1371125 - Don't save JSContext in nsSameProcessAsyncMessageBase

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, enhancement)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: patch

Saving a JSContext in nsSameProcessAsyncMessageBase causes problems for Quantum DOM. A message (with CPOWs) might be received on a different cooperative thread than the one it was sent, which involves a different context. We should look up the JSContext in TLS instead (via AutoJSAPI). This patch does that.

Comment 1

[Andrew McCreight [:mccr8]]

Comment on attachment 8875553 [details] [diff] [review]
patch

Review of attachment 8875553 [details] [diff] [review]:
-----------------------------------------------------------------

::: dom/base/nsFrameMessageManager.cpp
@@ +2068,5 @@
>    MOZ_ASSERT(mCalledInit);
>    if (aManager) {
> +    AutoJSAPI jsapi;
> +    jsapi.Init();
> +    SameProcessCpowHolder cpows(jsapi.cx(), mCpows);

Can you just call dom::RootingCx() here? Do we really need a fully set up AutoJSAPI?

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/207b0675c786
Stop saving JSContext in nsSameProcessAsyncMessageBase (r=mccr8)

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/207b0675c786