UseSHM)) { |
| // If UseLargePages is specified on the command line try both methods, |
| // if it's default, then try only HugeTLBFS. |
| if (FLAG_IS_DEFAULT(UseLargePages)) { |
| UseHugeTLBFS = true; |
| } else { |
| UseHugeTLBFS = UseSHM = true; |
| } |
| } |
| |
| if (LargePageSizeInBytes) { |
| _large_page_size = LargePageSizeInBytes; |
| } else { |
| // large_page_size on Linux is used to round up heap size. x86 uses either |
| // 2M or 4M page, depending on whether PAE (Physical Address Extensions) |
| // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use |
| // page as large as 256M. |
| // |
| // Here we try to figure out page size by parsing /proc/meminfo and looking |
| // for a line with the following format: |
| // Hugepagesize: 2048 kB |
| // |
| // If we can't determine the value (e.g. /proc is not mounted, or the text |
| // format has been changed), we'll use the largest page size supported by |
| // the processor. |
| |
| #ifndef ZERO |
| _large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M) |
| ARM_ONLY(2 * M) PPC_ONLY(4 * M); |
| #endif // ZERO |
| |
| FILE *fp = fopen("/proc/meminfo", "r"); |
| if (fp) { |
| while (!feof(fp)) { |
| int x = 0; |
| char buf[16]; |
| if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { |
| if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { |
| _large_page_size = x * K; |
| break; |
| } |
| } else { |
| // skip to next line |
| for (;;) { |
| int ch = fgetc(fp); |
| if (ch == EOF || ch == (int)'\n') break; |
| } |
| } |
| } |
| fclose(fp); |
| } |
| } |
| |
| // print a warning if any large page related flag is specified on command line |
| bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); |
| |
| const size_t default_page_size = (size_t)Linux::page_size(); |
| if (_large_page_size > default_page_size) { |
| _page_sizes[0] = _large_page_size; |
| _page_sizes[1] = default_page_size; |
| _page_sizes[2] = 0; |
| } |
| UseHugeTLBFS = UseHugeTLBFS && |
| Linux::hugetlbfs_sanity_check(warn_on_failure, _large_page_size); |
| |
| if (UseHugeTLBFS) |
| UseSHM = false; |
| |
| UseLargePages = UseHugeTLBFS || UseSHM; |
| |
| set_coredump_filter(); |
| } |
| |
| #ifndef SHM_HUGETLB |
| #define SHM_HUGETLB 04000 |
| #endif |
| |
| char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) { |
| // "exec" is passed in but not used. Creating the shared image for |
| // the code cache doesn't have an SHM_X executable permission to check. |
| assert(UseLargePages && UseSHM, "only for SHM large pages"); |
| |
| key_t key = IPC_PRIVATE; |
| char *addr; |
| |
| bool warn_on_failure = UseLargePages && |
| (!FLAG_IS_DEFAULT(UseLargePages) || |
| !FLAG_IS_DEFAULT(LargePageSizeInBytes) |
| ); |
| char msg[128]; |
| |
| // Create a large shared memory region to attach to based on size. |
| // Currently, size is the total size of the heap |
| int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); |
| if (shmid == -1) { |
| // Possible reasons for shmget failure: |
| // 1. shmmax is too small for Java heap. |
| // > check shmmax value: cat /proc/sys/kernel/shmmax |
| // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax |
| // 2. not enough large page memory. |
| // > check available large pages: cat /proc/meminfo |
| // > increase amount of large pages: |
| // echo new_value > /proc/sys/vm/nr_hugepages |
| // Note 1: different Linux may use different name for this property, |
| // e.g. on Redhat AS-3 it is "hugetlb_pool". |
| // Note 2: it's possible there's enough physical memory available but |
| // they are so fragmented after a long run that they can't |
| // coalesce into large pages. Try to reserve large pages when |
| // the system is still "fresh". |
| if (warn_on_failure) { |
| jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); |
| warning(msg); |
| } |
| return NULL; |
| } |
| |
| // attach to the region |
| addr = (char*)shmat(shmid, req_addr, 0); |
| int err = errno; |
| |
| // Remove shmid. If shmat() is successful, the actual shared memory segment |
| // will be deleted when it's detached by shmdt() or when the process |
| // terminates. If shmat() is not successful this will remove the shared |
| // segment immediately. |
| shmctl(shmid, IPC_RMID, NULL); |
| |
| if ((intptr_t)addr == -1) { |
| if (warn_on_failure) { |
| jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); |
| warning(msg); |
| } |
| return NULL; |
| } |
| |
| if ((addr != NULL) && UseNUMAInterleaving) { |
| numa_make_global(addr, bytes); |
| } |
| |
| return addr; |
| } |
| |
| bool os::release_memory_special(char* base, size_t bytes) { |
| // detaching the SHM segment will also delete it, see reserve_memory_special() |
| int rslt = shmdt(base); |
| return rslt == 0; |
| } |
| |
| size_t os::large_page_size() { |
| return _large_page_size; |
| } |
| |
| // HugeTLBFS allows application to commit large page memory on demand; |
| // with SysV SHM the entire memory region must be allocated as shared |
| // memory. |
| bool os::can_commit_large_page_memory() { |
| return UseHugeTLBFS; |
| } |
| |
| bool os::can_execute_large_page_memory() { |
| return UseHugeTLBFS; |
| } |
| |
| // Reserve memory at an arbitrary address, only if that area is |
| // available (and not reserved for something else). |
| |
| char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { |
| const int max_tries = 10; |
| char* base[max_tries]; |
| size_t size[max_tries]; |
| const size_t gap = 0x000000; |
| |
| // Assert only that the size is a multiple of the page size, since |
| // that's all that mmap requires, and since that's all we really know |
| // about at this low abstraction level. If we need higher alignment, |
| // we can either pass an alignment to this method or verify alignment |
| // in one of the methods further up the call chain. See bug 5044738. |
| assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); |
| |
| // Repeatedly allocate blocks until the block is allocated at the |
| // right spot. Give up after max_tries. Note that reserve_memory() will |
| // automatically update _highest_vm_reserved_address if the call is |
| // successful. The variable tracks the highest memory address every reserved |
| // by JVM. It is used to detect heap-stack collision if running with |
| // fixed-stack LinuxThreads. Because here we may attempt to reserve more |
| // space than needed, it could confuse the collision detecting code. To |
| // solve the problem, save current _highest_vm_reserved_address and |
| // calculate the correct value before return. |
| address old_highest = _highest_vm_reserved_address; |
| |
| // Linux mmap allows caller to pass an address as hint; give it a try first, |
| // if kernel honors the hint then we can return immediately. |
| char * addr = anon_mmap(requested_addr, bytes, false); |
| if (addr == requested_addr) { |
| return requested_addr; |
| } |
| |
| if (addr != NULL) { |
| // mmap() is successful but it fails to reserve at the requested address |
| anon_munmap(addr, bytes); |
| } |
| |
| int i; |
| for (i = 0; i < max_tries; ++i) { |
| base[i] = reserve_memory(bytes); |
| |
| if (base[i] != NULL) { |
| // Is this the block we wanted? |
| if (base[i] == requested_addr) { |
| size[i] = bytes; |
| break; |
| } |
| |
| // Does this overlap the block we wanted? Give back the overlapped |
| // parts and try again. |
| |
| size_t top_overlap = requested_addr + (bytes + gap) - base[i]; |
| if (top_overlap >= 0 && top_overlap < bytes) { |
| unmap_memory(base[i], top_overlap); |
| base[i] += top_overlap; |
| size[i] = bytes - top_overlap; |
| } else { |
| size_t bottom_overlap = base[i] + bytes - requested_addr; |
| if (bottom_overlap >= 0 && bottom_overlap < bytes) { |
| unmap_memory(requested_addr, bottom_overlap); |
| size[i] = bytes - bottom_overlap; |
| } else { |
| size[i] = bytes; |
| } |
| } |
| } |
| } |
| |
| // Give back the unused reserved pieces. |
| |
| for (int j = 0; j < i; ++j) { |
| if (base[j] != NULL) { |
| unmap_memory(base[j], size[j]); |
| } |
| } |
| |
| if (i < max_tries) { |
| _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); |
| return requested_addr; |
| } else { |
| _highest_vm_reserved_address = old_highest; |
| return NULL; |
| } |
| } |
| |
| size_t os::read(int fd, void *buf, unsigned int nBytes) { |
| return ::read(fd, buf, nBytes); |
| } |
| |
| // TODO-FIXME: reconcile Solaris' os::sleep with the linux variation. |
| // Solaris uses poll(), linux uses park(). |
| // Poll() is likely a better choice, assuming that Thread.interrupt() |
| // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with |
| // SIGSEGV, see 4355769. |
| |
| int os::sleep(Thread* thread, jlong millis, bool interruptible) { |
| assert(thread == Thread::current(), "thread consistency check"); |
| |
| ParkEvent * const slp = thread->_SleepEvent ; |
| slp->reset() ; |
| OrderAccess::fence() ; |
| |
| if (interruptible) { |
| jlong prevtime = javaTimeNanos(); |
| |
| for (;;) { |
| if (os::is_interrupted(thread, true)) { |
| return OS_INTRPT; |
| } |
| |
| jlong newtime = javaTimeNanos(); |
| |
| if (newtime - prevtime < 0) { |
| // time moving backwards, should only happen if no monotonic clock |
| // not a guarantee() because JVM should not abort on kernel/glibc bugs |
| assert(!Linux::supports_monotonic_clock(), "time moving backwards"); |
| } else { |
| millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; |
| } |
| |
| if(millis <= 0) { |
| return OS_OK; |
| } |
| |
| prevtime = newtime; |
| |
| { |
| assert(thread->is_Java_thread(), "sanity check"); |
| JavaThread *jt = (JavaThread *) thread; |
| ThreadBlockInVM tbivm(jt); |
| OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); |
| |
| jt->set_suspend_equivalent(); |
| // cleared by handle_special_suspend_equivalent_condition() or |
| // java_suspend_self() via check_and_wait_while_suspended() |
| |
| slp->park(millis); |
| |
| // were we externally suspended while we were waiting? |
| jt->check_and_wait_while_suspended(); |
| } |
| } |
| } else { |
| OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); |
| jlong prevtime = javaTimeNanos(); |
| |
| for (;;) { |
| // It'd be nice to avoid the back-to-back javaTimeNanos() calls on |
| // the 1st iteration ... |
| jlong newtime = javaTimeNanos(); |
| |
| if (newtime - prevtime < 0) { |
| // time moving backwards, should only happen if no monotonic clock |
| // not a guarantee() because JVM should not abort on kernel/glibc bugs |
| assert(!Linux::supports_monotonic_clock(), "time moving backwards"); |
| } else { |
| millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; |
| } |
| |
| if(millis <= 0) break ; |
| |
| prevtime = newtime; |
| slp->park(millis); |
| } |
| return OS_OK ; |
| } |
| } |
| |
| int os::naked_sleep() { |
| // %% make the sleep time an integer flag. for now use 1 millisec. |
| return os::sleep(Thread::current(), 1, false); |
| } |
| |
| // Sleep forever; naked call to OS-specific sleep; use with CAUTION |
| void os::infinite_sleep() { |
| while (true) { // sleep forever ... |
| ::sleep(100); // ... 100 seconds at a time |
