src/share/vm/utilities/ticks.hpp

/*
 * Copyright (c) 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
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#ifndef SHARE_VM_UTILITIES_TICKS_HPP
#define SHARE_VM_UTILITIES_TICKS_HPP

#include "memory/allocation.hpp"
#include "utilities/globalDefinitions.hpp"

class Ticks;

class Tickspan VALUE_OBJ_CLASS_SPEC {
  friend class Ticks;
  friend Tickspan operator-(const Ticks& end, const Ticks& start);

 private:
  jlong _span_ticks;

  Tickspan(const Ticks& end, const Ticks& start);

 public:
  Tickspan() : _span_ticks(0) {}

  Tickspan& operator+=(const Tickspan& rhs) {
    _span_ticks += rhs._span_ticks;
    return *this;
  }

  jlong value() const {
    return _span_ticks;
  }

};

class Ticks VALUE_OBJ_CLASS_SPEC {
 private:
  jlong _stamp_ticks;

 public:
  Ticks() : _stamp_ticks(0) {
    assert((_stamp_ticks = invalid_time_stamp) == invalid_time_stamp,
      "initial unstamped time value assignment");
  }

  Ticks& operator+=(const Tickspan& span) {
    _stamp_ticks += span.value();
    return *this;
  }

  Ticks& operator-=(const Tickspan& span) {
    _stamp_ticks -= span.value();
    return *this;
  }

  void stamp();

  jlong value() const {
    return _stamp_ticks;
  }

  static const Ticks now();

#ifdef ASSERT
  static const jlong invalid_time_stamp;
#endif

#ifndef PRODUCT
  // only for internal use by GC VM tests
  friend class TimePartitionPhasesIteratorTest;
  friend class GCTimerTest;

 private:
  // implicit type conversion
  Ticks(int ticks) : _stamp_ticks(ticks) {}

#endif // !PRODUCT

};

class TicksToTimeHelper : public AllStatic {
 public:
  enum Unit {
    SECONDS = 1,
    MILLISECONDS = 1000
  };
  static double seconds(const Tickspan& span);
  static jlong milliseconds(const Tickspan& span);
};

#endif // SHARE_VM_UTILITIES_TICKS_HPP