/*

 * Copyright (c) 2012, 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/g1/g1CollectedHeap.inline.hpp"

#include "gc_implementation/g1/g1GCPhaseTimes.hpp"

#include "gc_implementation/g1/g1Log.hpp"

// Helper class for avoiding interleaved logging

class LineBuffer: public StackObj {

private:

  static const int BUFFER_LEN = 1024;

  static const int INDENT_CHARS = 3;

  char _buffer[BUFFER_LEN];

  int _indent_level;

  int _cur;

  void vappend(const char* format, va_list ap) {

    int res = vsnprintf(&_buffer[_cur], BUFFER_LEN - _cur, format, ap);

    if (res != -1) {

      _cur += res;

    } else {

      DEBUG_ONLY(warning("buffer too small in LineBuffer");)

      _buffer[BUFFER_LEN -1] = 0;

      _cur = BUFFER_LEN; // vsnprintf above should not add to _buffer if we are called again

    }

  }

public:

  explicit LineBuffer(int indent_level): _indent_level(indent_level), _cur(0) {

    for (; (_cur < BUFFER_LEN && _cur < (_indent_level * INDENT_CHARS)); _cur++) {

      _buffer[_cur] = ' ';

    }

  }

#ifndef PRODUCT

  ~LineBuffer() {

    assert(_cur == _indent_level * INDENT_CHARS, "pending data in buffer - append_and_print_cr() not called?");

  }

#endif

  void append(const char* format, ...) {

    va_list ap;

    va_start(ap, format);

    vappend(format, ap);

    va_end(ap);

  }

  void append_and_print_cr(const char* format, ...) {

    va_list ap;

    va_start(ap, format);

    vappend(format, ap);

    va_end(ap);

    gclog_or_tty->print_cr("%s", _buffer);

    _cur = _indent_level * INDENT_CHARS;

  }

};

G1GCPhaseTimes::G1GCPhaseTimes(uint max_gc_threads) :

  _max_gc_threads(max_gc_threads),

  _min_clear_cc_time_ms(-1.0),

  _max_clear_cc_time_ms(-1.0),

  _cur_clear_cc_time_ms(0.0),

  _cum_clear_cc_time_ms(0.0),

  _num_cc_clears(0L)

{

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

  _par_last_gc_worker_start_times_ms = new double[_max_gc_threads];

  _par_last_ext_root_scan_times_ms = new double[_max_gc_threads];

  _par_last_satb_filtering_times_ms = new double[_max_gc_threads];

  _par_last_update_rs_times_ms = new double[_max_gc_threads];

  _par_last_update_rs_processed_buffers = new double[_max_gc_threads];

  _par_last_scan_rs_times_ms = new double[_max_gc_threads];

  _par_last_obj_copy_times_ms = new double[_max_gc_threads];

  _par_last_termination_times_ms = new double[_max_gc_threads];

  _par_last_termination_attempts = new double[_max_gc_threads];

  _par_last_gc_worker_end_times_ms = new double[_max_gc_threads];

  _par_last_gc_worker_times_ms = new double[_max_gc_threads];

  _par_last_gc_worker_other_times_ms = new double[_max_gc_threads];

}

void G1GCPhaseTimes::note_gc_start(double pause_start_time_sec, uint active_gc_threads,

  bool is_young_gc, bool is_initial_mark_gc, GCCause::Cause gc_cause) {

  assert(active_gc_threads > 0, "The number of threads must be > 0");

  assert(active_gc_threads <= _max_gc_threads, "The number of active threads must be <= the max nubmer of threads");

  _active_gc_threads = active_gc_threads;

  _pause_start_time_sec = pause_start_time_sec;

  _is_young_gc = is_young_gc;

  _is_initial_mark_gc = is_initial_mark_gc;

  _gc_cause = gc_cause;

#ifdef ASSERT

  // initialise the timing data to something well known so that we can spot

  // if something is not set properly

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

    _par_last_gc_worker_start_times_ms[i] = -1234.0;

    _par_last_ext_root_scan_times_ms[i] = -1234.0;

    _par_last_satb_filtering_times_ms[i] = -1234.0;

    _par_last_update_rs_times_ms[i] = -1234.0;

    _par_last_update_rs_processed_buffers[i] = -1234.0;

    _par_last_scan_rs_times_ms[i] = -1234.0;

    _par_last_obj_copy_times_ms[i] = -1234.0;

    _par_last_termination_times_ms[i] = -1234.0;

    _par_last_termination_attempts[i] = -1234.0;

    _par_last_gc_worker_end_times_ms[i] = -1234.0;

    _par_last_gc_worker_times_ms[i] = -1234.0;

    _par_last_gc_worker_other_times_ms[i] = -1234.0;

