1490055 - ParseTask can report OOM on the wrong context, and other improvements

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Jon Coppeard (:jonco)]

ParseTask is created with a main thread JSContext and then used on a helper thread with a different JSContext.  It contains two vectors which use the default TempAllocPolicy, which records the context used to create it and uses that to report OOM.  I think this means that multi script decode jobs can report OOM to the wrong context.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: bug1490055-parse-task-system-alloc

Patch to use SystemAllocPolicy for ParseTask vectors because it doesn't hold a pointer to a JSContext and so this confusion can't arise.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: bug1490055-parse-task-lifo-alloc

Helper thread JSContexts already have a LifoAlloc that we can use for parsing.  We don't need to create a new one for every parse task.

Comment 3

[Jon Coppeard (:jonco)]

Attachment: bug1490055-parse-task-refactor-callback

Finally, this patch removes the callback to finishParseTask.  We can run this code after it returns so we don't need the complexity.  I also renamed the finishParseTask methods to hopefully make things clearer and moved the contents of ParseTask::finish into finishParseTaskCommon.

Comment 4

[Nicolas B. Pierron [:nbp]]

Comment on attachment 9007832 [details] [diff] [review]
bug1490055-parse-task-refactor-callback

Review of attachment 9007832 [details] [diff] [review]:
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Thanks for these clean-ups!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/20e30197e490
Use SystemAllocPolicy for ParseTask which can be used by both main thread and helper thread contexts r=nbp
https://hg.mozilla.org/integration/mozilla-inbound/rev/44ca8ba219dd
Use JSContext's temp LifoAlloc for off-thread parsing r=nbp
https://hg.mozilla.org/integration/mozilla-inbound/rev/3f4e2a2ad3be
Refactor to remove callback passed when finishing a parse task r=nbp

Comment 6

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/20e30197e490
https://hg.mozilla.org/mozilla-central/rev/44ca8ba219dd
https://hg.mozilla.org/mozilla-central/rev/3f4e2a2ad3be