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Comparing Coro/Coro.pm (file contents):
Revision 1.14 by root, Tue Jul 17 02:21:56 2001 UTC vs.
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 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 23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel. 24threads but don't run in parallel.
25 25
26This module is still experimental, see the BUGS section below. 26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
32use Coro::State; 37use Coro::State;
33 38
39use vars qw($idle $main $current);
40
34use base Exporter; 41use base Exporter;
35 42
36$VERSION = 0.05; 43$VERSION = 0.8;
37 44
38@EXPORT = qw(async yield schedule terminate); 45@EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($current); 46%EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48);
49@EXPORT_OK = @{$EXPORT_TAGS{prio}};
40 50
41{ 51{
42 use subs 'async';
43
44 my @async; 52 my @async;
53 my $init;
45 54
46 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 56 sub import {
48 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
51 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
52 my @attrs; 61 my @attrs;
53 for (@_) { 62 for (@_) {
54 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
55 push @async, $ref; 64 push @async, $ref;
65 unless ($init++) {
66 eval q{
67 sub INIT {
68 &async(pop @async) while @async;
69 }
70 };
71 }
56 } else { 72 } else {
57 push @attrs, @_; 73 push @attrs, $_;
58 } 74 }
59 } 75 }
60 return $old ? $old->($package, $name, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 77 };
62 } 78 }
63 79
64 sub INIT {
65 async pop @async while @async;
66 }
67} 80}
81
82=over 4
68 83
69=item $main 84=item $main
70 85
71This coroutine represents the main program. 86This coroutine represents the main program.
72 87
73=cut 88=cut
74 89
75our $main = new Coro; 90$main = new Coro;
76 91
77=item $current 92=item $current (or as function: current)
78 93
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
80 95
81=cut 96=cut
82 97
83# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
84if ($current) { 99if ($current) {
85 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
86} 101}
87 102
88our $current = $main; 103$current = $main;
104
105sub current() { $current }
89 106
90=item $idle 107=item $idle
91 108
92The coroutine to switch to when no other coroutine is running. The default 109The coroutine to switch to when no other coroutine is running. The default
93implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
94 111
95=cut 112=cut
96 113
97# should be done using priorities :( 114# should be done using priorities :(
98our $idle = new Coro sub { 115$idle = new Coro sub {
99 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
100 exit(51); 117 exit(51);
101}; 118};
102 119
103# we really need priorities... 120# this coroutine is necessary because a coroutine
104## my @ready; #d# 121# cannot destroy itself.
105our @ready = (); # the ready queue. hehe, rather broken ;) 122my @destroy;
123my $manager;
124$manager = new Coro sub {
125 while() {
126 # by overwriting the state object with the manager we destroy it
127 # while still being able to schedule this coroutine (in case it has
128 # been readied multiple times. this is harmless since the manager
129 # can be called as many times as neccessary and will always
130 # remove itself from the runqueue
131 while (@destroy) {
132 my $coro = pop @destroy;
133 $coro->{status} ||= [];
134 $_->ready for @{delete $coro->{join} || []};
135 $coro->{_coro_state} = $manager->{_coro_state};
136 }
137 &schedule;
138 }
139};
106 140
107# static methods. not really. 141# static methods. not really.
142
143=back
108 144
109=head2 STATIC METHODS 145=head2 STATIC METHODS
110 146
111Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
112 148
… …
128 164
129=cut 165=cut
130 166
131sub async(&@) { 167sub async(&@) {
132 my $pid = new Coro @_; 168 my $pid = new Coro @_;
169 $manager->ready; # this ensures that the stack is cloned from the manager
133 $pid->ready; 170 $pid->ready;
134 $pid; 171 $pid;
135} 172}
136 173
137=item schedule 174=item schedule
… …
140into the ready queue, so calling this function usually means you will 177into the ready queue, so calling this function usually means you will
141never be called again. 178never be called again.
142 179
143=cut 180=cut
144 181
145my $prev;
146
147sub schedule {
148 # should be done using priorities :(
149 ($prev, $current) = ($current, shift @ready || $idle);
150 Coro::State::transfer($prev, $current);
151}
152
153=item yield 182=item cede
154 183
155Yield to other processes. This function puts the current process into the 184"Cede" to other processes. This function puts the current process into the
156ready queue and calls C<schedule>. 185ready queue and calls C<schedule>, which has the effect of giving up the
186current "timeslice" to other coroutines of the same or higher priority.
157 187
158=cut 188=cut
159 189
160sub yield { 190=item terminate [arg...]
191
192Terminates the current process.
193
194Future versions of this function will allow result arguments.
