Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2001, 2008, 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 "incls/_precompiled.incl"

 # include "incls/_perfMemory.cpp.incl"

 // 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;

   // if the StatSampler is active, then we don't want to remove

   // resources it may be dependent on. Typically, the StatSampler

   // is disengaged from the watcher thread when this method is called,

   // but it is not disengaged if this method is invoked during a

   // VM abort.

   //

   if (!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 = " SIZE_FORMAT ","

                " 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);

   }

   else {

     // the PerfMemory region was created as expected.

     if (PerfTraceMemOps) {

       tty->print("PerfMemory created: address = " INTPTR_FORMAT ","

                  " size = " SIZE_FORMAT "\n",

                  (void*)_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() {

   assert(_prologue != NULL, "prologue pointer must be initialized");

   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);

     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);

   jio_snprintf(dest_file, PERFDATA_FILENAME_LEN,

                "%s_%d", PERFDATA_NAME, os::current_process_id());

   return dest_file;

 }