[m-users.] Calling exit(3) from a foreign predicate

[Volker Wysk]

Am Freitag, dem 26.01.2024 um 15:44 +1100 schrieb Julien Fischer:
> On Wed, 24 Jan 2024, Volker Wysk wrote:
> 
> > Calling exit(3), without calling mercury_runtime_terminate() before, works.
> > All thread are terminated and the program exits. It's only
> > mercury_runtime_terminate() that blocks. I've read somewhere that it waits
> > for all threads to terminate. Is there another function which doesn't? I'd
> > like to properly shut down the Mercury runtime, if possible.
> 
> What mercury_runtime_terminate() does is the following:
> 
> 1. Runs any user-defined module finalizers.
> 2. Runs standard library finalization.
> 3. Some stuff to turn of debugging (if that is enabled).
> 4. Writes out trace counts (if the user has requested that).
> 5. Turns of profiling and writes out profiling results (if some form of
>     profiling is enabled).
> 6. Writes out tabling statistics (if requested).
> 7. Shuts down engines (in low-level C .par grades)
> 8. Writes out memory usages reports (if requested by user)
> 9. Return mercury_exit_status to its caller.

(This list should go into the Mercury User Guide...)

That's a lot, even though most is done only when turned on explicitly. I
think I better do an orderly shutdown. 

> I suspect the issue you are encountering is with (7), since that code
> assumes that all engines are idle and if you still have threads running
> at that point some of them won't be.
> 
> In the normal course of events, the runtime code that invokes main/2
> blocks at the completion of main/2 until all threads terminate.

Cheers,
Volker