The stacktrace unit test was flaking on arm32; my theory is that this
happened when the thread whose stack we were dumping was doing a
system call inside `params->deadlock_start_event.Set();` in
ThreadFunction(). (This would be a problem because, according to the
comment at the bottom of the file, "stack traces originating from
kernel space do not include user space stack traces for ARM32.")
Attempt to solve this problem by spinning on an atomic flag instead,
since this involve no system calls. And add a short sleep to the main
thread, to give the other thread time to get from the barrier to the
thing it's actually supposed to deadlock on.
Bug: webrtc:10420
Change-Id: I4c6392157c8a06c64cb11146ffe9368e5bade6fc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128340
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27158}
This is a reland of dc32cc00e8
Relanding because this CL was not the culprit for the Chrome bot.
(This code shouldn't even be executed in Chrome).
Original change's description:
> Android: Add helper methods for printing native stack traces
>
> This CL adds utility functions to unwind the stack for a given thread on
> Android ARM devices. This works on top of unwind.h and unwinds native
> (C++) stack traces only. Unwinding a thread from another thread is done
> by overriding the signal handler with a custom function and then
> interrupting the specific thread.
>
> Bug: webrtc:10168
> Change-Id: If5adffd3a6bb57bf502168743e09a7eefc292bf3
> Reviewed-on: https://webrtc-review.googlesource.com/c/118141
> Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
> Reviewed-by: Tommi <tommi@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#26328}
TBR=tommi
Bug: webrtc:10168
Change-Id: I4c33c2c147cf10c0172c98a55d32dd35a08517c8
Reviewed-on: https://webrtc-review.googlesource.com/c/118704
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26341}
This CL adds utility functions to unwind the stack for a given thread on
Android ARM devices. This works on top of unwind.h and unwinds native
(C++) stack traces only. Unwinding a thread from another thread is done
by overriding the signal handler with a custom function and then
interrupting the specific thread.
Bug: webrtc:10168
Change-Id: If5adffd3a6bb57bf502168743e09a7eefc292bf3
Reviewed-on: https://webrtc-review.googlesource.com/c/118141
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26328}