| } |
| } |
| |
| // Used to convert frequent JVM_Yield() to nops |
| bool os::dont_yield() { |
| return DontYieldALot; |
| } |
| |
| void os::yield() { |
| sched_yield(); |
| } |
| |
| os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} |
| |
| void os::yield_all(int attempts) { |
| // Yields to all threads, including threads with lower priorities |
| // Threads on Linux are all with same priority. The Solaris style |
| // os::yield_all() with nanosleep(1ms) is not necessary. |
| sched_yield(); |
| } |
| |
| // Called from the tight loops to possibly influence time-sharing heuristics |
| void os::loop_breaker(int attempts) { |
| os::yield_all(attempts); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // thread priority support |
| |
| // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER |
| // only supports dynamic priority, static priority must be zero. For real-time |
| // applications, Linux supports SCHED_RR which allows static priority (1-99). |
| // However, for large multi-threaded applications, SCHED_RR is not only slower |
| // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out |
| // of 5 runs - Sep 2005). |
| // |
| // The following code actually changes the niceness of kernel-thread/LWP. It |
| // has an assumption that setpriority() only modifies one kernel-thread/LWP, |
| // not the entire user process, and user level threads are 1:1 mapped to kernel |
| // threads. It has always been the case, but could change in the future. For |
| // this reason, the code should not be used as default (ThreadPriorityPolicy=0). |
| // It is only used when ThreadPriorityPolicy=1 and requires root privilege. |
| |
| int os::java_to_os_priority[CriticalPriority + 1] = { |
| 19, // 0 Entry should never be used |
| |
| 4, // 1 MinPriority |
| 3, // 2 |
| 2, // 3 |
| |
| 1, // 4 |
| 0, // 5 NormPriority |
| -1, // 6 |
| |
| -2, // 7 |
| -3, // 8 |
| -4, // 9 NearMaxPriority |
| |
| -5, // 10 MaxPriority |
| |
| -5 // 11 CriticalPriority |
| }; |
| |
| static int prio_init() { |
| if (ThreadPriorityPolicy == 1) { |
| // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 |
| // if effective uid is not root. Perhaps, a more elegant way of doing |
| // this is to test CAP_SYS_NICE capability, but that will require libcap.so |
| if (geteuid() != 0) { |
| if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { |
| warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); |
| } |
| ThreadPriorityPolicy = 0; |
| } |
| } |
| if (UseCriticalJavaThreadPriority) { |
| os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; |
| } |
| return 0; |
| } |
| |
| OSReturn os::set_native_priority(Thread* thread, int newpri) { |
| if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; |
| |
| int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); |
| return (ret == 0) ? OS_OK : OS_ERR; |
| } |
| |
| OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { |
| if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { |
| *priority_ptr = java_to_os_priority[NormPriority]; |
| return OS_OK; |
| } |
| |
| errno = 0; |
| *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); |
| return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); |
| } |
| |
| // Hint to the underlying OS that a task switch would not be good. |
| // Void return because it's a hint and can fail. |
| void os::hint_no_preempt() {} |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // suspend/resume support |
| |
| // the low-level signal-based suspend/resume support is a remnant from the |
| // old VM-suspension that used to be for java-suspension, safepoints etc, |
| // within hotspot. Now there is a single use-case for this: |
| // - calling get_thread_pc() on the VMThread by the flat-profiler task |
| // that runs in the watcher thread. |
| // The remaining code is greatly simplified from the more general suspension |
| // code that used to be used. |
| // |
| // The protocol is quite simple: |
| // - suspend: |
| // - sends a signal to the target thread |
| // - polls the suspend state of the osthread using a yield loop |
| // - target thread signal handler (SR_handler) sets suspend state |
| // and blocks in sigsuspend until continued |
| // - resume: |
| // - sets target osthread state to continue |
| // - sends signal to end the sigsuspend loop in the SR_handler |
| // |
| // Note that the SR_lock plays no role in this suspend/resume protocol. |
| // |
| |
| static void resume_clear_context(OSThread *osthread) { |
| osthread->set_ucontext(NULL); |
| osthread->set_siginfo(NULL); |
| } |
| |
| static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { |
| osthread->set_ucontext(context); |
| osthread->set_siginfo(siginfo); |
| } |
| |
| // |
| // Handler function invoked when a thread's execution is suspended or |
| // resumed. We have to be careful that only async-safe functions are |
| // called here (Note: most pthread functions are not async safe and |
| // should be avoided.) |
| // |
| // Note: sigwait() is a more natural fit than sigsuspend() from an |
| // interface point of view, but sigwait() prevents the signal hander |
| // from being run. libpthread would get very confused by not having |
| // its signal handlers run and prevents sigwait()'s use with the |
| // mutex granting granting signal. |
| // |
| // Currently only ever called on the VMThread and JavaThreads (PC sampling) |
| // |
| static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { |
| // Save and restore errno to avoid confusing native code with EINTR |
| // after sigsuspend. |
| int old_errno = errno; |
| |
| Thread* thread = Thread::current(); |
| OSThread* osthread = thread->osthread(); |
| assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); |
| |
| os::SuspendResume::State current = osthread->sr.state(); |
| if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { |
| suspend_save_context(osthread, siginfo, context); |
| |
| // attempt to switch the state, we assume we had a SUSPEND_REQUEST |
| os::SuspendResume::State state = osthread->sr.suspended(); |
| if (state == os::SuspendResume::SR_SUSPENDED) { |
| sigset_t suspend_set; // signals for sigsuspend() |
| |
| // get current set of blocked signals and unblock resume signal |
| pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); |
| sigdelset(&suspend_set, SR_signum); |
| |
| // wait here until we are resumed |
| while (1) { |
| sigsuspend(&suspend_set); |
| |
| os::SuspendResume::State result = osthread->sr.running(); |
| if (result == os::SuspendResume::SR_RUNNING) { |
| break; |
| } |
| } |
| |
| } else if (state == os::SuspendResume::SR_RUNNING) { |
| // request was cancelled, continue |
| } else { |
| ShouldNotReachHere(); |
| } |
| |
| resume_clear_context(osthread); |
| } else if (current == os::SuspendResume::SR_RUNNING) { |
| // request was cancelled, continue |
| } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { |
| // ignore |
| } else { |
| ShouldNotReachHere(); |
| } |
| |
| errno = old_errno; |
| } |
| |
| |
| static int SR_initialize() { |
| struct sigaction act; |
| char *s; |
| /* Get signal number to use for suspend/resume */ |
| if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { |
| int sig = ::strtol(s, 0, 10); |
| if (sig > 0 || sig < _NSIG) { |
| SR_signum = sig; |
| } |
| } |
| |
| assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, |
| "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); |
| |
| sigemptyset(&SR_sigset); |
| sigaddset(&SR_sigset, SR_signum); |
| |
| /* Set up signal handler for suspend/resume */ |
| act.sa_flags = SA_RESTART|SA_SIGINFO; |
| act.sa_handler = (void (*)(int)) SR_handler; |
| |
| // SR_signum is blocked by default. |
| // 4528190 - We also need to block pthread restart signal (32 on all |
| // supported Linux platforms). Note that LinuxThreads need to block |
| // this signal for all threads to work properly. So we don't have |
| // to use hard-coded signal number when setting up the mask. |
| pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); |
| |
| if (sigaction(SR_signum, &act, 0) == -1) { |
| return -1; |
| } |
| |
| // Save signal flag |
| os::Linux::set_our_sigflags(SR_signum, act.sa_flags); |
| return 0; |
| } |
| |
| static int SR_finalize() { |
| return 0; |
| } |
| |
| static int sr_notify(OSThread* osthread) { |
| int status = pthread_kill(osthread->pthread_id(), SR_signum); |
| assert_status(status == 0, status, "pthread_kill"); |
| return status; |
| } |
| |
| // "Randomly" selected value for how long we want to spin |
| // before bailing out on suspending a thread, also how often |
| // we send a signal to a thread we want to resume |
| static const int RANDOMLY_LARGE_INTEGER = 1000000; |
| static const int RANDOMLY_LARGE_INTEGER2 = 100; |
| |
| // returns true on success and false on error - really an error is fatal |
| // but this seems the normal response to library errors |
| static bool do_suspend(OSThread* osthread) { |
| assert(osthread->sr.is_running(), "thread should be running"); |
| // mark as suspended and send signal |
| |
| if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { |
| // failed to switch, state wasn't running? |
| ShouldNotReachHere(); |
| return false; |
| } |
| |
| if (sr_notify(osthread) != 0) { |
| // try to cancel, switch to running |
| |
| os::SuspendResume::State result = osthread->sr.cancel_suspend(); |
| if (result == os::SuspendResume::SR_RUNNING) { |
| // cancelled |
| return false; |
| } else if (result == os::SuspendResume::SR_SUSPENDED) { |
| // somehow managed to suspend |
| return true; |
| } else { |
| ShouldNotReachHere(); |
| return false; |
| } |
| } |
| |
| // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED |
| |
| for (int n = 0; !osthread->sr.is_suspended(); n++) { |
| for (int i = 0; i < RANDOMLY_LARGE_INTEGER2 && !osthread->sr.is_suspended(); i++) { |
| os::yield_all(i); |
| } |
| |
| // timeout, try to cancel the request |
| if (n >= RANDOMLY_LARGE_INTEGER) { |
| os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); |
| if (cancelled == os::SuspendResume::SR_RUNNING) { |
| return false; |
| } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { |
| return true; |
| } else { |
| ShouldNotReachHere(); |
| return false; |
| } |
| } |
| } |
| |
| guarantee(osthread->sr.is_suspended(), "Must be suspended"); |
| return true; |
| } |
| |
| static void do_resume(OSThread* osthread) { |
| assert(osthread->sr.is_suspended(), "thread should be suspended"); |
| |
| if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { |
| // failed to switch to WAKEUP_REQUEST |
| ShouldNotReachHere(); |
| return; |
| } |
| |
| while (!osthread->sr.is_running()) { |
| if (sr_notify(osthread) == 0) { |
| for (int n = 0; n < RANDOMLY_LARGE_INTEGER && !osthread->sr.is_running(); n++) { |
| for (int i = 0; i < 100 && !osthread->sr.is_running(); i++) { |
| os::yield_all(i); |
| } |
| } |
| } else { |
| ShouldNotReachHere(); |
| } |
| } |
| |
| guarantee(osthread->sr.is_running(), "Must be running!"); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // interrupt support |
