tree f6d25cd510f808941155164d6f20f5193abbfa84
parent 6bf3065fbf7e3fccca284d1d1d02dbe803330cf6
author Aaron Dierking <aarond@fb.com> 1530055332 -0700
committer Aaron Dierking <aarond@fb.com> 1530136772 -0700

Ignore Windows FLS destructors during process exit

There's a quirk on Windows where exiting the process will still run fiber-local
storage destructors for the thread that called ExitProcess() (but only for that
thread). pthreads-based platforms don't call any key destructors on exit, and
_libdispatch_tsd_cleanup() assumes this. So, on Windows, calling exit() from a
queue thread will trigger the fatal error in _dispatch_frame_cleanup().

Implement a reliable method of detecting whether the process is exiting, and if
it is, ignore calls to _libdispatch_tsd_cleanup().