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Java example source code file (gcTimer.cpp)

This example Java source code file (gcTimer.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

gcphase, gctimer\:\:register_gc_end, gctimer\:\:register_gc_pause_end, incorrect, pausephase, subphase1, subphase12, subphase2, subphase3, ticks, tickspan, timepartitionphasesiterator, timepartitions, too

The gcTimer.cpp Java example source code

/*
 * Copyright (c) 2012, 2013, 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 "gc_implementation/shared/gcTimer.hpp"
#include "utilities/growableArray.hpp"
#include "utilities/ticks.inline.hpp"

// the "time" parameter for most functions
// has a default value set by Ticks::now()

void GCTimer::register_gc_start(const Ticks& time) {
  _time_partitions.clear();
  _gc_start = time;
}

void GCTimer::register_gc_end(const Ticks& time) {
  assert(!_time_partitions.has_active_phases(),
      "We should have ended all started phases, before ending the GC");

  _gc_end = time;
}

void GCTimer::register_gc_pause_start(const char* name, const Ticks& time) {
  _time_partitions.report_gc_phase_start(name, time);
}

void GCTimer::register_gc_pause_end(const Ticks& time) {
  _time_partitions.report_gc_phase_end(time);
}

void GCTimer::register_gc_phase_start(const char* name, const Ticks& time) {
  _time_partitions.report_gc_phase_start(name, time);
}

void GCTimer::register_gc_phase_end(const Ticks& time) {
  _time_partitions.report_gc_phase_end(time);
}

void STWGCTimer::register_gc_start(const Ticks& time) {
  GCTimer::register_gc_start(time);
  register_gc_pause_start("GC Pause", time);
}

void STWGCTimer::register_gc_end(const Ticks& time) {
  register_gc_pause_end(time);
  GCTimer::register_gc_end(time);
}

void ConcurrentGCTimer::register_gc_pause_start(const char* name) {
  GCTimer::register_gc_pause_start(name);
}

void ConcurrentGCTimer::register_gc_pause_end() {
  GCTimer::register_gc_pause_end();
}

void PhasesStack::clear() {
  _next_phase_level = 0;
}

void PhasesStack::push(int phase_index) {
  assert(_next_phase_level < PHASE_LEVELS, "Overflow");

  _phase_indices[_next_phase_level] = phase_index;

  _next_phase_level++;
}

int PhasesStack::pop() {
  assert(_next_phase_level > 0, "Underflow");

  _next_phase_level--;

  return _phase_indices[_next_phase_level];
}

int PhasesStack::count() const {
  return _next_phase_level;
}


TimePartitions::TimePartitions() {
  _phases = new (ResourceObj::C_HEAP, mtGC) GrowableArray<PausePhase>(INITIAL_CAPACITY, true, mtGC);
  clear();
}

TimePartitions::~TimePartitions() {
  delete _phases;
  _phases = NULL;
}

void TimePartitions::clear() {
  _phases->clear();
  _active_phases.clear();
  _sum_of_pauses = Tickspan();
  _longest_pause = Tickspan();
}

void TimePartitions::report_gc_phase_start(const char* name, const Ticks& time) {
  assert(_phases->length() <= 1000, "Too many recored phases?");

  int level = _active_phases.count();

  PausePhase phase;
  phase.set_level(level);
  phase.set_name(name);
  phase.set_start(time);

  int index = _phases->append(phase);

  _active_phases.push(index);
}

void TimePartitions::update_statistics(GCPhase* phase) {
  // FIXME: This should only be done for pause phases
  if (phase->level() == 0) {
    const Tickspan pause = phase->end() - phase->start();
    _sum_of_pauses += pause;
    _longest_pause = MAX2(pause, _longest_pause);
  }
}

void TimePartitions::report_gc_phase_end(const Ticks& time) {
  int phase_index = _active_phases.pop();
  GCPhase* phase = _phases->adr_at(phase_index);
  phase->set_end(time);
  update_statistics(phase);
}

int TimePartitions::num_phases() const {
  return _phases->length();
}

GCPhase* TimePartitions::phase_at(int index) const {
  assert(index >= 0, "Out of bounds");
  assert(index < _phases->length(), "Out of bounds");

  return _phases->adr_at(index);
}

bool TimePartitions::has_active_phases() {
  return _active_phases.count() > 0;
}

bool TimePartitionPhasesIterator::has_next() {
  return _next < _time_partitions->num_phases();
}

GCPhase* TimePartitionPhasesIterator::next() {
  assert(has_next(), "Must have phases left");
  return _time_partitions->phase_at(_next++);
}


/////////////// Unit tests ///////////////

#ifndef PRODUCT

class TimePartitionPhasesIteratorTest {
 public:
  static void all() {
    one_pause();
    two_pauses();
    one_sub_pause_phase();
    many_sub_pause_phases();
    many_sub_pause_phases2();
    max_nested_pause_phases();
  }

  static void validate_pause_phase(GCPhase* phase, int level, const char* name, const Ticks& start, const Ticks& end) {
    assert(phase->level() == level, "Incorrect level");
    assert(strcmp(phase->name(), name) == 0, "Incorrect name");
    assert(phase->start() == start, "Incorrect start");
    assert(phase->end() == end, "Incorrect end");
  }

  static void one_pause() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase", 2);
    time_partitions.report_gc_phase_end(8);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase", 2, 8);
    assert(time_partitions.sum_of_pauses() == Ticks(8) - Ticks(2), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(8) - Ticks(2), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }

  static void two_pauses() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase1", 2);
    time_partitions.report_gc_phase_end(3);
    time_partitions.report_gc_phase_start("PausePhase2", 4);
    time_partitions.report_gc_phase_end(6);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase1", 2, 3);
    validate_pause_phase(iter.next(), 0, "PausePhase2", 4, 6);

