"Bastian" == Bastian Hammer <[EMAIL PROTECTED]> writes:
Bastian> Now I have to make sure, that both threads are Bastian> synchronal, 1 thread edits something and the other is Bastian> blocked until the first thread is ready.
Bastian> Isn´t it a good idea to do this with a semaphore?
Semaphore will do, but this is a classical use case for threading.Lock.
There should be lots of stuff regarding locks (or more googleably, "mutexes") on the net.
I don't agree. Mutexes (or locks) are best suited for critical sections (ie. sections that cannot be run by many thread at the same time). The kind of synchonisation Bastian want is not really semaphore either but more event. This python "Event" object is described in the section 7.5.5 of the documentation of Python 2.3. There is no example, but I think Event are quite strait forward : you creates it, then some thread block, waiting the event to occure while some other thread execute until it set the event, allowing the blocked thread to go on its own execution :)
Here a small working example :
***8<************8<***************8<********** import threading, time
class MyThread(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
self._event = threading.Event()
self._exit = False
def run(self):
while 1:
print "Waiting for an event to continue"
self._event.wait()
print "Ok, the thread is unblocked now :)"
if self._exit:
return
self._event.clear()
def unblock(self):
self._event.set()
def exit(self):
self._exit = True
self.unblock()t = MyThread() t.start() time.sleep(1) t.unblock() time.sleep(1) t.unblock() time.sleep(1) t.exit() ***8<************8<***************8<**********
Pierre -- http://mail.python.org/mailman/listinfo/python-list
