Mail::Box::Locker::POSIX

Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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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.

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/