barrier/base/CStopwatch.h

#ifndef CSTOPWATCH_H
#define CSTOPWATCH_H

#include "common.h"

//! A timer class
/*!
This class measures time intervals.  All time interval measurement
should use this class.
*/
class CStopwatch {
public:
	/*!
	The default constructor does an implicit reset() or setTrigger().
	If triggered == false then the clock starts ticking.
	*/
	CStopwatch(bool triggered = false);
	~CStopwatch();

	//! @name manipulators
	//@{

	//! Reset the timer to zero
	/*!
	Set the start time to the current time, returning the time since
	the last reset.  This does not remove the trigger if it's set nor
	does it start a stopped clock.  If the clock is stopped then
	subsequent reset()'s will return 0.
	*/
	double				reset();

	//! Stop the timer
	/*!
	Stop the stopwatch.  The time interval while stopped is not
	counted by the stopwatch.  stop() does not remove the trigger.
	Has no effect if already stopped.
	*/
	void				stop();

	//! Start the timer
	/*!
	Start the stopwatch.  start() removes the trigger, even if the
	stopwatch was already started.
	*/
	void				start();

	//! Stop the timer and set the trigger
	/*!
	setTrigger() stops the clock like stop() except there's an
	implicit start() the next time (non-const) getTime() is called.
	This is useful when you want the clock to start the first time
	you check it.
	*/
	void				setTrigger();

	//! Get elapsed time
	/*!
	Returns the time since the last reset() (or calls reset() and
	returns zero if the trigger is set).
	*/
	double				getTime();
	//! Same as getTime()
						operator double();
	//@}
	//! @name accessors
	//@{

	//! Check if timer is stopped
	/*!
	Returns true if the stopwatch is stopped.
	*/
	bool				isStopped() const;

	// return the time since the last reset().  
	//! Get elapsed time
	/*!
	Returns the time since the last reset().  This cannot trigger the
	stopwatch to start and will not clear the trigger.
	*/
	double				getTime() const;
	//! Same as getTime() const
						operator double() const;
	//@}

private:
	double				getClock() const;

private:
	double				m_mark;
	bool				m_triggered;
	bool				m_stopped;
};

#endif