Bug 224500

Summary: Have HTMLCanvasElement clear its buffer as soon as its script execution context goes away
Product: WebKit Reporter: Chris Dumez <cdumez>
Component: CanvasAssignee: Chris Dumez <cdumez>
Status: REOPENED ---    
Severity: Normal CC: changseok, dino, esprehn+autocc, ews-watchlist, ggaren, gyuyoung.kim, sabouhallawa, sam, simon.fraser, thorton, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
ews-feeder: commit-queue-
Patch ews-feeder: commit-queue-

Description Chris Dumez 2021-04-13 12:20:06 PDT 
Have HTMLCanvasElement clear its buffer as soon as its script execution context goes away. We used to do this only in the destructor, which would only get called after GC of the JS wrapper, which may delay release of the ImageBuffer and its memory.
Comment 1 Chris Dumez 2021-04-13 12:21:55 PDT 
Created attachment 425896 [details]
Patch
Comment 2 Chris Dumez 2021-04-13 13:10:01 PDT 
Created attachment 425906 [details]
Patch
Comment 3 Chris Dumez 2021-04-13 15:35:31 PDT 
This is web-observable.
Comment 4 Tim Horton 2021-08-05 12:05:36 PDT 
Comment on attachment 425906 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=425906&action=review

Additional motivation: https://bugs.webkit.org/show_bug.cgi?id=228747

> Source/WebCore/html/HTMLCanvasElement.cpp:1028
> +    setImageBuffer(nullptr);

I'm guessing we'd need to slurp some more code from the destructor to fix the assertions.
Comment 5 Tim Horton 2021-08-05 13:02:07 PDT 
Reopening because Sam and Chris and I all think we should try this again when we have lots of bake time :)

(Also, we already do it for WebGL)
Comment 6 Radar WebKit Bug Importer 2022-04-11 07:03:03 PDT 
<rdar://problem/91563038>