854739 - Suspending and resuming workers can lead to messages being delivered to the main thread out of order

Status: RESOLVED FIXED

(Core :: DOM: Workers, defect)

Description

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Because we only queue messages when we reach them while running the event queue, we can deliver messages out of order if we resume a worker while messages that were pending when it was suspended are still pending in the event queue.

Comment 1

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Attachment: Patch

Comment 2

[Bobby Holley (:bholley)]

Comment on attachment 743238 [details] [diff] [review]
Patch

Review of attachment 743238 [details] [diff] [review]:
-----------------------------------------------------------------

r=bholley on the JSContext stuff.

Comment 3

[Ben Turner (not reading bugmail, use the needinfo flag!)]

Comment on attachment 743238 [details] [diff] [review]
Patch

Review of attachment 743238 [details] [diff] [review]:
-----------------------------------------------------------------

r=me.

::: dom/workers/WorkerPrivate.cpp
@@ +1404,5 @@
>  };
>  
> +class SynchronizeAndResumeRunnable : public nsRunnable
> +{
> +protected:

You just want private.

@@ +1406,5 @@
> +class SynchronizeAndResumeRunnable : public nsRunnable
> +{
> +protected:
> +  WorkerPrivate* mWorkerPrivate;
> +  nsCOMPtr<nsIScriptContext> mCx;

Is there a risk that the nsIScriptContext could be modified somehow between the time this runnable is queued and executed? What happens if the window gets torn down or something? Obviously you're holding the context alive but will it work as expected?

Comment 4

[Ben Turner (not reading bugmail, use the needinfo flag!)]

Kyle, you going to land this?

Comment 5

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

If the tree is ever open when I'm around, yes.

Comment 6

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/2550c1e294cd

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/2550c1e294cd