628930 - JSAutoRequest in Handle::ToJSObject is not necessary

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

I audited all uses of AutoRequest in jetpack to see whether we have a valid compartment everywhere.

Handle::ToJSObject is called from the following places:

2 calls in JetpackActorCommon, both are in the variant2jsval code. That code can only be called after we have selected a valid compartment (since it allocates objects), so we are also in a request for sure.

From JetpackChild::CreateHandle. This function does JS_ReportError before calling to Handle::toJSObject, that would assert if we didn't have a request pending already prio to calling ToJSObject.

From JetpackParent::Createhandle, which enters a compartment immediately prior to calling toJSObject, and also a request.

Entering a request in ToJSObject is hence redundant. I am removing it because it doesn't enter a compartment at the same time, which would be an error if we ever entered without a request and a compartment already selected (we do not).

Comment 1

[Andreas Gal :gal]

Attachment: patch

Comment 2

[Andreas Gal :gal]

No difference running all jetpack tests.

Comment 3

[Andreas Gal :gal]

http://hg.mozilla.org/tracemonkey/rev/b0ae8b5a88a0

Comment 4

[Chris Leary [:cdleary] (not checking bugmail)]

cdleary-bot mozilla-central merge info:
http://hg.mozilla.org/mozilla-central/rev/b0ae8b5a88a0