Tcl Source Code

The manual page for Thread states "Windows currently does not support joinable threads. This flag value is therefore ignored on this platform."

A cursory look at the implementation shows that thread joining is implemented, but in a round-about way, using the ThreadJoin module that manages a list of joinable threads.

The proper way to join a thread (i.e., synchronously wait for a thread's termination) in Win32 is to Wait (e.g., WaitForSingleObject()) on the thread handle, returned e.g. by the _beginthreadex() function. The thread's exit status can be retrieved with the Win32 GetExitCodeThread() function. While the thread is still running, this function will return a fixed value (259), but once the thread has exited (when the thread's handle has been signaled), the unadulterated (32-bit) exit code is returned by GetExitCodeThread(). (The MSDN documentation is poorly written, so missing this is quite understandable.)

The current implementation closes this handle immediately, which is a mistake.

If you like, I could probably provide a patch.

Sorry, I misunderstood the fossil patch mechanism.  I was expected it to include commits, but in fact it includes only un-committed changes.

How do I communicate my changes back to you? Can I push to the main Tcl repo?

Patch has been added.

Is this ticket meant for the Thread package or for Tcl itself? See: https://core.tcl-lang.org/thread.

Whatever it's meant for, yes, a patch would help a lot!