802395 - frameworker json.parse occasional errors

Status: VERIFIED FIXED

(Firefox Graveyard :: SocialAPI, defect)

Description

[Shane Caraveo (:mixedpuppy)]

Attachment: parsefix.patch

I've been seeing occasional failures with json.parse in the frameworker ClientPort class, and couldn't figure out a repro for it.  Then with reload, Pam started running into it and had to work around it.  I finally chased it down to pending messages on the ports.  

fw_AbstractPort_onmessage first parses the json it receives, then if there is no handler it sticks that object in pending messages

When the port connects, it grabs the pending messages and calls fw_AbstractPort_onmessage again, but passing an object rather than a string.

with reload, content area's are more likely to create pending messages while the frameworker is reloading, thus easier to reproduce, and more likely to be a problem.

The attachement looks like the correct fix to me, but the port stuff is pretty involved, will ask Mark to look.

Comment 1

[Mark Hammond [:markh] [:mhammond]]

Comment on attachment 672057 [details] [diff] [review]
parsefix.patch

I agree that looks correct but think we need a test :)

So IIUC, to see this you will need to have a port which is connected but which has not yet set an onmessage handler when a message arrives?  Our tests probably don't do that, but it shouldn't be too hard to arrange in browser_frameworker?

Comment 2

[Shane Caraveo (:mixedpuppy)]

Attachment: parsefix.patch

https://tbpl.mozilla.org/?tree=Try&rev=3e86045e2829

Comment 3

[:Gavin Sharp [email: [e-mail]]]

Comment on attachment 672100 [details] [diff] [review]
parsefix.patch

good catch

Comment 4

[:Gavin Sharp [email: [e-mail]]]

Comment on attachment 672100 [details] [diff] [review]
parsefix.patch

[Triage Comment]
a+ for 17/18 given that it's a social-specific, simple fix

Comment 5

[:Gavin Sharp [email: [e-mail]]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/77deb50b07e1

Comment 6

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/77deb50b07e1

Comment 7

[Lukas Blakk [:lsblakk] use ?needinfo]

Please land to branches by EOD Pacific time on Monday so we're sure to get this into 17.0 Beta 3

Comment 8

[Scoobidiver (away)]

Beta 3 and Aurora missed despite the approval!

Comment 9

[Lukas Blakk [:lsblakk] use ?needinfo]

(In reply to Scoobidiver from comment #8)
> Beta 3 and Aurora missed despite the approval!

It's ok - I checked with gavin in irc ahead of time, we can take this in Beta 4 - please land this asap though, since it does have approval.

Comment 10

[:Felipe Gomes (needinfo for replies!)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/1e19bb30061f
https://hg.mozilla.org/releases/mozilla-beta/rev/7ca7a0794864

Comment 11

[u279076]

Marking verified fixed since this landed with tests. Please add verifyme keyword if there's something you need QA to test.