4.0 regression: test_libvlc_slaves fails pseudorandomly

FAIL: test_libvlc_slaves
========================

[000060e000000040] main libvlc warning: cannot read /home/remi/videolan/vlc/build/src/.libs/vlc/plugins/plugins.dat: No such file or directory
[000060e000001380] main libvlc warning: cannot read /home/remi/videolan/vlc/build/src/.libs/vlc/plugins/plugins.dat: No such file or directory
LibVLC fatal error joining thread (35) in thread 175333 at ../../src/posix/thread.c:227 in vlc_join
/usr/lib/x86_64-linux-gnu/libasan.so.6(+0x43df1)[0x7fcb7cd60df1]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x94b611)[0x7fcb7bba2611]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x94b773)[0x7fcb7bba2773]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(vlc_join+0x11c)[0x7fcb7bba3085]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(vlc_executor_Delete+0x438)[0x7fcb7bb0557a]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x62de7a)[0x7fcb7b884e7a]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(libvlc_InternalCleanup+0x5ba)[0x7fcb7b7d6c68]
/home/remi/videolan/vlc/build/lib/.libs/libvlc.so.12(libvlc_release+0x122)[0x7fcb7b183e57]
/home/remi/videolan/vlc/build/lib/.libs/libvlc.so.12(libvlc_media_release+0x63f)[0x7fcb7b19b940]
/home/remi/videolan/vlc/build/lib/.libs/libvlc.so.12(+0x8006a)[0x7fcb7b19a06a]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x62990a)[0x7fcb7b88090a]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x62bbb7)[0x7fcb7b882bb7]
/home/remi/videolan/vlc/build/src/.libs/libvlccore.so.9(+0x8acabf)[0x7fcb7bb03abf]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x8ea7)[0x7fcb7af33ea7]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7fcb7b052d4f]

## Testing --sub-autodetect-fuzzy 1 (everything)
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/test.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media
Check if slaves[0] is found
Check if slaves[1] is found
Check if slaves[2] is found
Check if slaves[3] is found

## Testing --sub-autodetect-fuzzy 2 (full, left, and right match)
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/test.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media
Check if slaves[0] is found
Check if slaves[1] is found
Check if slaves[2] is found

## Testing if the matching is not too permissive
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/t.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media

## Testing --sub-autodetect-fuzzy 3 (full and left match)
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/test.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media
Check if slaves[0] is found
Check if slaves[1] is found

## Testing --sub-autodetect-fuzzy 4 (full match)
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/test.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media
Check if slaves[0] is found

## Testing  --no-sub-autodetect-file (no match)
Parse media dir to get subitems
Main media mrl: 'file:///home/remi/videolan/vlc/build/test/../../test/samples/slaves/test.mp4'
Fetch main media from subitems
Found main media
Check if slaves are correclty attached to media
Thread error: Success
FAIL test_libvlc_slaves (exit status: 134)

Bisection not done as failure is intermittent. Looking at the stack trace, this is most likely caused by the migratiom of something onto the executor API.

added Component::Core Severity::normal Type::bug Version::master git + 1 deleted label

changed milestone to %4.0

added Severity::critical label and removed Severity::normal label

Still reproducible

here is the backtrace:

LibVLC fatal error joining thread (35) in thread 1374059 at ../../src/posix/thread.c:197 in vlc_join

Program terminated with signal SIGABRT, Aborted.
[#0](https://code.videolan.org/videolan/vlc/-/issues/0)  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
50	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
[Current thread is 1 (Thread 0x7fc951998700 (LWP 1374059))]
(gdb) bt
[#0](https://code.videolan.org/videolan/vlc/-/issues/0)  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
[#1](https://code.videolan.org/videolan/vlc/-/issues/1)  0x00007fc952017537 in __GI_abort () at abort.c:79
[#2](https://code.videolan.org/videolan/vlc/-/issues/2)  0x00007fc9522ef8cd in vlc_thread_fatal (
    action=action@entry=0x7fc9523286ab "joining thread", error=35, 
    function=function@entry=0x7fc952328748 <__func__.3> "vlc_join", line=line@entry=197, 
    file=0x7fc952328651 "../../src/posix/thread.c") at ../../src/posix/thread.c:96
[#3](https://code.videolan.org/videolan/vlc/-/issues/3)  0x00007fc9522ef962 in vlc_join (th=..., result=result@entry=0x0)
    at ../../src/posix/thread.c:197
[#4](https://code.videolan.org/videolan/vlc/-/issues/4)  0x00007fc9522d6dee in vlc_executor_Delete (executor=0x556aafae7160)
    at ../../src/misc/executor.c:277
[#5](https://code.videolan.org/videolan/vlc/-/issues/5)  0x00007fc95226f214 in input_preparser_Delete (preparser=0x556aafae9c00)
    at ../../src/preparser/preparser.c:425
[#6](https://code.videolan.org/videolan/vlc/-/issues/6)  0x00007fc95224881f in libvlc_InternalCleanup (p_libvlc=0x556aafa3e550)
    at ../../src/libvlc.c:374
[#7](https://code.videolan.org/videolan/vlc/-/issues/7)  0x00007fc952210214 in libvlc_release (p_instance=0x556aafa3e4e0) at ../../lib/core.c:85
[#8](https://code.videolan.org/videolan/vlc/-/issues/8)  0x00007fc952215780 in libvlc_media_release (p_md=0x556aafa3e680) at ../../lib/media.c:669
[#9](https://code.videolan.org/videolan/vlc/-/issues/9)  libvlc_media_release (p_md=0x556aafa3e680) at ../../lib/media.c:642
[#10](https://code.videolan.org/videolan/vlc/-/issues/10) 0x00007fc95226ea83 in NotifyPreparseEnded (task=0x556aafae9b50)
    at ../../src/preparser/preparser.c:137
[#11](https://code.videolan.org/videolan/vlc/-/issues/11) RunnableRun (userdata=0x556aafae9b50) at ../../src/preparser/preparser.c:282
[#12](https://code.videolan.org/videolan/vlc/-/issues/12) 0x00007fc9522d6a9c in ThreadRun (userdata=0x556aafa3e8d0)
    at ../../src/misc/executor.c:132
[#13](https://code.videolan.org/videolan/vlc/-/issues/13) 0x00007fc9521bfea7 in start_thread (arg=<optimized out>) at pthread_create.c:477
[#14](https://code.videolan.org/videolan/vlc/-/issues/14) 0x00007fc9520efd8f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

regression from a708c988091d6bc770212f5deeaba45e2395f4b2

The slaves.c test release the libvlc instance then do its media test. This cause the libvlc instance to be released from a media event.

There are many way to fix this issue:

• Put the libvlc_release() at the end of the test like every other tests
• libvlc should not be refcounted, so that the user can control when it's deleted, the same goes with the media player.
• and/or we should create a libvlc_preparser API that take care of holding the media and libvlc

Fixed in 7f19eca5, though we should move to libvlc_preparser API afterwards.

added Status::fixed label

closed

mentioned in issue #25357 (closed)

unassigned @MigrationBot