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android / platform / libcore / 71f2c75111e87091616f0f3b86bea6c4d345dad1 / . / src / hotspot / share / runtime / os.cpp
blob: 013a9a8957b6697fed84d1697f14e8195ee84c44 [file] [log] [blame]
/*
* Copyright (c) 1997, 2020, 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.
*
*/
#include "precompiled.hpp"
#include "jvm.h"
#include "classfile/classLoader.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/moduleEntry.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "code/codeCache.hpp"
#include "code/icBuffer.hpp"
#include "code/vtableStubs.hpp"
#include "gc/shared/vmGCOperations.hpp"
#include "logging/log.hpp"
#include "interpreter/interpreter.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#ifdef ASSERT
#include "memory/guardedMemory.hpp"
#endif
#include "memory/resourceArea.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvm_misc.hpp"
#include "prims/privilegedStack.hpp"
#include "runtime/arguments.hpp"
#include "runtime/atomic.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/os.inline.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/threadSMR.hpp"
#include "runtime/vm_version.hpp"
#include "services/attachListener.hpp"
#include "services/mallocTracker.hpp"
#include "services/memTracker.hpp"
#include "services/nmtCommon.hpp"
#include "services/threadService.hpp"
#include "utilities/align.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/events.hpp"
# include <signal.h>
# include <errno.h>
OSThread* os::_starting_thread = NULL;
address os::_polling_page = NULL;
volatile int32_t* os::_mem_serialize_page = NULL;
uintptr_t os::_serialize_page_mask = 0;
volatile unsigned int os::_rand_seed = 1;
int os::_processor_count = 0;
int os::_initial_active_processor_count = 0;
size_t os::_page_sizes[os::page_sizes_max];
#ifndef PRODUCT
julong os::num_mallocs = 0; // # of calls to malloc/realloc
julong os::alloc_bytes = 0; // # of bytes allocated
julong os::num_frees = 0; // # of calls to free
julong os::free_bytes = 0; // # of bytes freed
#endif
static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords
void os_init_globals() {
// Called from init_globals().
// See Threads::create_vm() in thread.cpp, and init.cpp.
os::init_globals();
}
int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
int result = os::vsnprintf(buf, len, fmt, args);
va_end(args);
return result;
}
// Fill in buffer with current local time as an ISO-8601 string.
// E.g., yyyy-mm-ddThh:mm:ss-zzzz.
// Returns buffer, or NULL if it failed.
// This would mostly be a call to
// strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
// except that on Windows the %z behaves badly, so we do it ourselves.
// Also, people wanted milliseconds on there,
// and strftime doesn't do milliseconds.
char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
// Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
// 1 2
// 12345678901234567890123456789
// format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
static const size_t needed_buffer = 29;
// Sanity check the arguments
if (buffer == NULL) {
assert(false, "NULL buffer");
return NULL;
}
if (buffer_length < needed_buffer) {
assert(false, "buffer_length too small");
return NULL;
}
// Get the current time
jlong milliseconds_since_19700101 = javaTimeMillis();
const int milliseconds_per_microsecond = 1000;
const time_t seconds_since_19700101 =
milliseconds_since_19700101 / milliseconds_per_microsecond;
const int milliseconds_after_second =
milliseconds_since_19700101 % milliseconds_per_microsecond;
// Convert the time value to a tm and timezone variable
struct tm time_struct;
if (utc) {
if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
assert(false, "Failed gmtime_pd");
return NULL;
}
} else {
if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
assert(false, "Failed localtime_pd");
return NULL;
}
}
const time_t seconds_per_minute = 60;
const time_t minutes_per_hour = 60;
const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
// No offset when dealing with UTC
time_t UTC_to_local = 0;
if (!utc) {
#if defined(_ALLBSD_SOURCE) || defined(_GNU_SOURCE)
UTC_to_local = -(time_struct.tm_gmtoff);
#elif defined(_WINDOWS)
long zone;
_get_timezone(&zone);
UTC_to_local = static_cast<time_t>(zone);
#else
UTC_to_local = timezone;
#endif
// tm_gmtoff already includes adjustment for daylight saving
#if !defined(_ALLBSD_SOURCE) && !defined(_GNU_SOURCE)
// If daylight savings time is in effect,
// we are 1 hour East of our time zone
if (time_struct.tm_isdst > 0) {
UTC_to_local = UTC_to_local - seconds_per_hour;
}
#endif
}
// Compute the time zone offset.
// localtime_pd() sets timezone to the difference (in seconds)
// between UTC and and local time.
// ISO 8601 says we need the difference between local time and UTC,
// we change the sign of the localtime_pd() result.
const time_t local_to_UTC = -(UTC_to_local);
// Then we have to figure out if if we are ahead (+) or behind (-) UTC.
char sign_local_to_UTC = '+';
time_t abs_local_to_UTC = local_to_UTC;
if (local_to_UTC < 0) {
sign_local_to_UTC = '-';
abs_local_to_UTC = -(abs_local_to_UTC);
}
// Convert time zone offset seconds to hours and minutes.
const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
const time_t zone_min =
((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
// Print an ISO 8601 date and time stamp into the buffer
const int year = 1900 + time_struct.tm_year;
const int month = 1 + time_struct.tm_mon;
const int printed = jio_snprintf(buffer, buffer_length,
"%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
year,
month,
time_struct.tm_mday,
time_struct.tm_hour,
time_struct.tm_min,
time_struct.tm_sec,
milliseconds_after_second,
sign_local_to_UTC,
zone_hours,
zone_min);
if (printed == 0) {
assert(false, "Failed jio_printf");
return NULL;
}
return buffer;
}
OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
debug_only(Thread::check_for_dangling_thread_pointer(thread);)
if ((p >= MinPriority && p <= MaxPriority) ||
(p == CriticalPriority && thread->is_ConcurrentGC_thread())) {
int priority = java_to_os_priority[p];
return set_native_priority(thread, priority);
} else {
assert(false, "Should not happen");
return OS_ERR;
}
}
// The mapping from OS priority back to Java priority may be inexact because
// Java priorities can map M:1 with native priorities. If you want the definite
// Java priority then use JavaThread::java_priority()
OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
int p;
int os_prio;
OSReturn ret = get_native_priority(thread, &os_prio);
if (ret != OS_OK) return ret;
if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
} else {
// niceness values are in reverse order
for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
}
priority = (ThreadPriority)p;
return OS_OK;
}
bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
return (n != -1);
}
#if !defined(LINUX) && !defined(_WINDOWS)
bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
committed_start = start;
committed_size = size;
return true;
}
#endif
// Helper for dll_locate_lib.
