Doubt with wx.CallAfter

[carlosperezs@alumnos.uvigo.es]

Hello together::

I have programmed this fuction:

def OnNewMovie(self , event):
""" Local user receives a new movie event from a user"""

#self.log.debug ( "Got OnNewMovie, " + `event`)
if event.data[0] == self.pubId:
fDep.write("New movie equal\n")
fDep.flush()
#self.log.debug ( "Returning, it's my movie")
# This lets two users connect at the same time
self.lockInitSe ssion.acquire()
if self.vInitSessi on == False:
self.vInitSessi on = True
self.lockInitSe ssion.release()
else:
self.lockInitSe ssion.release()

return


#self.log.debug ( "Doing remote load event id = " + `event.data[0]` + ",
myid=" + `self.pubId`)
self.lockInitSe ssion.acquire()
self.vInitSessi on = False
self.lockInitSe ssion.release()

self.sharedAppC lient.UpdateDat aCache()
self.GetState()
wx.CallAfter(se lf.sm.RemoteLoa dMovie)

This function is a handler that is executed when a event occurs. At the end is
wx.CallAfter call.
Imagine that two events occur simultaneously. This function takes one event.
After executing ax.CallAfter call would tke the second event. Then , my doubt
would be, would be there 2 threads simultanously executing: one belongs to
self.sm.RemoteL oadMovie and the another one belongs to the handler for the
second event?

Thank you. As you can see i do not know exactly how wx.CallAfter works.

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[Tim Roberts]

Re: Doubt with wx.CallAfter

carlosperezs@al umnos.uvigo.es wrote:[color=blue]
>
>Hello together::
>
>I have programmed this fuction:
>
>def OnNewMovie(self , event):
> """ Local user receives a new movie event from a user"""
>
> #self.log.debug ( "Got OnNewMovie, " + `event`)
> if event.data[0] == self.pubId:
> fDep.write("New movie equal\n")
> fDep.flush()
> #self.log.debug ( "Returning, it's my movie")
> # This lets two users connect at the same time
> self.lockInitSe ssion.acquire()
> if self.vInitSessi on == False:
> self.vInitSessi on = True
> self.lockInitSe ssion.release()
> else:
> self.lockInitSe ssion.release()
> return
>
> #self.log.debug ( "Doing remote load event id = " + `event.data[0]` + ",
>myid=" + `self.pubId`)
> self.lockInitSe ssion.acquire()
> self.vInitSessi on = False
> self.lockInitSe ssion.release()
>
> self.sharedAppC lient.UpdateDat aCache()
> self.GetState()
> wx.CallAfter(se lf.sm.RemoteLoa dMovie)
>
>This function is a handler that is executed when a event occurs. At the end is
>wx.CallAfter call.
>Imagine that two events occur simultaneously.[/color]

Two events cannot occur simultaneously. It is impossible. There is only
one message queue for your window. All messages will funnel through that
one queue. There is one message loop for the thread that owns the window,
which is pulling messages from the queue and dispatching them to message
handlers. It cannot pull another message from the queue until you have
finished processing this one and returned to the message loop.
[color=blue]
>This function takes one event.
>After executing ax.CallAfter call would tke the second event. Then , my doubt
>would be, would be there 2 threads simultanously executing: one belongs to
>self.sm.Remote LoadMovie and the another one belongs to the handler for the
>second event?[/color]

No. wxCallAfter basically posts another message to the message queue,
which will be handled after all the existing messages have been dispatched.
Windows message handling is quite synchronous.
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.