BrowserUk, thank you!

What I would say; and have said many times; is do not attempt to use fork & the windows signals emulation to try to port *nix idioms to windows; because you will be sadly let down.

Based on this, I will propose an addition to the documentation of function fork (and perhaps also kill) in the Perl Language reference.

You reinvented ... a thread-bomb.

And you are using a random delay -- sleep 0 equates to "relinquish the rest of the current timeslice" which is an unknowable quantum of time, that could range from 0 microseconds

My “thread-bomb” resulted in a patch. The patch http://perl5.git.perl.org/perl.git/commitdiff/82e24582 adds to t/op/fork.t:

+system $^X,  "-e", "if (\$pid=fork){sleep 1;kill(9, \$pid)} else {sle
+ep 5}";
[download]

Is this also a thread-bomb, or is it OK with non zero sleep?

The patch also changes win32/win32.c:

--- a/win32/win32.c
+++ b/win32/win32.c
@@ -1282,6 +1282,13 @@ win32_kill(int pid, int sig)
            case 9:
                 /* kill -9 style un-graceful exit */
                if (TerminateThread(hProcess, sig)) {
+                    /* Allow the scheduler to finish cleaning up the 
+other thread.
+                     * Otherwise, if we ExitProcess() before another 
+context switch
+                     * happens we will end up with a process exit cod
+e of "sig" instead
+                     * of our own exit status.
+                     * See also: https://rt.cpan.org/Ticket/Display.h
+tml?id=66016#txn-908976
+                     */
+                    Sleep(0);
                    remove_dead_pseudo_process(child);
                    return 0;
                }
[download]

Is it OK with “Sleep(0)”, or must it be a non zero parameter value? Can the non zero time value cause that we still sometimes get 9 as an erroneous exit value? What is the smallest non-zero value that can be used?