| |
| void os::interrupt(Thread* thread) { |
| assert(Thread::current() == thread || Threads_lock->owned_by_self(), |
| "possibility of dangling Thread pointer"); |
| |
| OSThread* osthread = thread->osthread(); |
| |
| if (!osthread->interrupted()) { |
| osthread->set_interrupted(true); |
| // More than one thread can get here with the same value of osthread, |
| // resulting in multiple notifications. We do, however, want the store |
| // to interrupted() to be visible to other threads before we execute unpark(). |
| OrderAccess::fence(); |
| ParkEvent * const slp = thread->_SleepEvent ; |
| if (slp != NULL) slp->unpark() ; |
| } |
| |
| // For JSR166. Unpark even if interrupt status already was set |
| if (thread->is_Java_thread()) |
| ((JavaThread*)thread)->parker()->unpark(); |
| |
| ParkEvent * ev = thread->_ParkEvent ; |
| if (ev != NULL) ev->unpark() ; |
| |
| } |
| |
| bool os::is_interrupted(Thread* thread, bool clear_interrupted) { |
| assert(Thread::current() == thread || Threads_lock->owned_by_self(), |
| "possibility of dangling Thread pointer"); |
| |
| OSThread* osthread = thread->osthread(); |
| |
| bool interrupted = osthread->interrupted(); |
| |
| if (interrupted && clear_interrupted) { |
| osthread->set_interrupted(false); |
| // consider thread->_SleepEvent->reset() ... optional optimization |
| } |
| |
| return interrupted; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////////// |
| // signal handling (except suspend/resume) |
| |
| // This routine may be used by user applications as a "hook" to catch signals. |
| // The user-defined signal handler must pass unrecognized signals to this |
| // routine, and if it returns true (non-zero), then the signal handler must |
| // return immediately. If the flag "abort_if_unrecognized" is true, then this |
| // routine will never retun false (zero), but instead will execute a VM panic |
| // routine kill the process. |
| // |
| // If this routine returns false, it is OK to call it again. This allows |
| // the user-defined signal handler to perform checks either before or after |
| // the VM performs its own checks. Naturally, the user code would be making |
| // a serious error if it tried to handle an exception (such as a null check |
| // or breakpoint) that the VM was generating for its own correct operation. |
| // |
| // This routine may recognize any of the following kinds of signals: |
| // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. |
| // It should be consulted by handlers for any of those signals. |
| // |
| // The caller of this routine must pass in the three arguments supplied |
| // to the function referred to in the "sa_sigaction" (not the "sa_handler") |
| // field of the structure passed to sigaction(). This routine assumes that |
| // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. |
| // |
| // Note that the VM will print warnings if it detects conflicting signal |
| // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". |
| // |
| extern "C" JNIEXPORT int |
| JVM_handle_linux_signal(int signo, siginfo_t* siginfo, |
| void* ucontext, int abort_if_unrecognized); |
| |
| void signalHandler(int sig, siginfo_t* info, void* uc) { |
| assert(info != NULL && uc != NULL, "it must be old kernel"); |
| JVM_handle_linux_signal(sig, info, uc, true); |
| } |
| |
| |
| // This boolean allows users to forward their own non-matching signals |
| // to JVM_handle_linux_signal, harmlessly. |
| bool os::Linux::signal_handlers_are_installed = false; |
| |
| // For signal-chaining |
| struct sigaction os::Linux::sigact[MAXSIGNUM]; |
| unsigned int os::Linux::sigs = 0; |
| bool os::Linux::libjsig_is_loaded = false; |
| typedef struct sigaction *(*get_signal_t)(int); |
| get_signal_t os::Linux::get_signal_action = NULL; |
| |
| struct sigaction* os::Linux::get_chained_signal_action(int sig) { |
| struct sigaction *actp = NULL; |
| |
| if (libjsig_is_loaded) { |
| // Retrieve the old signal handler from libjsig |
| actp = (*get_signal_action)(sig); |
| } |
| if (actp == NULL) { |
| // Retrieve the preinstalled signal handler from jvm |
| actp = get_preinstalled_handler(sig); |
| } |
| |
| return actp; |
| } |
| |
| static bool call_chained_handler(struct sigaction *actp, int sig, |
| siginfo_t *siginfo, void *context) { |
| // Call the old signal handler |
| if (actp->sa_handler == SIG_DFL) { |
| // It's more reasonable to let jvm treat it as an unexpected exception |
| // instead of taking the default action. |
| return false; |
| } else if (actp->sa_handler != SIG_IGN) { |
| if ((actp->sa_flags & SA_NODEFER) == 0) { |
| // automaticlly block the signal |
| sigaddset(&(actp->sa_mask), sig); |
| } |
| |
| sa_handler_t hand; |
| sa_sigaction_t sa; |
| bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; |
| // retrieve the chained handler |
| if (siginfo_flag_set) { |
| sa = actp->sa_sigaction; |
| } else { |
| hand = actp->sa_handler; |
| } |
| |
| if ((actp->sa_flags & SA_RESETHAND) != 0) { |
| actp->sa_handler = SIG_DFL; |
| } |
| |
| // try to honor the signal mask |
| sigset_t oset; |
| pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); |
| |
| // call into the chained handler |
| if (siginfo_flag_set) { |
| (*sa)(sig, siginfo, context); |
| } else { |
| (*hand)(sig); |
| } |
| |
| // restore the signal mask |
| pthread_sigmask(SIG_SETMASK, &oset, 0); |
| } |
| // Tell jvm's signal handler the signal is taken care of. |
| return true; |
| } |
| |
| bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { |
| bool chained = false; |
| // signal-chaining |
| if (UseSignalChaining) { |
| struct sigaction *actp = get_chained_signal_action(sig); |
| if (actp != NULL) { |
| chained = call_chained_handler(actp, sig, siginfo, context); |
| } |
| } |
| return chained; |
| } |
| |
| struct sigaction* os::Linux::get_preinstalled_handler(int sig) { |
| if ((( (unsigned int)1 << sig ) & sigs) != 0) { |
| return &sigact[sig]; |
| } |
| return NULL; |
| } |
| |
| void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { |
| assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); |
| sigact[sig] = oldAct; |
| sigs |= (unsigned int)1 << sig; |
| } |
| |
| // for diagnostic |
| int os::Linux::sigflags[MAXSIGNUM]; |
| |
| int os::Linux::get_our_sigflags(int sig) { |
| assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); |
| return sigflags[sig]; |
| } |
| |
| void os::Linux::set_our_sigflags(int sig, int flags) { |
| assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); |
| sigflags[sig] = flags; |
| } |
| |
| void os::Linux::set_signal_handler(int sig, bool set_installed) { |
| // Check for overwrite. |
| struct sigaction oldAct; |
| sigaction(sig, (struct sigaction*)NULL, &oldAct); |
| |
| void* oldhand = oldAct.sa_sigaction |
| ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) |
| : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); |
| if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && |
| oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && |
| oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { |
| if (AllowUserSignalHandlers || !set_installed) { |
| // Do not overwrite; user takes responsibility to forward to us. |
| return; |
| } else if (UseSignalChaining) { |
| // save the old handler in jvm |
| save_preinstalled_handler(sig, oldAct); |
| // libjsig also interposes the sigaction() call below and saves the |
| // old sigaction on it own. |
| } else { |
| fatal(err_msg("Encountered unexpected pre-existing sigaction handler " |
| "%#lx for signal %d.", (long)oldhand, sig)); |
| } |
| } |
| |
| struct sigaction sigAct; |
| sigfillset(&(sigAct.sa_mask)); |
| sigAct.sa_handler = SIG_DFL; |
| if (!set_installed) { |
| sigAct.sa_flags = SA_SIGINFO|SA_RESTART; |
| } else { |
| sigAct.sa_sigaction = signalHandler; |
| sigAct.sa_flags = SA_SIGINFO|SA_RESTART; |
| } |
| // Save flags, which are set by ours |
| assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); |
| sigflags[sig] = sigAct.sa_flags; |
| |
| int ret = sigaction(sig, &sigAct, &oldAct); |
| assert(ret == 0, "check"); |
| |
| void* oldhand2 = oldAct.sa_sigaction |
| ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) |
| : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); |
| assert(oldhand2 == oldhand, "no concurrent signal handler installation"); |
| } |
| |
| // install signal handlers for signals that HotSpot needs to |
| // handle in order to support Java-level exception handling. |
| |
| void os::Linux::install_signal_handlers() { |
| if (!signal_handlers_are_installed) { |
| signal_handlers_are_installed = true; |
| |
| // signal-chaining |
| typedef void (*signal_setting_t)(); |
| signal_setting_t begin_signal_setting = NULL; |
| signal_setting_t end_signal_setting = NULL; |
| begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, |
| dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); |
| if (begin_signal_setting != NULL) { |
| end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, |
| dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); |
| get_signal_action = CAST_TO_FN_PTR(get_signal_t, |
| dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); |
| libjsig_is_loaded = true; |
| assert(UseSignalChaining, "should enable signal-chaining"); |
| } |
| if (libjsig_is_loaded) { |
| // Tell libjsig jvm is setting signal handlers |
| (*begin_signal_setting)(); |
| } |
| |
| set_signal_handler(SIGSEGV, true); |
| set_signal_handler(SIGPIPE, true); |
| set_signal_handler(SIGBUS, true); |
| set_signal_handler(SIGILL, true); |
| set_signal_handler(SIGFPE, true); |
| set_signal_handler(SIGXFSZ, true); |
| |
| if (libjsig_is_loaded) { |
| // Tell libjsig jvm finishes setting signal handlers |
| (*end_signal_setting)(); |
| } |
| |
| // We don't activate signal checker if libjsig is in place, we trust ourselves |
| // and if UserSignalHandler is installed all bets are off. |
| // Log that signal checking is off only if -verbose:jni is specified. |
| if (CheckJNICalls) { |
| if (libjsig_is_loaded) { |
| if (PrintJNIResolving) { |
| tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); |
| } |
| check_signals = false; |
| } |
| if (AllowUserSignalHandlers) { |
| if (PrintJNIResolving) { |
| tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); |
| } |
| check_signals = false; |
| } |
| } |
| } |
| } |
| |
| // This is the fastest way to get thread cpu time on Linux. |
| // Returns cpu time (user+sys) for any thread, not only for current. |
| // POSIX compliant clocks are implemented in the kernels 2.6.16+. |
| // It might work on 2.6.10+ with a special kernel/glibc patch. |
| // For reference, please, see IEEE Std 1003.1-2004: |
| // http://www.unix.org/single_unix_specification |
| |
| jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { |
| struct timespec tp; |
| int rc = os::Linux::clock_gettime(clockid, &tp); |
| assert(rc == 0, "clock_gettime is expected to return 0 code"); |
| |
| return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; |
| } |
| |