// Pass buffer and printbuffer as we already printed the path to buffer
// when we called get_current_directory. This way we avoid another buffer
// of size MAX_PATH.
static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
const char* pname, char lastchar, const char* fname) {
// Concatenate path and file name, but don't print double path separators.
const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
"" : os::file_separator();
int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
// Check whether file exists.
if (ret != -1) {
struct stat statbuf;
return os::stat(buffer, &statbuf) == 0;
}
return false;
}
bool os::dll_locate_lib(char *buffer, size_t buflen,
const char* pname, const char* fname) {
bool retval = false;
size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
const size_t pnamelen = pname ? strlen(pname) : 0;
if (pnamelen == 0) {
// If no path given, use current working directory.
const char* p = get_current_directory(buffer, buflen);
if (p != NULL) {
const size_t plen = strlen(buffer);
const char lastchar = buffer[plen - 1];
retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
"", lastchar, fullfname);
}
} else if (strchr(pname, *os::path_separator()) != NULL) {
// A list of paths. Search for the path that contains the library.
int n;
char** pelements = split_path(pname, &n);
if (pelements != NULL) {
for (int i = 0; i < n; i++) {
char* path = pelements[i];
// Really shouldn't be NULL, but check can't hurt.
size_t plen = (path == NULL) ? 0 : strlen(path);
if (plen == 0) {
continue; // Skip the empty path values.
}
const char lastchar = path[plen - 1];
retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
if (retval) break;
}
// Release the storage allocated by split_path.
for (int i = 0; i < n; i++) {
if (pelements[i] != NULL) {
FREE_C_HEAP_ARRAY(char, pelements[i]);
}
}
FREE_C_HEAP_ARRAY(char*, pelements);
}
} else {
// A definite path.
const char lastchar = pname[pnamelen-1];
retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
}
}
FREE_C_HEAP_ARRAY(char*, fullfname);
return retval;
}
// --------------------- sun.misc.Signal (optional) ---------------------
// SIGBREAK is sent by the keyboard to query the VM state
#ifndef SIGBREAK
#define SIGBREAK SIGQUIT
#endif
// sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
static void signal_thread_entry(JavaThread* thread, TRAPS) {
os::set_priority(thread, NearMaxPriority);
while (true) {
int sig;
{
// FIXME : Currently we have not decided what should be the status
// for this java thread blocked here. Once we decide about
// that we should fix this.
sig = os::signal_wait();
}
if (sig == os::sigexitnum_pd()) {
// Terminate the signal thread
return;
}
switch (sig) {
case SIGBREAK: {
#if INCLUDE_SERVICES
// Check if the signal is a trigger to start the Attach Listener - in that
// case don't print stack traces.
if (!DisableAttachMechanism) {
// Attempt to transit state to AL_INITIALIZING.
AttachListenerState cur_state = AttachListener::transit_state(AL_INITIALIZING, AL_NOT_INITIALIZED);
if (cur_state == AL_INITIALIZING) {
// Attach Listener has been started to initialize. Ignore this signal.
continue;
} else if (cur_state == AL_NOT_INITIALIZED) {
// Start to initialize.
if (AttachListener::is_init_trigger()) {
// Attach Listener has been initialized.
// Accept subsequent request.
continue;
} else {
// Attach Listener could not be started.
// So we need to transit the state to AL_NOT_INITIALIZED.
AttachListener::set_state(AL_NOT_INITIALIZED);
}
} else if (AttachListener::check_socket_file()) {
// Attach Listener has been started, but unix domain socket file
// does not exist. So restart Attach Listener.
continue;
}
}
#endif
// Print stack traces
// Any SIGBREAK operations added here should make sure to flush
// the output stream (e.g. tty->flush()) after output. See 4803766.
// Each module also prints an extra carriage return after its output.
VM_PrintThreads op;
VMThread::execute(&op);
VM_PrintJNI jni_op;
VMThread::execute(&jni_op);
VM_FindDeadlocks op1(tty);
VMThread::execute(&op1);
Universe::print_heap_at_SIGBREAK();
if (PrintClassHistogram) {
VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
VMThread::execute(&op1);
}
if (JvmtiExport::should_post_data_dump()) {
JvmtiExport::post_data_dump();
}
break;
}
default: {
// Dispatch the signal to java
HandleMark hm(THREAD);
Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
if (klass != NULL) {
JavaValue result(T_VOID);
JavaCallArguments args;
args.push_int(sig);
JavaCalls::call_static(
&result,
klass,
vmSymbols::dispatch_name(),
vmSymbols::int_void_signature(),
&args,
THREAD
);
}
if (HAS_PENDING_EXCEPTION) {
// tty is initialized early so we don't expect it to be null, but
// if it is we can't risk doing an initialization that might
// trigger additional out-of-memory conditions
if (tty != NULL) {
char klass_name[256];
char tmp_sig_name[16];
const char* sig_name = "UNKNOWN";
InstanceKlass::cast(PENDING_EXCEPTION->klass())->
name()->as_klass_external_name(klass_name, 256);
if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
sig_name = tmp_sig_name;
warning("Exception %s occurred dispatching signal %s to handler"
"- the VM may need to be forcibly terminated",
klass_name, sig_name );
}
CLEAR_PENDING_EXCEPTION;
}
}
}
}
}
void os::init_before_ergo() {
initialize_initial_active_processor_count();
// We need to initialize large page support here because ergonomics takes some
// decisions depending on large page support and the calculated large page size.
large_page_init();
// We need to adapt the configured number of stack protection pages given
// in 4K pages to the actual os page size. We must do this before setting
// up minimal stack sizes etc. in os::init_2().
JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
// VM version initialization identifies some characteristics of the
// platform that are used during ergonomic decisions.