195
196=cut
197
198sub terminate {
199 $current->{status} = [@_];
161 $current->ready; 200 $current->cancel;
162 &schedule; 201 &schedule;
163} 202 die; # NORETURN
164
165=item terminate
166
167Terminates the current process.
168
169Future versions of this function will allow result arguments.
170
171=cut
172
173sub terminate {
174 $current->{_results} = [@_];
175 &schedule;
176} 203}
177 204
178=back 205=back
179 206
180# dynamic methods 207# dynamic methods
… …
186=over 4 213=over 4
187 214
188=item new Coro \&sub [, @args...] 215=item new Coro \&sub [, @args...]
189 216
190Create a new process and return it. When the sub returns the process 217Create a new process and return it. When the sub returns the process
191automatically terminates. To start the process you must first put it into 218automatically terminates as if C<terminate> with the returned values were
219called. To make the process run you must first put it into the ready queue
192the ready queue by calling the ready method. 220by calling the ready method.
193
194The coderef you submit MUST NOT be a closure that refers to variables
195in an outer scope. This does NOT work. Pass arguments into it instead.
196 221
197=cut 222=cut
198 223
199sub _newcoro { 224sub _newcoro {
200 terminate &{+shift}; 225 terminate &{+shift};
… …
207 }, $class; 232 }, $class;
208} 233}
209 234
210=item $process->ready 235=item $process->ready
211 236
212Put the current process into the ready queue. 237Put the given process into the ready queue.
213 238
214=cut 239=cut
215 240
216sub ready { 241=item $process->cancel
242
243Like C<terminate>, but terminates the specified process instead.
244
245=cut
246
247sub cancel {
217 push @ready, $_[0]; 248 push @destroy, $_[0];
249 $manager->ready;
250 &schedule if $current == $_[0];
251}
252
253=item $process->join
254
255Wait until the coroutine terminates and return any values given to the
256C<terminate> function. C<join> can be called multiple times from multiple
257processes.
258
259=cut
260
261sub join {
262 my $self = shift;
263 unless ($self->{status}) {
264 push @{$self->{join}}, $current;
265 &schedule;
266 }
267 wantarray ? @{$self->{status}} : $self->{status}[0];
268}
269
270=item $oldprio = $process->prio($newprio)
271
272Sets (or gets, if the argument is missing) the priority of the
273process. Higher priority processes get run before lower priority
274processes. Priorities are small signed integers (currently -4 .. +3),
275that you can refer to using PRIO_xxx constants (use the import tag :prio
276to get then):
277
278 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279 3 > 1 > 0 > -1 > -3 > -4
280
281 # set priority to HIGH
282 current->prio(PRIO_HIGH);
283
284The idle coroutine ($Coro::idle) always has a lower priority than any
285existing coroutine.
286
287Changing the priority of the current process will take effect immediately,
288but changing the priority of processes in the ready queue (but not
289running) will only take effect after the next schedule (of that
290process). This is a bug that will be fixed in some future version.
291
292=cut
293
294sub prio {
295 my $old = $_[0]{prio};
296 $_[0]{prio} = $_[1] if @_ > 1;
297 $old;
298}
299
300=item $newprio = $process->nice($change)
301
302Similar to C<prio>, but subtract the given value from the priority (i.e.
303higher values mean lower priority, just as in unix).
304
305=cut
306
307sub nice {
308 $_[0]{prio} -= $_[1];
309}
310
311=item $olddesc = $process->desc($newdesc)
312
313Sets (or gets in case the argument is missing) the description for this
314process. This is just a free-form string you can associate with a process.
315
316=cut
317
318sub desc {
319 my $old = $_[0]{desc};
320 $_[0]{desc} = $_[1] if @_ > 1;
321 $old;
218} 322}
219 323
220=back 324=back
221 325
222=cut 326=cut
223 327
2241; 3281;
225 329
226=head1 BUGS 330=head1 BUGS/LIMITATIONS
227 331
228 - could be faster, especially when the core would introduce special 332 - you must make very sure that no coro is still active on global
229 support for coroutines (like it does for threads). 333 destruction. very bad things might happen otherwise (usually segfaults).
230 - there is still a memleak on coroutine termination that I could not 334
231 identify. Could be as small as a single SV. 335 - this module is not thread-safe. You should only ever use this module
232 - this module is not well-tested. 336 from the same thread (this requirement might be losened in the future
337 to allow per-thread schedulers, but Coro::State does not yet allow
338 this).
233 339
234=head1 SEE ALSO 340=head1 SEE ALSO
235 341
236L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
237L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
238 345
239=head1 AUTHOR 346=head1 AUTHOR
240 347
241 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <pcg@goof.com>
242 http://www.goof.com/pcg/marc/ 349 http://www.goof.com/pcg/marc/

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