# Mail::Box::Locker::NFS - lock a folder with a separate file, NFS-safe - perldoc - [phpMan]

## NAME
    [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown) - lock a folder with a separate file, NFS-safe

## INHERITANCE
     [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown)
       is a [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)
       is a [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

## SYNOPSIS
     See [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

## DESCRIPTION
    Like the "::DotLock" locker, but then in an NFS-safe fashion. Over NFS, the creation of a file
    is not atomic. The "::DotLock" locker depends on an atomic "open" system call, hence in not
    usable to lock a folder which accessed over NFS. The "::NFS" locker is therefore more
    complicated (so therefore slower), but will work for NFS --and for local disks as well.

    Extends "DESCRIPTION" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

## METHODS
    Extends "METHODS" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

### Constructors
    Extends "Constructors" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown)->new(%options)
         -Option --Defined in       --Default
          expires  [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)  1 hour
          file     [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)  undef
          folder   [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)  <undef>
          log      [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)     'WARNINGS'
          method   [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)  'NFS'
          timeout  [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)  10
          trace    [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)     'WARNINGS'

        expires => SECONDS
        file => FILENAME
        folder => FOLDER
        log => LEVEL
        method => STRING|CLASS|ARRAY
        timeout => SECONDS|'NOTIMEOUT'
        trace => LEVEL

### Attributes
    Extends "Attributes" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    $obj->expires( [SECONDS] )
        Inherited, see "Attributes" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

    $obj->timeout( [SECONDS] )
        Inherited, see "Attributes" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

### The Locker
    Extends "The Locker" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    $obj->filename( [$filename] )
        Inherited, see "The Locker" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

    $obj->folder( [$folder] )
        Inherited, see "The Locker" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

    $obj->name()
        Inherited, see "The Locker" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

### Locking
    Extends "Locking" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    $obj->hasLock()
        Inherited, see "Locking" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

    $obj->isLocked()
        Inherited, see "Locking" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

    $obj->lock()
    $obj->unlock()
        Inherited, see "Locking" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

### Error handling
    Extends "Error handling" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    $obj->AUTOLOAD()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->addReport($object)
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
    [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown)->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->errors()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->log( [$level, [$strings]] )
    [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown)->log( [$level, [$strings]] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->logPriority($level)
    [Mail::Box::Locker::NFS](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker%3A%3ANFS/markdown)->logPriority($level)
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->logSettings()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->notImplemented()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->report( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->reportAll( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->trace( [$level] )
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

    $obj->warnings()
        Inherited, see "Error handling" in [Mail::Reporter](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AReporter/markdown)

### Cleanup
    Extends "Cleanup" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown).

    $obj->DESTROY()
        Inherited, see "Cleanup" in [Mail::Box::Locker](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3ABox%3A%3ALocker/markdown)

## DIAGNOSTICS
    Warning: Folder $folder already locked over nfs
        Do not try to lock the folder when the application already has the lock: it will give you
        dead-locks.

    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.

    Warning: Removed expired lockfile $filename.
        A lock file was found which was older than the expiration period as specified with
        new(timeout). The lock file was successfully removed.

    Error: Unable to remove expired lockfile $lockfile: $!
        A lock file was found which was older than the expiration period as specified with the
        new(timeout) option. It is impossible to remove that lock file, so we need to wait until it
        vanishes by some external cause.

## SEE ALSO
    This module is part of Mail-Box distribution version 3.010, built on July 18, 2023. Website:
    <http://perl.overmeer.net/CPAN/>

## LICENSE
    Copyrights 2001-2023 by [Mark Overmeer]. For other contributors see ChangeLog.

    This program is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself. See <http://dev.perl.org/licenses/>