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Threading and KeyError: 51 #52997
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I have a python script which runs a particular script large number of times (for monte carlo purpose) and the way I have scripted it is that, I queue up the script the desired number of times it should be run then I spawn threads and each thread runs the script once and again when its done. Once the script in a particular thread is finished, the output is written to a file by accessing a lock (so my guess was that only one thread accesses the lock at a given time). Once the lock is released by one thread, the next thread accesses it and adds its output to the previously written file and rewrites it. I am not facing a problem when the number of iterations is small like 10 or 20 but when its large like 50 or 150, python returns a KeyError: 51 telling me element doesn't exist and the error it points out to is within the lock which puzzles me since only one thread should access the lock at once and I do not expect an error. This is the class I use: class errorclass(threading.Thread):
def __init__(self, queue):
self.__queue=queue
threading.Thread.__init__(self)
def run(self):
while 1:
item = self.__queue.get()
if item is None: break
result = myfunction()
lock = threading.RLock()
lock.acquire()
ADD entries from current thread to entries in file and
REWRITE FILE
lock.release() |
Correct me if I'm wrong, but you seem to be creating a new lock object for each iteration in the loop? This doesn't seem to be a Python bug at all, but instead a problem in your implementation. It might be better to post this at stackoverflow.com or somewhere similar. |
As suggested, please post in c.l.py or other forums. Open a bug here only if you are sure that there is a bug in Python. |
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