Re: Lightweight Solution To "Only 1 Process Running" On AIX

The error in both cases is "unable to lock: A file descriptor does not refer to an open file."

Considering your code does a plain exit if the flock fails, I quite surprised you get any error message at all.

Perhaps the code you are showing isn't the code you are running?

Comment on Re: Lightweight Solution To "Only 1 Process Running" On AIX

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Re^2: Lightweight Solution To "Only 1 Process Running" On AIX by Limbic~Region (Chancellor) on May 01, 2009 at 15:17 UTC
JavaFan, The code shown is the extract from the slides presented by Dominus. I provided it here so people wouldn't have to go to an offsite location to see them. Here is complete running code that demonstrates the problem: `#!/usr/bin/perl use strict; use warnings; use Fcntl qw/:DEFAULT :flock/; open(SELF, '<', $0) or die "Unable to open '$0' for reading: $!"; flock SELF, LOCK_EX \| LOCK_NB or exit; print "I must be the only process running\n"; sleep 300;` [download] and `#!/usr/bin/perl use strict; use warnings; use Fcntl qw/:DEFAULT :flock/; flock DATA, LOCK_EX \| LOCK_NB or exit; print "I must be the only process running\n"; sleep 300; __DATA__` [download] Cheers - L~R	[reply] [d/l] [select]

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Re^2: Lightweight Solution To "Only 1 Process Running" On AIX
by Limbic~Region (Chancellor) on May 01, 2009 at 15:17 UTC

JavaFan

Dominus

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

open(SELF, '<', $0) or die "Unable to open '$0' for reading: $!";
flock SELF, LOCK_EX | LOCK_NB or exit;

print "I must be the only process running\n";
sleep 300;
[download]

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

flock DATA, LOCK_EX | LOCK_NB or exit;

print "I must be the only process running\n";
sleep 300;
__DATA__
[download]

Cheers - L~R

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