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}";
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;
}
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?
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.