NAME

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

INHERITANCE

        Mail::Box::Locker::POSIX
          is a Mail::Box::Locker
          is a Mail::Reporter

SYNOPSIS

         See Mail::Box::Locker

DESCRIPTION

       This locker object is created by the folder to get an exclusive lock on the file which contains the data
       using the kernel's POSIX facilities.  This lock is created on a separate file-handle to the folder file,
       so not the handle which is reading.

       WARNING: Not all platforms support POSIX locking (via fcntl) and not always in the same way.  This
       implementation does not use XS to access the structure of fcntl(): it is better to use the ::FcntlLock
       which does.  No, this implementation "guesses" the location of the bytes.

       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  POSIX
             posix_file                     <C<undef>>
             timeout     Mail::Box::Locker  10
             trace       Mail::Reporter     'WARNINGS'

           expires => $seconds
           file => $file
           folder => $folder
           log => LEVEL
           method => $name|CLASS|\@names
           posix_file => FILENAME
             Alternative name for "file", especially useful to avoid confusion when the multi-locker is used.

           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()
           Inherited, 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 lockf'd
           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 $file for $folder: $!
           To check whether the $file 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 POSIX lock file $file for $folder: $!
           For  POSIX  style  locking,  a  $folder  it  must be opened, which does not succeed for the specified
           reason.  Cast by lock()

       Error: Will never get a POSIX lock at $file for $folder: $!
           Tried to lock 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.

perl v5.40.1                                       2025-12-07                      Mail::Box::Locker::POSIX(3pm)