| ///// |
| // glibc on Linux platform uses non-documented flag |
| // to indicate, that some special sort of signal |
| // trampoline is used. |
| // We will never set this flag, and we should |
| // ignore this flag in our diagnostic |
| #ifdef SIGNIFICANT_SIGNAL_MASK |
| #undef SIGNIFICANT_SIGNAL_MASK |
| #endif |
| #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) |
| |
| static const char* get_signal_handler_name(address handler, |
| char* buf, int buflen) { |
| int offset; |
| bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); |
| if (found) { |
| // skip directory names |
| const char *p1, *p2; |
| p1 = buf; |
| size_t len = strlen(os::file_separator()); |
| while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; |
| jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); |
| } else { |
| jio_snprintf(buf, buflen, PTR_FORMAT, handler); |
| } |
| return buf; |
| } |
| |
| static void print_signal_handler(outputStream* st, int sig, |
| char* buf, size_t buflen) { |
| struct sigaction sa; |
| |
| sigaction(sig, NULL, &sa); |
| |
| // See comment for SIGNIFICANT_SIGNAL_MASK define |
| sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; |
| |
| st->print("%s: ", os::exception_name(sig, buf, buflen)); |
| |
| address handler = (sa.sa_flags & SA_SIGINFO) |
| ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) |
| : CAST_FROM_FN_PTR(address, sa.sa_handler); |
| |
| if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { |
| st->print("SIG_DFL"); |
| } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { |
| st->print("SIG_IGN"); |
| } else { |
| st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); |
| } |
| |
| st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask); |
| |
| address rh = VMError::get_resetted_sighandler(sig); |
| // May be, handler was resetted by VMError? |
| if(rh != NULL) { |
| handler = rh; |
| sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; |
| } |
| |
| st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags); |
| |
| // Check: is it our handler? |
| if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || |
| handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { |
| // It is our signal handler |
| // check for flags, reset system-used one! |
| if((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { |
| st->print( |
| ", flags was changed from " PTR32_FORMAT ", consider using jsig library", |
| os::Linux::get_our_sigflags(sig)); |
| } |
| } |
| st->cr(); |
| } |
| |
| |
| #define DO_SIGNAL_CHECK(sig) \ |
| if (!sigismember(&check_signal_done, sig)) \ |
| os::Linux::check_signal_handler(sig) |
| |
| // This method is a periodic task to check for misbehaving JNI applications |
| // under CheckJNI, we can add any periodic checks here |
| |
| void os::run_periodic_checks() { |
| |
| if (check_signals == false) return; |
| |
| // SEGV and BUS if overridden could potentially prevent |
| // generation of hs*.log in the event of a crash, debugging |
| // such a case can be very challenging, so we absolutely |
| // check the following for a good measure: |
| DO_SIGNAL_CHECK(SIGSEGV); |
| DO_SIGNAL_CHECK(SIGILL); |
| DO_SIGNAL_CHECK(SIGFPE); |
| DO_SIGNAL_CHECK(SIGBUS); |
| DO_SIGNAL_CHECK(SIGPIPE); |
| DO_SIGNAL_CHECK(SIGXFSZ); |
| |
| |
| // ReduceSignalUsage allows the user to override these handlers |
| // see comments at the very top and jvm_solaris.h |
| if (!ReduceSignalUsage) { |
| DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); |
| DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); |
| DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); |
| DO_SIGNAL_CHECK(BREAK_SIGNAL); |
| } |
| |
| DO_SIGNAL_CHECK(SR_signum); |
| DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); |
| } |
| |
| typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); |
| |
| static os_sigaction_t os_sigaction = NULL; |
| |
| void os::Linux::check_signal_handler(int sig) { |
| char buf[O_BUFLEN]; |
| address jvmHandler = NULL; |
| |
| |
| struct sigaction act; |
| if (os_sigaction == NULL) { |
| // only trust the default sigaction, in case it has been interposed |
| os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); |
| if (os_sigaction == NULL) return; |
| } |
| |
| os_sigaction(sig, (struct sigaction*)NULL, &act); |
| |
| |
| act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; |
| |
| address thisHandler = (act.sa_flags & SA_SIGINFO) |
| ? CAST_FROM_FN_PTR(address, act.sa_sigaction) |
| : CAST_FROM_FN_PTR(address, act.sa_handler) ; |
| |
| |
| switch(sig) { |
| case SIGSEGV: |
| case SIGBUS: |
| case SIGFPE: |
| case SIGPIPE: |
| case SIGILL: |
| case SIGXFSZ: |
| jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); |
| break; |
| |
| case SHUTDOWN1_SIGNAL: |
| case SHUTDOWN2_SIGNAL: |
| case SHUTDOWN3_SIGNAL: |
| case BREAK_SIGNAL: |
| jvmHandler = (address)user_handler(); |
| break; |
| |
| case INTERRUPT_SIGNAL: |
| jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); |
| break; |
| |
| default: |
| if (sig == SR_signum) { |
| jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); |
| } else { |
| return; |
| } |
| break; |
| } |
| |
| if (thisHandler != jvmHandler) { |
| tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); |
| tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); |
| tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); |
| // No need to check this sig any longer |
| sigaddset(&check_signal_done, sig); |
| } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { |
| tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); |
| tty->print("expected:" PTR32_FORMAT, os::Linux::get_our_sigflags(sig)); |
| tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); |
| // No need to check this sig any longer |
| sigaddset(&check_signal_done, sig); |
| } |
| |
| // Dump all the signal |
| if (sigismember(&check_signal_done, sig)) { |
| print_signal_handlers(tty, buf, O_BUFLEN); |
| } |
| } |
| |
| extern void report_error(char* file_name, int line_no, char* title, char* format, ...); |
| |
| extern bool signal_name(int signo, char* buf, size_t len); |
| |
| const char* os::exception_name(int exception_code, char* buf, size_t size) { |
| if (0 < exception_code && exception_code <= SIGRTMAX) { |
| // signal |
| if (!signal_name(exception_code, buf, size)) { |
| jio_snprintf(buf, size, "SIG%d", exception_code); |
| } |
| return buf; |
| } else { |
| return NULL; |
| } |
| } |
| |
| // this is called _before_ the most of global arguments have been parsed |
| void os::init(void) { |
| char dummy; /* used to get a guess on initial stack address */ |
| // first_hrtime = gethrtime(); |
| |
| // With LinuxThreads the JavaMain thread pid (primordial thread) |
| // is different than the pid of the java launcher thread. |
| // So, on Linux, the launcher thread pid is passed to the VM |
| // via the sun.java.launcher.pid property. |
| // Use this property instead of getpid() if it was correctly passed. |
| // See bug 6351349. |
| pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); |
| |
| _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); |
| |
| clock_tics_per_sec = sysconf(_SC_CLK_TCK); |
| |
| init_random(1234567); |
| |
| ThreadCritical::initialize(); |
| |
| Linux::set_page_size(sysconf(_SC_PAGESIZE)); |
| if (Linux::page_size() == -1) { |
| fatal(err_msg("os_linux.cpp: os::init: sysconf failed (%s)", |
| strerror(errno))); |
| } |
| init_page_sizes((size_t) Linux::page_size()); |
| |
| Linux::initialize_system_info(); |
| |
| // main_thread points to the aboriginal thread |
| Linux::_main_thread = pthread_self(); |
| |
| Linux::clock_init(); |
| initial_time_count = os::elapsed_counter(); |
| pthread_mutex_init(&dl_mutex, NULL); |
| } |
| |
| // To install functions for atexit system call |
| extern "C" { |
| static void perfMemory_exit_helper() { |
| perfMemory_exit(); |
| } |
| } |
| |
| // this is called _after_ the global arguments have been parsed |
| jint os::init_2(void) |
| { |
| Linux::fast_thread_clock_init(); |
| |
| // Allocate a single page and mark it as readable for safepoint polling |
| address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
| guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); |
| |
| os::set_polling_page( polling_page ); |
| |
| #ifndef PRODUCT |
| if(Verbose && PrintMiscellaneous) |
| tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); |
| #endif |
| |
| if (!UseMembar) { |
| address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
| guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); |
| os::set_memory_serialize_page( mem_serialize_page ); |
| |
| #ifndef PRODUCT |
| if(Verbose && PrintMiscellaneous) |
| tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); |
| #endif |
| } |
| |
| os::large_page_init(); |
| |
| // initialize suspend/resume support - must do this before signal_sets_init() |
| if (SR_initialize() != 0) { |
| perror("SR_initialize failed"); |
| return JNI_ERR; |
| } |
| |
| Linux::signal_sets_init(); |
| Linux::install_signal_handlers(); |
| |
| // Check minimum allowable stack size for thread creation and to initialize |
| // the java system classes, including StackOverflowError - depends on page |
| // size. Add a page for compiler2 recursion in main thread. |
| // Add in 2*BytesPerWord times page size to account for VM stack during |
| // class initialization depending on 32 or 64 bit VM. |
| os::Linux::min_stack_allowed = MAX2(os::Linux::min_stack_allowed, |
| (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ |
| 2*BytesPerWord COMPILER2_PRESENT(+1)) * Linux::page_size()); |
| |
| size_t threadStackSizeInBytes = ThreadStackSize * K; |
| if (threadStackSizeInBytes != 0 && |
| threadStackSizeInBytes < os::Linux::min_stack_allowed) { |
| tty->print_cr("\nThe stack size specified is too small, " |
| "Specify at least %dk", |
| os::Linux::min_stack_allowed/ K); |
| return JNI_ERR; |
| } |
| |
| // Make the stack size a multiple of the page size so that |
| // the yellow/red zones can be guarded. |
| JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, |
| vm_page_size())); |
| |
| Linux::capture_initial_stack(JavaThread::stack_size_at_create()); |
| |
| Linux::libpthread_init(); |
| if (PrintMiscellaneous && (Verbose || WizardMode)) { |
| tty->print_cr("[HotSpot is running with %s, %s(%s)]\n", |
| Linux::glibc_version(), Linux::libpthread_version(), |
| Linux::is_floating_stack() ? "floating stack" : "fixed stack"); |
| } |
| |
| if (UseNUMA) { |
| if (!Linux::libnuma_init()) { |
| UseNUMA = false; |
| } else { |
| if ((Linux::numa_max_node() < 1)) { |
| // There's only one node(they start from 0), disable NUMA. |
| UseNUMA = false; |
| } |
| } |
| // With SHM large pages we cannot uncommit a page, so there's not way |
| // we can make the adaptive lgrp chunk resizing work. If the user specified |
| // both UseNUMA and UseLargePages (or UseSHM) on the command line - warn and |
| // disable adaptive resizing. |
| if (UseNUMA && UseLargePages && UseSHM) { |
| if (!FLAG_IS_DEFAULT(UseNUMA)) { |
