Java example source code file (gcTimer.hpp)

This example Java source code file (gcTimer.hpp) 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.

Learn more about this Java project at its project page.

Java - Java tags/keywords

concurrentgctimer, concurrentphase, gcphase, gctimer, growablearray, initial_capacity, pausephase, phasesstack, share_vm_gc_implementation_shared_gctimer_hpp, ticks, ticks::now, tickspan, timepartitionphasesiterator, timepartitions

The gcTimer.hpp 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.
 *
 */

#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_GCTIMER_HPP
#define SHARE_VM_GC_IMPLEMENTATION_SHARED_GCTIMER_HPP

#include "memory/allocation.hpp"
#include "prims/jni_md.h"
#include "utilities/macros.hpp"
#include "utilities/ticks.hpp"

class ConcurrentPhase;
class GCPhase;
class PausePhase;

template <class E> class GrowableArray;

class PhaseVisitor {
 public:
  virtual void visit(GCPhase* phase) = 0;
  virtual void visit(PausePhase* phase) { visit((GCPhase*)phase); }
  virtual void visit(ConcurrentPhase* phase) { visit((GCPhase*)phase); }
};

class GCPhase {
  const char* _name;
  int _level;
  Ticks _start;
  Ticks _end;

 public:
  void set_name(const char* name) { _name = name; }
  const char* name() const { return _name; }

  int level() const { return _level; }
  void set_level(int level) { _level = level; }

  const Ticks start() const { return _start; }
  void set_start(const Ticks& time) { _start = time; }

  const Ticks end() const { return _end; }
  void set_end(const Ticks& time) { _end = time; }

  virtual void accept(PhaseVisitor* visitor) = 0;
};

class PausePhase : public GCPhase {
 public:
  void accept(PhaseVisitor* visitor) {
    visitor->visit(this);
  }
};

class ConcurrentPhase : public GCPhase {
  void accept(PhaseVisitor* visitor) {
    visitor->visit(this);
  }
};

class PhasesStack {
 public:
  // FIXME: Temporary set to 5 (used to be 4), since Reference processing needs it.
  static const int PHASE_LEVELS = 5;

 private:
  int _phase_indices[PHASE_LEVELS];
  int _next_phase_level;

 public:
  PhasesStack() { clear(); }
  void clear();

  void push(int phase_index);
  int pop();
  int count() const;
};

class TimePartitions {
  static const int INITIAL_CAPACITY = 10;

  // Currently we only support pause phases.
  GrowableArray<PausePhase>* _phases;
  PhasesStack _active_phases;

  Tickspan _sum_of_pauses;
  Tickspan _longest_pause;

 public:
  TimePartitions();
  ~TimePartitions();
  void clear();

  void report_gc_phase_start(const char* name, const Ticks& time);
  void report_gc_phase_end(const Ticks& time);

  int num_phases() const;
  GCPhase* phase_at(int index) const;

  const Tickspan sum_of_pauses() const { return _sum_of_pauses; }
  const Tickspan longest_pause() const { return _longest_pause; }

  bool has_active_phases();
 private:
  void update_statistics(GCPhase* phase);
};

class PhasesIterator {
 public:
  virtual bool has_next() = 0;
  virtual GCPhase* next() = 0;
};

class GCTimer : public ResourceObj {
  NOT_PRODUCT(friend class GCTimerTest;)
 protected:
  Ticks _gc_start;
  Ticks _gc_end;
  TimePartitions _time_partitions;

 public:
  virtual void register_gc_start(const Ticks& time = Ticks::now());
  virtual void register_gc_end(const Ticks& time = Ticks::now());

  void register_gc_phase_start(const char* name, const Ticks& time);
  void register_gc_phase_end(const Ticks& time);

  const Ticks gc_start() const { return _gc_start; }
  const Ticks gc_end() const { return _gc_end; }

  TimePartitions* time_partitions() { return &_time_partitions; }

 protected:
  void register_gc_pause_start(const char* name, const Ticks& time = Ticks::now());
  void register_gc_pause_end(const Ticks& time = Ticks::now());
};

class STWGCTimer : public GCTimer {
 public:
  virtual void register_gc_start(const Ticks& time = Ticks::now());
  virtual void register_gc_end(const Ticks& time = Ticks::now());
};

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

class TimePartitionPhasesIterator {
  TimePartitions* _time_partitions;
  int _next;

 public:
  TimePartitionPhasesIterator(TimePartitions* time_partitions) : _time_partitions(time_partitions), _next(0) { }

  virtual bool has_next();
  virtual GCPhase* next();
};


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

#ifndef PRODUCT

class GCTimerAllTest {
 public:
  static void all();
};

#endif

#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_GCTIMER_HPP