| /* |
| * Copyright (c) 2001, 2015, 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 "memory/allocation.inline.hpp" |
| #include "runtime/arguments.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/mutex.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/orderAccess.inline.hpp" |
| #include "runtime/os.hpp" |
| #include "runtime/perfData.hpp" |
| #include "runtime/perfMemory.hpp" |
| #include "runtime/safepoint.hpp" |
| #include "runtime/statSampler.hpp" |
| #include "utilities/globalDefinitions.hpp" |
| |
| // Prefix of performance data file. |
| const char PERFDATA_NAME[] = "hsperfdata"; |
| |
| // Add 1 for the '_' character between PERFDATA_NAME and pid. The '\0' terminating |
| // character will be included in the sizeof(PERFDATA_NAME) operation. |
| static const size_t PERFDATA_FILENAME_LEN = sizeof(PERFDATA_NAME) + |
| UINT_CHARS + 1; |
| |
| char* PerfMemory::_start = NULL; |
| char* PerfMemory::_end = NULL; |
| char* PerfMemory::_top = NULL; |
| size_t PerfMemory::_capacity = 0; |
| jint PerfMemory::_initialized = false; |
| PerfDataPrologue* PerfMemory::_prologue = NULL; |
| |
| void perfMemory_init() { |
| |
| if (!UsePerfData) return; |
| |
| PerfMemory::initialize(); |
| } |
| |
| void perfMemory_exit() { |
| |
| if (!UsePerfData) return; |
| if (!PerfMemory::is_initialized()) return; |
| |
| // Only destroy PerfData objects if we're at a safepoint and the |
| // StatSampler is not active. Otherwise, we risk removing PerfData |
| // objects that are currently being used by running JavaThreads |
| // or the StatSampler. This method is invoked while we are not at |
| // a safepoint during a VM abort so leaving the PerfData objects |
| // around may also help diagnose the failure. In rare cases, |
| // PerfData objects are used in parallel with a safepoint. See |
| // the work around in PerfDataManager::destroy(). |
| // |
| if (SafepointSynchronize::is_at_safepoint() && !StatSampler::is_active()) { |
| PerfDataManager::destroy(); |
| } |
| |
| // Remove the persistent external resources, if any. This method |
| // does not unmap or invalidate any virtual memory allocated during |
| // initialization. |
| // |
| PerfMemory::destroy(); |
| } |
| |
| void PerfMemory::initialize() { |
| |
| if (_prologue != NULL) |
| // initialization already performed |
| return; |
| |
| size_t capacity = align_size_up(PerfDataMemorySize, |
| os::vm_allocation_granularity()); |
| |
| if (PerfTraceMemOps) { |
| tty->print("PerfDataMemorySize = " SIZE_FORMAT "," |
| " os::vm_allocation_granularity = %d," |
| " adjusted size = " SIZE_FORMAT "\n", |
| PerfDataMemorySize, |
| os::vm_allocation_granularity(), |
| capacity); |
| } |
| |
| // allocate PerfData memory region |
| create_memory_region(capacity); |
| |
| if (_start == NULL) { |
| |
| // the PerfMemory region could not be created as desired. Rather |
| // than terminating the JVM, we revert to creating the instrumentation |
| // on the C heap. When running in this mode, external monitoring |
| // clients cannot attach to and monitor this JVM. |
| // |
| // the warning is issued only in debug mode in order to avoid |
| // additional output to the stdout or stderr output streams. |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("Could not create PerfData Memory region, reverting to malloc"); |
| } |
| |
| _prologue = NEW_C_HEAP_OBJ(PerfDataPrologue, mtInternal); |
| } |
| else { |
| |
| // the PerfMemory region was created as expected. |
| |
| if (PerfTraceMemOps) { |
| tty->print("PerfMemory created: address = " INTPTR_FORMAT "," |
| " size = " SIZE_FORMAT "\n", |
| p2i(_start), |
| _capacity); |
| } |
| |
| _prologue = (PerfDataPrologue *)_start; |
| _end = _start + _capacity; |
| _top = _start + sizeof(PerfDataPrologue); |
| } |
| |
| assert(_prologue != NULL, "prologue pointer must be initialized"); |
| |
| #ifdef VM_LITTLE_ENDIAN |
| _prologue->magic = (jint)0xc0c0feca; |
| _prologue->byte_order = PERFDATA_LITTLE_ENDIAN; |
| #else |
| _prologue->magic = (jint)0xcafec0c0; |
