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 Mail::Box::Locker

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".

       See documentation in the base class.

METHODS

       See documentation in the base class.

   Constructors
       See documentation in the base class.

       Mail::Box::Locker::Flock->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  'FLOCK'
             timeout  Mail::Box::Locker  10 seconds
             trace    Mail::Reporter     'WARNINGS'

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

   The Locker
       See documentation in the base class.

       $obj->filename([FILENAME])
           See "The Locker" in Mail::Box::Locker

       $obj->folder([FOLDER])
           See "The Locker" in Mail::Box::Locker

       $obj->name()
           See "The Locker" in Mail::Box::Locker

   Locking
       See documentation in the base class.

       $obj->hasLock()
           See "Locking" in Mail::Box::Locker

       $obj->isLocked()
       $obj->lock()
       $obj->unlock()
           See "Locking" in Mail::Box::Locker

   Error handling
       See documentation in the base class.

       $obj->AUTOLOAD()
           See "Error handling" in Mail::Reporter

       $obj->addReport(OBJECT)
           See "Error handling" in Mail::Reporter

       $obj->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
       Mail::Box::Locker::Flock->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
           See "Error handling" in Mail::Reporter

       $obj->errors()
           See "Error handling" in Mail::Reporter

       $obj->log([LEVEL [,STRINGS]])
       Mail::Box::Locker::Flock->log([LEVEL [,STRINGS]])
           See "Error handling" in Mail::Reporter

       $obj->logPriority(LEVEL)
       Mail::Box::Locker::Flock->logPriority(LEVEL)
           See "Error handling" in Mail::Reporter

       $obj->logSettings()
           See "Error handling" in Mail::Reporter

       $obj->notImplemented()
           See "Error handling" in Mail::Reporter

       $obj->report([LEVEL])
           See "Error handling" in Mail::Reporter

       $obj->reportAll([LEVEL])
           See "Error handling" in Mail::Reporter

       $obj->trace([LEVEL])
           See "Error handling" in Mail::Reporter

       $obj->warnings()
           See "Error handling" in Mail::Reporter

   Cleanup
       See documentation in the base class.

       $obj->DESTROY()
           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 dependend, and therefore should not be attempted.  The second lock is ignored (but the
           unlock isn't)

       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 flock file $filename for $folder: $!
           For flock-ing a folder it must be opened, which does not succeed for the specified reason.

       Error: Will never get a flock at $filename 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.

SEE ALSO

       This module is part of Mail-Box distribution version 2.110, built on January 05, 2014. Website:
       http://perl.overmeer.net/mailbox/

LICENSE

       Copyrights 2001-2014 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://www.perl.com/perl/misc/Artistic.html