Opened 4 years ago

Last modified 18 months ago

#12463 new bug

Debugger hangs while saving debug report (automatic mode)

Reported by: pulkomandy Owned by: anevilyak
Priority: normal Milestone: Unscheduled
Component: Applications/Debugger Version: R1/Development
Keywords: Cc:
Blocked By: Blocking:
Has a Patch: no Platform: All

Description

I have the debug_server set to save reports automatically for DumpRenderTree when it crashes in the webkit tesuite. The debug report is created but incomplete (no backtrace), and Debugger never exits and stays idle. From a quick look at the backtrace there seem to be a deadlock.

Attachments (1)

Debugger-40438-debug-13-11-2015-07-14-05.report (17.4 KB ) - added by pulkomandy 4 years ago.
Debug report of deadlocked Debugger

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Change History (5)

by pulkomandy, 4 years ago

Debug report of deadlocked Debugger

comment:1 by anevilyak, 4 years ago

From the looks of it, something failed while trying to retrieve the thread's backtrace, at least the report generator thread is waiting for the stack trace retrieval job.

Two things appear odd however: 1) the worker thread that executes jobs appears to be missing entirely, and 2) the team debug controller for the team is already quitting, which shouldn't be the case until after the report generator indicates it's complete.

Are you by any chance able to narrow down which test in the suite is triggering such a crash? If so, can you see if you get similar behavior when trying to save reports manually rather than automatic mode?

comment:2 by pulkomandy, 4 years ago

I get dozens of these while running the testsuite, but it's hard to tell which tests in particular it is. The test suite engine has a timeout, if it gets no answer from DumpRenderTree it will kill it. The report I extracted is probably from after this happened.

comment:3 by anevilyak, 4 years ago

That would actually explain the situation almost perfectly, the controller will try to terminate if it receives a signal that the debugged team was destroyed (the kernel won't prevent a team with an attached debugged session from being killed), so apparently somewhere along the way the report generator isn't properly told to quit. Will see what I can do about the hang, but if that is indeed the case, there isn't really a way for us to get a useful report out of it either.

comment:4 by pulkomandy, 18 months ago

I'm still getting this problem when running the webkit testsuite. It's a bit annoying because I can't just leave it running and do something else: stuck Debugger instances will accumulate and eventually my machine will run out of memory and the testsuite will stop. So I need to watch over it and periodically kill the stuck processes.

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