Re^3: Faster locking

[bbs2web]

Could someone please confirm that Perl would skip trying to acquire a lock when the first 'if' condition is true?

Should I rather place the test in to a nested condition, completely outside of the first?

if ( (1 == 1) || (!flock $lockfile, LOCK_EX | LOCK_NB) )

PS: Things appear to be working as expected, but I would still like to know, for my own peace of mind.

[bbs2web]

Okay, so it works as expected:

Test code:

#!/usr/bin/perl
use strict;
use warnings;
use Fcntl qw(:flock);

open our $lockfile, '<', $0 || die $!;
if ( (1 == 1) || (!flock $lockfile, LOCK_EX | LOCK_NB) ) {
  print "in loop\n";
  sleep 30;
  if (flock $lockfile, LOCK_EX | LOCK_NB) {
    print "locked\n";
  } else {
    print "not locked\n";
  }
  sleep 30;
}

First instance:

in loop
locked

Second instance:

in loop
not locked