808907 - Enable android Binder ipc thread

Status: RESOLVED DUPLICATE of bug 803471

(Core :: Audio/Video, defect)

Description

[Sotaro Ikeda [:sotaro]]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4

Steps to reproduce:

Current FirefoxOS could not detect AudioFlinger' died event/restart. If it happens, b2g/b2g-container processes that cached IAudioFlinger interface could not play/control audio anymore.

Current FirefoxOS uses AudioFlinger in mediaserver process. For ipc to communicate with AudioFlinger, android Binder ipc is used. But FirefoxOS do not enable Binder ipc thread. Without the Binder ipc thread, b2g/b2g-container process could send ipc message to AudioFlinger. But could not receive ipc message from AudioFlinger.

In normal situation, there is no problem from this restriction. But by this restriction, b2g/b2g-container could not detect AudioFlinger died event. AudioFlinger died event is delivered by using Binder ipc thread.

I tried following
- power on FirefoxOS phone
- unlock lockscreen
- unlock sound is played
- kill mediaserver process by using "adb shell ps" and "adb shell kill" command
- return to lock screen
- unlock sound is played even after mediaserver killed 

Same thing could be done by using music app.



Actual results:

unlock sound is not played after mediaserver killed 


Expected results:

unlock sound is played even after mediaserver killed

Comment 1

[Sotaro Ikeda [:sotaro]]

mediaserver is automatically restarted by init after get killed

Comment 2

[Sotaro Ikeda [:sotaro]]

IAudioFlinger interface is stored as static member
http://androidxref.com/4.0.4/xref/frameworks/base/include/media/AudioSystem.h#230
http://androidxref.com/4.0.4/xref/frameworks/base/media/libmedia/AudioSystem.cpp#34

The interface is cleared when died event is detected
AudioSystem::AudioFlingerClient::binderDied(const wp<IBinder>& who)
http://androidxref.com/4.0.4/xref/frameworks/base/media/libmedia/AudioSystem.cpp#375

Comment 3

[Sotaro Ikeda [:sotaro]]

Attachment: Enable android Binder ipc thread

after applying the patch, I confirmed that unlock lockscreen sound is played even after mediaserver get killed.

Comment 4

[Sotaro Ikeda [:sotaro]]

If b2g/b2g-container process do not receive AudioFlinger died event, the process continue to use invalid IAudioFlinger interface.

Therefore it is necessary to clear invalid interface. Next time, AudioSystem class try to get new IAudioFlinger interface.