JezK
Edit File: Semaphore.pm
################################################################################ # # Version 2.x, Copyright (C) 2007-2013, Marcus Holland-Moritz <mhx@cpan.org>. # Version 1.x, Copyright (C) 1997, Graham Barr <gbarr@pobox.com>. # # This program is free software; you can redistribute it and/or # modify it under the same terms as Perl itself. # ################################################################################ package IPC::Semaphore; use IPC::SysV qw(GETNCNT GETZCNT GETVAL SETVAL GETPID GETALL SETALL IPC_STAT IPC_SET IPC_RMID); use strict; use vars qw($VERSION); use Carp; $VERSION = '2.07'; # Figure out if we have support for native sized types my $N = do { my $foo = eval { pack "L!", 0 }; $@ ? '' : '!' }; { package IPC::Semaphore::stat; use Class::Struct qw(struct); struct 'IPC::Semaphore::stat' => [ uid => '$', gid => '$', cuid => '$', cgid => '$', mode => '$', ctime => '$', otime => '$', nsems => '$', ]; } sub new { @_ == 4 || croak 'new ' . __PACKAGE__ . '( KEY, NSEMS, FLAGS )'; my $class = shift; my $id = semget($_[0],$_[1],$_[2]); defined($id) ? bless \$id, $class : undef; } sub id { my $self = shift; $$self; } sub remove { my $self = shift; my $result = semctl($$self,0,IPC_RMID,0); undef $$self; $result; } sub getncnt { @_ == 2 || croak '$sem->getncnt( SEM )'; my $self = shift; my $sem = shift; my $v = semctl($$self,$sem,GETNCNT,0); $v ? 0 + $v : undef; } sub getzcnt { @_ == 2 || croak '$sem->getzcnt( SEM )'; my $self = shift; my $sem = shift; my $v = semctl($$self,$sem,GETZCNT,0); $v ? 0 + $v : undef; } sub getval { @_ == 2 || croak '$sem->getval( SEM )'; my $self = shift; my $sem = shift; my $v = semctl($$self,$sem,GETVAL,0); $v ? 0 + $v : undef; } sub getpid { @_ == 2 || croak '$sem->getpid( SEM )'; my $self = shift; my $sem = shift; my $v = semctl($$self,$sem,GETPID,0); $v ? 0 + $v : undef; } sub op { @_ >= 4 || croak '$sem->op( OPLIST )'; my $self = shift; croak 'Bad arg count' if @_ % 3; my $data = pack("s$N*",@_); semop($$self,$data); } sub stat { my $self = shift; my $data = ""; semctl($$self,0,IPC_STAT,$data) or return undef; IPC::Semaphore::stat->new->unpack($data); } sub set { my $self = shift; my $ds; if(@_ == 1) { $ds = shift; } else { croak 'Bad arg count' if @_ % 2; my %arg = @_; $ds = $self->stat or return undef; my($key,$val); $ds->$key($val) while(($key,$val) = each %arg); } my $v = semctl($$self,0,IPC_SET,$ds->pack); $v ? 0 + $v : undef; } sub getall { my $self = shift; my $data = ""; semctl($$self,0,GETALL,$data) or return (); (unpack("s$N*",$data)); } sub setall { my $self = shift; my $data = pack("s$N*",@_); semctl($$self,0,SETALL,$data); } sub setval { @_ == 3 || croak '$sem->setval( SEM, VAL )'; my $self = shift; my $sem = shift; my $val = shift; semctl($$self,$sem,SETVAL,$val); } 1; __END__ =head1 NAME IPC::Semaphore - SysV Semaphore IPC object class =head1 SYNOPSIS use IPC::SysV qw(IPC_PRIVATE S_IRUSR S_IWUSR IPC_CREAT); use IPC::Semaphore; $sem = IPC::Semaphore->new(IPC_PRIVATE, 10, S_IRUSR | S_IWUSR | IPC_CREAT); $sem->setall( (0) x 10); @sem = $sem->getall; $ncnt = $sem->getncnt; $zcnt = $sem->getzcnt; $ds = $sem->stat; $sem->remove; =head1 DESCRIPTION A class providing an object based interface to SysV IPC semaphores. =head1 METHODS =over 4 =item new ( KEY , NSEMS , FLAGS ) Create a new semaphore set associated with C<KEY>. C<NSEMS> is the number of semaphores in the set. A new set is created if =over 4 =item * C<KEY> is equal to C<IPC_PRIVATE> =item * C<KEY> does not already have a semaphore identifier associated with it, and C<I<FLAGS> & IPC_CREAT> is true. =back On creation of a new semaphore set C<FLAGS> is used to set the permissions. Be careful not to set any flags that the Sys V IPC implementation does not allow: in some systems setting execute bits makes the operations fail. =item getall Returns the values of the semaphore set as an array. =item getncnt ( SEM ) Returns the number of processes waiting for the semaphore C<SEM> to become greater than its current value =item getpid ( SEM ) Returns the process id of the last process that performed an operation on the semaphore C<SEM>. =item getval ( SEM ) Returns the current value of the semaphore C<SEM>. =item getzcnt ( SEM ) Returns the number of processes waiting for the semaphore C<SEM> to become zero. =item id Returns the system identifier for the semaphore set. =item op ( OPLIST ) C<OPLIST> is a list of operations to pass to C<semop>. C<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 L<semop(2)> for more details. For example $sem->op( 0, -1, IPC_NOWAIT, 1, 1, IPC_NOWAIT ); =item remove Remove and destroy the semaphore set from the system. =item set ( STAT ) =item set ( NAME => VALUE [, NAME => VALUE ...] ) C<set> will set the following values of the C<stat> structure associated with the semaphore set. uid gid mode (only the permission bits) C<set> accepts either a stat object, as returned by the C<stat> method, or a list of I<name>-I<value> pairs. =item setall ( VALUES ) Sets all values in the semaphore set to those given on the C<VALUES> list. C<VALUES> must contain the correct number of values. =item setval ( N , VALUE ) Set the C<N>th value in the semaphore set to C<VALUE> =item stat Returns an object of type C<IPC::Semaphore::stat> which is a sub-class of C<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 =back =head1 SEE ALSO L<IPC::SysV>, L<Class::Struct>, L<semget(2)>, L<semctl(2)>, L<semop(2)> =head1 AUTHORS Graham Barr <gbarr@pobox.com>, Marcus Holland-Moritz <mhx@cpan.org> =head1 COPYRIGHT Version 2.x, Copyright (C) 2007-2013, Marcus Holland-Moritz. Version 1.x, Copyright (c) 1997, Graham Barr. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut