/*

 * Copyright (c) 2012, 2018, 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/shared/gcTimer.hpp"

#include "utilities/growableArray.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, const Ticks& time) {

  assert(!_is_concurrent_phase_active, "A pause phase can't be started while a concurrent phase is active.");

  GCTimer::register_gc_pause_start(name, time);

}

void ConcurrentGCTimer::register_gc_pause_end(const Ticks& time) {

  assert(!_is_concurrent_phase_active, "A pause phase can't be ended while a concurrent phase is active.");

  GCTimer::register_gc_pause_end(time);

}

void ConcurrentGCTimer::register_gc_concurrent_start(const char* name, const Ticks& time) {

  assert(!_is_concurrent_phase_active, "A concurrent phase is already active.");

  _time_partitions.report_gc_phase_start(name, time, GCPhase::ConcurrentPhaseType);

  _is_concurrent_phase_active = true;

}

void ConcurrentGCTimer::register_gc_concurrent_end(const Ticks& time) {

  assert(_is_concurrent_phase_active, "A concurrent phase is not active.");

  _time_partitions.report_gc_phase_end(time, GCPhase::ConcurrentPhaseType);

  _is_concurrent_phase_active = false;

}

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<GCPhase>(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, GCPhase::PhaseType type) {

  assert(_phases->length() <= 1000, "Too many recored phases?");

  int level = _active_phases.count();

  GCPhase phase;

  phase.set_type(type);

  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) {

  if ((phase->type() == GCPhase::PausePhaseType) && (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, GCPhase::PhaseType type) {

  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();

    one_concurrent();

  }

  static void validate_gc_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_gc_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_gc_phase(iter.next(), 0, "PausePhase1", 2, 3);

    validate_gc_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_gc_phase(iter.next(), 0, "PausePhase", 2, 5);

    validate_gc_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_gc_phase(iter.next(), 0, "PausePhase", 2, 9);

    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 8);

    validate_gc_phase(iter.next(), 2, "SubPhase2", 4, 7);

    validate_gc_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_gc_phase(iter.next(), 0, "PausePhase", 2, 11);

    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 4);

    validate_gc_phase(iter.next(), 1, "SubPhase2", 5, 6);

    validate_gc_phase(iter.next(), 1, "SubPhase3", 7, 8);

    validate_gc_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_gc_phase(iter.next(), 0, "PausePhase", 2, 17);

    validate_gc_phase(iter.next(), 1, "SubPhase1", 3, 8);

    validate_gc_phase(iter.next(), 2, "SubPhase11", 4, 5);

    validate_gc_phase(iter.next(), 2, "SubPhase12", 6, 7);

    validate_gc_phase(iter.next(), 1, "SubPhase2", 9, 14);

    validate_gc_phase(iter.next(), 2, "SubPhase21", 10, 11);

    validate_gc_phase(iter.next(), 2, "SubPhase22", 12, 13);

    validate_gc_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");

  }

  static void one_concurrent() {

    TimePartitions time_partitions;

    time_partitions.report_gc_phase_start("ConcurrentPhase", 2, GCPhase::ConcurrentPhaseType);

    time_partitions.report_gc_phase_end(8, GCPhase::ConcurrentPhaseType);

    TimePartitionPhasesIterator iter(&time_partitions);

    validate_gc_phase(iter.next(), 0, "ConcurrentPhase", 2, 8);

    // ConcurrentPhaseType should not affect to both 'sum_of_pauses()' and 'longest_pause()'.

    assert(time_partitions.sum_of_pauses() == Tickspan(), "Incorrect");

    assert(time_partitions.longest_pause() == Tickspan(), "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);

  }

  static void gc_end() {

    GCTimer gc_timer;

    gc_timer.register_gc_start(1);

    gc_timer.register_gc_end(2);

  }

};

void GCTimer_test() {

  GCTimerTest::all();

  TimePartitionPhasesIteratorTest::all();

}

#endif