Module sched :: Class scheduler
[hide private]
[frames] | no frames]

_ClassType scheduler

Instance Methods [hide private]
 
__init__(self, timefunc, delayfunc)
Initialize a new instance, passing the time and delay functions
 
enterabs(self, time, priority, action, argument)
Enter a new event in the queue at an absolute time.
 
enter(self, delay, priority, action, argument)
A variant that specifies the time as a relative time.
 
cancel(self, event)
Remove an event from the queue.
 
empty(self)
Check whether the queue is empty.
 
run(self)
Execute events until the queue is empty.
Method Details [hide private]

enterabs(self, time, priority, action, argument)

 

Enter a new event in the queue at an absolute time.

Returns an ID for the event which can be used to remove it, if necessary.

enter(self, delay, priority, action, argument)

 

A variant that specifies the time as a relative time.

This is actually the more commonly used interface.

cancel(self, event)

 

Remove an event from the queue.

This must be presented the ID as returned by enter(). If the event is not in the queue, this raises RuntimeError.

run(self)

 

Execute events until the queue is empty.

When there is a positive delay until the first event, the delay function is called and the event is left in the queue; otherwise, the event is removed from the queue and executed (its action function is called, passing it the argument). If the delay function returns prematurely, it is simply restarted.

It is legal for both the delay function and the action function to to modify the queue or to raise an exception; exceptions are not caught but the scheduler's state remains well-defined so run() may be called again.

A questionably hack is added to allow other threads to run: just after an event is executed, a delay of 0 is executed, to avoid monopolizing the CPU when other threads are also runnable.