VM_Version::init_before_ergo();
}
void os::initialize_jdk_signal_support(TRAPS) {
if (!ReduceSignalUsage) {
// Setup JavaThread for processing signals
const char thread_name[] = "Signal Dispatcher";
Handle string = java_lang_String::create_from_str(thread_name, CHECK);
// Initialize thread_oop to put it into the system threadGroup
Handle thread_group (THREAD, Universe::system_thread_group());
Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(),
vmSymbols::threadgroup_string_void_signature(),
thread_group,
string,
CHECK);
Klass* group = SystemDictionary::ThreadGroup_klass();
JavaValue result(T_VOID);
JavaCalls::call_special(&result,
thread_group,
group,
vmSymbols::add_method_name(),
vmSymbols::thread_void_signature(),
thread_oop,
CHECK);
{ MutexLocker mu(Threads_lock);
JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
// At this point it may be possible that no osthread was created for the
// JavaThread due to lack of memory. We would have to throw an exception
// in that case. However, since this must work and we do not allow
// exceptions anyway, check and abort if this fails.
if (signal_thread == NULL || signal_thread->osthread() == NULL) {
vm_exit_during_initialization("java.lang.OutOfMemoryError",
os::native_thread_creation_failed_msg());
}
java_lang_Thread::set_thread(thread_oop(), signal_thread);
java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
java_lang_Thread::set_daemon(thread_oop());
signal_thread->set_threadObj(thread_oop());
Threads::add(signal_thread);
Thread::start(signal_thread);
}
// Handle ^BREAK
os::signal(SIGBREAK, os::user_handler());
}
}
void os::terminate_signal_thread() {
if (!ReduceSignalUsage)
signal_notify(sigexitnum_pd());
}
// --------------------- loading libraries ---------------------
typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
extern struct JavaVM_ main_vm;
static void* _native_java_library = NULL;
void* os::native_java_library() {
if (_native_java_library == NULL) {
char buffer[JVM_MAXPATHLEN];
char ebuf[1024];
// Try to load verify dll first. In 1.3 java dll depends on it and is not
// always able to find it when the loading executable is outside the JDK.
// In order to keep working with 1.2 we ignore any loading errors.
if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
"verify")) {
dll_load(buffer, ebuf, sizeof(ebuf));
}
// Load java dll
if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
"java")) {
_native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
}
if (_native_java_library == NULL) {
vm_exit_during_initialization("Unable to load native library", ebuf);
}
#if defined(__OpenBSD__)
// Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
// ignore errors
if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
"net")) {
dll_load(buffer, ebuf, sizeof(ebuf));
}
#endif
}
return _native_java_library;
}
/*
* Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
* If check_lib == true then we are looking for an
* Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
* this library is statically linked into the image.
* If check_lib == false then we will look for the appropriate symbol in the
* executable if agent_lib->is_static_lib() == true or in the shared library
* referenced by 'handle'.
*/
void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
const char *syms[], size_t syms_len) {
assert(agent_lib != NULL, "sanity check");
const char *lib_name;
void *handle = agent_lib->os_lib();
void *entryName = NULL;
char *agent_function_name;
size_t i;
// If checking then use the agent name otherwise test is_static_lib() to
// see how to process this lookup
lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
for (i = 0; i < syms_len; i++) {
agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
if (agent_function_name == NULL) {
break;
}
entryName = dll_lookup(handle, agent_function_name);
FREE_C_HEAP_ARRAY(char, agent_function_name);
if (entryName != NULL) {
break;
}
}
return entryName;
}
// See if the passed in agent is statically linked into the VM image.
bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
size_t syms_len) {
void *ret;
void *proc_handle;
void *save_handle;
assert(agent_lib != NULL, "sanity check");
if (agent_lib->name() == NULL) {
return false;
}
proc_handle = get_default_process_handle();
// Check for Agent_OnLoad/Attach_lib_name function
save_handle = agent_lib->os_lib();
// We want to look in this process' symbol table.
agent_lib->set_os_lib(proc_handle);
ret = find_agent_function(agent_lib, true, syms, syms_len);
if (ret != NULL) {
// Found an entry point like Agent_OnLoad_lib_name so we have a static agent
agent_lib->set_valid();
agent_lib->set_static_lib(true);
return true;
}
agent_lib->set_os_lib(save_handle);
return false;
}
// --------------------- heap allocation utilities ---------------------
char *os::strdup(const char *str, MEMFLAGS flags) {
size_t size = strlen(str);
char *dup_str = (char *)malloc(size + 1, flags);
if (dup_str == NULL) return NULL;
strcpy(dup_str, str);
return dup_str;
}
char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
char* p = os::strdup(str, flags);
if (p == NULL) {
vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
}
return p;
}
#define paranoid 0 /* only set to 1 if you suspect checking code has bug */
#ifdef ASSERT
static void verify_memory(void* ptr) {
GuardedMemory guarded(ptr);
if (!guarded.verify_guards()) {
LogTarget(Warning, malloc, free) lt;
ResourceMark rm;
LogStream ls(lt);
ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
ls.print_cr("## memory stomp:");
guarded.print_on(&ls);
fatal("memory stomping error");
}
}
#endif
//
// This function supports testing of the malloc out of memory
// condition without really running the system out of memory.
//
static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
if (MallocMaxTestWords > 0) {
size_t words = (alloc_size / BytesPerWord);
if ((cur_malloc_words + words) > MallocMaxTestWords) {
return true;
}
Atomic::add(words, &cur_malloc_words);
}
return false;
}
void* os::malloc(size_t size, MEMFLAGS flags) {
return os::malloc(size, flags, CALLER_PC);
}
void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
// Since os::malloc can be called when the libjvm.{dll,so} is
// first loaded and we don't have a thread yet we must accept NULL also here.
assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
"malloc() not allowed when crash protection is set");
if (size == 0) {
// return a valid pointer if size is zero
// if NULL is returned the calling functions assume out of memory.
size = 1;
}
// NMT support
NMT_TrackingLevel level = MemTracker::tracking_level();
size_t nmt_header_size = MemTracker::malloc_header_size(level);
#ifndef ASSERT
const size_t alloc_size = size + nmt_header_size;
#else
const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
if (size + nmt_header_size > alloc_size) { // Check for rollover.
return NULL;
}
#endif
// For the test flag -XX:MallocMaxTestWords
if (has_reached_max_malloc_test_peak(size)) {
return NULL;
}
u_char* ptr;
ptr = (u_char*)::malloc(alloc_size);
#ifdef ASSERT
if (ptr == NULL) {
return NULL;
}
// Wrap memory with guard
GuardedMemory guarded(ptr, size + nmt_header_size);
ptr = guarded.get_user_ptr();
#endif
if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
breakpoint();
}
debug_only(if (paranoid) verify_memory(ptr));
// we do not track guard memory
return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
}
void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
return os::realloc(memblock, size, flags, CALLER_PC);
}
void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
// For the test flag -XX:MallocMaxTestWords
if (has_reached_max_malloc_test_peak(size)) {
return NULL;
}
if (size == 0) {
// return a valid pointer if size is zero
// if NULL is returned the calling functions assume out of memory.
