Re: synchronized method

From: Max Ischenko (max_at_ucmg.com.ua.remove.it)
Date: 02/10/04 

Date: Tue, 10 Feb 2004 14:54:32 +0200

Graham Dumpleton wrote:

>>I wrote simple implementation of the "synchronized" methods (a-la Java),
>>could you please check if it is OK:
>>
>>def synchronized(method):
>>
>> """
>> Guards method execution, similar to Java's synchronized keyword.
>>
>> The class which uses this method, is required to have a
>> L{threading.Lock} primitive as an attribute named 'lock'.
>> """
>>
>> def wrapper(self, *args):
>> self.lock.acquire()
>> try:
>> return method(self, *args)
>> finally:
>> self.lock.release()
>> return wrapper
>
>
> Under normal execution the lock will not be released because you return
> from the try clause.

Hmm. I think you must be wrong:

>>> def foo():
        try:
                return 1
        finally:
                print 'ok'

                
>>> foo()
ok
1

> There is also the case that method isn't defined.

Indeed, thanks for pointing this out.

> Someone else was asking about this sort of thing back the end of January.
> The post is included below. As much as doing this sort of thing may sound
> like a good way of handling synchronisation, it still has its problems.

[ cut ]

I'll look into it.

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