use strict;
use warnings;
use threads;

$|=1;

my $niter  = 10;
# Seems to mostly work with $nforks = 2 but usually fails with $nforks = 3.
my $nforks = 3;
my $Cmd = 'invalid_command';

warn "start niter=$niter nforks=$nforks cmd='$Cmd'\n";

sub do_one_kid {
   my $kid = shift;
   warn "kid $kid pid=$$ run cmd='$Cmd'\n";
   for my $i (1..$niter) {
      my $out = `$Cmd 2>&1`;
      my $rc = $? >> 8;
      warn "$i: kid $kid pid=$$ rc=$rc\n";
   }
   warn "kid $kid pid=$$ exit\n";
   return 42;
}

my @kids = ();
for my $n (1..$nforks)
{
   warn "$n: forking\n";
   my $t = threads->new(\&do_one_kid, $n);
   warn "I am the parent\n";
   push(@kids, $t);
}

for my $t (@kids) {
   warn "parent waiting\n";
   my $rc = $t->join();
   warn "parent $$: thread exited rc=$rc\n";
}

warn "end main\n";