size = 1;
}
#ifndef ASSERT
NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
// NMT support
NMT_TrackingLevel level = MemTracker::tracking_level();
void* membase = MemTracker::record_free(memblock, level);
size_t nmt_header_size = MemTracker::malloc_header_size(level);
void* ptr = ::realloc(membase, size + nmt_header_size);
return MemTracker::record_malloc(ptr, size, memflags, stack, level);
#else
if (memblock == NULL) {
return os::malloc(size, memflags, stack);
}
if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
breakpoint();
}
// NMT support
void* membase = MemTracker::malloc_base(memblock);
verify_memory(membase);
// always move the block
void* ptr = os::malloc(size, memflags, stack);
// Copy to new memory if malloc didn't fail
if (ptr != NULL ) {
GuardedMemory guarded(MemTracker::malloc_base(memblock));
// Guard's user data contains NMT header
size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
memcpy(ptr, memblock, MIN2(size, memblock_size));
if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
log_warning(malloc, free)("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
breakpoint();
}
os::free(memblock);
}
return ptr;
#endif
}
void os::free(void *memblock) {
NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
#ifdef ASSERT
if (memblock == NULL) return;
if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
breakpoint();
}
void* membase = MemTracker::record_free(memblock, MemTracker::tracking_level());
verify_memory(membase);
GuardedMemory guarded(membase);
size_t size = guarded.get_user_size();
inc_stat_counter(&free_bytes, size);
membase = guarded.release_for_freeing();
::free(membase);
#else
void* membase = MemTracker::record_free(memblock, MemTracker::tracking_level());
::free(membase);
#endif
}
void os::init_random(unsigned int initval) {
_rand_seed = initval;
}
static int random_helper(unsigned int rand_seed) {
/* standard, well-known linear congruential random generator with
* next_rand = (16807*seed) mod (2**31-1)
* see
* (1) "Random Number Generators: Good Ones Are Hard to Find",
* S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
* (2) "Two Fast Implementations of the 'Minimal Standard' Random
* Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
*/
const unsigned int a = 16807;
const unsigned int m = 2147483647;
const int q = m / a; assert(q == 127773, "weird math");
const int r = m % a; assert(r == 2836, "weird math");
// compute az=2^31p+q
unsigned int lo = a * (rand_seed & 0xFFFF);
unsigned int hi = a * (rand_seed >> 16);
lo += (hi & 0x7FFF) << 16;
// if q overflowed, ignore the overflow and increment q
if (lo > m) {
lo &= m;
++lo;
}
lo += hi >> 15;
// if (p+q) overflowed, ignore the overflow and increment (p+q)
if (lo > m) {
lo &= m;
++lo;
}
return lo;
}
int os::random() {
// Make updating the random seed thread safe.
while (true) {
unsigned int seed = _rand_seed;
unsigned int rand = random_helper(seed);
if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
return static_cast<int>(rand);
}
}
}
// The INITIALIZED state is distinguished from the SUSPENDED state because the
// conditions in which a thread is first started are different from those in which
// a suspension is resumed. These differences make it hard for us to apply the
// tougher checks when starting threads that we want to do when resuming them.
// However, when start_thread is called as a result of Thread.start, on a Java
// thread, the operation is synchronized on the Java Thread object. So there
// cannot be a race to start the thread and hence for the thread to exit while
// we are working on it. Non-Java threads that start Java threads either have
// to do so in a context in which races are impossible, or should do appropriate
// locking.
void os::start_thread(Thread* thread) {
// guard suspend/resume
MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
OSThread* osthread = thread->osthread();
osthread->set_state(RUNNABLE);
pd_start_thread(thread);
}
void os::abort(bool dump_core) {
abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
}
//---------------------------------------------------------------------------
// Helper functions for fatal error handler
void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
start = align_down(start, unitsize);
int cols = 0;
int cols_per_line = 0;
switch (unitsize) {
case 1: cols_per_line = 16; break;
case 2: cols_per_line = 8; break;
case 4: cols_per_line = 4; break;
case 8: cols_per_line = 2; break;
default: return;
}
address p = start;
st->print(PTR_FORMAT ": ", p2i(start));
while (p < end) {
if (is_readable_pointer(p)) {
switch (unitsize) {
case 1: st->print("%02x", *(u1*)p); break;
case 2: st->print("%04x", *(u2*)p); break;
case 4: st->print("%08x", *(u4*)p); break;
case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
}
} else {
st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????");
}
p += unitsize;
cols++;
if (cols >= cols_per_line && p < end) {
cols = 0;
st->cr();
st->print(PTR_FORMAT ": ", p2i(p));
} else {
st->print(" ");
}
}
st->cr();
}
void os::print_dhm(outputStream* st, const char* startStr, long sec) {
long days = sec/86400;
long hours = (sec/3600) - (days * 24);
long minutes = (sec/60) - (days * 1440) - (hours * 60);
if (startStr == NULL) startStr = "";
st->print_cr("%s %ld days %ld:%02ld hours", startStr, days, hours, minutes);
}
void os::print_instructions(outputStream* st, address pc, int unitsize) {
st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
print_hex_dump(st, pc - 256, pc + 256, unitsize);
}
void os::print_environment_variables(outputStream* st, const char** env_list) {
if (env_list) {
st->print_cr("Environment Variables:");
for (int i = 0; env_list[i] != NULL; i++) {
char *envvar = ::getenv(env_list[i]);
if (envvar != NULL) {
st->print("%s", env_list[i]);
st->print("=");
st->print_cr("%s", envvar);
}
}
}
}
void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
// cpu
st->print("CPU:");
st->print("total %d", os::processor_count());
// It's not safe to query number of active processors after crash
// st->print("(active %d)", os::active_processor_count()); but we can
// print the initial number of active processors.
