1550613 - JSWindowActor crashes when sending messages early in lifecycle for in-process actors

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, defect, P1)

Description

[Nika Layzell [:nika] (ni? for response)]

Currently when we send a message within the current process, we get the "other side" of the actor synchronously within the sending side. If the constructor hasn't been received yet, however, this means we'll get a null, and a crash will occur.

It seems like the best option here would be to do one of two things:

1. Only hold mManager when sending the message, and get the other side actor when in the handler on the other side of the event loop, or:
2. Synchronously create both sides using ManagedEndpoint<PWindowGlobal> to skip going through IPC to create the WindowGlobalParent object.

As, in general, it would be nice to keep stuff to usual IPC ordering, and avoid needing to do synchronous work in the in-process case, I think the easiest initial option here is (1). I'll attach a bug for this case shortly.

Comment 1

[Nika Layzell [:nika] (ni? for response)]

Attachment: Bug 1550613 - Part 1: Get other side actor after posting to the event loop,

This patch changes the timing of when the other side actor is created to
be after posting the message to the event loop, to avoid situations
early during actor creation when the parent side hasn't been created yet
triggering null pointer crashes.

Comment 2

[Nika Layzell [:nika] (ni? for response)]

Attachment: Bug 1550613 - Part 2: Add test for early-lifecycle in-process messages,

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Hey nika, these patches look good to go from out here - are these almost ready to land?

Comment 4

[Nika Layzell [:nika] (ni? for response)]

Yeah, I think they're good to land, just been busy & haven't gotten around to landing them yet. I'll rebase them & queue them up for autoland, so hopefully everything works out :-)

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3476eec1fb49
Part 1: Get other side actor after posting to the event loop, r=jdai
https://hg.mozilla.org/integration/autoland/rev/00c0737c9721
Part 2: Add test for early-lifecycle in-process messages, r=jdai

Comment 6

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/3476eec1fb49
https://hg.mozilla.org/mozilla-central/rev/00c0737c9721