| commit | 3af63b0dc9d8444ca5480dfcccd1f87fa05eb232 | [log] [tgz] |
|---|---|---|
| author | deadbeef <deadbeef@webrtc.org> | Wed Aug 09 00:59:47 2017 |
| committer | Commit Bot <commit-bot@chromium.org> | Wed Aug 09 00:59:47 2017 |
| tree | 25bfd0382e9c7c67d61a037c80b985badeb7a13a | |
| parent | 42f96d53f3acf7a721d456b6eae872bb6f37a0a0 [diff] |
Fixing race between ~AsyncInvoker and ~AsyncClosure, using ref-counting. The AsyncInvoker destructor waits for all invoked tasks to be complete (in other words, all AsyncClosures to be destructed). They were using an event to wake up the destructor, but a race made it possible for this event to be dereferenced after it's destroyed. This CL makes the event reference counted, such that if the destructor runs right after AsyncClosure decrements "pending_invocations_", setting the event will be a no-op, and the event will be destructed in the AsyncClosure destructor. This CL also fixes a deadlock that may occur for "re-entrant" invocations. The deadlock occurs if the AsyncInvoker is destroyed on thread A while a task on thread B is running, which AsyncInvokes a task back on thread A. This was causing pending_invocations_ to end up negative, because an AsyncClosure that's never added to a thread's message queue (due to the "destroying_" flag) caused the count to be decremented but not incremented. BUG=webrtc:7656 Review-Url: https://codereview.webrtc.org/2885143005 Cr-Commit-Position: refs/heads/master@{#19278}
WebRTC is a free, open software project that provides browsers and mobile applications with Real-Time Communications (RTC) capabilities via simple APIs. The WebRTC components have been optimized to best serve this purpose.
Our mission: To enable rich, high-quality RTC applications to be developed for the browser, mobile platforms, and IoT devices, and allow them all to communicate via a common set of protocols.
The WebRTC initiative is a project supported by Google, Mozilla and Opera, amongst others.
See http://www.webrtc.org/native-code/development for instructions on how to get started developing with the native code.