Am 12.10.2012 00:06, schrieb Wenhua Zhao:
On Wed, Oct 10, 2012 at 12:21 PM, Ian Kelly <ian.g.ke...@gmail.com> wrote:
Can you demonstrate an API bug that is caused by this?
A simple demo of this error is:
[...]
print "in main cv._is_owned: ", cv._is_owned()
That is kind of cheating, because as far as I can tell that function is
private and not even documented in any way. You can use wait() though,
which should always raise a RuntimeError:
----------->8------------------------>8----------------------
import time
from threading import Condition, Lock, Thread
cv = Condition(Lock())
def do_acquire():
cv.acquire()
print "cv acquired in thread"
time.sleep(5)
cv.release()
print "cv released in thread"
thread = Thread(target=do_acquire)
thread.start()
for i in range(10):
try:
cv.wait()
print "in main cv.wait() succeeded"
except RuntimeError:
print "in main cv.wait() raised RuntimeError"
time.sleep(1)
----------->8------------------------>8----------------------
This gives me the following output:
in main cv.wait() raised RuntimeErrorcv acquired in thread
Exception in thread Thread-1:
Traceback (most recent call last):
File "C:\Python27\lib\threading.py", line 551, in __bootstrap_inner
self.run()
File "C:\Python27\lib\threading.py", line 504, in run
self.__target(*self.__args, **self.__kwargs)
File "ttest.py", line 10, in do_acquire
cv.release()
error: release unlocked lock
Following that, the program hangs. It seems the wait() released the lock
that it didn't own, causing the error in do_acquire(). It then hung in
wait(), although it should have raised a RuntimeError instead.
Uli
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