phpman > perldoc > Mail::Box::Locker::POSIX(3pm)

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/