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otk::Timer Class Reference

#include <timer.hh>

List of all members.

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Detailed Description

The Timer class implements timed callbacks.

The Timer class can be used to have a callback fire after a given time interval. A created Timer will fire repetitively until it is destroyed.

Definition at line 32 of file timer.hh.

Public Types
typedef void(*	TimeoutHandler )(void *data)
	Data type of Timer callback.
Public Methods
	Timer (long delay, TimeoutHandler cb, void *data)
	Constructs a new running timer and queues it.
void	operator delete (void *self)
	Overloaded delete so we can leave deleted objects in queue for later reap.
Static Public Methods
void	dispatchTimers (bool wait=true)
	Dispatches all elligible timers, then optionally waits for X events.
bool	nearestTimeout (struct timeval &tm)
	Returns a relative timeval (to pass select) of the next timer.
void	initialize (void)
	Initializes internal data before use.
void	destroy (void)
	Deletes all waiting timers.
Private Types
typedef std::priority_queue< Timer *, std::vector< Timer * >, TimerCompare >	TimerQ
Static Private Methods
void	realDelete (Timer *self)
	Really delete something (not just flag for later).
void	timevalAdd (timeval &a, long msec)
	Adds a millisecond delay to a timeval structure.
Private Attributes
long	_delay
	Milliseconds between timer firings.
TimeoutHandler	_action
	Callback for timer expiry.
void *	_data
	Data sent to callback.
bool	_del_me
	We overload the delete operator to just set this to true.
timeval	_last
	The time the last fire should've been at.
timeval	_timeout
	When this timer will next trigger.
Static Private Attributes
TimerQ	_q
	Queue of pending timers.
timeval	_nearest_timeout
	Time next timer will expire.
timeval	_now
	Time at start of current processing loop.
Friends
struct	TimerCompare

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Member Typedef Documentation

typedef void(* otk::Timer::TimeoutHandler)(void *data)

Data type of Timer callback. Definition at line 35 of file timer.hh.

typedef std::priority_queue<Timer*, std::vector<Timer*>, TimerCompare> otk::Timer::TimerQ [private]

Definition at line 48 of file timer.hh.

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Constructor & Destructor Documentation

otk::Timer::Timer (  long    delay, TimeoutHandler    cb, void *    data )

Constructs a new running timer and queues it. Parameters: delay  Time in milliseconds between firings cb  The function to be called on fire. data  Data to be passed to the callback on fire. Definition at line 103 of file timer.cc. References _q, and timevalAdd(). : _delay(delay), _action(action), _data(data), _del_me(false), _last(_now), _timeout(_now) { timevalAdd(_timeout, delay); _q.push(this); }

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Member Function Documentation

void otk::Timer::destroy (  void    )  [static]

Deletes all waiting timers. Definition at line 134 of file timer.cc. References _q, and realDelete(). Referenced by ob::Openbox::~Openbox(). { while(!_q.empty()) { realDelete(_q.top()); _q.pop(); } }

void otk::Timer::dispatchTimers (  bool    wait = true )  [static]

Dispatches all elligible timers, then optionally waits for X events. Parameters: wait  Whether to wait for X events after processing timers. Definition at line 53 of file timer.cc. References _action, _data, _del_me, _delay, _last, _nearest_timeout, _now, _q, _timeout, nearestTimeout(), realDelete(), and timevalAdd(). Referenced by ob::Openbox::eventLoop(). { fd_set selset; int fd; timeval next; Timer *curr; gettimeofday(&_now, NULL); _nearest_timeout = _now; _nearest_timeout.tv_sec += 10000; while (!_q.empty()) { curr = _q.top(); /* since we overload the destructor to keep from removing from the middle of the priority queue, set _del_me, we have to do our real delete in here. */ if (curr->_del_me) { _q.pop(); realDelete(curr); continue; } // the queue is sorted, so if this timer shouldn't fire, none are ready _nearest_timeout = curr->_timeout; if (!timercmp(&_now, &_nearest_timeout, >)) break; /* we set the last fired time to delay msec after the previous firing, then re-insert. timers maintain their order and may trigger more than once if they've waited more than one delay's worth of time. */ _q.pop(); timevalAdd(curr->_last, curr->_delay); curr->_action(curr->_data); timevalAdd(curr->_timeout, curr->_delay); _q.push(curr); } if (wait) { // wait for the nearest trigger, or for X to do something interesting fd = ConnectionNumber(**display); FD_ZERO(&selset); FD_SET(fd, &selset); if (nearestTimeout(next)) select(fd + 1, &selset, NULL, NULL, &next); else select(fd + 1, &selset, NULL, NULL, NULL); } }

void otk::Timer::initialize (  void    )  [static]

