barrier/base/CStopwatch.h

#ifndef CSTOPWATCH_H
#define CSTOPWATCH_H

#include "common.h"

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();

    // manipulators

    // 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 and start the stopwatch.  while stopped, no time elapses.
    // stop() does not remove the trigger but start() does, even if
    // the clock was already started.
    void				stop();
    void				start();

    // 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();

    // return the time since the last reset() (or call reset() and
    // return zero if the trigger is set).
    double				getTime();
						operator double();

    // accessors

    // returns true if the watch is stopped
    bool				isStopped() const;

    // return the time since the last reset().  these cannot trigger
    // the clock to start so if the trigger is set it's as if it wasn't.
    double				getTime() const;
						operator double() const;

  private:
    double				getClock() const;

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

#endif