/*

 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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/workerDataArray.inline.hpp"

#include "gc/shenandoah/shenandoahCollectorPolicy.hpp"

#include "gc/shenandoah/shenandoahPhaseTimings.hpp"

#include "gc/shenandoah/shenandoahHeap.hpp"

#include "gc/shenandoah/shenandoahHeuristics.hpp"

#include "gc/shenandoah/shenandoahUtils.hpp"

#include "utilities/ostream.hpp"

#define GC_PHASE_DECLARE_NAME(type, title) \

  title,

const char* ShenandoahPhaseTimings::_phase_names[] = {

  SHENANDOAH_GC_PHASE_DO(GC_PHASE_DECLARE_NAME)

};

#undef GC_PHASE_DECLARE_NAME

ShenandoahPhaseTimings::ShenandoahPhaseTimings() : _policy(NULL) {

  uint max_workers = MAX2(ConcGCThreads, ParallelGCThreads);

  _worker_times = new ShenandoahWorkerTimings(max_workers);

  _termination_times = new ShenandoahTerminationTimings(max_workers);

  _policy = ShenandoahHeap::heap()->shenandoah_policy();

  assert(_policy != NULL, "Can not be NULL");

}

void ShenandoahPhaseTimings::record_phase_start(Phase phase) {

  _timing_data[phase]._start = os::elapsedTime();

}

void ShenandoahPhaseTimings::record_phase_end(Phase phase) {

  assert(_policy != NULL, "Not yet initialized");

  double end = os::elapsedTime();

  double elapsed = end - _timing_data[phase]._start;

  if (!_policy->is_at_shutdown()) {

    _timing_data[phase]._secs.add(elapsed);

  }

  ShenandoahHeap::heap()->heuristics()->record_phase_time(phase, elapsed);

}

void ShenandoahPhaseTimings::record_phase_time(Phase phase, double time) {

  assert(_policy != NULL, "Not yet initialized");

  if (!_policy->is_at_shutdown()) {

    _timing_data[phase]._secs.add(time);

  }

}

void ShenandoahPhaseTimings::record_workers_start(Phase phase) {

  for (uint i = 0; i < GCParPhasesSentinel; i++) {

    _worker_times->reset(i);

  }

}

void ShenandoahPhaseTimings::record_workers_end(Phase phase) {

  if (_policy->is_at_shutdown()) {

    // Do not record the past-shutdown events

    return;

  }

  guarantee(phase == init_evac ||

            phase == scan_roots ||

            phase == update_roots ||

            phase == init_traversal_gc_work ||

            phase == final_traversal_gc_work ||

            phase == final_traversal_update_roots ||

            phase == final_update_refs_roots ||

            phase == full_gc_roots ||

            phase == degen_gc_update_roots ||

            phase == _num_phases,

            "only in these phases we can add per-thread phase times");

  if (phase != _num_phases) {

    // Merge _phase_time to counters below the given phase.

    for (uint i = 0; i < GCParPhasesSentinel; i++) {

      double t = _worker_times->average(i);

      _timing_data[phase + i + 1]._secs.add(t);

    }

  }

}

void ShenandoahPhaseTimings::print_on(outputStream* out) const {

  out->cr();

  out->print_cr("GC STATISTICS:");

  out->print_cr("  \"(G)\" (gross) pauses include VM time: time to notify and block threads, do the pre-");

  out->print_cr("        and post-safepoint housekeeping. Use -Xlog:safepoint+stats to dissect.");

  out->print_cr("  \"(N)\" (net) pauses are the times spent in the actual GC code.");

  out->print_cr("  \"a\" is average time for each phase, look at levels to see if average makes sense.");

  out->print_cr("  \"lvls\" are quantiles: 0%% (minimum), 25%%, 50%% (median), 75%%, 100%% (maximum).");

  out->cr();

  for (uint i = 0; i < _num_phases; i++) {

    if (_timing_data[i]._secs.maximum() != 0) {

      print_summary_sd(out, _phase_names[i], &(_timing_data[i]._secs));

    }

  }

}

void ShenandoahPhaseTimings::print_summary_sd(outputStream* out, const char* str, const HdrSeq* seq) const {

  out->print_cr("%-27s = %8.2lf s (a = %8.0lf us) (n = " INT32_FORMAT_W(5) ") (lvls, us = %8.0lf, %8.0lf, %8.0lf, %8.0lf, %8.0lf)",

          str,

          seq->sum(),

          seq->avg() * 1000000.0,

          seq->num(),

          seq->percentile(0)  * 1000000.0,

          seq->percentile(25) * 1000000.0,

          seq->percentile(50) * 1000000.0,

          seq->percentile(75) * 1000000.0,

          seq->maximum() * 1000000.0

  );

}

ShenandoahWorkerTimings::ShenandoahWorkerTimings(uint max_gc_threads) :

        _max_gc_threads(max_gc_threads)

{

  assert(max_gc_threads > 0, "Must have some GC threads");

#define GC_PAR_PHASE_DECLARE_WORKER_DATA(type, title) \

  _gc_par_phases[ShenandoahPhaseTimings::type] = new WorkerDataArray<double>(max_gc_threads, title);

  // Root scanning phases

  SHENANDOAH_GC_PAR_PHASE_DO(GC_PAR_PHASE_DECLARE_WORKER_DATA)

#undef GC_PAR_PHASE_DECLARE_WORKER_DATA

}

// record the time a phase took in seconds

void ShenandoahWorkerTimings::record_time_secs(ShenandoahPhaseTimings::GCParPhases phase, uint worker_i, double secs) {

  _gc_par_phases[phase]->set(worker_i, secs);

}

double ShenandoahWorkerTimings::average(uint i) const {

  return _gc_par_phases[i]->average();

}

void ShenandoahWorkerTimings::reset(uint i) {

  _gc_par_phases[i]->reset();

}

void ShenandoahWorkerTimings::print() const {

  for (uint i = 0; i < ShenandoahPhaseTimings::GCParPhasesSentinel; i++) {

    _gc_par_phases[i]->print_summary_on(tty);

  }

}

ShenandoahTerminationTimings::ShenandoahTerminationTimings(uint max_gc_threads) {

  _gc_termination_phase = new WorkerDataArray<double>(max_gc_threads, "Task Termination (ms):");

}

void ShenandoahTerminationTimings::record_time_secs(uint worker_id, double secs) {

  if (_gc_termination_phase->get(worker_id) == WorkerDataArray<double>::uninitialized()) {

    _gc_termination_phase->set(worker_id, secs);

  } else {

    // worker may re-enter termination phase

    _gc_termination_phase->add(worker_id, secs);

  }

}

void ShenandoahTerminationTimings::print() const {

  _gc_termination_phase->print_summary_on(tty);

}

double ShenandoahTerminationTimings::average() const {

  return _gc_termination_phase->average();

}

void ShenandoahTerminationTimings::reset() {

  _gc_termination_phase->reset();

}