async mode is necessary to handle return nullprt from GonkNativeWindow::getCurrentBuffer() situation. It happen when gecko side hold more than GonkBufferQueue::mMaxAcquiredBufferCount+1 buffer. Bug 1036539 added "Add async mode support" until KK. In android, this should not happen. But on b2g this could happen. If it happens, GonkBufferQueue always continue to hold one additional frame.

(In reply to Sotaro Ikeda [:sotaro] from comment #0) > > In android, this should not happen. But on b2g this could happen. > If it happens, GonkBufferQueue always continue to hold one additional frame. When we do not extend MaxAcquiredBufferCount by the following call, it is easily happen during WebRTC. > consumer->setMaxAcquiredBufferCount(WEBRTC_OMX_H264_MIN_DECODE_BUFFERS);

Nominate this case as "2.2?" for triage. -- Keven

(In reply to Sotaro Ikeda [:sotaro] from comment #0) > async mode is necessary to handle return nullprt from > GonkNativeWindow::getCurrentBuffer() situation. It happen when gecko side > hold more than GonkBufferQueue::mMaxAcquiredBufferCount+1 buffer. Each time when it happens, GonkBufferQueue accumulate one more buffer in the GonkBufferQueue.

Hi Sotaro, what would be the user implication of this bug on 2.2? Would it simply consume more memory than it needs to? Just want to know about its priority level. thanks!

(In reply to No-Jun Park [:njpark] from comment #4) > Hi Sotaro, what would be the user implication of this bug on 2.2? Would it > simply consume more memory than it needs to? Just want to know about its > priority level. thanks! camera preview stream add more lags. It affect to the camera preview's responsiveness. And If GonkNativeWindow accumulate too much video frame, it could block camera preview update.

Comment on attachment 8575392 [details] [diff] [review] patch - Add async mode support to GonkNativeWindow on Lollipop Gonk Review of attachment 8575392 [details] [diff] [review]: ----------------------------------------------------------------- LGTM

Comment on attachment 8575392 [details] [diff] [review] patch - Add async mode support to GonkNativeWindow on Lollipop Gonk NOTE: Please see https://wiki.mozilla.org/Release_Management/B2G_Landing to better understand the B2G approval process and landings. [Approval Request Comment] Bug caused by (feature/regressing bug #): none User impact if declined: User could face a lag of camera preview during WebRTC. Testing completed: locally tested. Risk to taking this patch (and alternatives if risky): low. String or UUID changes made by this patch: none.