Tcl Source Code

The attachment contains a diff against core-8-branch at [c8be6c32f12bd5f112654cdb4482ae3dc0f88110]

Implementation in 8.7 branch now: [1a6b389968]

Fine. Now, that tip-511 almost went into production, let us hope that FlightAware will pick it up, somewhat. As stated earlier TclX will be the most prominent test case. And please FlightAware people, find ideas for patching on www.androwish.org

Jan, when no more errors show up in the CI, yes please merge. I'm aware that it requires still more test cases in the tests directory and infrastructure for it in tclTest.c but let's go ahead anyways.

MacOS Build on GITHUB succeeded now.

@chw, any more final tweaks you want to make? Is it ready now to be merged to core-8-branch?

Musing over the latest patch: that problem is only manifest for use cases of the fork command in TclX. Not at all for the usual Tcl test cases, where in a subprocess something is immediately exec'ed. But anyway, since Tcl can be used as a toolbox/library forking should be fully supported.

Please try the attached macos-tip511.diff (should fix the issue hopefully).

Just a guess: there's a call to StartNotifierThread() at the end of AtForkChild() in order to have early signal handling proper. Maybe this is the culprit.

MacOS Build on GITHUB failed: https://github.com/tcltk/tcl/runs/3358643773?check_suite_focus=true. Any idea what could be the reason?

Tests began at Wed Aug 18 07:43:24 UTC 2021
aaa_exit.test
Test file error: child killed: illegal instruction
append.test
Test file error: child killed: illegal instruction
....

There's a 'tip-511' implementation branch now, derived from tip511.diff5 with a few additional tweaks:

1) Adapted unix/configure.ac to autoconf-70, and re-generated unix/configure

2) Moved stub entry, preventing a conflict with TIP #568 (which will - hopefully - be voted on soon)

I didn't review it further, but will do that soon. Other people wanting to review the implementation, please go ahead! If nothing comes up the coming weeks, I'll be happy to sponsor this TIP.

A typo is fixed in attachment tip511.diff5

A missing if block in Tcl_AsyncInvoke is fixed in the attached tip511.diff4 plus the Async.3 man page is updated.

Forgot a function for the MacOSX version. This is now in tip511.diff3 which hopefully is the final candidate.

The second attachment (tip511.diff2) replaces the first and improves the code path for signal handlers not to use pthread_get_specific(), which according to the documentation available on the internet is not listed as a async-signal-safe function.