0007350: WeakSet tend to grow because they don't recycle nil slots

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Category

Severity

Reproducibility

Date Submitted

Last Update

0007350

[Squeak] Collections

minor

always

05-06-09 22:08

02-06-11 23:48

Reporter

nicolas cellier

View Status

public

Assigned To

leves

Priority

normal

Resolution

fixed

Status

closed

Product Version

3.10.2

Summary

0007350: WeakSet tend to grow because they don't recycle nil slots

Description

When objects are reclaimed, they are replaced with nil in the WeakSet array.
However, due to implementation of #scanFor: these nilled-slots are never reused until the next WeakSet #grow.

Adrian Lienhard reported a nice example at
http://permalink.gmane.org/gmane.comp.lang.smalltalk.squeak.general/133778 [^]

Additional Information

Beware, nil slot cannot be recycled without taking care of possible collisions as developped in the squeak-dev thread above.

We must first take care to #fixCollisionsFrom: nilIndex.

Please find a fix attempt below. To be tested extensively!

Attached Files

M7350-WeakSet-recycleNilSlots-nice.1.cs [^] (2,011 bytes) 05-06-09 22:10

M7350-WeakSet-recycleNilSlots-nice.2.cs [^] (2,540 bytes) 05-06-09 23:43

M7350-WeakSet-tests-nice.1.cs [^] (5,076 bytes) 05-06-09 23:44

Relationships

Notes
(0013120 - 112 - 118 - 118 - 118 - 118 - 118) nicolas cellier 05-06-09 23:44	Sorry, M7350-WeakSet-recycleNilSlots-nice.1.cs was bugged ! Try M7350-WeakSet-recycleNilSlots-nice.2.cs instead

(0013122 - 176 - 230 - 230 - 230 - 230 - 230) nicolas cellier 05-07-09 10:05	"fix begin" Installer mantis bug: 7350 fix: 'M7350-WeakSet-recycleNilSlots-nice.2.cs'. "fix test" Installer mantis bug: 7350 fix: 'M7350-WeakSet-tests-nice.1.cs'. "fix end"

(0013907 - 141 - 141 - 141 - 141 - 141 - 141) leves 11-07-10 02:19	The problem was solved in Squeak 4.1 in a different way. Slots are reclaimed during growing and removal. I integrated the tests to the Trunk.

Issue History
Date Modified	Username	Field	Change
05-06-09 22:08	nicolas cellier	New Issue
05-06-09 22:10	nicolas cellier	File Added: M7350-WeakSet-recycleNilSlots-nice.1.cs
05-06-09 23:43	nicolas cellier	File Added: M7350-WeakSet-recycleNilSlots-nice.2.cs
05-06-09 23:44	nicolas cellier	File Added: M7350-WeakSet-tests-nice.1.cs
05-06-09 23:44	nicolas cellier	Note Added: 0013120
05-07-09 03:19	lewis	Issue Monitored: lewis
05-07-09 10:05	nicolas cellier	Note Added: 0013122
11-07-10 02:19	leves	Status	new => resolved
11-07-10 02:19	leves	Fixed in Version	=> trunk
11-07-10 02:19	leves	Resolution	open => fixed
11-07-10 02:19	leves	Assigned To	=> leves
11-07-10 02:19	leves	Note Added: 0013907
02-06-11 23:48	leves	Status	resolved => closed

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