| _prologue->byte_order = PERFDATA_BIG_ENDIAN; |
| #endif |
| |
| _prologue->major_version = PERFDATA_MAJOR_VERSION; |
| _prologue->minor_version = PERFDATA_MINOR_VERSION; |
| _prologue->accessible = 0; |
| |
| _prologue->entry_offset = sizeof(PerfDataPrologue); |
| _prologue->num_entries = 0; |
| _prologue->used = 0; |
| _prologue->overflow = 0; |
| _prologue->mod_time_stamp = 0; |
| |
| OrderAccess::release_store(&_initialized, 1); |
| } |
| |
| void PerfMemory::destroy() { |
| |
| if (_prologue == NULL) return; |
| |
| if (_start != NULL && _prologue->overflow != 0) { |
| |
| // This state indicates that the contiguous memory region exists and |
| // that it wasn't large enough to hold all the counters. In this case, |
| // we output a warning message to the user on exit if the -XX:+Verbose |
| // flag is set (a debug only flag). External monitoring tools can detect |
| // this condition by monitoring the _prologue->overflow word. |
| // |
| // There are two tunables that can help resolve this issue: |
| // - increase the size of the PerfMemory with -XX:PerfDataMemorySize=<n> |
| // - decrease the maximum string constant length with |
| // -XX:PerfMaxStringConstLength=<n> |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("PerfMemory Overflow Occurred.\n" |
| "\tCapacity = " SIZE_FORMAT " bytes" |
| " Used = " SIZE_FORMAT " bytes" |
| " Overflow = " INT32_FORMAT " bytes" |
| "\n\tUse -XX:PerfDataMemorySize=<size> to specify larger size.", |
| PerfMemory::capacity(), |
| PerfMemory::used(), |
| _prologue->overflow); |
| } |
| } |
| |
| if (_start != NULL) { |
| |
| // this state indicates that the contiguous memory region was successfully |
| // and that persistent resources may need to be cleaned up. This is |
| // expected to be the typical condition. |
| // |
| delete_memory_region(); |
| } |
| |
| _start = NULL; |
| _end = NULL; |
| _top = NULL; |
| _prologue = NULL; |
| _capacity = 0; |
| } |
| |
| // allocate an aligned block of memory from the PerfData memory |
| // region. This method assumes that the PerfData memory region |
| // was aligned on a double word boundary when created. |
| // |
| char* PerfMemory::alloc(size_t size) { |
| |
| if (!UsePerfData) return NULL; |
| |
| MutexLocker ml(PerfDataMemAlloc_lock); |
| |
| assert(_prologue != NULL, "called before initialization"); |
| |
| // check that there is enough memory for this request |
| if ((_top + size) >= _end) { |
| |
| _prologue->overflow += (jint)size; |
| |
| return NULL; |
| } |
| |
| char* result = _top; |
| |
| _top += size; |
| |
| assert(contains(result), "PerfData memory pointer out of range"); |
| |
| _prologue->used = (jint)used(); |
| _prologue->num_entries = _prologue->num_entries + 1; |
| |
| return result; |
| } |
| |
| void PerfMemory::mark_updated() { |
| if (!UsePerfData) return; |
| |
| _prologue->mod_time_stamp = os::elapsed_counter(); |
| } |
| |
| // Returns the complete path including the file name of performance data file. |
| // Caller is expected to release the allocated memory. |
| char* PerfMemory::get_perfdata_file_path() { |
| char* dest_file = NULL; |
| |
| if (PerfDataSaveFile != NULL) { |
| // dest_file_name stores the validated file name if file_name |
| // contains %p which will be replaced by pid. |
| dest_file = NEW_C_HEAP_ARRAY(char, JVM_MAXPATHLEN, mtInternal); |
| if(!Arguments::copy_expand_pid(PerfDataSaveFile, strlen(PerfDataSaveFile), |
| dest_file, JVM_MAXPATHLEN)) { |
| FREE_C_HEAP_ARRAY(char, dest_file); |
| if (PrintMiscellaneous && Verbose) { |
| warning("Invalid performance data file path name specified, "\ |
| "fall back to a default name"); |
| } |
| } else { |
| return dest_file; |
| } |
| } |
| // create the name of the file for retaining the instrumentation memory. |
| dest_file = NEW_C_HEAP_ARRAY(char, PERFDATA_FILENAME_LEN, mtInternal); |
| jio_snprintf(dest_file, PERFDATA_FILENAME_LEN, |
| "%s_%d", PERFDATA_NAME, os::current_process_id()); |
| |
| return dest_file; |
| } |