1274725 - Remaining "Nightly Web Content" process after browser have been closed

Status: RESOLVED DUPLICATE of bug 1268559

(Core :: DOM: Content Processes, defect)

Description

[Clément Lefèvre]

Attachment: Nightly_process_sample.txt

I just noticed on my computer running OS X that there was a remaining process from Nightly called "Nightly Web Content" long time after I closed the browser. Its parent process was not alive anymore, and the system was telling its ppid is 1 (launchd on OS X).

The process was the following one:

mbp :: ~ » ps aux | grep 20045
clement         20045   5,8  8,5  5507868 888756   ??  S     4:19    31:05.97 /Applications/FirefoxNightly.app/Contents/MacOS/plugin-container.app/Contents/MacOS/plugin-container -greomni /Applications/FirefoxNightly.app/Contents/Resources/omni.ja -appomni /Applications/FirefoxNightly.app/Contents/Resources/browser/omni.ja -appdir /Applications/FirefoxNightly.app/Contents/Resources/browser 20042 gecko-crash-server-pipe.20042 org.mozilla.machname.1582198594 tab

I did gathered a process dump before killing it. You can find it attached.

As additional informations, the process was not declared as zombie, was still consuming CPU and memory usage was increasing over the time and would have indefinitely if I didn't killed the process.

Comment 1

[Andrew Overholt [:overholt]]

Mike, wdyt?

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Sounds similar to something dolske reported in bug 1276330. Adding this to the e10s triage.

Comment 3

[Mike Conley (:mconley) (:⚙️)]

That process sample is interesting. If I'm interpreting it right, it looks like some page is doing a (sync?) XHR on the pagehide event that's being fired on TabChild teardown.

Comment 4

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

This is probably bug 1268559 in another form.

Comment 6

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

I managed to reproduce something like this. I made a testcase that does a sync XHR to a slow web site in a pagehide event handler. Then I also opened Treeherder along with this tab. While Treeherder is still loading, I hit Ctrl-Q. The parent process crashes in a shutdown hang while the child lives forever. I'm not sure why I get a shutdown hang on Linux while Mac people don't seem to get that.

Anyway, my shutdown hang is in the compositor shutdown code, so I'm not quite confident this is a dupe.