Coro/Coro/Signal.pm

=head1 NAME

Coro::Signal - coroutine signals (binary semaphores)

=head1 SYNOPSIS

 use Coro::Signal;

 $sig = new Coro::Signal;

 $sig->wait; # wait for signal

 # ... some other "thread"

 $sig->send;

=head1 DESCRIPTION

=over 4

=cut

package Coro::Signal;

use Coro ();

$VERSION = 0.09;

=item $s = new Coro::Signal;

Create a new signal.

=cut

sub new {
   # [flag, [pid's]]
   bless [], $_[0];
}

=item $s->wait

Wait for the signal to occur. Returns immediately if the signal has been
sent before.

=cut

sub wait {
   if ($_[0][0]) {
      $_[0][0] = 0;
   } else {
      push @{$_[0][1]}, $Coro::current;
      Coro::schedule;
   }
}

=item $s->send

Send the signal, waking up I<one> waiting process or remember the signal
if no process is waiting.

=cut

sub send {
   if (@{$_[0][1]}) {
      (shift @{$_[0][1]})->ready;
   } else {
      $_[0][0] = 1;
   }
}

=item $s->broadcast

Send the signal, waking up I<all> waiting process. If no process is
waiting the signal is lost.

=cut

sub broadcast {
   (shift @{$_[0][1]})->ready while @{$_[0][1]};
}

=item $s->awaited

Return true when the signal is beign awaited by some process.

=cut

sub awaited {
   !!@{$_[0][1]};
}

1;

=back

=head1 AUTHOR

 Marc Lehmann <pcg@goof.com>
 http://www.goof.com/pcg/marc/

=cut

Revision:	1.8
Committed:	Sat Jul 21 02:49:09 2001 UTC (22 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.7:	+7 -4 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.2	Coro::Signal - coroutine signals (binary semaphores)
4	root	1.1
5			=head1 SYNOPSIS
6
7			use Coro::Signal;
8
9			$sig = new Coro::Signal;
10
11			$sig->wait; # wait for signal
12
13			# ... some other "thread"
14
15			$sig->send;
16
17			=head1 DESCRIPTION
18
19			=over 4
20
21			=cut
22
23			package Coro::Signal;
24
25	root	1.5	use Coro ();
26	root	1.1
27	root	1.8	$VERSION = 0.09;
28	root	1.1
29	root	1.3	=item $s = new Coro::Signal;
30
31			Create a new signal.
32
33			=cut
34
35	root	1.1	sub new {
36	root	1.3	# [flag, [pid's]]
37	root	1.1	bless [], $_[0];
38			}
39
40	root	1.3	=item $s->wait
41
42	root	1.8	Wait for the signal to occur. Returns immediately if the signal has been
43			sent before.
44	root	1.3
45			=cut
46
47	root	1.1	sub wait {
48	root	1.3	if ($_[0][0]) {
49			$_[0][0] = 0;
50	root	1.1	} else {
51	root	1.5	push @{$_[0][1]}, $Coro::current;
52			Coro::schedule;
53	root	1.1	}
54			}
55
56	root	1.3	=item $s->send
57
58	root	1.8	Send the signal, waking up I<one> waiting process or remember the signal
59			if no process is waiting.
60	root	1.3
61			=cut
62
63	root	1.1	sub send {
64	root	1.3	if (@{$_[0][1]}) {
65			(shift @{$_[0][1]})->ready;
66	root	1.1	} else {
67	root	1.3	$_[0][0] = 1;
68	root	1.1	}
69			}
70
71	root	1.3	=item $s->broadcast
72
73	root	1.8	Send the signal, waking up I<all> waiting process. If no process is
74			waiting the signal is lost.
75	root	1.3
76			=cut
77
78			sub broadcast {
79			(shift @{$_[0][1]})->ready while @{$_[0][1]};
80			}
81
82			=item $s->awaited
83
84			Return true when the signal is beign awaited by some process.
85
86			=cut
87
88	root	1.1	sub awaited {
89	root	1.3	!!@{$_[0][1]};
90	root	1.1	}
91
92			1;
93
94			=back
95
96			=head1 AUTHOR
97
98			Marc Lehmann <pcg@goof.com>
99			http://www.goof.com/pcg/marc/
100
101			=cut
102