I wrote a similar construct for an updated version of Proc::Daemon - The updated code has not been released under the Proc::Daemon namespace as yet however as I am waiting to hear back from Earl Hood, the maintainer of Proc::Daemon, with his comments on the proposed code changes.

The updated Fork subroutine code follows:

sub Fork {
    my $pid;
    my $retry = 0;

    #   The following loop structure is responsible for performing a f
+ork safely - 
    #   If the core fork function returns a valid process identificati
+on value, 
    #   this is returned and this subroutine is exited.  If however, a
+n error 
    #   occurs, an attempt is made to retry the fork, if the error mes
+sage is the 
    #   result of no additional processes.  This is attempted $RETRY t
+imes after 
    #   sleeping for $SLEEP seconds before execution is abandoned.

    FORK: {
        if ( defined( $pid = fork ) ) {
            return $pid;
        } elsif ( $! =~ /No more process/i ) {
            if ( ++$retry > ( $RETRY || 3 ) ) {
                croak( __PACKAGE__, '::Fork - Cannot fork process, ret
+ry count exceeded - ', $! );
            }

            sleep ( $SLEEP || 5 );
            redo FORK;
        } else {
            croak( __PACKAGE__, '::Fork - Cannot fork process - ', $! 
+);
        }
    }
}

[download]

 

perl -le 'print+unpack("N",pack("B32","00000000000000000000001000101111"))'

In reply to Re: Safe fork() construct by rob_au
in thread Safe fork() construct by fokat

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.