NAME

Win32::Semaphore - Use Win32 semaphore objects from Perl

VERSION

This document describes version 1.09 of Win32::Semaphore, released November 15, 2014 as part of Win32-IPC version 1.11.

SYNOPSIS

        require Win32::Semaphore;

        $sem = Win32::Semaphore->new($initial,$maximum,$name);
        $sem->wait;

DESCRIPTION

This module allows access to Win32 semaphore objects. The wait method and wait_all & wait_any functions are inherited from the the Win32::IPC manpage module.

Methods

$semaphore = Win32::Semaphore->new($initial, $maximum, [$name]): Constructor for a new semaphore object. $initial is the initial count, and $maximum is the maximum count for the semaphore. If $name is omitted or undef, creates an unnamed semaphore object.; If $name signifies an existing semaphore object, then $initial and $maximum are ignored and the object is opened. If this happens, $^E will be set to 183 (ERROR_ALREADY_EXISTS).
$semaphore = Win32::Semaphore->open($name): Constructor for opening an existing semaphore object.
$semaphore->release([$increment, [$previous]]): Increment the count of $semaphore by $increment (default 1). If $increment plus the semaphore's current count is more than its maximum count, the count is not changed. Returns true if the increment is successful, or zero if it fails (additional error information can be found in $^E).; The semaphore's count (before incrementing) is stored in the second argument (if any).; It is not necessary to wait on a semaphore before calling release, but you'd better know what you're doing.
$semaphore->wait([$timeout]): Wait for $semaphore's count to be nonzero, then decrement it by 1. See the Win32::IPC manpage.

Deprecated Functions and Methods

Win32::Semaphore still supports the ActiveWare syntax, but its use is deprecated.

Win32::Semaphore::Create($SemObject,$Initial,$Max,$Name): Use $SemObject = Win32::Semaphore->new($Initial,$Max,$Name) instead.
Win32::Semaphore::Open($SemObject, $Name): Use $SemObject = Win32::Semaphore->open($Name) instead.
$SemObj->Release($Count,$LastVal): Use $SemObj->release($Count,$LastVal) instead.

CONFIGURATION AND ENVIRONMENT

Win32::Semaphore requires no configuration files or environment variables.

It runs under 32-bit or 64-bit Microsoft Windows, either natively or under Cygwin.

DEPENDENCIES

the Win32::IPC manpage

INCOMPATIBILITIES

Prior to version 1.06, the Win32 IPC modules treated undef values differently. In version 1.06 and later, passing undef as the value of an optional parameter is the same as omitting that parameter. In previous versions, undef was interpreted as either the empty string or 0 (along with a warning about ``Use of uninitialized value...'').

BUGS AND LIMITATIONS

Signal handlers will not be called during the wait method. See BUGS AND LIMITATIONS in the Win32::IPC manpage for details.

AUTHOR

Christopher J. Madsen <perl AT cjmweb.net>

Please report any bugs or feature requests to <bug-Win32-IPC AT rt.cpan.org> or through the web interface at http://rt.cpan.org/Public/Bug/Report.html.

You can follow or contribute to Win32-IPC's development at https://github.com/madsen/win32-ipc.

Loosely based on the original module by ActiveWare Internet Corp., http://www.ActiveState.com

COPYRIGHT AND LICENSE

  Other modifications (c) 1997 by Gurusamy Sarathy <gsar AT cpan.org>

This module is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENSE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Win32::Semaphore - Use Win32 semaphore objects from Perl