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;
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 <EM>FLAGS</EM> & IPC_CREAT is true.
On creation of a new semaphore set FLAGS is used to set the permissions.
SEM to become greater than it's 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 the semop manpage 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 (oly 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
IPC::Semaphore::stat which is a sub-class of
Class::Struct. It provides the following fields. For a description of these fields see
you system documentation.
uid
gid
cuid
cgid
mode
ctime
otime
nsems
SysV Struct the semget manpage the semctl manpage the semop manpage
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.
If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.