1156938 - TSan: data race dom/media/gstreamer/GStreamerReader.cpp:1191 Eos

Status: RESOLVED WONTFIX

(Core :: Audio/Video: Playback, defect, P5)

Description

[Nathan Froyd [:froydnj]]

Attachment: gstreamer-eos-race.txt

The attached logfile shows a thread/data race detected by TSan (ThreadSanitizer).

* Specific information about this bug

It looks like we have two threads racing to set members of GStreamerReader.  One of them is doing it under a monitor, but the other one is doing it "in the clear", as it were.  That seems like a bad thing.

* General information about TSan, data races, etc.

Typically, races reported by TSan are not false positives, but it is possible that the race is benign. Even in this case though, we should try to come up with a fix unless this would cause unacceptable performance issues. Also note that seemingly benign races can possibly be harmful (also depending on the compiler and the architecture) [1][2].

If the bug cannot be fixed, then this bug should be used to either make a compile-time annotation for blacklisting or add an entry to the runtime blacklist.

[1] http://software.intel.com/en-us/blogs/2013/01/06/benign-data-races-what-could-possibly-go-wrong
[2] _How to miscompile programs with "benign" data races_: https://www.usenix.org/legacy/events/hotpar11/tech/final_files/Boehm.pdf

Comment 1

[Jean-Yves Avenard [:jya]]

gstreamer is going in bug 1234092