| if (FLAG_IS_DEFAULT(UseLargePages) && FLAG_IS_DEFAULT(UseSHM)) { |
| UseLargePages = false; |
| } else { |
| warning("UseNUMA is not fully compatible with SHM large pages, disabling adaptive resizing"); |
| UseAdaptiveSizePolicy = false; |
| UseAdaptiveNUMAChunkSizing = false; |
| } |
| } else { |
| UseNUMA = false; |
| } |
| } |
| if (!UseNUMA && ForceNUMA) { |
| UseNUMA = true; |
| } |
| } |
| |
| if (MaxFDLimit) { |
| // set the number of file descriptors to max. print out error |
| // if getrlimit/setrlimit fails but continue regardless. |
| struct rlimit nbr_files; |
| int status = getrlimit(RLIMIT_NOFILE, &nbr_files); |
| if (status != 0) { |
| if (PrintMiscellaneous && (Verbose || WizardMode)) |
| perror("os::init_2 getrlimit failed"); |
| } else { |
| nbr_files.rlim_cur = nbr_files.rlim_max; |
| status = setrlimit(RLIMIT_NOFILE, &nbr_files); |
| if (status != 0) { |
| if (PrintMiscellaneous && (Verbose || WizardMode)) |
| perror("os::init_2 setrlimit failed"); |
| } |
| } |
| } |
| |
| // Initialize lock used to serialize thread creation (see os::create_thread) |
| Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); |
| |
| // at-exit methods are called in the reverse order of their registration. |
| // atexit functions are called on return from main or as a result of a |
| // call to exit(3C). There can be only 32 of these functions registered |
| // and atexit() does not set errno. |
| |
| if (PerfAllowAtExitRegistration) { |
| // only register atexit functions if PerfAllowAtExitRegistration is set. |
| // atexit functions can be delayed until process exit time, which |
| // can be problematic for embedded VM situations. Embedded VMs should |
| // call DestroyJavaVM() to assure that VM resources are released. |
| |
| // note: perfMemory_exit_helper atexit function may be removed in |
| // the future if the appropriate cleanup code can be added to the |
| // VM_Exit VMOperation's doit method. |
| if (atexit(perfMemory_exit_helper) != 0) { |
| warning("os::init2 atexit(perfMemory_exit_helper) failed"); |
| } |
| } |
| |
| // initialize thread priority policy |
| prio_init(); |
| |
| return JNI_OK; |
| } |
| |
| // this is called at the end of vm_initialization |
| void os::init_3(void) |
| { |
| #ifdef JAVASE_EMBEDDED |
| // Start the MemNotifyThread |
| if (LowMemoryProtection) { |
| MemNotifyThread::start(); |
| } |
| return; |
| #endif |
| } |
| |
| // Mark the polling page as unreadable |
| void os::make_polling_page_unreadable(void) { |
| if( !guard_memory((char*)_polling_page, Linux::page_size()) ) |
| fatal("Could not disable polling page"); |
| }; |
| |
| // Mark the polling page as readable |
| void os::make_polling_page_readable(void) { |
| if( !linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { |
| fatal("Could not enable polling page"); |
| } |
| }; |
| |
| int os::active_processor_count() { |
| // Linux doesn't yet have a (official) notion of processor sets, |
| // so just return the number of online processors. |
| int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); |
| assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check"); |
| return online_cpus; |
| } |
| |
| void os::set_native_thread_name(const char *name) { |
| // Not yet implemented. |
| return; |
| } |
| |
| bool os::distribute_processes(uint length, uint* distribution) { |
| // Not yet implemented. |
| return false; |
| } |
| |
| bool os::bind_to_processor(uint processor_id) { |
| // Not yet implemented. |
| return false; |
| } |
| |
| /// |
| |
| void os::SuspendedThreadTask::internal_do_task() { |
| if (do_suspend(_thread->osthread())) { |
| SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); |
| do_task(context); |
| do_resume(_thread->osthread()); |
| } |
| } |
| |
| class PcFetcher : public os::SuspendedThreadTask { |
| public: |
| PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} |
| ExtendedPC result(); |
| protected: |
| void do_task(const os::SuspendedThreadTaskContext& context); |
| private: |
| ExtendedPC _epc; |
| }; |
| |
| ExtendedPC PcFetcher::result() { |
| guarantee(is_done(), "task is not done yet."); |
| return _epc; |
| } |
| |
| void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { |
| Thread* thread = context.thread(); |
| OSThread* osthread = thread->osthread(); |
| if (osthread->ucontext() != NULL) { |
| _epc = os::Linux::ucontext_get_pc((ucontext_t *) context.ucontext()); |
| } else { |
| // NULL context is unexpected, double-check this is the VMThread |
| guarantee(thread->is_VM_thread(), "can only be called for VMThread"); |
| } |
| } |
| |
| // Suspends the target using the signal mechanism and then grabs the PC before |
| // resuming the target. Used by the flat-profiler only |
| ExtendedPC os::get_thread_pc(Thread* thread) { |
| // Make sure that it is called by the watcher for the VMThread |
| assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); |
| assert(thread->is_VM_thread(), "Can only be called for VMThread"); |
| |
| PcFetcher fetcher(thread); |
| fetcher.run(); |
| return fetcher.result(); |
| } |
| |
| int os::Linux::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) |
| { |
| if (is_NPTL()) { |
| return pthread_cond_timedwait(_cond, _mutex, _abstime); |
| } else { |
| #ifndef IA64 |
| // 6292965: LinuxThreads pthread_cond_timedwait() resets FPU control |
| // word back to default 64bit precision if condvar is signaled. Java |
| // wants 53bit precision. Save and restore current value. |
| int fpu = get_fpu_control_word(); |
| #endif // IA64 |
| int status = pthread_cond_timedwait(_cond, _mutex, _abstime); |
| #ifndef IA64 |
| set_fpu_control_word(fpu); |
| #endif // IA64 |
| return status; |
| } |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // debug support |
| |
| static address same_page(address x, address y) { |
| int page_bits = -os::vm_page_size(); |
| if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits)) |
| return x; |
| else if (x > y) |
| return (address)(intptr_t(y) | ~page_bits) + 1; |
| else |
| return (address)(intptr_t(y) & page_bits); |
| } |
| |
| bool os::find(address addr, outputStream* st) { |
| Dl_info dlinfo; |
| memset(&dlinfo, 0, sizeof(dlinfo)); |
| if (dladdr(addr, &dlinfo)) { |
| st->print(PTR_FORMAT ": ", addr); |
| if (dlinfo.dli_sname != NULL) { |
| st->print("%s+%#x", dlinfo.dli_sname, |
| addr - (intptr_t)dlinfo.dli_saddr); |
| } else if (dlinfo.dli_fname) { |
| st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); |
| } else { |
| st->print("<absolute address>"); |
| } |
| if (dlinfo.dli_fname) { |
| st->print(" in %s", dlinfo.dli_fname); |
| } |
| if (dlinfo.dli_fbase) { |
| st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); |
| } |
| st->cr(); |
| |
| if (Verbose) { |
| // decode some bytes around the PC |
| address begin = same_page(addr-40, addr); |
| address end = same_page(addr+40, addr); |
| address lowest = (address) dlinfo.dli_sname; |
| if (!lowest) lowest = (address) dlinfo.dli_fbase; |
| if (begin < lowest) begin = lowest; |
| Dl_info dlinfo2; |
| if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr |
| && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) |
| end = (address) dlinfo2.dli_saddr; |
| Disassembler::decode(begin, end, st); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // misc |
| |
| // This does not do anything on Linux. This is basically a hook for being |
| // able to use structured exception handling (thread-local exception filters) |
| // on, e.g., Win32. |
| void |
| os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, |
| JavaCallArguments* args, Thread* thread) { |
| f(value, method, args, thread); |
| } |
| |
| void os::print_statistics() { |
| } |
| |
| int os::message_box(const char* title, const char* message) { |
| int i; |
| fdStream err(defaultStream::error_fd()); |
| for (i = 0; i < 78; i++) err.print_raw("="); |
| err.cr(); |
| err.print_raw_cr(title); |
| for (i = 0; i < 78; i++) err.print_raw("-"); |
| err.cr(); |
| err.print_raw_cr(message); |
| for (i = 0; i < 78; i++) err.print_raw("="); |
| err.cr(); |
| |
| char buf[16]; |
| // Prevent process from exiting upon "read error" without consuming all CPU |
| while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } |
| |
| return buf[0] == 'y' || buf[0] == 'Y'; |
| } |
| |
| int os::stat(const char *path, struct stat *sbuf) { |
| char pathbuf[MAX_PATH]; |
| if (strlen(path) > MAX_PATH - 1) { |
| errno = ENAMETOOLONG; |
| return -1; |
| } |
| os::native_path(strcpy(pathbuf, path)); |
| return ::stat(pathbuf, sbuf); |
| } |
| |
| bool os::check_heap(bool force) { |
| return true; |
| } |
| |
| int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { |
| return ::vsnprintf(buf, count, format, args); |
| } |
| |
| // Is a (classpath) directory empty? |
| bool os::dir_is_empty(const char* path) { |
| DIR *dir = NULL; |
| struct dirent *ptr; |
| |
| dir = opendir(path); |
| if (dir == NULL) return true; |
| |
| /* Scan the directory */ |
| bool result = true; |
| char buf[sizeof(struct dirent) + MAX_PATH]; |
| while (result && (ptr = ::readdir(dir)) != NULL) { |
| if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { |
| result = false; |
| } |
| } |
| closedir(dir); |
| return result; |
| } |
| |
| // This code originates from JDK's sysOpen and open64_w |
| // from src/solaris/hpi/src/system_md.c |
| |
| #ifndef O_DELETE |
| #define O_DELETE 0x10000 |
| #endif |
| |
| // Open a file. Unlink the file immediately after open returns |
| // if the specified oflag has the O_DELETE flag set. |
| // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c |
| |
| int os::open(const char *path, int oflag, int mode) { |
| |
| if (strlen(path) > MAX_PATH - 1) { |
| errno = ENAMETOOLONG; |
| return -1; |
| } |
| int fd; |
| int o_delete = (oflag & O_DELETE); |
| oflag = oflag & ~O_DELETE; |
| |
| fd = ::open64(path, oflag, mode); |
| if (fd == -1) return -1; |
| |
| //If the open succeeded, the file might still be a directory |
| { |
| struct stat64 buf64; |
| int ret = ::fstat64(fd, &buf64); |
| int st_mode = buf64.st_mode; |
| |
| if (ret != -1) { |
| if ((st_mode & S_IFMT) == S_IFDIR) { |
| errno = EISDIR; |
| ::close(fd); |
| return -1; |
| } |
| } else { |
| ::close(fd); |
| return -1; |
| } |
| } |
| |
| /* |
| * All file descriptors that are opened in the JVM and not |
| * specifically destined for a subprocess should have the |
| * close-on-exec flag set. If we don't set it, then careless 3rd |
| * party native code might fork and exec without closing all |
| * appropriate file descriptors (e.g. as we do in closeDescriptors in |
| * UNIXProcess.c), and this in turn might: |
| * |
| * - cause end-of-file to fail to be detected on some file |
| * descriptors, resulting in mysterious hangs, or |
| * |
| * - might cause an fopen in the subprocess to fail on a system |
| * suffering from bug 1085341. |
| * |
| * (Yes, the default setting of the close-on-exec flag is a Unix |
| * design flaw) |
| * |
| * See: |
| * 1085341: 32-bit stdio routines should support file descriptors >255 |
