+ # try to create and lock a lockfile (this isn't atomic but
+ # should do for now
+ $lockfn = "$root/perl/cluster.lock"; # lock file name
+ if (-e $lockfn) {
+ open(CLLOCK, "$lockfn") or die "Can't open Lockfile ($lockfn) $!";
+ my $pid = <CLLOCK>;
+ chomp $pid;
+ die "Lockfile ($lockfn) and process $pid exist, another cluster running?" if kill 0, $pid;
+ close CLLOCK;
+ }
+ open(CLLOCK, ">$lockfn") or die "Can't open Lockfile ($lockfn) $!";
+ print CLLOCK "$$\n";
+ close CLLOCK;