There's this, if you have IO::Socket:

# Perl Cookbook, 1st Edition, pg. 626
use strict;
use IO::Socket;
use Symbol;
use POSIX qw(:signal_h :errno_h :sys_wait_h);

my $PREFORK        = 2;     # number of kids to maintain
my %kids           = ();    # child process ids
my $kids           = 0;     # number of children
my @jobs           = qw(a b c d e f g h);

sub REAPER {
   $SIG{CHLD} = \&REAPER;
   my $pid    = waitpid(-1, &WNOHANG);
   if ($pid   == -1) {
      # ignore - no child waiting
   } elsif (&WIFEXITED($?)) {
      $kids--;
      delete($kids{$pid});
   } else {
      # false alarm
   }
   $SIG{CHLD} = \&REAPER;    # in case of unreliable signals
}

sub HUNTSMAN {
   local($SIG{CHLD}) = 'IGNORE';
   kill 'INT' => keys %kids;
   exit;
}

sub HEADCOUNT {
   $PREFORK +=5;
   print "I have $kids kids; increasing to $PREFORK...\n";
}

# install signal handlers
$SIG{CHLD}   = \&REAPER;
$SIG{INT}    = \&HUNTSMAN;
$SIG{HUP}    = \&HEADCOUNT;

print "starting $PREFORK users...\n";
for (1 .. $PREFORK) {
   &make_new_child(shift(@jobs));
}

# and maintain population
while (scalar @jobs) {   # or 'while (1)' for perpetual
   sleep;                # wait for a signal
   for ($kids .. $PREFORK) {
      &make_new_child(shift(@jobs));
   }
}

sub make_new_child {
   my $pid;
   my $sigset;

   sleep 3;

   # block signal for fork
   $sigset = POSIX::SigSet->new(SIGINT);
   sigprocmask(SIG_BLOCK, $sigset) or die("Can't block SIGINT for fork
+: $!\n");
   die "fork: $!"  unless defined ($pid = fork);

   if ($pid) {
      # parent records child and returns
      sigprocmask(SIG_UNBLOCK, $sigset) or die("Can't unblock SIGINT f
+or fork: $!\n");
      $kids{$pid} = 1;
      $kids++;
      return;

   } else {

      # child must *not* return from this subroutine
      $SIG{INT}   = 'DEFAULT';       # make it kill us as before
      $SIG{HUP}   = 'IGNORE';        # only parent needs this

      #unblock signals
      sigprocmask(SIG_UNBLOCK, $sigset) or die("Can't unblock SIGINT f
+or fork: $!\n");

      # do something
      my $job = shift;
      print "I am $$, doing job $job\n";
      sleep 10;
      exit;
   }
}
[download]

I used basically the same to stress an application by perpetually spawning connections and adding heat with HUP.

Update: Sorry! When I cut-and-pasted this, I missed three essential lines. See the three lines after the comment, "Install signal handlers".

Update2: I clarified my reference to the Cookbook. I now have the 2nd Edition, which doesn't have the same recipe.

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