ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC vs.
Revision 1.35 by root, Mon Sep 24 00:16:30 2001 UTC

… …
14 14
15 sub some_func : Coro { 15 sub some_func : Coro {
16 # some more async code 16 # some more async code
17 } 17 }
18 18
19 yield; 19 cede;
20 20
21=head1 DESCRIPTION 21=head1 DESCRIPTION
22 22
23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel.
25
26This module is still experimental, see the BUGS section below.
27
28In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most
31important global variables.
32
23=cut 33=cut
24 34
25package Coro; 35package Coro;
26 36
27use Coro::State; 37use Coro::State;
28 38
29use base Exporter; 39use base Exporter;
30 40
31$VERSION = 0.04; 41$VERSION = 0.5;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($current); 44%EXPORT_TAGS = (
45 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46);
47@EXPORT_OK = @{$EXPORT_TAGS{prio}};
35 48
36{ 49{
37 use subs 'async';
38
39 my @async; 50 my @async;
51 my $init;
40 52
41 # this way of handling attributes simply is NOT scalable ;() 53 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 54 sub import {
43 Coro->export_to_level(1, @_); 55 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
46 my ($package, $ref) = (shift, shift); 58 my ($package, $ref) = (shift, shift);
47 my @attrs; 59 my @attrs;
48 for (@_) { 60 for (@_) {
49 if ($_ eq "Coro") { 61 if ($_ eq "Coro") {
50 push @async, $ref; 62 push @async, $ref;
63 unless ($init++) {
64 eval q{
65 sub INIT {
66 &async(pop @async) while @async;
67 }
68 };
69 }
51 } else { 70 } else {
52 push @attrs, @_; 71 push @attrs, $_;
53 } 72 }
54 } 73 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 74 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 75 };
57 } 76 }
58 77
59 sub INIT {
60 async pop @async while @async;
61 }
62} 78}
63 79
64=item $main 80=item $main
65 81
66This coroutine represents the main program. 82This coroutine represents the main program.
67 83
68=cut 84=cut
69 85
70our $main = new Coro; 86our $main = new Coro;
71 87
72=item $current 88=item $current (or as function: current)
73 89
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 90The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 91
76=cut 92=cut
77 93
… …
79if ($current) { 95if ($current) {
80 $main->{specific} = $current->{specific}; 96 $main->{specific} = $current->{specific};
81} 97}
82 98
83our $current = $main; 99our $current = $main;
100
101sub current() { $current }
84 102
85=item $idle 103=item $idle
86 104
87The coroutine to switch to when no other coroutine is running. The default 105The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 106implementation prints "FATAL: deadlock detected" and exits.
… …
93our $idle = new Coro sub { 111our $idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 112 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 113 exit(51);
96}; 114};
97 115
98# we really need priorities... 116# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 117# cannot destroy itself.
118my @destroy;
119my $manager = new Coro sub {
120 while() {
121 delete ((pop @destroy)->{_coro_state}) while @destroy;
122 &schedule;
123 }
124};
100 125
101# static methods. not really. 126# static methods. not really.
102 127
103=head2 STATIC METHODS 128=head2 STATIC METHODS
104 129
105Static methods are actually functions that operate on the current process only. 130Static methods are actually functions that operate on the current process only.
106 131
107=over 4 132=over 4
108 133
109=item async { ... }; 134=item async { ... } [@args...]
110 135
111Create a new asynchronous process and return it's process object 136Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 137(usually unused). When the sub returns the new process is automatically
113terminated. 138terminated.
114 139
115=cut 140 # create a new coroutine that just prints its arguments
141 async {
142 print "@_\n";
143 } 1,2,3,4;
116 144
145The coderef you submit MUST NOT be a closure that refers to variables
146in an outer scope. This does NOT work. Pass arguments into it instead.
147
148=cut
149
117sub async(&) { 150sub async(&@) {
118 my $pid = new Coro $_[0]; 151 my $pid = new Coro @_;
152 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 153 $pid->ready;
120 $pid; 154 $pid;
121} 155}
122 156
123=item schedule 157=item schedule
… …
126into the ready queue, so calling this function usually means you will 160into the ready queue, so calling this function usually means you will
127never be called again. 161never be called again.
