diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/runtime/perfMemory.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/runtime/perfMemory.cpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,270 @@ +/* + * Copyright (c) 2001, 2017, 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 "logging/log.hpp" +#include "memory/allocation.inline.hpp" +#include "prims/jvm.h" +#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/align.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_up(PerfDataMemorySize, + os::vm_allocation_granularity()); + + log_debug(perf, memops)("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. + + log_debug(perf, memops)("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= + // - decrease the maximum string constant length with + // -XX:PerfMaxStringConstLength= + // + if (PrintMiscellaneous && Verbose) { + warning("PerfMemory Overflow Occurred.\n" + "\tCapacity = " SIZE_FORMAT " bytes" + " Used = " SIZE_FORMAT " bytes" + " Overflow = " INT32_FORMAT " bytes" + "\n\tUse -XX:PerfDataMemorySize= 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; +}