Re: [TCLCORE] The ongoing dispute over TIP#509

[Jan N. <jan...@gm...>]

Op ma 13 okt 2025 om 12:17 schreef Harald Oehlmann:
> A clear warning "breaking backward compatibility of a never working
> feature" would also be great for formal reasons.

Well, the feature worked well, as long as it was not used in combination
with Tcl_Condition's. See here:
     <https://github.com/flightaware/Tcl-bounties/issues/32>
My interpretation is that using recursive mutexes fixed a rare deadlock in TclX.
Reverting TIP #509 will bring back this possible deadlock.

The motivation for TIP #509 was:
      "... enforcing a consistent behavior on all core-supported
platforms regarding reentrancy"
So, accepting this TIP means the "consistent behavior" will be gone:
On Windows using
Tcl_Mutex recursively will appear to work, on UNIX it will give a deadlock.

I think the TIP should mention the relation with this flightaware issue, and
define what "consistent" behavior we expect.

Hope this helps,
       Jan Nijtmans