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Bug 3412 - Infinite wait in SDL_CloseAudioDevice using winmm audio driver
Summary: Infinite wait in SDL_CloseAudioDevice using winmm audio driver
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: audio (show other bugs)
Version: HG 2.1
Hardware: x86_64 Windows 10
: P2 normal
Assignee: Ryan C. Gordon
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-08-24 20:26 UTC by Kieran Yee
Modified: 2017-05-19 19:32 UTC (History)
2 users (show)

See Also:

Attachments
Short program to demonstrate the problem (830 bytes, text/x-csrc)
2016-08-24 20:26 UTC, Kieran Yee 		Details
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Description Kieran Yee 2016-08-24 20:26:24 UTC 
Created attachment 2554 [details]
Short program to demonstrate the problem

Tested compiling with both Visual Studio and MinGW-w64, using SDL2 compiled from fresh (rev 10222) sources, as well as 2.0.4 sources. The sample program will reproduce the problem, but the gist of it is:

- Make sure SDL is using the winmm audio driver (export/set SDL_AUDIODRIVER=winmm)
- Open an audio device
- Immediately close that audio device

SDL_CloseAudioDevice will never return.

Only occurs when using the winmm audio driver. Adding a delay of any length between the two steps using SDL_Delay will "solve" the problem. I think this happens because of the audio device being placed in shutdown before the child thread gets to run? Will continue investigating.
Comment 1 Philipp Wiesemann 2016-08-25 20:48:00 UTC 
SDL_CloseAudioDevice() waits for the audio thread to finish. This thread spins in WINMM_WaitDone() because the shutdown was requested before the playback was started.
Comment 2 Ryan C. Gordon 2017-05-19 19:32:05 UTC 
This bug should be fixed when we stopped letting the audio targets be in charge of draining their own buffers on exit:

https://hg.libsdl.org/SDL/rev/d6427519ca66

(Please feel free to reopen this bug if this is still a problem though!)

--ryan.