Stopping playback in audio only mode SIGSEGV's the server

[PureTryOut]

Trying to stop playback, of both a file and a URL, causes the server to crash with a SIGSEGV error. This is using 0.2-alpha0.

$ nymphcast_server -c /etc/nymphcast/nymphcast_audio_config.ini -a /usr/share/nymphcast/apps
Detected Host Little Endian.
Setting wallpapers folder to default location.
Setting resource folder to default location.
Adding app: HelloCast
Adding app: SoundCloud
Initialising server...
Dispatcher: Setting max pool size to 10 workers.
Registering methods...
Format MPEG-PS (MPEG-2 Program Stream), duration -9223372036854775808 usEOF is 1
EOF is 1
EOF is 1
stream 2 : no PTS found at end of file, duration not set
Input #0, mpeg, from '':
  Duration: 00:00:00.11, start: 0.053622, bitrate: 18040430 kb/s
  Stream #0:0[0x1bf]: Data: dvd_nav_packet
  Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn
      Side data:
        cpb: bitrate max/min/avg: 7500000/0/0 buffer size: 1835008 vbv_delay: N/A
  Stream #0:2[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
Finding audio stream...
Found audio stream: 2.
A: 2, V: -1, S: -1
SetDuration. 0
Exiting event loop...
Goto 'fail'. Exiting main loop...
SetDuration. 0
Closing audio stream component...
Closing audio device...
fish: Job 1, 'nymphcast_server -c /etc/nymphc…' terminated by signal SIGSEGV (Address boundary error)

This doesn't happen when using the video config, only when using the audio config.

[MayaPosch]

What is the platform? Alpine Linux?

[PureTryOut]

Yes

[PureTryOut]

Sadly this is still occurring, so I guess it was different from #101 after all.

[MayaPosch]

Thank you for that update, so far I haven't been able to replicate the issue, but I'll give it a shot on a few more configurations including the server running on some Linux systems.

[MayaPosch]

Update: replicated this issue under Linux. Under Windows (MSVC or MinGW) it does not happen.

I'll see whether I can fix it quickly so that I can tag a new release as per #101

[MayaPosch]

It took me a bit after I couldn't replicate it on RPi OS on a Pi 3B and a Linux VM decided to die on me, but after that scenic detour I managed to more or less replicate the issue on Arch Linux on x86 (real hardware, N100-based system) I had a crash even on regular finishing of playback.

It appears to be due to a shared video-state structure between two threads that got improperly accessed in the update thread. This basically caused a bit of a race condition where it was down to basically luck whether or not the update thread would access while the structure was still valid.

To address this I have added an additional atomic check to prevent this scenario. It should also fix the similar crash when a filter configuration occurs, as seen in other cases.

In a Manjaro Linux VM on which the stopping issue got replicated directly the fix that got pushed earlier today seems to have resolved the issue. I'll be testing it on the Arch Linux system as well, but feel free to give it a shot and see whether it fixes the issue for you.