/ 
App-DistSync-1.10
River stage zero No dependents
/ App::DistSync::LockFile

NAME

App::DistSync::LockFile - Lock File management package

SYNOPSIS

use App::DistSync::LockFile;

my $lf = App::DistSync::LockFile->new (
    file => '/tmp/file.lock',
    pid  => $$,
    auto => 0,
);

if ( my $pid = $lf->check ) {
    warn $lf->error if $lf->error;
    die "Already running: $pid";
}

$lf->lock;
die $lf->error if $lf->error;

# . . . do stuff . . .

$lf->unlock;
die $lf->error if $lf->error;

... or with auto-lock and auto-unlock:

my $lf = App::DistSync::LockFile->new (
    file => '/tmp/file.lock',
    pid  => $$,
    auto => 1,
);

die $lf->error if $lf->error;
die "Already running" if $lf->check;

# . . . do stuff . . .

DESCRIPTION

This package manages a lock files. It will create a lock file, query the process within to discover if it's still running, and remove the lock file. This module based on File::Pid, Lock::File, File::TinyLock, JIP::LockFile and LockFile::Simple.

METHODS

This module implements the following methods

new

my $lf = new App::DistSync::LockFile(
    file    => '/tmp/file.lock',
    delay   => 60,
    retries => 5,
    pid     => $$,
    auto    => 1,
);

This constructor takes several optional attributes:

auto
auto => 0

If this flag specified as true, then will be saved the lock file automatically while instance create and removed the lock file automatically on DESTROY phase. Default: false

debug
debug => 0

Print debugging messages to STDERR (0=Off (default), 1=On)

delay
delay => 60

Number of seconds to wait between retries to getting a lockfile

Default: 60

file
file => '/tmp/test.lock'

The name of the lock file to work on. If not specified, a lock file located in current directory will be created that matches ./basename($0).lock.

pid
pid => $$

The pid to write to a new lockfile. If not specified, $$ is used when the lock file doesn't exist. When the lock file does exist, the pid inside it is used.

retries
retries => 5

Number of times to retry getting a lockfile

Default: 5

check

if ( my $pid = $lf->check ) {
    warn $lf->error if $lf->error;
    die "Already running: $pid";
}

This method checks the lock file and returns the PID of the process that first acquired the lock. Otherwise returns 0 if no lock file found

error

my $error = $lf->error;

Returns current error message

file

my $file = $lf->file;

Accessor for the filename used as the lock file.

lock

$self = $self->lock;

This method creates a lock file and stores the current PID in it.

own

$lf->own(123);
my $owner_did = $lf->own;

Accessor/mutator for the pid being saved to the lock file.

pid

my $pid = $lf->pid;

Accessor for the pid being saved to the lock file.

unlock

$self = $self->unlock;

This method performs unlocking the lock file and removes it

HISTORY

See Changes file

TO DO

See TODO file

SEE ALSO

Acme::Ghost::FilePid, Lock::File, File::TinyLock, JIP::LockFile and LockFile::Simple

AUTHOR

Serż Minus (Sergey Lepenkov) https://www.serzik.com <abalama@cpan.org>

COPYRIGHT

Copyright (C) 1998-2025 D&D Corporation. All Rights Reserved

LICENSE

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See LICENSE file and https://dev.perl.org/licenses/