Nick Coghlan <[EMAIL PROTECTED]> writes:
> Michael Hudson wrote:
>> Option 1) Call PyEval_ThreadsInitialized() in PyGilState_Release().
>> Non-invasive, but bleh.
>
> Tim rejected this option back when PyEval_ThreadsInitialized() was
> added to the API [1].
Well, not really. The patch that was rejected was much larger than
any proposal of mine. My option 1) is this:
--- pystate.c 09 Feb 2005 10:56:18 +0000 2.39
+++ pystate.c 07 Apr 2005 13:19:55 +0100
@@ -502,7 +502,8 @@
PyThread_delete_key_value(autoTLSkey);
}
/* Release the lock if necessary */
- else if (oldstate == PyGILState_UNLOCKED)
- PyEval_ReleaseThread(tcur);
+ else if (oldstate == PyGILState_UNLOCKED
+ && PyEval_ThreadsInitialized())
+ PyEval_ReleaseThread();
}
#endif /* WITH_THREAD */
> Gustavo was having a similar problem with pygtk, and the end result
> was to add the ThreadsInitialized API so that pygtk could make its
> own check without slowing down the default case in the core.
Well, Gustavo seemed to be complaining about the cost of the locking.
I'm complaining about crashes.
>> Option 2) Call PyEval_SaveThread() instead of
>> PyEval_ReleaseThread()[1] in PyGilState_Release(). This is my
>> favourite option (PyGilState_Ensure() calls PyEval_RestoreThread which
>> is PyEval_SaveThread()s "mate") and I guess you can distill this long
>> mail into the question "why doesn't PyGilState_Release do this
>> already?"
This option corresponds to this patch:
--- pystate.c 09 Feb 2005 10:56:18 +0000 2.39
+++ pystate.c 07 Apr 2005 13:24:33 +0100
@@ -503,6 +503,6 @@
}
/* Release the lock if necessary */
else if (oldstate == PyGILState_UNLOCKED)
- PyEval_ReleaseThread(tcur);
+ PyEval_SaveThread();
}
#endif /* WITH_THREAD */
> See above. Although I'm now wondering about the opposite question: Why
> doesn't PyGilState_Ensure use PyEval_AcquireThread?
Well, that would make more sense than what we have now. OTOH, I'd
*much* rather make the PyGilState functions more tolerant -- I thought
being vaguely easy to use was part of their point.
I fail to believe the patch associated with option 2) has any
detectable performance cost.
Cheers,
mwh
--
People think I'm a nice guy, and the fact is that I'm a scheming,
conniving bastard who doesn't care for any hurt feelings or lost
hours of work if it just results in what I consider to be a better
system. -- Linus Torvalds
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