400321 - Fix appshell workarounds for Camino crashing on exit

Status: RESOLVED FIXED

(Core :: Widget: Cocoa, defect, P2)

Description

[Steven Michaud [:smichaud] (Retired)]

Attachment: Fix appshell workarounds for Camino crashing on exit

My appshell patch to process Gecko events on demand (bug 395397)
contained two workarounds for a problem in Camino that it seemed to
trigger -- with this appshell patch, Camino was much more likely to
crash on exit.

But these workarounds were only partially effective, and Camino
continues to be quite likely to crash on exit (see bug 398002).

This patch's workaround gets to the bottom of the problem, and seems
to resolve it entirely.  It replaces the two previous workarounds.

The basic problem is a design flaw in Camino:  When you quit Camino
with at least one window open, Camino (indirectly) destroys the
currently running appshell as the last browser window (class
BrowserWindow) is closed.  This means that some Camino code will run
_after_ the appshell is destroyed.  But as the appshell is destroyed
it releases all its own autorelease pools -- which can (and normally
should) cause all objects in any autorelease pool to be released,
including all of the remaining autorelease pools.  This should (and
with the new appshell often does) lead to errors (in the system
console) about objects being leaked because no autorelease pool is in
place, and to crashes caused by references to deleted objects.

These problems should have been visible before my bug 395397 appshell
patch was landed -- I don't know why they weren't.  But in any case
they _are_ now quite visible.

In principle this problem should be resolved in Camino.  But that
could be a lot of trouble, and I've found a very simple and effective
workaround.

Comment 1

[Steven Michaud [:smichaud] (Retired)]

Josh, please mark this blocking1.9+.

Then I'll seek approval to land it.

Comment 2

[Mike Beltzner [:beltzner, not reading bugmail]]

Comment on attachment 285400 [details] [diff] [review]
Fix appshell workarounds for Camino crashing on exit

a=endgame drivers for after M9 freeze

Comment 3

[Steven Michaud [:smichaud] (Retired)]

Landed on trunk.