// We access the raw value here because the assert in the accessor will
// fail if the crash occurs before initialization of this value.
st->print(" (initial active %d)", _initial_active_processor_count);
st->print(" %s", VM_Version::features_string());
st->cr();
pd_print_cpu_info(st, buf, buflen);
}
// Print a one line string summarizing the cpu, number of cores, memory, and operating system version
void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
st->print("Host: ");
#ifndef PRODUCT
if (get_host_name(buf, buflen)) {
st->print("%s, ", buf);
}
#endif // PRODUCT
get_summary_cpu_info(buf, buflen);
st->print("%s, ", buf);
size_t mem = physical_memory()/G;
if (mem == 0) { // for low memory systems
mem = physical_memory()/M;
st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
} else {
st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
}
get_summary_os_info(buf, buflen);
st->print_raw(buf);
st->cr();
}
void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
const int secs_per_day = 86400;
const int secs_per_hour = 3600;
const int secs_per_min = 60;
time_t tloc;
(void)time(&tloc);
char* timestring = ctime(&tloc); // ctime adds newline.
// edit out the newline
char* nl = strchr(timestring, '\n');
if (nl != NULL) {
*nl = '\0';
}
struct tm tz;
if (localtime_pd(&tloc, &tz) != NULL) {
::strftime(buf, buflen, "%Z", &tz);
st->print("Time: %s %s", timestring, buf);
} else {
st->print("Time: %s", timestring);
}
double t = os::elapsedTime();
// NOTE: a crash using printf("%f",...) on Linux was historically noted here.
int eltime = (int)t; // elapsed time in seconds
int eltimeFraction = (int) ((t - eltime) * 1000000);
// print elapsed time in a human-readable format:
int eldays = eltime / secs_per_day;
int day_secs = eldays * secs_per_day;
int elhours = (eltime - day_secs) / secs_per_hour;
int hour_secs = elhours * secs_per_hour;
int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
int minute_secs = elmins * secs_per_min;
int elsecs = (eltime - day_secs - hour_secs - minute_secs);
st->print_cr(" elapsed time: %d.%06d seconds (%dd %dh %dm %ds)", eltime, eltimeFraction, eldays, elhours, elmins, elsecs);
}
// Check if pointer can be read from (4-byte read access).
// Helps to prove validity of a not-NULL pointer.
// Returns true in very early stages of VM life when stub is not yet generated.
#define SAFEFETCH_DEFAULT true
bool os::is_readable_pointer(const void* p) {
if (!CanUseSafeFetch32()) {
return SAFEFETCH_DEFAULT;
}
int* const aligned = (int*) align_down((intptr_t)p, 4);
int cafebabe = 0xcafebabe; // tester value 1
int deadbeef = 0xdeadbeef; // tester value 2
return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef);
}
bool os::is_readable_range(const void* from, const void* to) {
if ((uintptr_t)from >= (uintptr_t)to) return false;
for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) {
if (!is_readable_pointer((const void*)p)) {
return false;
}
}
return true;
}
// moved from debug.cpp (used to be find()) but still called from there
// The verbose parameter is only set by the debug code in one case
void os::print_location(outputStream* st, intptr_t x, bool verbose) {
address addr = (address)x;
// Handle NULL first, so later checks don't need to protect against it.
if (addr == NULL) {
st->print_cr("0x0 is NULL");
return;
}
// Check if addr points into a code blob.
CodeBlob* b = CodeCache::find_blob_unsafe(addr);
if (b != NULL) {
b->dump_for_addr(addr, st, verbose);
return;
}
// Check if addr points into Java heap.
if (Universe::heap()->is_in(addr)) {
oop o = oopDesc::oop_or_null(addr);
if (o != NULL) {
if ((HeapWord*)o == (HeapWord*)addr) {
st->print(INTPTR_FORMAT " is an oop: ", p2i(addr));
} else {
st->print(INTPTR_FORMAT " is pointing into object: " , p2i(addr));
}
o->print_on(st);
return;
}
} else if (Universe::heap()->is_in_reserved(addr)) {
st->print_cr(INTPTR_FORMAT " is an unallocated location in the heap", p2i(addr));
return;
}
// Compressed oop needs to be decoded first.
#ifdef _LP64
if (UseCompressedOops && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
narrowOop narrow_oop = (narrowOop)(uintptr_t)addr;
oop o = oopDesc::decode_oop_raw(narrow_oop);
if (oopDesc::is_valid(o)) {
st->print(UINT32_FORMAT " is a compressed pointer to object: ", narrow_oop);
o->print_on(st);
return;
}
}
#endif
bool accessible = is_readable_pointer(addr);
// Check if addr is a JNI handle.
if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) {
if (JNIHandles::is_global_handle((jobject) addr)) {
st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
return;
}
if (JNIHandles::is_weak_global_handle((jobject) addr)) {
st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
return;
}
#ifndef PRODUCT
// we don't keep the block list in product mode
if (JNIHandles::is_local_handle((jobject) addr)) {
st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
return;
}
#endif
}
// Check if addr belongs to a Java thread.
for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
// Check for privilege stack
if (thread->privileged_stack_top() != NULL &&
thread->privileged_stack_top()->contains(addr)) {
st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
"for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
if (verbose) thread->print_on(st);
return;
}
// If the addr is a java thread print information about that.
if (addr == (address)thread) {
if (verbose) {
thread->print_on(st);
} else {
st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
}
return;
}
// If the addr is in the stack region for this thread then report that
// and print thread info
if (thread->on_local_stack(addr)) {
st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
INTPTR_FORMAT, p2i(addr), p2i(thread));
if (verbose) thread->print_on(st);
return;
}
}
// Check if in metaspace and print types that have vptrs
if (Metaspace::contains(addr)) {
if (Klass::is_valid((Klass*)addr)) {
st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr));
((Klass*)addr)->print_on(st);
} else if (Method::is_valid_method((const Method*)addr)) {
((Method*)addr)->print_value_on(st);
st->cr();
} else {
// Use addr->print() from the debugger instead (not here)
st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
}
return;
}
// Compressed klass needs to be decoded first.
#ifdef _LP64
if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr;
Klass* k = Klass::decode_klass_raw(narrow_klass);
if (Klass::is_valid(k)) {
st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k));
k->print_on(st);
return;
}
}
#endif
// Try an OS specific find
if (os::find(addr, st)) {
return;
}
if (accessible) {
st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr));
if (is_aligned(addr, sizeof(intptr_t))) {
st->print(" " PTR_FORMAT " |", *(intptr_t*)addr);
}
for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) {
st->print(" %02x", *(u1*)p);
}
st->cr();
return;
}
st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
}
// Looks like all platforms can use the same function to check if C
// stack is walkable beyond current frame. The check for fp() is not
// necessary on Sparc, but it's harmless.
bool os::is_first_C_frame(frame* fr) {
// Load up sp, fp, sender sp and sender fp, check for reasonable values.
