Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / devtools / amd64 / lib / perl5 / 5.8.8 / i86pc-solaris-64-ld / IPC / Msg.pm

# IPC::Msg.pm
#
# Copyright (c) 1997 Graham Barr <gbarr@pobox.com>. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.

package IPC::Msg;

use IPC::SysV qw(IPC_STAT IPC_SET IPC_RMID);
use strict;
use vars qw($VERSION);
use Carp;

$VERSION = "1.02";
$VERSION = eval $VERSION;

{
   package IPC::Msg::stat;

   use Class::Struct qw(struct);

   struct 'IPC::Msg::stat' => [
       uid     => '$',
       gid     => '$',
       cuid    => '$',
       cgid    => '$',
       mode    => '$',
       qnum    => '$',
       qbytes  => '$',
       lspid   => '$',
       lrpid   => '$',
       stime   => '$',
       rtime   => '$',
       ctime   => '$',
   ];
}

sub new {
   @_ == 3 || croak 'new IPC::Msg ( KEY , FLAGS )';
   my $class = shift;

   my $id = msgget($_[0],$_[1]);

   defined($id)
       ? bless \$id, $class
       : undef;
}

sub id {
   my $self = shift;
   $$self;
}

sub stat {
   my $self = shift;
   my $data = "";
   msgctl($$self,IPC_STAT,$data) or
       return undef;
   IPC::Msg::stat->new->unpack($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);
   }

   msgctl($$self,IPC_SET,$ds->pack);
}

sub remove {
   my $self = shift;
   (msgctl($$self,IPC_RMID,0), undef $$self)[0];
}

sub rcv {
   @_ <= 5 && @_ >= 3 or croak '$msg->rcv( BUF, LEN, TYPE, FLAGS )';
   my $self = shift;
   my $buf = "";
   msgrcv($$self,$buf,$_[1],$_[2] || 0, $_[3] || 0) or
       return;
   my $type;
   ($type,$_[0]) = unpack("l! a*",$buf);
   $type;
}

sub snd {
   @_ <= 4 && @_ >= 3 or  croak '$msg->snd( TYPE, BUF, FLAGS )';
   my $self = shift;
   msgsnd($$self,pack("l! a*",$_[0],$_[1]), $_[2] || 0);
}


1;

__END__

=head1 NAME

IPC::Msg - SysV Msg IPC object class

=head1 SYNOPSIS

   use IPC::SysV qw(IPC_PRIVATE S_IRWXU);
   use IPC::Msg;

   $msg = new IPC::Msg(IPC_PRIVATE, S_IRWXU);

   $msg->snd(pack("l! a*",$msgtype,$msg));

   $msg->rcv($buf,256);

   $ds = $msg->stat;

   $msg->remove;

=head1 DESCRIPTION

A class providing an object based interface to SysV IPC message queues.

=head1 METHODS

=over 4

=item new ( KEY , FLAGS )

Creates a new message queue associated with C<KEY>. A new queue is
created if

=over 4

=item *

C<KEY> is equal to C<IPC_PRIVATE>

=item *

C<KEY> does not already  have  a  message queue
associated with it, and C<I<FLAGS> & IPC_CREAT> is true.

=back

On creation of a new message queue C<FLAGS> is used to set the
permissions.

=item id

Returns the system message queue identifier.

=item rcv ( BUF, LEN [, TYPE [, FLAGS ]] )

Read a message from the queue. Returns the type of the message read.
See L<msgrcv>.  The  BUF becomes tainted.

=item remove

Remove and destroy the message queue 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 message queue.

   uid
   gid
   mode (oly the permission bits)
   qbytes

C<set> accepts either a stat object, as returned by the C<stat> method,
or a list of I<name>-I<value> pairs.

=item snd ( TYPE, MSG [, FLAGS ] )

Place a message on the queue with the data from C<MSG> and with type C<TYPE>.
See L<msgsnd>.

=item stat

Returns an object of type C<IPC::Msg::stat> which is a sub-class of
C<Class::Struct>. It provides the following fields. For a description
of these fields see you system documentation.

   uid
   gid
   cuid
   cgid
   mode
   qnum
   qbytes
   lspid
   lrpid
   stime
   rtime
   ctime

=back

=head1 SEE ALSO

L<IPC::SysV> L<Class::Struct>

=head1 AUTHOR

Graham Barr <gbarr@pobox.com>

=head1 COPYRIGHT

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.

=cut