NAME

Mail::Box::Locker::NFS - lock a folder with a separate file, NFS-safe

INHERITANCE

 Mail::Box::Locker::NFS
   is a Mail::Box::Locker
   is a Mail::Reporter

SYNOPSIS

 See Mail::Box::Locker

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.

METHODS

Constructors

Mail::Box::Locker::NFS->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  'NFS'
  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

$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

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

Error handling

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

$obj->DESTROY: See "Cleanup" in Mail::Box::Locker
$obj->inGlobalDestruction: See "Cleanup" in Mail::Reporter

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.

LICENSE

Copyrights 2001-2011 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