// Check usp first, because if that's bad the other accessors may fault
// on some architectures. Ditto ufp second, etc.
uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
// sp on amd can be 32 bit aligned.
uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
uintptr_t usp = (uintptr_t)fr->sp();
if ((usp & sp_align_mask) != 0) return true;
uintptr_t ufp = (uintptr_t)fr->fp();
if ((ufp & fp_align_mask) != 0) return true;
uintptr_t old_sp = (uintptr_t)fr->sender_sp();
if ((old_sp & sp_align_mask) != 0) return true;
if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
uintptr_t old_fp = (uintptr_t)fr->link();
if ((old_fp & fp_align_mask) != 0) return true;
if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
// stack grows downwards; if old_fp is below current fp or if the stack
// frame is too large, either the stack is corrupted or fp is not saved
// on stack (i.e. on x86, ebp may be used as general register). The stack
// is not walkable beyond current frame.
if (old_fp < ufp) return true;
if (old_fp - ufp > 64 * K) return true;
return false;
}
// Set up the boot classpath.
char* os::format_boot_path(const char* format_string,
const char* home,
int home_len,
char fileSep,
char pathSep) {
assert((fileSep == '/' && pathSep == ':') ||
(fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
// Scan the format string to determine the length of the actual
// boot classpath, and handle platform dependencies as well.
int formatted_path_len = 0;
const char* p;
for (p = format_string; *p != 0; ++p) {
if (*p == '%') formatted_path_len += home_len - 1;
++formatted_path_len;
}
char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
if (formatted_path == NULL) {
return NULL;
}
// Create boot classpath from format, substituting separator chars and
// java home directory.
char* q = formatted_path;
for (p = format_string; *p != 0; ++p) {
switch (*p) {
case '%':
strcpy(q, home);
q += home_len;
break;
case '/':
*q++ = fileSep;
break;
case ':':
*q++ = pathSep;
break;
default:
*q++ = *p;
}
}
*q = '\0';
assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
return formatted_path;
}
// This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
// that ensures automatic closing of the file on exec. If it can not find support in
// the underlying c library, it will make an extra system call (fcntl) to ensure automatic
// closing of the file on exec.
FILE* os::fopen(const char* path, const char* mode) {
char modified_mode[20];
assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
FILE* file = ::fopen(path, modified_mode);
#if !(defined LINUX || defined BSD || defined _WINDOWS)
// assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
// is not supported as mode in fopen
if (file != NULL) {
int fd = fileno(file);
if (fd != -1) {
int fd_flags = fcntl(fd, F_GETFD);
if (fd_flags != -1) {
fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
}
}
}
#endif
return file;
}
bool os::set_boot_path(char fileSep, char pathSep) {
const char* home = Arguments::get_java_home();
int home_len = (int)strlen(home);
struct stat st;
// modular image if "modules" jimage exists
char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
if (jimage == NULL) return false;
bool has_jimage = (os::stat(jimage, &st) == 0);
if (has_jimage) {
Arguments::set_sysclasspath(jimage, true);
FREE_C_HEAP_ARRAY(char, jimage);
return true;
}
FREE_C_HEAP_ARRAY(char, jimage);
// check if developer build with exploded modules
char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
if (base_classes == NULL) return false;
if (os::stat(base_classes, &st) == 0) {
Arguments::set_sysclasspath(base_classes, false);
FREE_C_HEAP_ARRAY(char, base_classes);
return true;
}
FREE_C_HEAP_ARRAY(char, base_classes);
return false;
}
/*
* Splits a path, based on its separator, the number of
* elements is returned back in n.
* It is the callers responsibility to:
* a> check the value of n, and n may be 0.
* b> ignore any empty path elements
* c> free up the data.
*/
char** os::split_path(const char* path, int* n) {
*n = 0;
if (path == NULL || strlen(path) == 0) {
return NULL;
}
const char psepchar = *os::path_separator();
char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
if (inpath == NULL) {
return NULL;
}
strcpy(inpath, path);
int count = 1;
char* p = strchr(inpath, psepchar);
// Get a count of elements to allocate memory
while (p != NULL) {
count++;
p++;
p = strchr(p, psepchar);
}
char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
if (opath == NULL) {
return NULL;
}
// do the actual splitting
p = inpath;
for (int i = 0 ; i < count ; i++) {
size_t len = strcspn(p, os::path_separator());
if (len > JVM_MAXPATHLEN) {
return NULL;
}
// allocate the string and add terminator storage
char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
if (s == NULL) {
return NULL;
}
strncpy(s, p, len);
s[len] = '\0';
opath[i] = s;
p += len + 1;
}
FREE_C_HEAP_ARRAY(char, inpath);
*n = count;
return opath;
}
void os::set_memory_serialize_page(address page) {
// S/390: Cast to (uintptr_t) to remove ambiguity; see JDK-8222286
int count = log2_intptr((uintptr_t) sizeof(class JavaThread)) - log2_int(64);
_mem_serialize_page = (volatile int32_t *)page;
// We initialize the serialization page shift count here
// We assume a cache line size of 64 bytes
assert(SerializePageShiftCount == count, "JavaThread size changed; "
"SerializePageShiftCount constant should be %d", count);
set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
}
static volatile intptr_t SerializePageLock = 0;
// This method is called from signal handler when SIGSEGV occurs while the current
// thread tries to store to the "read-only" memory serialize page during state
// transition.
void os::block_on_serialize_page_trap() {
log_debug(safepoint)("Block until the serialize page permission restored");
// When VMThread is holding the SerializePageLock during modifying the
// access permission of the memory serialize page, the following call
// will block until the permission of that page is restored to rw.
// Generally, it is unsafe to manipulate locks in signal handlers, but in
// this case, it's OK as the signal is synchronous and we know precisely when
// it can occur.
Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
Thread::muxRelease(&SerializePageLock);
}
// Serialize all thread state variables
void os::serialize_thread_states() {
// On some platforms such as Solaris & Linux, the time duration of the page
// permission restoration is observed to be much longer than expected due to
// scheduler starvation problem etc. To avoid the long synchronization
// time and expensive page trap spinning, 'SerializePageLock' is used to block
// the mutator thread if such case is encountered. See bug 6546278 for details.
Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
os::protect_memory((char *)os::get_memory_serialize_page(),
os::vm_page_size(), MEM_PROT_READ);
os::protect_memory((char *)os::get_memory_serialize_page(),
os::vm_page_size(), MEM_PROT_RW);
Thread::muxRelease(&SerializePageLock);
}
// Returns true if the current stack pointer is above the stack shadow
// pages, false otherwise.
bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
if (!thread->is_Java_thread()) return false;
// Check if we have StackShadowPages above the yellow zone. This parameter
// is dependent on the depth of the maximum VM call stack possible from
// the handler for stack overflow. 'instanceof' in the stack overflow
// handler or a println uses at least 8k stack of VM and native code
// respectively.
const int framesize_in_bytes =
Interpreter::size_top_interpreter_activation(method()) * wordSize;
address limit = ((JavaThread*)thread)->stack_end() +
(JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
return sp > (limit + framesize_in_bytes);
}
size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
assert(min_pages > 0, "sanity");
if (UseLargePages) {
const size_t max_page_size = region_size / min_pages;
for (size_t i = 0; _page_sizes[i] != 0; ++i) {
const size_t page_size = _page_sizes[i];
if (page_size <= max_page_size) {
if (!must_be_aligned || is_aligned(region_size, page_size)) {
return page_size;
}
}
}
}
return vm_page_size();
}
size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
return page_size_for_region(region_size, min_pages, true);
}
size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
return page_size_for_region(region_size, min_pages, false);
}
static const char* errno_to_string (int e, bool short_text) {
#define ALL_SHARED_ENUMS(X) \
X(E2BIG, "Argument list too long") \
X(EACCES, "Permission denied") \
X(EADDRINUSE, "Address in use") \
X(EADDRNOTAVAIL, "Address not available") \
X(EAFNOSUPPORT, "Address family not supported") \
X(EAGAIN, "Resource unavailable, try again") \
X(EALREADY, "Connection already in progress") \
X(EBADF, "Bad file descriptor") \
X(EBADMSG, "Bad message") \
X(EBUSY, "Device or resource busy") \
X(ECANCELED, "Operation canceled") \
X(ECHILD, "No child processes") \
X(ECONNABORTED, "Connection aborted") \
X(ECONNREFUSED, "Connection refused") \
X(ECONNRESET, "Connection reset") \
X(EDEADLK, "Resource deadlock would occur") \
X(EDESTADDRREQ, "Destination address required") \
X(EDOM, "Mathematics argument out of domain of function") \
X(EEXIST, "File exists") \
X(EFAULT, "Bad address") \
X(EFBIG, "File too large") \
X(EHOSTUNREACH, "Host is unreachable") \
X(EIDRM, "Identifier removed") \
X(EILSEQ, "Illegal byte sequence") \
X(EINPROGRESS, "Operation in progress") \
X(EINTR, "Interrupted function") \
X(EINVAL, "Invalid argument") \
X(EIO, "I/O error") \
X(EISCONN, "Socket is connected") \
X(EISDIR, "Is a directory") \
X(ELOOP, "Too many levels of symbolic links") \
X(EMFILE, "Too many open files") \
X(EMLINK, "Too many links") \
X(EMSGSIZE, "Message too large") \
X(ENAMETOOLONG, "Filename too long") \
X(ENETDOWN, "Network is down") \
X(ENETRESET, "Connection aborted by network") \
X(ENETUNREACH, "Network unreachable") \
X(ENFILE, "Too many files open in system") \
X(ENOBUFS, "No buffer space available") \
X(ENODATA, "No message is available on the STREAM head read queue") \
X(ENODEV, "No such device") \
X(ENOENT, "No such file or directory") \
X(ENOEXEC, "Executable file format error") \
X(ENOLCK, "No locks available") \
X(ENOLINK, "Reserved") \
X(ENOMEM, "Not enough space") \
X(ENOMSG, "No message of the desired type") \
X(ENOPROTOOPT, "Protocol not available") \
X(ENOSPC, "No space left on device") \
X(ENOSR, "No STREAM resources") \
X(ENOSTR, "Not a STREAM") \
X(ENOSYS, "Function not supported") \
X(ENOTCONN, "The socket is not connected") \
X(ENOTDIR, "Not a directory") \
X(ENOTEMPTY, "Directory not empty") \
X(ENOTSOCK, "Not a socket") \
X(ENOTSUP, "Not supported") \
X(ENOTTY, "Inappropriate I/O control operation") \
X(ENXIO, "No such device or address") \
X(EOPNOTSUPP, "Operation not supported on socket") \
X(EOVERFLOW, "Value too large to be stored in data type") \
X(EPERM, "Operation not permitted") \
X(EPIPE, "Broken pipe") \
X(EPROTO, "Protocol error") \
X(EPROTONOSUPPORT, "Protocol not supported") \
X(EPROTOTYPE, "Protocol wrong type for socket") \
X(ERANGE, "Result too large") \
X(EROFS, "Read-only file system") \
X(ESPIPE, "Invalid seek") \
X(ESRCH, "No such process") \
X(ETIME, "Stream ioctl() timeout") \
X(ETIMEDOUT, "Connection timed out") \
X(ETXTBSY, "Text file busy") \
X(EWOULDBLOCK, "Operation would block") \
X(EXDEV, "Cross-device link")
#define DEFINE_ENTRY(e, text) { e, #e, text },
static const struct {
int v;
const char* short_text;
const char* long_text;
} table [] = {
ALL_SHARED_ENUMS(DEFINE_ENTRY)
// The following enums are not defined on all platforms.
#ifdef ESTALE
DEFINE_ENTRY(ESTALE, "Reserved")
#endif
#ifdef EDQUOT
DEFINE_ENTRY(EDQUOT, "Reserved")
#endif
#ifdef EMULTIHOP
DEFINE_ENTRY(EMULTIHOP, "Reserved")
#endif
// End marker.
