IPC::Semaphore - SysV Semaphore IPC object class
use IPC::SysV qw(IPC_PRIVATE S_IRWXU IPC_CREAT); use IPC::Semaphore; $sem = new IPC::Semaphore(IPC_PRIVATE, 10, S_IRWXU | IPC_CREAT); $sem->setall( (0) x 10); @sem = $sem->getall; $ncnt = $sem->getncnt; $zcnt = $sem->getzcnt; $ds = $sem->stat; $sem->remove;
A class providing an object based interface to SysV IPC semaphores.
Create a new semaphore set associated with KEY. NSEMS is the number of semaphores in the set. A new set is created if
KEY
NSEMS
KEY is equal to IPC_PRIVATE
IPC_PRIVATE
KEY does not already have a semaphore identifier associated with it, and FLAGS & IPC_CREAT is true.
FLAGS & IPC_CREAT
On creation of a new semaphore set FLAGS is used to set the permissions.
FLAGS
Returns the values of the semaphore set as an array.
Returns the number of processes waiting for the semaphore SEM to become greater than its current value
SEM
Returns the process id of the last process that performed an operation on the semaphore SEM.
Returns the current value of the semaphore SEM.
Returns the number of processes waiting for the semaphore SEM to become zero.
Returns the system identifier for the semaphore set.
OPLIST is a list of operations to pass to semop. OPLIST is a concatenation of smaller lists, each which has three values. The first is the semaphore number, the second is the operation and the last is a flags value. See semop for more details. For example
OPLIST
semop
$sem->op( 0, -1, IPC_NOWAIT, 1, 1, IPC_NOWAIT );
Remove and destroy the semaphore set from the system.
set will set the following values of the stat structure associated with the semaphore set.
set
stat
uid gid mode (only the permission bits)
set accepts either a stat object, as returned by the stat method, or a list of name-value pairs.
Sets all values in the semaphore set to those given on the VALUES list. VALUES must contain the correct number of values.
VALUES
Set the Nth value in the semaphore set to VALUE
N
VALUE
Returns an object of type IPC::Semaphore::stat which is a sub-class of Class::Struct. It provides the following fields. For a description of these fields see your system documentation.
IPC::Semaphore::stat
Class::Struct
uid gid cuid cgid mode ctime otime nsems
IPC::SysV Class::Struct semget semctl semop
Graham Barr <gbarr@pobox.com>
Copyright (c) 1997 Graham Barr. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Env, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Env
CPAN shell
perl -MCPAN -e shell install Env
For more information on module installation, please visit the detailed CPAN module installation guide.