/*

 * Copyright (c) 1997, 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_RUNTIME_TIMER_HPP

#define SHARE_VM_RUNTIME_TIMER_HPP

#include "utilities/globalDefinitions.hpp"

// Timers for simple measurement.

class elapsedTimer VALUE_OBJ_CLASS_SPEC {

  friend class VMStructs;

 private:

  jlong _counter;

  jlong _start_counter;

  bool  _active;

 public:

  elapsedTimer()             { _active = false; reset(); }

  elapsedTimer(jlong time, jlong timeUnitsPerSecond);

  void add(elapsedTimer t);

  void start();

  void stop();

  void reset()               { _counter = 0; }

  double seconds() const;

  jlong milliseconds() const;

  jlong ticks() const        { return _counter; }

  jlong active_ticks() const;

  bool  is_active() const { return _active; }

};

// TimeStamp is used for recording when an event took place.

class TimeStamp VALUE_OBJ_CLASS_SPEC {

 private:

  jlong _counter;

 public:

  TimeStamp()  { _counter = 0; }

  void clear() { _counter = 0; }

  // has the timestamp been updated since being created or cleared?

  bool is_updated() const { return _counter != 0; }

  // update to current elapsed time

  void update();

  // update to given elapsed time

  void update_to(jlong ticks);

  // returns seconds since updated

  // (must not be in a cleared state:  must have been previously updated)

  double seconds() const;

  jlong milliseconds() const;

  // ticks elapsed between VM start and last update

  jlong ticks() const { return _counter; }

  // ticks elapsed since last update

  jlong ticks_since_update() const;

};

// TraceTime is used for tracing the execution time of a block

// Usage:

//  { TraceTime t("block time")

//    some_code();

//  }

//

class TraceTime: public StackObj {

 private:

  bool          _active;    // do timing

  bool          _verbose;   // report every timing

  elapsedTimer  _t;         // timer

  elapsedTimer* _accum;     // accumulator

 public:

  // Constructors

  TraceTime(const char* title,

            bool doit = true);

  TraceTime(const char* title,

            elapsedTimer* accumulator,

            bool doit = true,

            bool verbose = false);

  ~TraceTime();

  // Accessors

  void set_verbose(bool verbose)  { _verbose = verbose; }

  bool verbose() const            { return _verbose;    }

  // Activation

  void suspend()  { if (_active) _t.stop();  }

  void resume()   { if (_active) _t.start(); }

};

class TraceCPUTime: public StackObj {

 private:

  bool _active;                 // true if times will be measured and printed

  bool _print_cr;               // if true print carriage return at end

  double _starting_user_time;   // user time at start of measurement

  double _starting_system_time; // system time at start of measurement

  double _starting_real_time;   // real time at start of measurement

  outputStream* _logfile;       // output is printed to this stream

  bool _error;                  // true if an error occurred, turns off output

 public:

  TraceCPUTime(bool doit = true,

               bool print_cr = true,

               outputStream *logfile = NULL);

  ~TraceCPUTime();

};

class TimeHelper {

 public:

  static double counter_to_seconds(jlong counter);

  static double counter_to_millis(jlong counter);

};

#endif // SHARE_VM_RUNTIME_TIMER_HPP