text: //
  // Stopwatch.h
  //
  // $Id: //poco/1.4/Foundation/include/Poco/Stopwatch.h#1 $
  //
  // Library: Foundation
  // Package: DateTime
  // Module:  Stopwatch
  //
  // Definition of the Stopwatch class.
  //
  // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
  // and Contributors.
  //
  // Permission is hereby granted, free of charge, to any person or organization
  // obtaining a copy of the software and accompanying documentation covered by
  // this license (the "Software") to use, reproduce, display, distribute,
  // execute, and transmit the Software, and to prepare derivative works of the
  // Software, and to permit third-parties to whom the Software is furnished to
  // do so, all subject to the following:
  // 
  // The copyright notices in the Software and this entire statement, including
  // the above license grant, this restriction and the following disclaimer,
  // must be included in all copies of the Software, in whole or in part, and
  // all derivative works of the Software, unless such copies or derivative
  // works are solely in the form of machine-executable object code generated by
  // a source language processor.
  // 
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  // DEALINGS IN THE SOFTWARE.
  //
  
  
  #ifndef Foundation_Stopwatch_INCLUDED
  #define Foundation_Stopwatch_INCLUDED
  
  
  #include "Poco/Foundation.h"
  #include "Poco/Timestamp.h"
  
  
  namespace Poco {
  
  
  class Foundation_API Stopwatch
  	/// A simple facility to measure time intervals
  	/// with microsecond resolution.
  	///
  	/// Note that Stopwatch is based on the Timestamp
  	/// class. Therefore, if during a Stopwatch run,
  	/// the system time is changed, the measured time
  	/// will not be correct.
  {
  public:
  	Stopwatch();
  	~Stopwatch();
  
  	void start();
  		/// Starts (or restarts) the stopwatch.
  		
  	void stop();
  		/// Stops or pauses the stopwatch.
  	
  	void reset();
  		/// Resets the stopwatch.
  		
  	void restart();
  		/// Resets and starts the stopwatch.
  		
  	Timestamp::TimeDiff elapsed() const;
  		/// Returns the elapsed time in microseconds
  		/// since the stopwatch started.
  		
  	int elapsedSeconds() const;
  		/// Returns the number of seconds elapsed
  		/// since the stopwatch started.
  
  	static Timestamp::TimeVal resolution();
  		/// Returns the resolution of the stopwatch.
  
  private:
  	Stopwatch(const Stopwatch&);
  	Stopwatch& operator = (const Stopwatch&);
  
  	Timestamp           _start;
  	Timestamp::TimeDiff _elapsed;
  	bool                _running;
  };
  
  
  //
  // inlines
  //
  inline void Stopwatch::start()
  {
  	if (!_running)
  	{
  		_start.update();
  		_running = true;
  	}
  }
  
  
  inline void Stopwatch::stop()
  {
  	if (_running)
  	{
  		Timestamp current;
  		_elapsed += current - _start;
  		_running = false;
  	}
  }
  
  
  inline int Stopwatch::elapsedSeconds() const
  {
  	return int(elapsed()/resolution());
  }
  
  
  inline Timestamp::TimeVal Stopwatch::resolution()
  {
  	return Timestamp::resolution();
  }
  
  
  } // namespace Poco
  
  
  #endif // Foundation_Stopwatch_INCLUDED
  