On Feb 22, 10:20 am, mark <[EMAIL PROTECTED]> wrote:
> On 21 Feb 2007 14:47:50 -0800, placid <[EMAIL PROTECTED]> wrote:
>
>
>
> > On Feb 22, 3:23 am, mark <[EMAIL PROTECTED]> wrote:
> > > On 20 Feb 2007 21:26:18 -0800, placid <[EMAIL PROTECTED]> wrote:
>
> > > > On Feb 21, 4:21 pm, "placid" <[EMAIL PROTECTED]> wrote:
> > > > > On Feb 21, 4:12 pm, mark <[EMAIL PROTECTED]> wrote:
> > > > > > On 20 Feb 2007 20:47:57 -0800, placid <[EMAIL PROTECTED]> wrote:
> > > > > > > On Feb 21, 3:08 pm, mark <[EMAIL PROTECTED]> 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.
Hope this helps.
Cheers
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