| msg55480 - (view) |
Author: Guido van Rossum (gvanrossum) *  |
Date: 2007-08-30 13:48 |
| The various caches in abc.py should be turned into weak sets so that the caches don't keep the subclass objects alive forever. |
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| msg55483 - (view) |
Author: Thomas Wouters (twouters) * |
Date: 2007-08-30 15:07 |
| Here's a working version of that idea, with a WeakSet implementation I had lying around (but never really used.) It seems to work, and fixes the refcount issues, but the WeakSet could do with some extra tests ;-) |
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| msg55490 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2007-08-30 16:36 |
| On 8/30/07, Thomas Wouters <report@bugs.python.org> wrote: > > Thomas Wouters added the comment: > > Here's a working version of that idea, with a WeakSet implementation I > had lying around (but never really used.) It seems to work, and fixes > the refcount issues, but the WeakSet could do with some extra tests ;-) I was torturing the WeakSet implementation, but didn't get very far: Python 3.0x (py3k, Aug 30 2007, 09:27:35) [GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from weakref import WeakSet as WS [40407 refs] >>> a = WS([1, 2, 3]) Fatal Python error: Cannot recover from stack overflow. Aborted |
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| msg55502 - (view) |
Author: Georg Brandl (georg.brandl) * |
Date: 2007-08-30 19:02 |
| Guido van Rossum schrieb: > Guido van Rossum added the comment: > > On 8/30/07, Thomas Wouters <report@bugs.python.org> wrote: >> >> Thomas Wouters added the comment: >> >> Here's a working version of that idea, with a WeakSet implementation I >> had lying around (but never really used.) It seems to work, and fixes >> the refcount issues, but the WeakSet could do with some extra tests ;-) > > I was torturing the WeakSet implementation, but didn't get very far: > > Python 3.0x (py3k, Aug 30 2007, 09:27:35) > [GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2 > Type "help", "copyright", "credits" or "license" for more information. >>>> from weakref import WeakSet as WS > [40407 refs] >>>> a = WS([1, 2, 3]) > Fatal Python error: Cannot recover from stack overflow. > Aborted The update() method can not be implemented in terms of converting the argument to a WeakSet, since that leads to infinite recursion on creation (as to why you get this fatal error, not a RuntimeError, no idea). Also, the fact that the operator-versions of set operations only support other sets as their second operands, while the method-versions support any iterable, is not preserved. Georg |
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| msg55504 - (view) |
Author: Martin v. Löwis (loewis) * |
Date: 2007-08-30 19:10 |
| The fatal error is raised if the stack overflows in the process of handling RuntimeError. In certain cases, the C algorithms won't bail out if a RuntimeError is raised, and just catch it. If that then causes another stack overflow, Python gives up. One such case is an overflow occuring during a comparison operation of a dictionary lookup, IIRC. |
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| msg55511 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2007-08-30 20:45 |
| Georg, would you have time to submit an improved patch? |
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| msg56602 - (view) |
Author: Georg Brandl (georg.brandl) * |
Date: 2007-10-20 07:42 |
| Attaching a new patch; this one passes regrtest -R:: of test_io without apparent reference leaks. |
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| msg56666 - (view) |
Author: Guido van Rossum (gvanrossum) * |
Date: 2007-10-23 03:49 |
| Thanks Georg; please check it in! |
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| msg56671 - (view) |
Author: Georg Brandl (georg.brandl) * |
Date: 2007-10-23 06:27 |
| Committed r58602. |
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