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Diffstat (limited to 'winsup/cygwin/DevNotes')
| -rw-r--r-- | winsup/cygwin/DevNotes | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/winsup/cygwin/DevNotes b/winsup/cygwin/DevNotes index aeca33076..efa338afd 100644 --- a/winsup/cygwin/DevNotes +++ b/winsup/cygwin/DevNotes @@ -1,3 +1,27 @@ +2012-12-21 cgf-000017 + +The changes in this set are to work around the issue noted here: + +http://cygwin.com/ml/cygwin/2012-12/threads.html#00140 + +The problem is, apparently, that the return value of an ExitThread() +will take precedence over the return value of TerminateProcess/ExitProcess +if the thread is the last one exiting. That's rather amazing... + +For the fix, I replaced all calls to ExitThread with exit_thread(). The +exit_thread function, creates a handle to the current thread and sends +it to a packet via sig_send(__SIGTHREADEXIT). Then it acquires the +process lock and calls ExitThread. + +wait_sig will then wait for the handle, indicating that the thread has +exited, and, when that has happened, remove the process lock on behalf +of the now-defunct thread. wait_sig will now also avoid actually +exiting since it could trigger the same problem. + +Holding process_lock should prevent threads from exiting while a Cygwin +process is shutting down. They will just block forever in that case - +just like wait_sig. + 2012-08-17 cgf-000016 While debugging another problem I finally noticed that |