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 is equal to IPC_PRIVATE
KEY does not already have a semaphore identifier
associated with it, and FLAGS & IPC_CREAT is true.
On creation of a new semaphore set FLAGS is used to set the
permissions.
SEM to
become greater than its current value
SEM.
SEM.
SEM to
become zero.
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
$sem->op(
0, -1, IPC_NOWAIT,
1, 1, IPC_NOWAIT
);
set will set the following values of the stat structure associated
with the semaphore set.
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.
VALUES list.
VALUES must contain the correct number of values.
Nth value in the semaphore set to 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.
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.