System information (version)

• OpenCV => 4.5.3
• Operating System / Platform => UNIX
• Compiler => clang

Detailed description

Our thread sanitizer finds the following race condition:
WARNING: ThreadSanitizer: data race (pid=5750)
Write of size 1 at 0x562bc541ed81 by main thread:
#0 ~DisposedSingletonMark OpenCV/v4_5_3/modules/core/src/system.cpp:1387:14
#1 cv::details::TlsAbstraction::~TlsAbstraction() OpenCV/v4_5_3/modules/core/src/system.cpp:1510:1
#2 cxa_at_exit_wrapper(void*) tsan_interceptors_posix.cpp

Previous read of size 1 at 0x562bc541ed81 by thread T31:
#0 isDisposed OpenCV/v4_5_3/modules/core/src/system.cpp:1390:39
#1 getTlsAbstraction OpenCV/v4_5_3/modules/core/src/system.cpp:1435:12
#2 cv::details::TlsStorage::releaseThread(void*) OpenCV/v4_5_3/modules/core/src/system.cpp:1559:31
#3 cv::details::opencv_tls_destructor(void*) OpenCV/v4_5_3/modules/core/src/system.cpp:1753:21

Location is global 'cv::details::DisposedSingletonMarkcv::details::TlsAbstraction::mark' of size 1 at 0x562bc541ed81

Line numbers might be slightly off.

If I understand correctly, it seems that ~DisposedSingletonMark/~TlsAbstraction can be called by the main thread (thus setting mark = true) when destroying static TlsAbstraction g_tls; in getTlsAbstraction_ in the termination of the main thread.
At the same time DisposedSingletonMark::isDisposed() reads mark when called from releaseThread in a secondary thread.

I cannot find the order in which static variables are destroyed at https://en.cppreference.com/w/cpp/utility/program/exit (basically whether it waits for other threads to be done or not) so I guess it is implementation defined.

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  forum.opencv.org, Stack Overflow, etc and have not found solution
• I updated to latest OpenCV version and the issue is still there