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.

       Mail::Box::Locker::POSIX->new(%options)
            -Option    --Defined in       --Default
             expires     Mail::Box::Locker  1 hour
             file        Mail::Box::Locker  undef
             folder      Mail::Box::Locker  <undef>
             log         Mail::Reporter     'WARNINGS'
             method      Mail::Box::Locker  POSIX
             posix_file                     <undef>
             timeout     Mail::Box::Locker  10
             trace       Mail::Reporter     'WARNINGS'

           expires => SECONDS
           file => FILENAME
           folder => FOLDER
           log => LEVEL
           method => STRING|CLASS|ARRAY
           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->timeout( [SECONDS] )
           Inherited, see "Attributes" in Mail::Box::Locker

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

       $obj->filename( [$filename] )
           Inherited, see "The Locker" in Mail::Box::Locker

       $obj->folder( [$folder] )
           Inherited, see "The Locker" in Mail::Box::Locker

       $obj->name()
           Inherited, see "The Locker" in Mail::Box::Locker

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

       $obj->hasLock()
           Inherited, see "Locking" in Mail::Box::Locker

       $obj->isLocked()
       $obj->lock()
       $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

       $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
       Mail::Box::Locker::POSIX->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level,
       $callback] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->errors()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->log( [$level, [$strings]] )
       Mail::Box::Locker::POSIX->log( [$level, [$strings]] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logPriority($level)
       Mail::Box::Locker::POSIX->logPriority($level)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logSettings()
           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
       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.

       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.

       Error: Unable to open POSIX lock file $filename for $folder: $!
           For POSIX style locking, a folder it must be opened, which does not succeed for the
           specified reason.

       Error: Will never get a POSIX lock at $filename 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.

SEE ALSO

       This module is part of Mail-Box distribution version 3.009, built on August 18, 2020.
       Website: http://perl.overmeer.net/CPAN/

LICENSE

       Copyrights 2001-2020 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/