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/cvs/Coro/Coro.pm
Revision: 1.8
Committed: Sat Jul 14 22:14:21 2001 UTC (22 years, 10 months ago) by root
Branch: MAIN
Changes since 1.7: +141 -83 lines
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File Contents

# Content
1 =head1 NAME
2
3 Coro - coroutine process abstraction
4
5 =head1 SYNOPSIS
6
7 use Coro;
8
9 async {
10 # some asynchronous thread of execution
11 };
12
13 # alternatively create an async process like this:
14
15 sub some_func : Coro {
16 # some more async code
17 }
18
19 yield;
20
21 =head1 DESCRIPTION
22
23 =cut
24
25 package Coro;
26
27 use Coro::State;
28
29 use base Exporter;
30
31 $VERSION = 0.03;
32
33 @EXPORT = qw(async yield schedule);
34 @EXPORT_OK = qw($current);
35
36 {
37 use subs 'async';
38
39 my @async;
40
41 # this way of handling attributes simply is NOT scalable ;()
42 sub import {
43 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
45 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
46 my ($package, $ref) = (shift, shift);
47 my @attrs;
48 for (@_) {
49 if ($_ eq "Coro") {
50 push @async, $ref;
51 } else {
52 push @attrs, @_;
53 }
54 }
55 return $old ? $old->($package, $name, @attrs) : @attrs;
56 };
57 }
58
59 sub INIT {
60 async pop @async while @async;
61 }
62 }
63
64 my $idle = new Coro sub {
65 &yield while 1;
66 };
67
68 =item $main
69
70 This coroutine represents the main program.
71
72 =cut
73
74 $main = new Coro;
75
76 =item $current
77
78 The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
79
80 =cut
81
82 # maybe some other module used Coro::Specific before...
83 if ($current) {
84 $main->{specific} = $current->{specific};
85 }
86
87 $current = $main;
88
89 # we really need priorities...
90 my @ready = (); # the ready queue. hehe, rather broken ;)
91
92 # static methods. not really.
93
94 =head2 STATIC METHODS
95
96 Static methods are actually functions that operate on the current process only.
97
98 =over 4
99
100 =item async { ... };
101
102 Create a new asynchronous process and return it's process object
103 (usually unused). When the sub returns the new process is automatically
104 terminated.
105
106 =cut
107
108 sub async(&) {
109 (new Coro $_[0])->ready;
110 }
111
112 =item schedule
113
114 Calls the scheduler. Please note that the current process will not be put
115 into the ready queue, so calling this function usually means you will
116 never be called again.
117
118 =cut
119
120 my $prev;
121
122 sub schedule {
123 ($prev, $current) = ($current, shift @ready);
124 Coro::State::transfer($prev, $current);
125 }
126
127 =item yield
128
129 Yield to other processes. This function puts the current process into the
130 ready queue and calls C<schedule>.
131
132 =cut
133
134 sub yield {
135 $current->ready;
136 &schedule;
137 }
138
139 =item terminate
140
141 Terminates the current process.
142
143 =cut
144
145 sub terminate {
146 &schedule;
147 }
148
149 =back
150
151 # dynamic methods
152
153 =head2 PROCESS METHODS
154
155 These are the methods you can call on process objects.
156
157 =over 4
158
159 =item new Coro \&sub;
160
161 Create a new process and return it. When the sub returns the process
162 automatically terminates. To start the process you must first put it into
163 the ready queue by calling the ready method.
164
165 =cut
166
167 sub new {
168 my $class = shift;
169 my $proc = $_[0];
170 bless {
171 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
172 }, $class;
173 }
174
175 =item $process->ready
176
177 Put the current process into the ready queue.
178
179 =cut
180
181 sub ready {
182 push @ready, $_[0];
183 }
184
185 =back
186
187 =cut
188
189 1;
190
191 =head1 AUTHOR
192
193 Marc Lehmann <pcg@goof.com>
194 http://www.goof.com/pcg/marc/
195
196 =cut
197