| * 4843136: (process) pipe file descriptor from Runtime.exec not being closed |
| * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 |
| */ |
| #ifdef FD_CLOEXEC |
| { |
| int flags = ::fcntl(fd, F_GETFD); |
| if (flags != -1) |
| ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); |
| } |
| #endif |
| |
| if (o_delete != 0) { |
| ::unlink(path); |
| } |
| return fd; |
| } |
| |
| |
| // create binary file, rewriting existing file if required |
| int os::create_binary_file(const char* path, bool rewrite_existing) { |
| int oflags = O_WRONLY | O_CREAT; |
| if (!rewrite_existing) { |
| oflags |= O_EXCL; |
| } |
| return ::open64(path, oflags, S_IREAD | S_IWRITE); |
| } |
| |
| // return current position of file pointer |
| jlong os::current_file_offset(int fd) { |
| return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); |
| } |
| |
| // move file pointer to the specified offset |
| jlong os::seek_to_file_offset(int fd, jlong offset) { |
| return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); |
| } |
| |
| // This code originates from JDK's sysAvailable |
| // from src/solaris/hpi/src/native_threads/src/sys_api_td.c |
| |
| int os::available(int fd, jlong *bytes) { |
| jlong cur, end; |
| int mode; |
| struct stat64 buf64; |
| |
| if (::fstat64(fd, &buf64) >= 0) { |
| mode = buf64.st_mode; |
| if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { |
| /* |
| * XXX: is the following call interruptible? If so, this might |
| * need to go through the INTERRUPT_IO() wrapper as for other |
| * blocking, interruptible calls in this file. |
| */ |
| int n; |
| if (::ioctl(fd, FIONREAD, &n) >= 0) { |
| *bytes = n; |
| return 1; |
| } |
| } |
| } |
| if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { |
| return 0; |
| } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { |
| return 0; |
| } else if (::lseek64(fd, cur, SEEK_SET) == -1) { |
| return 0; |
| } |
| *bytes = end - cur; |
| return 1; |
| } |
| |
| int os::socket_available(int fd, jint *pbytes) { |
| // Linux doc says EINTR not returned, unlike Solaris |
| int ret = ::ioctl(fd, FIONREAD, pbytes); |
| |
| //%% note ioctl can return 0 when successful, JVM_SocketAvailable |
| // is expected to return 0 on failure and 1 on success to the jdk. |
| return (ret < 0) ? 0 : 1; |
| } |
| |
| // Map a block of memory. |
| char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, |
| char *addr, size_t bytes, bool read_only, |
| bool allow_exec) { |
| int prot; |
| int flags = MAP_PRIVATE; |
| |
| if (read_only) { |
| prot = PROT_READ; |
| } else { |
| prot = PROT_READ | PROT_WRITE; |
| } |
| |
| if (allow_exec) { |
| prot |= PROT_EXEC; |
| } |
| |
| if (addr != NULL) { |
| flags |= MAP_FIXED; |
| } |
| |
| char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, |
| fd, file_offset); |
| if (mapped_address == MAP_FAILED) { |
| return NULL; |
| } |
| return mapped_address; |
| } |
| |
| |
| // Remap a block of memory. |
| char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, |
| char *addr, size_t bytes, bool read_only, |
| bool allow_exec) { |
| // same as map_memory() on this OS |
| return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, |
| allow_exec); |
| } |
| |
| |
| // Unmap a block of memory. |
| bool os::pd_unmap_memory(char* addr, size_t bytes) { |
| return munmap(addr, bytes) == 0; |
| } |
| |
| static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); |
| |
| static clockid_t thread_cpu_clockid(Thread* thread) { |
| pthread_t tid = thread->osthread()->pthread_id(); |
| clockid_t clockid; |
| |
| // Get thread clockid |
| int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); |
| assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); |
| return clockid; |
| } |
| |
| // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) |
| // are used by JVM M&M and JVMTI to get user+sys or user CPU time |
| // of a thread. |
| // |
| // current_thread_cpu_time() and thread_cpu_time(Thread*) returns |
| // the fast estimate available on the platform. |
| |
| jlong os::current_thread_cpu_time() { |
| if (os::Linux::supports_fast_thread_cpu_time()) { |
| return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); |
| } else { |
| // return user + sys since the cost is the same |
| return slow_thread_cpu_time(Thread::current(), true /* user + sys */); |
| } |
| } |
| |
| jlong os::thread_cpu_time(Thread* thread) { |
| // consistent with what current_thread_cpu_time() returns |
| if (os::Linux::supports_fast_thread_cpu_time()) { |
| return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); |
| } else { |
| return slow_thread_cpu_time(thread, true /* user + sys */); |
| } |
| } |
| |
| jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { |
| if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { |
| return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); |
| } else { |
| return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); |
| } |
| } |
| |
| jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { |
| if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { |
| return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); |
| } else { |
| return slow_thread_cpu_time(thread, user_sys_cpu_time); |
| } |
| } |
| |
| // |
| // -1 on error. |
| // |
| |
| static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { |
| static bool proc_pid_cpu_avail = true; |
| static bool proc_task_unchecked = true; |
| static const char *proc_stat_path = "/proc/%d/stat"; |
| pid_t tid = thread->osthread()->thread_id(); |
| int i; |
| char *s; |
| char stat[2048]; |
| int statlen; |
| char proc_name[64]; |
| int count; |
| long sys_time, user_time; |
| char string[64]; |
| char cdummy; |
| int idummy; |
| long ldummy; |
| FILE *fp; |
| |
| // We first try accessing /proc/<pid>/cpu since this is faster to |
| // process. If this file is not present (linux kernels 2.5 and above) |
| // then we open /proc/<pid>/stat. |
| if ( proc_pid_cpu_avail ) { |
| sprintf(proc_name, "/proc/%d/cpu", tid); |
| fp = fopen(proc_name, "r"); |
| if ( fp != NULL ) { |
| count = fscanf( fp, "%s %lu %lu\n", string, &user_time, &sys_time); |
| fclose(fp); |
| if ( count != 3 ) return -1; |
| |
| if (user_sys_cpu_time) { |
| return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); |
| } else { |
| return (jlong)user_time * (1000000000 / clock_tics_per_sec); |
| } |
| } |
| else proc_pid_cpu_avail = false; |
| } |
| |
| // The /proc/<tid>/stat aggregates per-process usage on |
| // new Linux kernels 2.6+ where NPTL is supported. |
| // The /proc/self/task/<tid>/stat still has the per-thread usage. |
| // See bug 6328462. |
| // There can be no directory /proc/self/task on kernels 2.4 with NPTL |
| // and possibly in some other cases, so we check its availability. |
| if (proc_task_unchecked && os::Linux::is_NPTL()) { |
| // This is executed only once |
| proc_task_unchecked = false; |
| fp = fopen("/proc/self/task", "r"); |
| if (fp != NULL) { |
| proc_stat_path = "/proc/self/task/%d/stat"; |
| fclose(fp); |
| } |
| } |
| |
| sprintf(proc_name, proc_stat_path, tid); |
| fp = fopen(proc_name, "r"); |
| if ( fp == NULL ) return -1; |
| statlen = fread(stat, 1, 2047, fp); |
| stat[statlen] = '\0'; |
| fclose(fp); |
| |
| // Skip pid and the command string. Note that we could be dealing with |
| // weird command names, e.g. user could decide to rename java launcher |
| // to "java 1.4.2 :)", then the stat file would look like |
| // 1234 (java 1.4.2 :)) R ... ... |
| // We don't really need to know the command string, just find the last |
| // occurrence of ")" and then start parsing from there. See bug 4726580. |
| s = strrchr(stat, ')'); |
| i = 0; |
| if (s == NULL ) return -1; |
| |
| // Skip blank chars |
| do s++; while (isspace(*s)); |
| |
| count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", |
| &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, |
| &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, |
| &user_time, &sys_time); |
| if ( count != 13 ) return -1; |
| if (user_sys_cpu_time) { |
| return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); |
| } else { |
| return (jlong)user_time * (1000000000 / clock_tics_per_sec); |
| } |
| } |
| |
| void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { |
| info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits |
| info_ptr->may_skip_backward = false; // elapsed time not wall time |
| info_ptr->may_skip_forward = false; // elapsed time not wall time |
| info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned |
| } |
| |
| void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { |
| info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits |
| info_ptr->may_skip_backward = false; // elapsed time not wall time |
| info_ptr->may_skip_forward = false; // elapsed time not wall time |
| info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned |
| } |
| |
| bool os::is_thread_cpu_time_supported() { |
| return true; |
| } |
| |
| // System loadavg support. Returns -1 if load average cannot be obtained. |
| // Linux doesn't yet have a (official) notion of processor sets, |
| // so just return the system wide load average. |
| int os::loadavg(double loadavg[], int nelem) { |
| return ::getloadavg(loadavg, nelem); |
| } |
| |
| void os::pause() { |
| char filename[MAX_PATH]; |
| if (PauseAtStartupFile && PauseAtStartupFile[0]) { |
| jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); |
| } else { |
| jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); |
| } |
| |
| int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); |
| if (fd != -1) { |
| struct stat buf; |
| ::close(fd); |
| while (::stat(filename, &buf) == 0) { |
| (void)::poll(NULL, 0, 100); |
| } |
| } else { |
| jio_fprintf(stderr, |
| "Could not open pause file '%s', continuing immediately.\n", filename); |
| } |
| } |
| |
| |
| // Refer to the comments in os_solaris.cpp park-unpark. |
| // |
| // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can |
| // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. |
| // For specifics regarding the bug see GLIBC BUGID 261237 : |
| // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. |
| // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future |
| // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar |
| // is used. (The simple C test-case provided in the GLIBC bug report manifests the |
| // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() |
| // and monitorenter when we're using 1-0 locking. All those operations may result in |
| // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version |
| // of libpthread avoids the problem, but isn't practical. |
| // |
| // Possible remedies: |
| // |
| // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. |
| // This is palliative and probabilistic, however. If the thread is preempted |
| // between the call to compute_abstime() and pthread_cond_timedwait(), more |
| // than the minimum period may have passed, and the abstime may be stale (in the |
| // past) resultin in a hang. Using this technique reduces the odds of a hang |
