--- /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=<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;
+}