{ -1, "Unknown errno", "Unknown error" }
};
#undef DEFINE_ENTRY
#undef ALL_FLAGS
int i = 0;
while (table[i].v != -1 && table[i].v != e) {
i ++;
}
return short_text ? table[i].short_text : table[i].long_text;
}
const char* os::strerror(int e) {
return errno_to_string(e, false);
}
const char* os::errno_name(int e) {
return errno_to_string(e, true);
}
void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
LogTarget(Info, pagesize) log;
if (log.is_enabled()) {
LogStream out(log);
out.print("%s: ", str);
for (int i = 0; i < count; ++i) {
out.print(" " SIZE_FORMAT, page_sizes[i]);
}
out.cr();
}
}
#define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
void os::trace_page_sizes(const char* str,
const size_t region_min_size,
const size_t region_max_size,
const size_t page_size,
const char* base,
const size_t size) {
log_info(pagesize)("%s: "
" min=" SIZE_FORMAT "%s"
" max=" SIZE_FORMAT "%s"
" base=" PTR_FORMAT
" page_size=" SIZE_FORMAT "%s"
" size=" SIZE_FORMAT "%s",
str,
trace_page_size_params(region_min_size),
trace_page_size_params(region_max_size),
p2i(base),
trace_page_size_params(page_size),
trace_page_size_params(size));
}
void os::trace_page_sizes_for_requested_size(const char* str,
const size_t requested_size,
const size_t page_size,
const size_t alignment,
const char* base,
const size_t size) {
log_info(pagesize)("%s:"
" req_size=" SIZE_FORMAT "%s"
" base=" PTR_FORMAT
" page_size=" SIZE_FORMAT "%s"
" alignment=" SIZE_FORMAT "%s"
" size=" SIZE_FORMAT "%s",
str,
trace_page_size_params(requested_size),
p2i(base),
trace_page_size_params(page_size),
trace_page_size_params(alignment),
trace_page_size_params(size));
}
// This is the working definition of a server class machine:
// >= 2 physical CPU's and >=2GB of memory, with some fuzz
// because the graphics memory (?) sometimes masks physical memory.
// If you want to change the definition of a server class machine
// on some OS or platform, e.g., >=4GB on Windows platforms,
// then you'll have to parameterize this method based on that state,
// as was done for logical processors here, or replicate and
// specialize this method for each platform. (Or fix os to have
// some inheritance structure and use subclassing. Sigh.)
// If you want some platform to always or never behave as a server
// class machine, change the setting of AlwaysActAsServerClassMachine
// and NeverActAsServerClassMachine in globals*.hpp.
bool os::is_server_class_machine() {
// First check for the early returns
if (NeverActAsServerClassMachine) {
return false;
}
if (AlwaysActAsServerClassMachine) {
return true;
}
// Then actually look at the machine
bool result = false;
const unsigned int server_processors = 2;
const julong server_memory = 2UL * G;
// We seem not to get our full complement of memory.
// We allow some part (1/8?) of the memory to be "missing",
// based on the sizes of DIMMs, and maybe graphics cards.
const julong missing_memory = 256UL * M;
/* Is this a server class machine? */
if ((os::active_processor_count() >= (int)server_processors) &&
(os::physical_memory() >= (server_memory - missing_memory))) {
const unsigned int logical_processors =
VM_Version::logical_processors_per_package();
if (logical_processors > 1) {
const unsigned int physical_packages =
os::active_processor_count() / logical_processors;
if (physical_packages >= server_processors) {
result = true;
}
} else {
result = true;
}
}
return result;
}
void os::initialize_initial_active_processor_count() {
assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
_initial_active_processor_count = active_processor_count();
log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
}
void os::SuspendedThreadTask::run() {
internal_do_task();
_done = true;
}
bool os::create_stack_guard_pages(char* addr, size_t bytes) {
return os::pd_create_stack_guard_pages(addr, bytes);
}
char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
char* result = NULL;
if (file_desc != -1) {
// Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
// but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
result = os::map_memory_to_file(addr, bytes, file_desc);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
}
} else {
result = pd_reserve_memory(bytes, addr, alignment_hint);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
}
}
return result;
}
char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
MEMFLAGS flags) {
char* result = pd_reserve_memory(bytes, addr, alignment_hint);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
MemTracker::record_virtual_memory_type((address)result, flags);
}
return result;
}
char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
char* result = NULL;
if (file_desc != -1) {
result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
}
} else {
result = pd_attempt_reserve_memory_at(bytes, addr);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
}
}
return result;
}
void os::split_reserved_memory(char *base, size_t size,
size_t split, bool realloc) {
pd_split_reserved_memory(base, size, split, realloc);
}
bool os::commit_memory(char* addr, size_t bytes, bool executable) {
bool res = pd_commit_memory(addr, bytes, executable);
if (res) {
MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
}
return res;
}
bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
bool executable) {
bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
if (res) {
MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
}
return res;
}
void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
const char* mesg) {
pd_commit_memory_or_exit(addr, bytes, executable, mesg);
MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
}
void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
bool executable, const char* mesg) {
os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
}
bool os::uncommit_memory(char* addr, size_t bytes) {
bool res;
if (MemTracker::tracking_level() > NMT_minimal) {
Tracker tkr(Tracker::uncommit);
res = pd_uncommit_memory(addr, bytes);
if (res) {
tkr.record((address)addr, bytes);
}
} else {
res = pd_uncommit_memory(addr, bytes);
}
return res;
}
bool os::release_memory(char* addr, size_t bytes) {
bool res;
if (MemTracker::tracking_level() > NMT_minimal) {
Tracker tkr(Tracker::release);
res = pd_release_memory(addr, bytes);
if (res) {
tkr.record((address)addr, bytes);
}
} else {
res = pd_release_memory(addr, bytes);
}
return res;
}
void os::pretouch_memory(void* start, void* end, size_t page_size) {
for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
*p = 0;
}
}
char* os::map_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec) {
char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
if (result != NULL) {
MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
}
return result;
}
char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec) {
return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
read_only, allow_exec);
}
bool os::unmap_memory(char *addr, size_t bytes) {
bool result;
if (MemTracker::tracking_level() > NMT_minimal) {
Tracker tkr(Tracker::release);
result = pd_unmap_memory(addr, bytes);
if (result) {
tkr.record((address)addr, bytes);
}
} else {
result = pd_unmap_memory(addr, bytes);
}
return result;
}
void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
pd_free_memory(addr, bytes, alignment_hint);
}
void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
pd_realign_memory(addr, bytes, alignment_hint);
}
#ifndef _WINDOWS
/* try to switch state from state "from" to state "to"
* returns the state set after the method is complete
*/
os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
os::SuspendResume::State to)
{
os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
if (result == from) {
// success
return to;
}
return result;
}
#endif