IPC::Semaphore
See the current Perl documentation for IPC::Semaphore.
Here is our local, out-dated (pre-5.6) version:
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-&g
- new ( KEY , NSEMS , FLAGS )
-
Create a new semaphore set associated with
KEY . NSEMS is the number of semaphores in the set.
A new set is created if
On creation of a new semaphore set FLAGS is used to set the permissions.
- getall
-
Returns the values of the semaphore set as an array.
- getncnt ( SEM )
-
Returns the number of processed waiting for the semaphore
SEM to become greater than it's current value
- getpid ( SEM )
-
Returns the process id of the last process that performed an operation on
the semaphore
SEM .
- getval ( SEM )
-
Returns the current value of the semaphore
SEM .
- getzcnt ( SEM )
-
Returns the number of processed waiting for the semaphore
SEM to become zero.
- id
-
Returns the system identifier for the semaphore set.
- op ( OPLIST )
-
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
);
- remove
-
Remove and destroy the semaphore set from the system.
- set ( STAT )
-
- set ( NAME => VALUE [, NAME => VALUE ...] )
-
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.
- setall ( VALUES )
-
Sets all values in the semaphore set to those given on the
VALUES list.
VALUES must contain the correct number of values.
- setval ( N , VALUE )
-
Set the
N th value in the semaphore set to VALUE
- stat
-
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
you system documentation.
uid
gid
cuid
cgid
mode
ctime
otime
nsems
SysV 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.
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