942931 - Can't close browser when debugger is paused

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P2)

Description

[Victor Porof [:vporof][:vp]]

This is exactly like bug 916458, but I'm reincarnating it here.

Same str:

1. Open http://htmlpad.org/debugger/
2. Open Debugger
3. Click me
4. Cmd+Q


Happens on fx-team tip.

Comment 1

[Brian Grinstead [:bgrins]]

I'm running into this as well.  It causes a hang and I end up needing to kill the process.

Comment 2

[Panos Astithas (he/him) [:past] (please ni?)]

When hunting down leaks we disabled the test from bug 916458, which would have caught this regression.
*facepalm*

Comment 3

[Panos Astithas (he/him) [:past] (please ni?)]

This is regression from bug 941787. I have a fix that I'm currently testing.

Comment 4

[Panos Astithas (he/him) [:past] (please ni?)]

Attachment: Properly exit nested event loops when a tab is abruptly closed

The patch in bug 941787 expected unrolling the nested event loops in the abrupt shutdown case to proceed normally, but unfortunately that is not the case. When the tab is already gone, we can no longer resume events and timeouts and just need to keep exiting any nested event loops.

Comment 5

[Panos Astithas (he/him) [:past] (please ni?)]

Try: https://tbpl.mozilla.org/?tree=Try&rev=0ca46c541bc9

Comment 6

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

Comment on attachment 8342504 [details] [diff] [review]
Properly exit nested event loops when a tab is abruptly closed

Review of attachment 8342504 [details] [diff] [review]:
-----------------------------------------------------------------

Can we re-enable the test for this?

Comment 7

[Panos Astithas (he/him) [:past] (please ni?)]

I also tried to re-enable the browser_dbg_clean-exit-window.js test, but it is still leaking (bug 933950).

Comment 8

[Shu-yu Guo [:shu]]

If that assert is tripping, that means we didn't pop all the nested event loops before closing the tab, and that we are leaking.

The fact that the tab is gone and you can't resume events is precisely how the windows leak. Delayed events that were queued while the events were suppressed get held in nsFocusManager, holding the window alive. I recommend figuring out why the nested event loop depth isn't 0.

Comment 9

[Panos Astithas (he/him) [:past] (please ni?)]

Landed this interim fix as discussed on IRC, while we keep trying to fix the leak on window close in bug 933950:

https://hg.mozilla.org/integration/fx-team/rev/9473d7b659e9

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/9473d7b659e9

Comment 11

[Ioana (away)]

I tried to reproduce this issue with the 11/25 Nightly (Fx28) on Mac OS X 10.8.5 and Ubuntu 13.04, but with no results. I tried the steps from comment 0 plus setting multiple breakpoints and trying to close the browser with Ctrl/Cmd + Q when the debugger pauses at a point.

Victor, did you do anything else to reproduce this?

Comment 12

[Victor Porof [:vporof][:vp]]

Steps in comment 0 should be exact and sufficient. Make sure you're trying to close the process completely, not hide the window. Alternatively, this might have been uplifted on Firefox 28 without the tracking flags being updated for some reason.

Comment 13

[Ioana (away)]

(In reply to Victor Porof [:vporof][:vp] from comment #12)
> Steps in comment 0 should be exact and sufficient. Make sure you're trying
> to close the process completely, not hide the window. 

This is exactly what I'm doing. I checked each time and the process was closed.