http://searchfox.org/mozilla-central/rev/4012e61cc38758ffa1f7ce26039173f67b048853/dom/media/platforms/agnostic/gmp/MediaDataDecoderProxy.cpp#27 Accessing mIsShutdown on the proxy thread is a data race because it is modified in Shutdown() on another thread. In addition, the assertion is not right because there is no guarantee that InternalInit() always happens before Shutdown().

Comment on attachment 8805420 [details] Bug 1313557 - remove the assertion from InternalInit() to avoid data race. https://reviewboard.mozilla.org/r/89138/#review88300 to me it would be nicer to make this thread-safe by making IsShutdown atomic. Also, if we're shutdown, there's no point attempting to initialise the GMP so may as well reject the promise immediately. But seeing this is done only for debugging purposes... meh

Comment on attachment 8805420 [details] Bug 1313557 - remove the assertion from InternalInit() to avoid data race. https://reviewboard.mozilla.org/r/89138/#review88300 It would be optimal to do that. But it won't buy us much because the chance of InternalInit() and Shutdown() happening at the same time is quite low.

Comment on attachment 8805420 [details] Bug 1313557 - remove the assertion from InternalInit() to avoid data race. https://reviewboard.mozilla.org/r/89138/#review88300 I'm amazed you would settle for less than perfect ! :)

Pushed by jwwang@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/9c50b4bafe2e remove the assertion from InternalInit() to avoid data race. r=jya