[PyQt] Are QThreads compatible with python's threading.RLock?

Darren Dale dsdale24 at gmail.com
Sun Jul 27 13:55:02 BST 2008

On Saturday 26 July 2008 03:48:53 you wrote:
> On Fri, 25 Jul 2008 17:41:22 -0400, Darren Dale <dsdale24 at gmail.com> wrote:
> > I use a library that provides rudimentary thread safety of its objects
> and
> > file
> > I/O using threading.RLock from the python standard library. Could anyone
> > tell
> > me if PyQt4's QThreads are compatible with these recursive locks?
> Other than the fact that they will both be implemented using the same OS
> primitives, Python's and Qt's threading know nothing about each other.

Thanks Phil. The author of this other library I use added a mechanism to 
accommodate alternative threading libraries: users can provide their own lock 
object, provided it is reentrant and respect python's context manager 
protocol. So I think I can can do this:

class MyRLock(QtCore.QMutex):

    def __init__(self):
        super(MyRLock, self).__init__(QtCore.QMutex.Recursive)

    def __enter__(self):
        return self.lock()

    def __exit__(self, type, value, traceback):

    def acquire(self):
        return self.lock()

    def release(self):

h5.config.RLock = MyRLock

One last question, concerning context managers: I think the current PyQt4 way 

    def foo(self):
        with QMutexLocker(self.mutex):

but if QMutex and friends had __enter__ and __exit__ methods, like MyRLock, we 
could do:

    def foo(self):
        with self.mutex:

Is there a reason (performance?) for using Qt's QMutexLocker to provide the 
context manager, rather than the QMutex itself?


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