| // but the JVM is still vulnerable, particularly on heavily loaded systems. |
| // |
| // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead |
| // of the usual flag-condvar-mutex idiom. The write side of the pipe is set |
| // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) |
| // reduces to poll()+read(). This works well, but consumes 2 FDs per extant |
| // thread. |
| // |
| // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread |
| // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing |
| // a timeout request to the chron thread and then blocking via pthread_cond_wait(). |
| // This also works well. In fact it avoids kernel-level scalability impediments |
| // on certain platforms that don't handle lots of active pthread_cond_timedwait() |
| // timers in a graceful fashion. |
| // |
| // 4. When the abstime value is in the past it appears that control returns |
| // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. |
| // Subsequent timedwait/wait calls may hang indefinitely. Given that, we |
| // can avoid the problem by reinitializing the condvar -- by cond_destroy() |
| // followed by cond_init() -- after all calls to pthread_cond_timedwait(). |
| // It may be possible to avoid reinitialization by checking the return |
| // value from pthread_cond_timedwait(). In addition to reinitializing the |
| // condvar we must establish the invariant that cond_signal() is only called |
| // within critical sections protected by the adjunct mutex. This prevents |
| // cond_signal() from "seeing" a condvar that's in the midst of being |
| // reinitialized or that is corrupt. Sadly, this invariant obviates the |
| // desirable signal-after-unlock optimization that avoids futile context switching. |
| // |
| // I'm also concerned that some versions of NTPL might allocate an auxilliary |
| // structure when a condvar is used or initialized. cond_destroy() would |
| // release the helper structure. Our reinitialize-after-timedwait fix |
| // put excessive stress on malloc/free and locks protecting the c-heap. |
| // |
| // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. |
| // It may be possible to refine (4) by checking the kernel and NTPL verisons |
| // and only enabling the work-around for vulnerable environments. |
| |
| // utility to compute the abstime argument to timedwait: |
| // millis is the relative timeout time |
| // abstime will be the absolute timeout time |
| // TODO: replace compute_abstime() with unpackTime() |
| |
| static struct timespec* compute_abstime(timespec* abstime, jlong millis) { |
| if (millis < 0) millis = 0; |
| struct timeval now; |
| int status = gettimeofday(&now, NULL); |
| assert(status == 0, "gettimeofday"); |
| jlong seconds = millis / 1000; |
| millis %= 1000; |
| if (seconds > 50000000) { // see man cond_timedwait(3T) |
| seconds = 50000000; |
| } |
| abstime->tv_sec = now.tv_sec + seconds; |
| long usec = now.tv_usec + millis * 1000; |
| if (usec >= 1000000) { |
| abstime->tv_sec += 1; |
| usec -= 1000000; |
| } |
| abstime->tv_nsec = usec * 1000; |
| return abstime; |
| } |
| |
| |
| // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. |
| // Conceptually TryPark() should be equivalent to park(0). |
| |
| int os::PlatformEvent::TryPark() { |
| for (;;) { |
| const int v = _Event ; |
| guarantee ((v == 0) || (v == 1), "invariant") ; |
| if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; |
| } |
| } |
| |
| void os::PlatformEvent::park() { // AKA "down()" |
| // Invariant: Only the thread associated with the Event/PlatformEvent |
| // may call park(). |
| // TODO: assert that _Assoc != NULL or _Assoc == Self |
| int v ; |
| for (;;) { |
| v = _Event ; |
| if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; |
| } |
| guarantee (v >= 0, "invariant") ; |
| if (v == 0) { |
| // Do this the hard way by blocking ... |
| int status = pthread_mutex_lock(_mutex); |
| assert_status(status == 0, status, "mutex_lock"); |
| guarantee (_nParked == 0, "invariant") ; |
| ++ _nParked ; |
| while (_Event < 0) { |
| status = pthread_cond_wait(_cond, _mutex); |
| // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... |
| // Treat this the same as if the wait was interrupted |
| if (status == ETIME) { status = EINTR; } |
| assert_status(status == 0 || status == EINTR, status, "cond_wait"); |
| } |
| -- _nParked ; |
| |
| _Event = 0 ; |
| status = pthread_mutex_unlock(_mutex); |
| assert_status(status == 0, status, "mutex_unlock"); |
| // Paranoia to ensure our locked and lock-free paths interact |
| // correctly with each other. |
| OrderAccess::fence(); |
| } |
| guarantee (_Event >= 0, "invariant") ; |
| } |
| |
| int os::PlatformEvent::park(jlong millis) { |
| guarantee (_nParked == 0, "invariant") ; |
| |
| int v ; |
| for (;;) { |
| v = _Event ; |
| if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; |
| } |
| guarantee (v >= 0, "invariant") ; |
| if (v != 0) return OS_OK ; |
| |
| // We do this the hard way, by blocking the thread. |
| // Consider enforcing a minimum timeout value. |
| struct timespec abst; |
| compute_abstime(&abst, millis); |
| |
| int ret = OS_TIMEOUT; |
| int status = pthread_mutex_lock(_mutex); |
| assert_status(status == 0, status, "mutex_lock"); |
| guarantee (_nParked == 0, "invariant") ; |
| ++_nParked ; |
| |
| // Object.wait(timo) will return because of |
| // (a) notification |
| // (b) timeout |
| // (c) thread.interrupt |
| // |
| // Thread.interrupt and object.notify{All} both call Event::set. |
| // That is, we treat thread.interrupt as a special case of notification. |
| // The underlying Solaris implementation, cond_timedwait, admits |
| // spurious/premature wakeups, but the JLS/JVM spec prevents the |
| // JVM from making those visible to Java code. As such, we must |
| // filter out spurious wakeups. We assume all ETIME returns are valid. |
| // |
| // TODO: properly differentiate simultaneous notify+interrupt. |
| // In that case, we should propagate the notify to another waiter. |
| |
| while (_Event < 0) { |
| status = os::Linux::safe_cond_timedwait(_cond, _mutex, &abst); |
| if (status != 0 && WorkAroundNPTLTimedWaitHang) { |
| pthread_cond_destroy (_cond); |
| pthread_cond_init (_cond, NULL) ; |
| } |
| assert_status(status == 0 || status == EINTR || |
| status == ETIME || status == ETIMEDOUT, |
| status, "cond_timedwait"); |
| if (!FilterSpuriousWakeups) break ; // previous semantics |
| if (status == ETIME || status == ETIMEDOUT) break ; |
| // We consume and ignore EINTR and spurious wakeups. |
| } |
| --_nParked ; |
| if (_Event >= 0) { |
| ret = OS_OK; |
| } |
| _Event = 0 ; |
| status = pthread_mutex_unlock(_mutex); |
| assert_status(status == 0, status, "mutex_unlock"); |
| assert (_nParked == 0, "invariant") ; |
| // Paranoia to ensure our locked and lock-free paths interact |
| // correctly with each other. |
| OrderAccess::fence(); |
| return ret; |
| } |
| |
| void os::PlatformEvent::unpark() { |
| // Transitions for _Event: |
| // 0 :=> 1 |
| // 1 :=> 1 |
| // -1 :=> either 0 or 1; must signal target thread |
| // That is, we can safely transition _Event from -1 to either |
| // 0 or 1. Forcing 1 is slightly more efficient for back-to-back |
| // unpark() calls. |
| // See also: "Semaphores in Plan 9" by Mullender & Cox |
| // |
| // Note: Forcing a transition from "-1" to "1" on an unpark() means |
| // that it will take two back-to-back park() calls for the owning |
| // thread to block. This has the benefit of forcing a spurious return |
| // from the first park() call after an unpark() call which will help |
| // shake out uses of park() and unpark() without condition variables. |
| |
| if (Atomic::xchg(1, &_Event) >= 0) return; |
| |
| // Wait for the thread associated with the event to vacate |
| int status = pthread_mutex_lock(_mutex); |
| assert_status(status == 0, status, "mutex_lock"); |
| int AnyWaiters = _nParked; |
| assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); |
| if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { |
| AnyWaiters = 0; |
| pthread_cond_signal(_cond); |
| } |
| status = pthread_mutex_unlock(_mutex); |
| assert_status(status == 0, status, "mutex_unlock"); |
| if (AnyWaiters != 0) { |
| status = pthread_cond_signal(_cond); |
| assert_status(status == 0, status, "cond_signal"); |
| } |
| |
| // Note that we signal() _after dropping the lock for "immortal" Events. |
| // This is safe and avoids a common class of futile wakeups. In rare |
| // circumstances this can cause a thread to return prematurely from |
| // cond_{timed}wait() but the spurious wakeup is benign and the victim will |
| // simply re-test the condition and re-park itself. |
| } |
| |
| |
| // JSR166 |
| // ------------------------------------------------------- |
| |
| /* |
| * The solaris and linux implementations of park/unpark are fairly |
| * conservative for now, but can be improved. They currently use a |
| * mutex/condvar pair, plus a a count. |
| * Park decrements count if > 0, else does a condvar wait. Unpark |
| * sets count to 1 and signals condvar. Only one thread ever waits |
| * on the condvar. Contention seen when trying to park implies that someone |
| * is unparking you, so don't wait. And spurious returns are fine, so there |
| * is no need to track notifications. |
| */ |
| |
| #define MAX_SECS 100000000 |
| /* |
| * This code is common to linux and solaris and will be moved to a |
| * common place in dolphin. |
| * |
| * The passed in time value is either a relative time in nanoseconds |
| * or an absolute time in milliseconds. Either way it has to be unpacked |
| * into suitable seconds and nanoseconds components and stored in the |
| * given timespec structure. |
| * Given time is a 64-bit value and the time_t used in the timespec is only |
| * a signed-32-bit value (except on 64-bit Linux) we have to watch for |
| * overflow if times way in the future are given. Further on Solaris versions |
| * prior to 10 there is a restriction (see cond_timedwait) that the specified |
| * number of seconds, in abstime, is less than current_time + 100,000,000. |
| * As it will be 28 years before "now + 100000000" will overflow we can |
| * ignore overflow and just impose a hard-limit on seconds using the value |
| * of "now + 100,000,000". This places a limit on the timeout of about 3.17 |
| * years from "now". |
| */ |
| |
| static void unpackTime(timespec* absTime, bool isAbsolute, jlong time) { |
| assert (time > 0, "convertTime"); |
| |
| struct timeval now; |
| int status = gettimeofday(&now, NULL); |
| assert(status == 0, "gettimeofday"); |
| |
| time_t max_secs = now.tv_sec + MAX_SECS; |
| |
| if (isAbsolute) { |
| jlong secs = time / 1000; |
| if (secs > max_secs) { |
| absTime->tv_sec = max_secs; |
| } |
| else { |
| absTime->tv_sec = secs; |
| } |
| absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; |
| } |
| else { |
| jlong secs = time / NANOSECS_PER_SEC; |
| if (secs >= MAX_SECS) { |
| absTime->tv_sec = max_secs; |