128 162
129=cut 163=cut
130 164
131my $prev;
132
133sub schedule {
134 # should be done using priorities :(
135 ($prev, $current) = ($current, shift @ready || $idle);
136 Coro::State::transfer($prev, $current);
137}
138
139=item yield 165=item cede
140 166
141Yield to other processes. This function puts the current process into the 167"Cede" to other processes. This function puts the current process into the
142ready queue and calls C<schedule>. 168ready queue and calls C<schedule>, which has the effect of giving up the
169current "timeslice" to other coroutines of the same or higher priority.
143 170
144=cut 171=cut
145 172
146sub yield { 173=item terminate
174
175Terminates the current process.
176
177Future versions of this function will allow result arguments.
178
179=cut
180
181sub terminate {
147 $current->ready; 182 $current->cancel;
148 &schedule; 183 &schedule;
149} 184 die; # NORETURN
150
151=item terminate
152
153Terminates the current process.
154
155=cut
156
157sub terminate {
158 &schedule;
159} 185}
160 186
161=back 187=back
162 188
163# dynamic methods 189# dynamic methods
… …
166 192
167These are the methods you can call on process objects. 193These are the methods you can call on process objects.
168 194
169=over 4 195=over 4
170 196
171=item new Coro \&sub; 197=item new Coro \&sub [, @args...]
172 198
173Create a new process and return it. When the sub returns the process 199Create a new process and return it. When the sub returns the process
174automatically terminates. To start the process you must first put it into 200automatically terminates. To start the process you must first put it into
175the ready queue by calling the ready method. 201the ready queue by calling the ready method.
176 202
203The coderef you submit MUST NOT be a closure that refers to variables
204in an outer scope. This does NOT work. Pass arguments into it instead.
205
177=cut 206=cut
207
208sub _newcoro {
209 terminate &{+shift};
210}
178 211
179sub new { 212sub new {
180 my $class = shift; 213 my $class = shift;
181 my $proc = $_[0];
182 bless { 214 bless {
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 215 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
184 }, $class; 216 }, $class;
185} 217}
186 218
187=item $process->ready 219=item $process->ready
188 220
189Put the current process into the ready queue. 221Put the current process into the ready queue.
190 222
191=cut 223=cut
192 224
193sub ready { 225=item $process->cancel
226
227Like C<terminate>, but terminates the specified process instead.
228
229=cut
230
231sub cancel {
194 push @ready, $_[0]; 232 push @destroy, $_[0];
233 $manager->ready;
234 &schedule if $current == $_[0];
235}
236
237=item $oldprio = $process->prio($newprio)
238
239Sets the priority of the process. Higher priority processes get run before
240lower priority processes. Priorities are smalled signed integer (currently
241-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
242tag :prio to get then):
243
244 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
245 3 > 1 > 0 > -1 > -3 > -4
246
247 # set priority to HIGH
248 current->prio(PRIO_HIGH);
249
250The idle coroutine ($Coro::idle) always has a lower priority than any
251existing coroutine.
252
253Changing the priority of the current process will take effect immediately,
254but changing the priority of processes in the ready queue (but not
255running) will only take effect after the next schedule (of that
256process). This is a bug that will be fixed in some future version.
257
258=cut
259
260sub prio {
261 my $old = $_[0]{prio};
262 $_[0]{prio} = $_[1] if @_ > 1;
263 $old;
264}
265
266=item $newprio = $process->nice($change)
267
268Similar to C<prio>, but subtract the given value from the priority (i.e.
269higher values mean lower priority, just as in unix).
270
271=cut
272
273sub nice {
274 $_[0]{prio} -= $_[1];
195} 275}
196 276
197=back 277=back
198 278
199=cut 279=cut
200 280
2011; 2811;
202 282
283=head1 BUGS/LIMITATIONS
284
285 - you must make very sure that no coro is still active on global destruction.
286 very bad things might happen otherwise (usually segfaults).
287 - this module is not thread-safe. You must only ever use this module from
288 the same thread (this requirement might be loosened in the future to
289 allow per-thread schedulers, but Coro::State does not yet allow this).
290
203=head1 SEE ALSO 291=head1 SEE ALSO
204 292
205L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 293L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
206L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 294L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
295L<Coro::Handle>, L<Coro::Socket>.
207 296
208=head1 AUTHOR 297=head1 AUTHOR
209 298
210 Marc Lehmann <pcg@goof.com> 299 Marc Lehmann <pcg@goof.com>
211 http://www.goof.com/pcg/marc/ 300 http://www.goof.com/pcg/marc/

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines