964531 - Don't start the SessionWorker on shutdown

Status: RESOLVED WORKSFORME

(Firefox :: Session Restore, defect)

Description

[Tim Taubert [:ttaubert] (inactive)]

Having a non-worker routine to read the session file (bug 959598) we would omit spawning the worker at startup. If we now quit the browser right after startup the first thing that would spawn the worker is the SessionFile.write call on shutdown.

Now the problem is that the Worker isn't actually going to do anything here but still we return a promise that blocks async shutdown. We will thus "hang" on shutdown and time out after 60s.

It sounds like either we would make the Worker work, or track whether we have used the SessionWorker before and if not fall back to a native write.

In theory, the OS.File shared worker could suffer from the same problem. It doesn't block async shutdown (or does it?) but it won't do anything either.

Comment 1

[Tim Taubert [:ttaubert] (inactive)]

Weird, we're locking up even with the SessionWorker not passing anything useful to addBlocker(). The timeout message isn't printed either. Maybe the SessionWorker would work if we get that fixed, whatever "that" is.

Comment 2

[Tim Taubert [:ttaubert] (inactive)]

Alternative title for this issue: Make OS.File/SessionWorker write when spawned on shutdown :)

Comment 3

[Steven MacLeod [:smacleod]]

Because of this, we currently send a noop to the worker at startup so that it will always be ready to write at shutdown. We should eventually fix this and remove that hack.

Comment 4

[David Teller [:Yoric] - still alive but not very active]

...and, this hack ends up causing bug 1251347, which was not visible until now because of bugs in sanitize.js.

The exciting life of developing Firefox :)

Comment 5

[Mathew Hodson]

Session store doesn't use a worker as of bug 1752853.