    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(2) - Ticks(0), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }

  static void one_sub_pause_phase() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase", 2);
    time_partitions.report_gc_phase_start("SubPhase", 3);
    time_partitions.report_gc_phase_end(4);
    time_partitions.report_gc_phase_end(5);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase", 2, 5);
    validate_pause_phase(iter.next(), 1, "SubPhase", 3, 4);

    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(3) - Ticks(0), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }

  static void max_nested_pause_phases() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase", 2);
    time_partitions.report_gc_phase_start("SubPhase1", 3);
    time_partitions.report_gc_phase_start("SubPhase2", 4);
    time_partitions.report_gc_phase_start("SubPhase3", 5);
    time_partitions.report_gc_phase_end(6);
    time_partitions.report_gc_phase_end(7);
    time_partitions.report_gc_phase_end(8);
    time_partitions.report_gc_phase_end(9);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase", 2, 9);
    validate_pause_phase(iter.next(), 1, "SubPhase1", 3, 8);
    validate_pause_phase(iter.next(), 2, "SubPhase2", 4, 7);
    validate_pause_phase(iter.next(), 3, "SubPhase3", 5, 6);

    assert(time_partitions.sum_of_pauses() == Ticks(7) - Ticks(0), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(7) - Ticks(0), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }

  static void many_sub_pause_phases() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase", 2);

    time_partitions.report_gc_phase_start("SubPhase1", 3);
    time_partitions.report_gc_phase_end(4);
    time_partitions.report_gc_phase_start("SubPhase2", 5);
    time_partitions.report_gc_phase_end(6);
    time_partitions.report_gc_phase_start("SubPhase3", 7);
    time_partitions.report_gc_phase_end(8);
    time_partitions.report_gc_phase_start("SubPhase4", 9);
    time_partitions.report_gc_phase_end(10);

    time_partitions.report_gc_phase_end(11);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase", 2, 11);
    validate_pause_phase(iter.next(), 1, "SubPhase1", 3, 4);
    validate_pause_phase(iter.next(), 1, "SubPhase2", 5, 6);
    validate_pause_phase(iter.next(), 1, "SubPhase3", 7, 8);
    validate_pause_phase(iter.next(), 1, "SubPhase4", 9, 10);

    assert(time_partitions.sum_of_pauses() == Ticks(9) - Ticks(0), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(9) - Ticks(0), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }

  static void many_sub_pause_phases2() {
    TimePartitions time_partitions;
    time_partitions.report_gc_phase_start("PausePhase", 2);

    time_partitions.report_gc_phase_start("SubPhase1", 3);
    time_partitions.report_gc_phase_start("SubPhase11", 4);
    time_partitions.report_gc_phase_end(5);
    time_partitions.report_gc_phase_start("SubPhase12", 6);
    time_partitions.report_gc_phase_end(7);
    time_partitions.report_gc_phase_end(8);
    time_partitions.report_gc_phase_start("SubPhase2", 9);
    time_partitions.report_gc_phase_start("SubPhase21", 10);
    time_partitions.report_gc_phase_end(11);
    time_partitions.report_gc_phase_start("SubPhase22", 12);
    time_partitions.report_gc_phase_end(13);
    time_partitions.report_gc_phase_end(14);
    time_partitions.report_gc_phase_start("SubPhase3", 15);
    time_partitions.report_gc_phase_end(16);

    time_partitions.report_gc_phase_end(17);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_pause_phase(iter.next(), 0, "PausePhase", 2, 17);
    validate_pause_phase(iter.next(), 1, "SubPhase1", 3, 8);
    validate_pause_phase(iter.next(), 2, "SubPhase11", 4, 5);
    validate_pause_phase(iter.next(), 2, "SubPhase12", 6, 7);
    validate_pause_phase(iter.next(), 1, "SubPhase2", 9, 14);
    validate_pause_phase(iter.next(), 2, "SubPhase21", 10, 11);
    validate_pause_phase(iter.next(), 2, "SubPhase22", 12, 13);
    validate_pause_phase(iter.next(), 1, "SubPhase3", 15, 16);

    assert(time_partitions.sum_of_pauses() == Ticks(15) - Ticks(0), "Incorrect");
    assert(time_partitions.longest_pause() == Ticks(15) - Ticks(0), "Incorrect");

    assert(!iter.has_next(), "Too many elements");
  }
};

class GCTimerTest {
public:
  static void all() {
    gc_start();
    gc_end();
  }

  static void gc_start() {
    GCTimer gc_timer;
    gc_timer.register_gc_start(1);

    assert(gc_timer.gc_start() == 1, "Incorrect");
  }

  static void gc_end() {
    GCTimer gc_timer;
    gc_timer.register_gc_start(1);
    gc_timer.register_gc_end(2);

    assert(gc_timer.gc_end() == 2, "Incorrect");
  }
};

void GCTimerAllTest::all() {
  GCTimerTest::all();
  TimePartitionPhasesIteratorTest::all();
}

#endif

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