Closed
Bug 1727262
Opened 3 years ago
Closed 3 years ago
MediaEventSource can cause shutdown hangs
Categories
(Core :: Audio/Video: Playback, task, P2)
Core
Audio/Video: Playback
Tracking
()
RESOLVED
FIXED
94 Branch
| Tracking | Status | |
|---|---|---|
| firefox94 | --- | fixed |
People
(Reporter: pehrsons, Assigned: pehrsons)
References
Details
Attachments
(2 files)
This is similar to bug 1702823 but for mTarget instead of mFunction.
The solution cannot be the same, since Notify() needs mTarget, and syncing this through revocation status is impossible (races) unless we switch to a Mutex. mFunctionWrapper could be removed on the target thread since that's where revocation happens.
Prerequisites:
- A MediaEventListener target that sits on top of a SharedThreadPool, for instance a TaskQueue (common), where the target's shutdown sequence is triggered by destruction, i.e., all hard refs to it are removed (probably not so common)
- A MediaEventProducer owned by a garbage collected object
Example sequence causing a shutdown hang:
- Listener is hooked up to the source
- XPCOM shutdown
- Listener is revoked (clearing the function but not the target)
- The MediaEventProducer owner is part of a ref-cycle and although CCed, lives on to CC-shutdown, which is after xpcom-shutdown-threads
- xpcom-shutdown-threads is blocked on a SharedThreadPool being alive
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Assignee | |
Comment 1•3 years ago
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Updated•3 years ago
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Attachment #9237705 -
Attachment description: Bug 1727262 - Add an escape hatch to MediaEventSource so it can clear all listeners and possibly unblock shutdown. r?alwu! → Bug 1727262 - Ensure MediaEventListener revocation eventually clears all members to prevent shutdown hangs. r?alwu!, r?bryce!
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Assignee | |
Comment 2•3 years ago
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Updated•3 years ago
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Attachment #9237705 -
Attachment description: Bug 1727262 - Ensure MediaEventListener revocation eventually clears all members to prevent shutdown hangs. r?alwu!, r?bryce! → Bug 1727262 - Ensure MediaEventListener revocation clears all members to prevent shutdown hangs. r?alwu!, r?bryce!
Pushed by pehrsons@gmail.com: https://hg.mozilla.org/integration/autoland/rev/0b8b1d0ee784 Add gtest. r=alwu https://hg.mozilla.org/integration/autoland/rev/46173dc5f5e6 Ensure MediaEventListener revocation clears all members to prevent shutdown hangs. r=alwu,bryce
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Comment 4•3 years ago
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| bugherder | ||
https://hg.mozilla.org/mozilla-central/rev/0b8b1d0ee784
https://hg.mozilla.org/mozilla-central/rev/46173dc5f5e6
Status: ASSIGNED → RESOLVED
Closed: 3 years ago
status-firefox94:
--- → fixed
Resolution: --- → FIXED
Target Milestone: --- → 94 Branch
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Description
•