| absTime->tv_nsec = 0; |
| } |
| else { |
| absTime->tv_sec = now.tv_sec + secs; |
| absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; |
| if (absTime->tv_nsec >= NANOSECS_PER_SEC) { |
| absTime->tv_nsec -= NANOSECS_PER_SEC; |
| ++absTime->tv_sec; // note: this must be <= max_secs |
| } |
| } |
| } |
| assert(absTime->tv_sec >= 0, "tv_sec < 0"); |
| assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); |
| assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); |
| assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); |
| } |
| |
| void Parker::park(bool isAbsolute, jlong time) { |
| // Ideally we'd do something useful while spinning, such |
| // as calling unpackTime(). |
| |
| // Optional fast-path check: |
| // Return immediately if a permit is available. |
| // We depend on Atomic::xchg() having full barrier semantics |
| // since we are doing a lock-free update to _counter. |
| if (Atomic::xchg(0, &_counter) > 0) return; |
| |
| Thread* thread = Thread::current(); |
| assert(thread->is_Java_thread(), "Must be JavaThread"); |
| JavaThread *jt = (JavaThread *)thread; |
| |
| // Optional optimization -- avoid state transitions if there's an interrupt pending. |
| // Check interrupt before trying to wait |
| if (Thread::is_interrupted(thread, false)) { |
| return; |
| } |
| |
| // Next, demultiplex/decode time arguments |
| timespec absTime; |
| if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all |
| return; |
| } |
| if (time > 0) { |
| unpackTime(&absTime, isAbsolute, time); |
| } |
| |
| |
| // Enter safepoint region |
| // Beware of deadlocks such as 6317397. |
| // The per-thread Parker:: mutex is a classic leaf-lock. |
| // In particular a thread must never block on the Threads_lock while |
| // holding the Parker:: mutex. If safepoints are pending both the |
| // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. |
| ThreadBlockInVM tbivm(jt); |
| |
| // Don't wait if cannot get lock since interference arises from |
| // unblocking. Also. check interrupt before trying wait |
| if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { |
| return; |
| } |
| |
| int status ; |
| if (_counter > 0) { // no wait needed |
| _counter = 0; |
| status = pthread_mutex_unlock(_mutex); |
| assert (status == 0, "invariant") ; |
| // Paranoia to ensure our locked and lock-free paths interact |
| // correctly with each other and Java-level accesses. |
| OrderAccess::fence(); |
| return; |
| } |
| |
| #ifdef ASSERT |
| // Don't catch signals while blocked; let the running threads have the signals. |
| // (This allows a debugger to break into the running thread.) |
| sigset_t oldsigs; |
| sigset_t* allowdebug_blocked = os::Linux::allowdebug_blocked_signals(); |
| pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); |
| #endif |
| |
| OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); |
| jt->set_suspend_equivalent(); |
| // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() |
| |
| if (time == 0) { |
| status = pthread_cond_wait (_cond, _mutex) ; |
| } else { |
| status = os::Linux::safe_cond_timedwait (_cond, _mutex, &absTime) ; |
| if (status != 0 && WorkAroundNPTLTimedWaitHang) { |
| pthread_cond_destroy (_cond) ; |
| pthread_cond_init (_cond, NULL); |
| } |
| } |
| assert_status(status == 0 || status == EINTR || |
| status == ETIME || status == ETIMEDOUT, |
| status, "cond_timedwait"); |
| |
| #ifdef ASSERT |
| pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); |
| #endif |
| |
| _counter = 0 ; |
| status = pthread_mutex_unlock(_mutex) ; |
| assert_status(status == 0, status, "invariant") ; |
| // Paranoia to ensure our locked and lock-free paths interact |
| // correctly with each other and Java-level accesses. |
| OrderAccess::fence(); |
| |
| // If externally suspended while waiting, re-suspend |
| if (jt->handle_special_suspend_equivalent_condition()) { |
| jt->java_suspend_self(); |
| } |
| } |
| |
| void Parker::unpark() { |
| int s, status ; |
| status = pthread_mutex_lock(_mutex); |
| assert (status == 0, "invariant") ; |
| s = _counter; |
| _counter = 1; |
| if (s < 1) { |
| if (WorkAroundNPTLTimedWaitHang) { |
| status = pthread_cond_signal (_cond) ; |
| assert (status == 0, "invariant") ; |
| status = pthread_mutex_unlock(_mutex); |
| assert (status == 0, "invariant") ; |
| } else { |
| status = pthread_mutex_unlock(_mutex); |
| assert (status == 0, "invariant") ; |
| status = pthread_cond_signal (_cond) ; |
| assert (status == 0, "invariant") ; |
| } |
| } else { |
| pthread_mutex_unlock(_mutex); |
| assert (status == 0, "invariant") ; |
| } |
| } |
| |
| |
| extern char** environ; |
| |
| #ifndef __NR_fork |
| #define __NR_fork IA32_ONLY(2) IA64_ONLY(not defined) AMD64_ONLY(57) |
| #endif |
| |
| #ifndef __NR_execve |
| #define __NR_execve IA32_ONLY(11) IA64_ONLY(1033) AMD64_ONLY(59) |
| #endif |
| |
| // Run the specified command in a separate process. Return its exit value, |
| // or -1 on failure (e.g. can't fork a new process). |
| // Unlike system(), this function can be called from signal handler. It |
| // doesn't block SIGINT et al. |
| int os::fork_and_exec(char* cmd) { |
| const char * argv[4] = {"sh", "-c", cmd, NULL}; |
| |
| // fork() in LinuxThreads/NPTL is not async-safe. It needs to run |
| // pthread_atfork handlers and reset pthread library. All we need is a |
| // separate process to execve. Make a direct syscall to fork process. |
| // On IA64 there's no fork syscall, we have to use fork() and hope for |
| // the best... |
| pid_t pid = NOT_IA64(syscall(__NR_fork);) |
| IA64_ONLY(fork();) |
| |
| if (pid < 0) { |
| // fork failed |
| return -1; |
| |
| } else if (pid == 0) { |
| // child process |
| |
| // execve() in LinuxThreads will call pthread_kill_other_threads_np() |
| // first to kill every thread on the thread list. Because this list is |
| // not reset by fork() (see notes above), execve() will instead kill |
| // every thread in the parent process. We know this is the only thread |
| // in the new process, so make a system call directly. |
| // IA64 should use normal execve() from glibc to match the glibc fork() |
| // above. |
| NOT_IA64(syscall(__NR_execve, "/bin/sh", argv, environ);) |
| IA64_ONLY(execve("/bin/sh", (char* const*)argv, environ);) |
| |
| // execve failed |
| _exit(-1); |
| |
| } else { |
| // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't |
| // care about the actual exit code, for now. |
| |
| int status; |
| |
| // Wait for the child process to exit. This returns immediately if |
| // the child has already exited. */ |
| while (waitpid(pid, &status, 0) < 0) { |
| switch (errno) { |
| case ECHILD: return 0; |
| case EINTR: break; |
| default: return -1; |
| } |
| } |
| |
| if (WIFEXITED(status)) { |
| // The child exited normally; get its exit code. |
| return WEXITSTATUS(status); |
| } else if (WIFSIGNALED(status)) { |
| // The child exited because of a signal |
| // The best value to return is 0x80 + signal number, |
| // because that is what all Unix shells do, and because |
| // it allows callers to distinguish between process exit and |
| // process death by signal. |
| return 0x80 + WTERMSIG(status); |
| } else { |
| // Unknown exit code; pass it through |
| return status; |
| } |
| } |
| } |
| |
| // is_headless_jre() |
| // |
| // Test for the existence of xawt/libmawt.so or libawt_xawt.so |
| // in order to report if we are running in a headless jre |
| // |
| // Since JDK8 xawt/libmawt.so was moved into the same directory |
| // as libawt.so, and renamed libawt_xawt.so |
| // |
| bool os::is_headless_jre() { |
| struct stat statbuf; |
| char buf[MAXPATHLEN]; |
| char libmawtpath[MAXPATHLEN]; |
| const char *xawtstr = "/xawt/libmawt.so"; |
| const char *new_xawtstr = "/libawt_xawt.so"; |
| char *p; |
| |
| // Get path to libjvm.so |
| os::jvm_path(buf, sizeof(buf)); |
| |
| // Get rid of libjvm.so |
| p = strrchr(buf, '/'); |
| if (p == NULL) return false; |
| else *p = '\0'; |
| |
| // Get rid of client or server |
| p = strrchr(buf, '/'); |
| if (p == NULL) return false; |
| else *p = '\0'; |
| |
| // check xawt/libmawt.so |
| strcpy(libmawtpath, buf); |
| strcat(libmawtpath, xawtstr); |
| if (::stat(libmawtpath, &statbuf) == 0) return false; |
| |
| // check libawt_xawt.so |
| strcpy(libmawtpath, buf); |
| strcat(libmawtpath, new_xawtstr); |
| if (::stat(libmawtpath, &statbuf) == 0) return false; |
| |
| return true; |
| } |
| |
| // Get the default path to the core file |
| // Returns the length of the string |
| int os::get_core_path(char* buffer, size_t bufferSize) { |
| const char* p = get_current_directory(buffer, bufferSize); |
| |
| if (p == NULL) { |
| assert(p != NULL, "failed to get current directory"); |
| return 0; |
| } |
| |
| return strlen(buffer); |
| } |
| |
| #ifdef JAVASE_EMBEDDED |
| // |
| // A thread to watch the '/dev/mem_notify' device, which will tell us when the OS is running low on memory. |
| // |
| MemNotifyThread* MemNotifyThread::_memnotify_thread = NULL; |
| |
| // ctor |
| // |
| MemNotifyThread::MemNotifyThread(int fd): Thread() { |
| assert(memnotify_thread() == NULL, "we can only allocate one MemNotifyThread"); |
| _fd = fd; |
| |
| if (os::create_thread(this, os::os_thread)) { |
| _memnotify_thread = this; |
| os::set_priority(this, NearMaxPriority); |
| os::start_thread(this); |
| } |
| } |
| |
| // Where all the work gets done |
| // |
| void MemNotifyThread::run() { |
| assert(this == memnotify_thread(), "expected the singleton MemNotifyThread"); |
| |
| // Set up the select arguments |
| fd_set rfds; |
| if (_fd != -1) { |
| FD_ZERO(&rfds); |
| FD_SET(_fd, &rfds); |
| } |
| |
| // Now wait for the mem_notify device to wake up |
| while (1) { |
| // Wait for the mem_notify device to signal us.. |
| int rc = select(_fd+1, _fd != -1 ? &rfds : NULL, NULL, NULL, NULL); |
| if (rc == -1) { |
| perror("select!\n"); |
| break; |
| } else if (rc) { |
| //ssize_t free_before = os::available_memory(); |
| //tty->print ("Notified: Free: %dK \n",os::available_memory()/1024); |
| |
| // The kernel is telling us there is not much memory left... |
| // try to do something about that |
| |
| // If we are not already in a GC, try one. |
| if (!Universe::heap()->is_gc_active()) { |
| Universe::heap()->collect(GCCause::_allocation_failure); |
| |
| //ssize_t free_after = os::available_memory(); |
| //tty->print ("Post-Notify: Free: %dK\n",free_after/1024); |
| //tty->print ("GC freed: %dK\n", (free_after - free_before)/1024); |
| } |
| // We might want to do something like the following if we find the GC's are not helping... |
| // Universe::heap()->size_policy()->set_gc_time_limit_exceeded(true); |
| } |
| } |
| } |
| |
| // |
| // See if the /dev/mem_notify device exists, and if so, start a thread to monitor it. |
| // |
| void MemNotifyThread::start() { |
| int fd; |
| fd = open ("/dev/mem_notify", O_RDONLY, 0); |
| if (fd < 0) { |
| return; |
| } |
| |
| if (memnotify_thread() == NULL) { |
| new MemNotifyThread(fd); |
| } |
| } |
| #endif // JAVASE_EMBEDDED |