[issue11987] queue.Queue.put should acquire mutex for unfinished_tasks

[patrick vrijlandt]

patrick vrijlandt <patrick.vrijla...@gmail.com> added the comment:

I agree. Please close the ticket.

Thanks,

Patrick

2011/5/3 Raymond Hettinger <rep...@bugs.python.org>

>
> Raymond Hettinger <raymond.hettin...@gmail.com> added the comment:
>
> > This line should be protected by acquiring the all_tasks_done lock.
>
> All of three of the condition variables share the same underlying lock.
>  The increment occurs only with the lock has been acquired.
>
> > Theoretically, the increment could occur somewhere during task_done()!
>
> I don't understand what you mean.  The semantics of task_done() method
> implies that the count gets decremented.
>
> > Personally, I would like the increment to occur *before*
> > instead of *after* _put().
>
> There may be some merit to this but I don't see how it matters much since
> both occur within the context of the same lock being held.  A user defined
> method can still add or subtract any number it wants from the unfinished
> task count.  The result of +1 -5 is the same as -5 +1.
>
> I'm reluctant to change the order though because the code is already
> published and some user's _put code may be inspecting the unfinished tasks
> count.  I wouldn't want to break that code without good reason.
>
> ----------
>
> _______________________________________
> Python tracker <rep...@bugs.python.org>
> <http://bugs.python.org/issue11987>
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Added file: http://bugs.python.org/file21877/unnamed

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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue11987>
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I agree. Please close the 
ticket.<div><br></div><div>Thanks,</div><div><br></div><div>Patrick<br><br><div 
class="gmail_quote">2011/5/3 Raymond Hettinger <span dir="ltr">&lt;<a 
href="mailto:rep...@bugs.python.org";>rep...@bugs.python.org</a>&gt;</span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc 
solid;padding-left:1ex;"><br>
Raymond Hettinger &lt;<a 
href="mailto:raymond.hettin...@gmail.com";>raymond.hettin...@gmail.com</a>&gt; 
added the comment:<br>
<div class="im"><br>
&gt; This line should be protected by acquiring the all_tasks_done lock.<br>
<br>
</div>All of three of the condition variables share the same underlying lock. 
 The increment occurs only with the lock has been acquired.<br>
<div class="im"><br>
&gt; Theoretically, the increment could occur somewhere during task_done()!<br>
<br>
</div>I don&#39;t understand what you mean.  The semantics of task_done() 
method implies that the count gets decremented.<br>
<div class="im"><br>
&gt; Personally, I would like the increment to occur *before*<br>
&gt; instead of *after* _put().<br>
<br>
</div>There may be some merit to this but I don&#39;t see how it matters much 
since both occur within the context of the same lock being held.  A user 
defined method can still add or subtract any number it wants from the 
unfinished task count.  The result of +1 -5 is the same as -5 +1.<br>

<br>
I&#39;m reluctant to change the order though because the code is already 
published and some user&#39;s _put code may be inspecting the unfinished tasks 
count.  I wouldn&#39;t want to break that code without good reason.<br>

<br>
----------<br>
<div><div></div><div class="h5"><br>
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&lt;<a href="http://bugs.python.org/issue11987"; 
target="_blank">http://bugs.python.org/issue11987</a>&gt;<br>
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</div></div></blockquote></div><br></div>

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