|Anonymous | Login||10-22-2021 18:17 UTC|
|Main | My View | View Issues | Change Log | Docs|
|Viewing Issue Simple Details [ Jump to Notes ]||[ View Advanced ] [ Issue History ] [ Print ]|
|ID||Category||Severity||Reproducibility||Date Submitted||Last Update|
|0006955||[Squeak] Collections||major||always||02-26-08 14:30||02-26-08 14:30|
|Summary||0006955: Weak collections are not thread safe with respect to finalization|
Weak collections (excluding WeakRegistry) may get finalized while being accessed (by a process with priority > userInterruptPriority) leading to a misrepresentation of whether they contain a particular element/key at any given moment.
For instance, with a WeakKeyDictionary, on doing #at:ifAbsentPut: may insert new entries with identical keys.
One option would be to expose the WeakArray FinalizationLock to process that modify such weak collections though this would effectively be a global lock across all weak collections.
As a better approach, weak collections should be protected in a similar manner to WeakRegistry for any operation that could change their underlying state.
The following code highlights the problem most of the time!
d := WeakIdentityKeyDictionary new.
WeakArray addWeakDependent: d.
oc := OrderedCollection new.
[1000 timesRepeat: [
o := Morph new.
2 atRandom > 1 ifTrue: [oc add: o].
d at: o ifAbsentPut: ['something'].
10 timesRepeat: [
d at: o ifAbsent: [self error: 'duplicate ', o oopString].
(Delay forMilliseconds: 1) wait]].
self inform: 'completed'] forkAt: Processor lowIOPriority
|There are no notes attached to this issue.|
| Mantis 1.0.8[^]
Copyright © 2000 - 2007 Mantis Group
27 total queries executed.|
24 unique queries executed.