getting a thread out of sleep

[mark]

On 21 Feb 2007 16:10:51 -0800, placid <Bulkan at gmail.com> wrote:
> On Feb 22, 10:20 am, mark <rkmr... at gmail.com> wrote:
> > On 21 Feb 2007 14:47:50 -0800, placid <Bul... at gmail.com> wrote:
> >
> >
> >
> > > On Feb 22, 3:23 am, mark <rkmr... at gmail.com> wrote:
> > > > On 20 Feb 2007 21:26:18 -0800, placid <Bul... at gmail.com> wrote:
> >
> > > > > On Feb 21, 4:21 pm, "placid" <Bul... at gmail.com> wrote:
> > > > > > On Feb 21, 4:12 pm, mark <rkmr... at gmail.com> wrote:
> > > > > > > On 20 Feb 2007 20:47:57 -0800, placid <Bul... at gmail.com> wrote:
> > > > > > > > On Feb 21, 3:08 pm, mark <rkmr... at gmail.com> wrote:
> > > > > > > > > Right now I have a thread that  sleeps for sometime and check if an
> > > > > > > > > event has happened and go back to sleep. Now instead I want the thread
> > > > > > > > > to sleep until the event has occured process the event and go back to sleep
> >
> > > > > > > > > class eventhndler(threading.Thread):
> > > > > > > > >     def __init__(self):
> > > > > > > > >         threading.Thread.__init__(self)
> > > > > > > > >     def run(self):
> > > > > > > > >         while True:
> > > > > > > > >             time.sleep(SLEEPTIME)
> > > > > > > > >             ''''do event stuff'''
> >
> > > > > > > > The way i would do this is by using an threading.Event (
> > > > > > > >http://docs.python.org/lib/event-objects.html)
> >
> > > > > > > > <code>
> >
> > > > > > > > class eventhandler(threading.Thread):
> > > > > > > >     def __init__(self):
> > > > > > > >         threading.Thread.__init__(self)
> > > > > > > >         self.event = threading.Event()
> > > > > > > >     def run:
> > > > > > > >         while True:
> > > > > > > >             # block until some event happens
> > > > > > > >             self.event.wait()
> > > > > > > >             """ do stuff here """
> > > > > > > >             self.event.clear()
> > > > > > > > </code>
> >
> > > > > > > > the way to use this is to get the main/separate thread to set() the
> > > > > > > > event object.
> >
> > > > > > > Can you give an example of how to get the main threead to set teh event object?
> > > > > > > this is exactly what i wanted to do!
> > > > > > > thanks a lot!
> > > > > > > mark>
> > > > > oops I've miss-typed the thread variable name the following should
> > > > > work
> >
> > > > > <code>
> > > > > if __name__ == "__main__":
> > > > >     evtHandlerThread = eventhandler()
> > > > >     evtHandlerThread.start()
> >
> > > > >     # do something here #
> > > > >     evtHandlerThread.event.set()
> >
> > > > >     # do more stuff here #
> > > > >     evtHandlerThread.event.set()
> >
> > > > > </code>
> >
> > > > Can I have the same thread process two or more events? Can you tell
> > > > how to do this? The code you gave is waiting on one event right. How
> > > > can I do it for more events?
> > > > thanks a lot!
> > > > mark
> >
> > > I don't think a thread can block on more than one event at a time. But
> > > you can make it block on more then one event one at a time.
> >
> > > <code>
> >
> > > class eventhandler(threading.Thread):
> > >    def __init__(self):
> > >        threading.Thread.__init__(self)
> > >        self.events = [threading.Event(), threading.Event()]
> > >        self.currentEvent = None
> > >    def run:
> > >        while True:
> > >            for event in self.events:
> > >                self.currentEvent = event
> > >                # block until some event happens
> > >                self.currentEvent.wait()
> > >                """ do stuff here """
> > >                self.currentEvent.clear()
> >
> > > if __name__ == "__main__":
> > >     evtHandlerThread = eventhandler()
> > >     evtHandlerThread.start()
> >
> > >     # do something here #
> > >     evtHandlerThread.currentEvent.set()
> >
> > >     # do more stuff here #
> > >     evtHandlerThread.currentEvent.set()
> >
> > > </code>
> >
> > > what the thread does is sequentially waits for two events to happen
> > > and then execute the same code. You could change this code to perform
> > > different functions for different event objects.
> >
> > Once the thread starts it is going to wait on the event that is the
> > first element of the list right?  This would mean :
>
> This is correct.
>
> > evtHandlerThread.currentEvent.set(): that I have only one event right?
>
> this means that the current event occurred.
>
> > Can you explain how I can have different event objects. I dont see how
> > I can do different functinos for same event.
> >
> > Thanks a lot!
> >
> > mark
>
> To run different functions for the same event is easy, just write a
> wrapper class around threading.event() and include some method that
> you will run and assign this to different functions for each
> EventWrapper.
>
> <code>
>
> class EventWrapper():
>     def __init__(self,work ):
>          self.event = threading.Event()
>          self.eventWork = work
>
>    def wait(self):
>         self.event.wait()
>
>    def clear(self)
>         self.event.clear()
>
>     def eventWork(self):
>         print "no work"
>
> class eventhandler(threading.Thread):
>      def __init__(self, events = None):
>          threading.Thread.__init__(self)
>          self.events = events
>          self.currentEvent = None
>      def run:
>          while True:
>              if self.events:
>                  for event in self.events:
>                      self.currentEvent = event
>                      # block until the current event happens
>                      self.currentEvent.wait()
>                      self.currentEvent.eventWork()
>                      self.currentEvent.clear()
>
> def eventOneWork():
>     # do some event 1 specific work here
>
> def eventTwoWork():
>     # do some event 2 specific work here
>
> if __name__ == "__main__":
>       events = [EventWrapper(eventOneWork),EventWrapper(eventTwoWork)]
>
>       evtHandlerThread = eventhandler(events)
>       evtHandlerThread.start()
>
>       # do something here #
>       evtHandlerThread.currentEvent.set()
>       # do more stuff here #
>       evtHandlerThread.currentEvent.set()
>
> </code>
>
> So you have a EventWrapper class that now contains the Event object
> and a workEvent() method which is assigned to a function you create.
>
THanks  a lot! Does this have to have event1 and event2 occur in
sequence? Will this still work even if only event2 occurs and event1
never occurs?
thanks
mark