[Python-Dev] thread semantics for file objects

[Samuele Pedroni]

Jeremy Hylton wrote:
> On Thu, 17 Mar 2005 16:25:44 -0500, Aahz <aahz at pythoncraft.com> wrote:
> 
>>On Thu, Mar 17, 2005, Jeremy Hylton wrote:
>>
>>>Are the thread semantics for file objecst documented anywhere?  I
>>>don't see anything in the library manual, which is where I expected to
>>>find it.  It looks like read and write are atomic by virtue of fread
>>>and fwrite being atomic.
>>
>>Uncle Timmy will no doubt agree with me: the semantics don't matter.
>>NEVER, NEVER access the same file object from multiple threads, unless
>>you're using a lock.  And even using a lock is stupid.
> 
> 
> I'm not looking for your permission or approval.  I just want to know
> what semantics are intended.  If the documentation wants to say that
> the semantics are undefined that okay, although I think we need to say
> more because some behavior has been provided by the implementation for
> a long time.
> 

I think this is left unspecified for example by Java too. I would be 
surprised if Jython would offer the same characteristics in this respect 
as CPython.