Initializes internal data before use. Definition at line 127 of file timer.cc. References _nearest_timeout. Referenced by ob::Openbox::Openbox(). { gettimeofday(&_now, NULL); _nearest_timeout.tv_sec = 100000; _nearest_timeout.tv_usec = 0; }

bool otk::Timer::nearestTimeout (  struct timeval &    tm )  [static]

Returns a relative timeval (to pass select) of the next timer. Parameters: tm  Changed to hold the time until next timer. Returns: true if there are any timers queued, and the timeout is being returned in 'tm'. false if there are no timers queued. Definition at line 34 of file timer.cc. References _nearest_timeout, _now, and _q. Referenced by dispatchTimers(). { if (_q.empty()) return false; tm.tv_sec = _nearest_timeout.tv_sec - _now.tv_sec; tm.tv_usec = _nearest_timeout.tv_usec - _now.tv_usec; while (tm.tv_usec < 0) { tm.tv_usec += 1000000; tm.tv_sec--; } tm.tv_sec += tm.tv_usec / 1000000; tm.tv_usec %= 1000000; if (tm.tv_sec < 0) tm.tv_sec = 0; return true; }

void otk::Timer::operator delete (  void *    self )

Overloaded delete so we can leave deleted objects in queue for later reap. Parameters: self  Pointer to current instance of Timer. Definition at line 115 of file timer.cc. References _del_me. { Timer *t; t = (Timer *)self; t->_del_me = true; }

void otk::Timer::realDelete (  Timer *    self )  [static, private]

Really delete something (not just flag for later). Parameters: self  Timer to be deleted. Definition at line 122 of file timer.cc. Referenced by destroy(), and dispatchTimers(). { ::delete me; }

void otk::Timer::timevalAdd (  timeval &    a, long    msec )  [static, private]

Adds a millisecond delay to a timeval structure. Parameters: a  Amount of time to increment. msec  Number of milliseconds to increment by. Definition at line 26 of file timer.cc. Referenced by dispatchTimers(), and Timer(). { a.tv_sec += msec / 1000; a.tv_usec += (msec % 1000) * 1000; a.tv_sec += a.tv_usec / 1000000; a.tv_usec %= 1000000; }

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Friends And Related Function Documentation

friend struct TimerCompare [friend]

Definition at line 45 of file timer.hh.

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Member Data Documentation

TimeoutHandler otk::Timer::_action [private]

Callback for timer expiry. Definition at line 53 of file timer.hh. Referenced by dispatchTimers().

void* otk::Timer::_data [private]

Data sent to callback. Definition at line 55 of file timer.hh. Referenced by dispatchTimers().

bool otk::Timer::_del_me [private]

We overload the delete operator to just set this to true. Definition at line 57 of file timer.hh. Referenced by dispatchTimers(), and operator delete().

long otk::Timer::_delay [private]

Milliseconds between timer firings. Definition at line 51 of file timer.hh. Referenced by dispatchTimers().

struct timeval otk::Timer::_last [private]

The time the last fire should've been at. Definition at line 59 of file timer.hh. Referenced by dispatchTimers().

timeval otk::Timer::_nearest_timeout [static, private]

Time next timer will expire. Definition at line 23 of file timer.cc. Referenced by dispatchTimers(), initialize(), and nearestTimeout().

timeval otk::Timer::_now [static, private]

Time at start of current processing loop. Definition at line 23 of file timer.cc. Referenced by dispatchTimers(), and nearestTimeout().

Timer::TimerQ otk::Timer::_q [static, private]

Queue of pending timers. Definition at line 24 of file timer.cc. Referenced by destroy(), dispatchTimers(), nearestTimeout(), and Timer().

struct timeval otk::Timer::_timeout [private]

When this timer will next trigger. Definition at line 61 of file timer.hh. Referenced by dispatchTimers(), and otk::Timer::TimerCompare::operator()().

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The documentation for this class was generated from the following files:

• /otk/timer.hh
• /otk/timer.cc

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