Re: Scheduling Perl Tasks

To prevent multiple instances of the same script from running, I found it very beneficial to (try to) lock $0.

This approach will fail for symlinks and hardlinks maybe.

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Re^2: Scheduling Perl Tasks by marioroy (Prior) on Mar 23, 2017 at 23:24 UTC
That's a good point Corion regarding locking $0. I updated the code by not appending the suffix ".lock" when path is given. The lock is released automatically upon termination of the script. `use Mutex::Flock; ( my $mutex = Mutex::Flock->new( path => $0 ) )->lock_exclusive; ...` [download] Another way, with the timewait method. `my $mutex = MCE::Mutex::Flock->new( path => $0 ); # terminate script if a previous instance is still running exit unless $mutex->timedwait(2); ...` [download] The module is beneficial regarding supporting threads and processes. I will make time to complete it and subsequently a release for CPAN. Regards, Mario Edit: Added timedwait example.	[reply] [d/l] [select]

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Re^2: Scheduling Perl Tasks
by marioroy (Prior) on Mar 23, 2017 at 23:24 UTC

That's a good point Corion regarding locking $0. I updated the code by not appending the suffix ".lock" when path is given. The lock is released automatically upon termination of the script.

use Mutex::Flock;

( my $mutex = Mutex::Flock->new( path => $0 ) )->lock_exclusive;

...
[download]

Another way, with the timewait method.

my $mutex = MCE::Mutex::Flock->new( path => $0 );

# terminate script if a previous instance is still running
exit unless $mutex->timedwait(2);

...
[download]

The module is beneficial regarding supporting threads and processes. I will make time to complete it and subsequently a release for CPAN.

Regards, Mario

Edit: Added timedwait example.

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