/ 
Mail-Box-3.012
River stage one • 8 direct dependents • 8 total dependents
/ Mail::Box::Locker::Flock

NAME

Mail::Box::Locker::Flock - lock a folder using kernel file-locking

INHERITANCE

Mail::Box::Locker::Flock
  is a Mail::Box::Locker
  is a Mail::Reporter

SYNOPSIS

See the generic Mail::Box::Locker interface

DESCRIPTION

The ::Flock object locks the folder by creating an exclusive lock on the file using the kernel's flock facilities. This lock is created on a separate file-handle to the folder file, so not the handle which is reading.

File locking does not work in some situations, for instance for operating systems do not support flock.

Extends "DESCRIPTION" in Mail::Box::Locker.

METHODS

Extends "METHODS" in Mail::Box::Locker.

Constructors

Extends "Constructors" in Mail::Box::Locker.

$class->new(%options)

Inherited, see "METHODS" in Mail::Box::Locker

-Option --Defined in       --Default
 expires  Mail::Box::Locker  1 hour
 file     Mail::Box::Locker  undef
 folder   Mail::Box::Locker  <C<undef>>
 log      Mail::Reporter     'WARNINGS'
 method   Mail::Box::Locker  'FLOCK'
 timeout  Mail::Box::Locker  10
 trace    Mail::Reporter     'WARNINGS'
expires => $seconds
file => $file
folder => $folder
log => LEVEL
method => $name|CLASS|\@names
timeout => $seconds|'NOTIMEOUT'
trace => LEVEL

Attributes

Extends "Attributes" in Mail::Box::Locker.

$obj->expires( [SECONDS] )

Inherited, see "Attributes" in Mail::Box::Locker

$obj->filename( [$filename] )

Inherited, see "Attributes" in Mail::Box::Locker

$obj->folder( [$folder] )

Inherited, see "Attributes" in Mail::Box::Locker

$obj->logSettings()

Inherited, see "Attributes" in Mail::Reporter

$obj->name()

Inherited, see "Attributes" in Mail::Box::Locker

$obj->timeout( [SECONDS] )

Inherited, see "Attributes" in Mail::Box::Locker

Locking

Extends "Locking" in Mail::Box::Locker.

$obj->hasLock()

Inherited, see "Locking" in Mail::Box::Locker

$obj->isLocked()

Inherited, see "Locking" in Mail::Box::Locker

$obj->lock()

Acquire a lock on the folder. Improves base, see "Locking" in Mail::Box::Locker

$obj->unlock()

Inherited, see "Locking" in Mail::Box::Locker

Error handling

Extends "Error handling" in Mail::Box::Locker.

$obj->AUTOLOAD()

Inherited, see "Error handling" in Mail::Reporter

$obj->addReport($object)

Inherited, see "Error handling" in Mail::Reporter

$any->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )

Inherited, see "Error handling" in Mail::Reporter

$obj->errors()

Inherited, see "Error handling" in Mail::Reporter

$any->log( [$level, [$strings]] )

Inherited, see "Error handling" in Mail::Reporter

$any->logPriority($level)

Inherited, see "Error handling" in Mail::Reporter

$obj->notImplemented()

Inherited, see "Error handling" in Mail::Reporter

$obj->report( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->reportAll( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->trace( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->warnings()

Inherited, see "Error handling" in Mail::Reporter

Cleanup

Extends "Cleanup" in Mail::Box::Locker.

$obj->DESTROY()

Inherited, see "Cleanup" in Mail::Box::Locker

DIAGNOSTICS

Warning: Folder $folder already flocked

The $folder is already locked, but you attempt to lock it again. The behavior of double flock's is platform dependent, and therefore should not be attempted. The second lock is ignored (but the unlock isn't). Cast by lock()

Error: Package $package does not implement $method.

Fatal error: the specific package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package. Cast by notImplemented()

Error: Unable to check lock file $filename for $folder: $!

To check whether the $filename is used to flock a $folder, the file must be opened. Apparently this fails, which does not mean that the folder is locked neither that it is unlocked. Cast by isLocked()

Error: Unable to open flock file $file for $folder: $!

For flock-ing a $folder it must be opened, which does not succeed for the specified reason. Cast by lock()

Error: Will never get a flock at $file for $folder: $!

Tried to flock the $folder, but it did not succeed. The error code received from the OS indicates that it will not succeed ever, so we do not need to try again. Cast by lock()

SEE ALSO

This module is part of Mail-Box version 3.012, built on November 27, 2025. Website: http://perl.overmeer.net/CPAN/

LICENSE

For contributors see file ChangeLog.

This software is copyright (c) 2001-2025 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.