  }

#endif

}

void G1GCPhaseTimes::note_gc_end(double pause_end_time_sec) {

  if (G1Log::fine()) {

    double pause_time_ms = (pause_end_time_sec - _pause_start_time_sec) * MILLIUNITS;

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

      _par_last_gc_worker_times_ms[i] = _par_last_gc_worker_end_times_ms[i] -

        _par_last_gc_worker_start_times_ms[i];

      double worker_known_time = _par_last_ext_root_scan_times_ms[i] +

        _par_last_satb_filtering_times_ms[i] +

        _par_last_update_rs_times_ms[i] +

        _par_last_scan_rs_times_ms[i] +

        _par_last_obj_copy_times_ms[i] +

        _par_last_termination_times_ms[i];

      _par_last_gc_worker_other_times_ms[i] = _par_last_gc_worker_times_ms[i] -

        worker_known_time;

    }

    print(pause_time_ms);

  }

}

void G1GCPhaseTimes::print_par_stats(int level,

                                        const char* str,

                                        double* data,

                                        bool showDecimals) {

  double min = data[0], max = data[0];

  double total = 0.0;

  LineBuffer buf(level);

  buf.append("[%s (ms):", str);

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

    double val = data[i];

    if (val < min)

      min = val;

    if (val > max)

      max = val;

    total += val;

    if (G1Log::finest()) {

      if (showDecimals) {

        buf.append("  %.1lf", val);

      } else {

        buf.append("  %d", (int)val);

      }

    }

  }

  if (G1Log::finest()) {

    buf.append_and_print_cr("");

  }

  double avg = total / (double) _active_gc_threads;

  if (showDecimals) {

    buf.append_and_print_cr(" Min: %.1lf, Avg: %.1lf, Max: %.1lf, Diff: %.1lf, Sum: %.1lf]",

      min, avg, max, max - min, total);

  } else {

    buf.append_and_print_cr(" Min: %d, Avg: %d, Max: %d, Diff: %d, Sum: %d]",

      (int)min, (int)avg, (int)max, (int)max - (int)min, (int)total);

  }

}

void G1GCPhaseTimes::print_stats(int level, const char* str, double value) {

  LineBuffer(level).append_and_print_cr("[%s: %.1lf ms]", str, value);

}

void G1GCPhaseTimes::print_stats(int level, const char* str, double value, int workers) {

  LineBuffer(level).append_and_print_cr("[%s: %.1lf ms, GC Workers: %d]", str, value, workers);

}

void G1GCPhaseTimes::print_stats(int level, const char* str, int value) {

  LineBuffer(level).append_and_print_cr("[%s: %d]", str, value);

}

double G1GCPhaseTimes::avg_value(double* data) {

  if (G1CollectedHeap::use_parallel_gc_threads()) {

    double ret = 0.0;

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

      ret += data[i];

    }

    return ret / (double) _active_gc_threads;

  } else {

    return data[0];

  }

}

double G1GCPhaseTimes::max_value(double* data) {

  if (G1CollectedHeap::use_parallel_gc_threads()) {

    double ret = data[0];

    for (uint i = 1; i < _active_gc_threads; ++i) {

      if (data[i] > ret) {

        ret = data[i];

      }

    }

    return ret;

  } else {

    return data[0];

  }

}

double G1GCPhaseTimes::sum_of_values(double* data) {

  if (G1CollectedHeap::use_parallel_gc_threads()) {

    double sum = 0.0;

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

      sum += data[i];

    }

    return sum;

  } else {

    return data[0];

  }

}

double G1GCPhaseTimes::max_sum(double* data1, double* data2) {

  double ret = data1[0] + data2[0];

  if (G1CollectedHeap::use_parallel_gc_threads()) {

    for (uint i = 1; i < _active_gc_threads; ++i) {

      double data = data1[i] + data2[i];

      if (data > ret) {

        ret = data;

      }

    }

  }

  return ret;

}

void G1GCPhaseTimes::collapse_par_times() {

    _ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);

    _satb_filtering_time = avg_value(_par_last_satb_filtering_times_ms);

    _update_rs_time = avg_value(_par_last_update_rs_times_ms);

    _update_rs_processed_buffers =

      sum_of_values(_par_last_update_rs_processed_buffers);

    _scan_rs_time = avg_value(_par_last_scan_rs_times_ms);

    _obj_copy_time = avg_value(_par_last_obj_copy_times_ms);

    _termination_time = avg_value(_par_last_termination_times_ms);

}

double G1GCPhaseTimes::accounted_time_ms() {

    // Subtract the root region scanning wait time. It's initialized to

    // zero at the start of the pause.

    double misc_time_ms = _root_region_scan_wait_time_ms;

    misc_time_ms += _cur_collection_par_time_ms;

