1479645 - Don't unwrap CPOWs in middleman processes

Status: RESOLVED FIXED

(Core Graveyard :: Web Replay, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

Unwrapping CPOWs in middleman processes doesn't work because they don't have a CPOW manager.  Because the message will also be received in the recording child of the middleman, avoiding this unwrapping shouldn't lead to any leaks.

Comment 1

[Andrew McCreight [:mccr8]]

Comment on attachment 8996173 [details] [diff] [review]
patch

Review of attachment 8996173 [details] [diff] [review]:
-----------------------------------------------------------------

Makes sense. Does the Unwrap in CrossProcessCpowHolder::ToObject() just not get called?

Comment 2

[Andrew McCreight [:mccr8]]

Maybe you could assert in JavaScriptShared::Unwrap() that we're not in the middleman process.

Comment 3

[Brian Hackett [Laid off!]]

(In reply to Andrew McCreight [:mccr8] (away Aug 6 - 10) from comment #1)
> Comment on attachment 8996173 [details] [diff] [review]
> patch
> 
> Review of attachment 8996173 [details] [diff] [review]:
> -----------------------------------------------------------------
> 
> Makes sense. Does the Unwrap in CrossProcessCpowHolder::ToObject() just not
> get called?

Yeah, we receive async messages in both middleman and recording processes, but most messages are ignored by the message manager in the middleman (per DirectMessageToMiddleman in dom/base/nsFrameMessageManager.cpp).  I think that we run into the issue in this bug when one of those ignored messages contains a CPOW.

(In reply to Andrew McCreight [:mccr8] (away Aug 6 - 10) from comment #2)
> Maybe you could assert in JavaScriptShared::Unwrap() that we're not in the
> middleman process.

Sure, I'll add an assert.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/b0f58c6bf907
Don't unwrap CPOWs in middleman processes, r=mccr8.

Comment 5

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/b0f58c6bf907