    // Now subtract the time taken to fix up roots in generated code

    misc_time_ms += _cur_collection_code_root_fixup_time_ms;

    // Subtract the time taken to clean the card table from the

    // current value of "other time"

    misc_time_ms += _cur_clear_ct_time_ms;

    return misc_time_ms;

}

void G1GCPhaseTimes::print(double pause_time_ms) {

  if (PrintGCTimeStamps) {

    gclog_or_tty->stamp();

    gclog_or_tty->print(": ");

  }

  GCCauseString gc_cause_str = GCCauseString("GC pause", _gc_cause)

    .append(_is_young_gc ? " (young)" : " (mixed)")

    .append(_is_initial_mark_gc ? " (initial-mark)" : "");

  gclog_or_tty->print_cr("[%s, %3.7f secs]", (const char*)gc_cause_str, pause_time_ms / 1000.0);

  if (!G1Log::finer()) {

    return;

  }

  if (_root_region_scan_wait_time_ms > 0.0) {

    print_stats(1, "Root Region Scan Waiting", _root_region_scan_wait_time_ms);

  }

  if (G1CollectedHeap::use_parallel_gc_threads()) {

    print_stats(1, "Parallel Time", _cur_collection_par_time_ms, _active_gc_threads);

    print_par_stats(2, "GC Worker Start", _par_last_gc_worker_start_times_ms);

    print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);

    if (_satb_filtering_time > 0.0) {

      print_par_stats(2, "SATB Filtering", _par_last_satb_filtering_times_ms);

    }

    print_par_stats(2, "Update RS", _par_last_update_rs_times_ms);

    if (G1Log::finest()) {

      print_par_stats(3, "Processed Buffers", _par_last_update_rs_processed_buffers,

        false /* showDecimals */);

    }

    print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);

    print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);

    print_par_stats(2, "Termination", _par_last_termination_times_ms);

    if (G1Log::finest()) {

      print_par_stats(3, "Termination Attempts", _par_last_termination_attempts,

        false /* showDecimals */);

    }

    print_par_stats(2, "GC Worker Other", _par_last_gc_worker_other_times_ms);

    print_par_stats(2, "GC Worker Total", _par_last_gc_worker_times_ms);

    print_par_stats(2, "GC Worker End", _par_last_gc_worker_end_times_ms);

  } else {

    print_stats(1, "Ext Root Scanning", _ext_root_scan_time);

    if (_satb_filtering_time > 0.0) {

      print_stats(1, "SATB Filtering", _satb_filtering_time);

    }

    print_stats(1, "Update RS", _update_rs_time);

    if (G1Log::finest()) {

      print_stats(2, "Processed Buffers", (int)_update_rs_processed_buffers);

    }

    print_stats(1, "Scan RS", _scan_rs_time);

    print_stats(1, "Object Copying", _obj_copy_time);

  }

  print_stats(1, "Code Root Fixup", _cur_collection_code_root_fixup_time_ms);

  print_stats(1, "Clear CT", _cur_clear_ct_time_ms);

  if (Verbose && G1Log::finest()) {

    print_stats(1, "Cur Clear CC", _cur_clear_cc_time_ms);

    print_stats(1, "Cum Clear CC", _cum_clear_cc_time_ms);

    print_stats(1, "Min Clear CC", _min_clear_cc_time_ms);

    print_stats(1, "Max Clear CC", _max_clear_cc_time_ms);

    if (_num_cc_clears > 0) {

      print_stats(1, "Avg Clear CC", _cum_clear_cc_time_ms / ((double)_num_cc_clears));

    }

  }

  double misc_time_ms = pause_time_ms - accounted_time_ms();

  print_stats(1, "Other", misc_time_ms);

  print_stats(2, "Choose CSet",

    (_recorded_young_cset_choice_time_ms +

    _recorded_non_young_cset_choice_time_ms));

  print_stats(2, "Ref Proc", _cur_ref_proc_time_ms);

  print_stats(2, "Ref Enq", _cur_ref_enq_time_ms);

  print_stats(2, "Free CSet",

    (_recorded_young_free_cset_time_ms +

    _recorded_non_young_free_cset_time_ms));

}

void G1GCPhaseTimes::record_cc_clear_time_ms(double ms) {

  if (!(Verbose && G1Log::finest())) {

    return;

  }

  if (_min_clear_cc_time_ms < 0.0 || ms <= _min_clear_cc_time_ms) {

    _min_clear_cc_time_ms = ms;

  }

  if (_max_clear_cc_time_ms < 0.0 || ms >= _max_clear_cc_time_ms) {

    _max_clear_cc_time_ms = ms;

  }

  _cur_clear_cc_time_ms = ms;

  _cum_clear_cc_time_ms += ms;

  _num_cc_clears++;

}