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Comparing Coro/Coro.pm (file contents):
Revision 1.21 by root, Sun Jul 22 03:24:10 2001 UTC vs.
Revision 1.54 by pcg, Sun Sep 28 09:00:48 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
26This module is still experimental, see the BUGS section below.
27 25
28In this module, coroutines are defined as "callchain + lexical variables 26In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's 27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30own set of lexicals and it's own set of perl's most important global 28callchain, it's own set of lexicals and it's own set of perl's most
31variables. 29important global variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38 30
39=cut 31=cut
40 32
41package Coro; 33package Coro;
42 34
35no warnings qw(uninitialized);
36
43use Coro::State; 37use Coro::State;
44 38
45use base Exporter; 39use base Exporter;
46 40
47$VERSION = 0.10; 41$VERSION = 0.7;
48 42
49@EXPORT = qw(async yield schedule terminate current); 43@EXPORT = qw(async cede schedule terminate current);
50@EXPORT_OK = qw($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}};
51 48
52{ 49{
53 my @async; 50 my @async;
51 my $init;
54 52
55 # this way of handling attributes simply is NOT scalable ;() 53 # this way of handling attributes simply is NOT scalable ;()
56 sub import { 54 sub import {
57 Coro->export_to_level(1, @_); 55 Coro->export_to_level(1, @_);
58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
60 my ($package, $ref) = (shift, shift); 58 my ($package, $ref) = (shift, shift);
61 my @attrs; 59 my @attrs;
62 for (@_) { 60 for (@_) {
63 if ($_ eq "Coro") { 61 if ($_ eq "Coro") {
64 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 }
65 } else { 70 } else {
66 push @attrs, $_; 71 push @attrs, $_;
67 } 72 }
68 } 73 }
69 return $old ? $old->($package, $ref, @attrs) : @attrs; 74 return $old ? $old->($package, $ref, @attrs) : @attrs;
70 }; 75 };
71 } 76 }
72 77
73 sub INIT {
74 &async(pop @async) while @async;
75 }
76} 78}
79
80=over 4
77 81
78=item $main 82=item $main
79 83
80This coroutine represents the main program. 84This coroutine represents the main program.
81 85
… …
109our $idle = new Coro sub { 113our $idle = new Coro sub {
110 print STDERR "FATAL: deadlock detected\n"; 114 print STDERR "FATAL: deadlock detected\n";
111 exit(51); 115 exit(51);
112}; 116};
113 117
114# we really need priorities... 118# this coroutine is necessary because a coroutine
115my @ready; # the ready queue. hehe, rather broken ;) 119# cannot destroy itself.
120my @destroy;
121my $manager;
122$manager = new Coro sub {
123 while() {
124 # by overwriting the state object with the manager we destroy it
125 # while still being able to schedule this coroutine (in case it has
126 # been readied multiple times. this is harmless since the manager
127 # can be called as many times as neccessary and will always
128 # remove itself from the runqueue
129 while (@destroy) {
130 my $coro = pop @destroy;
131 $coro->{status} ||= [];
132 $_->ready for @{delete $coro->{join} || []};
133 $coro->{_coro_state} = $manager->{_coro_state};
134 }
135 &schedule;
136 }
137};
116 138
117# static methods. not really. 139# static methods. not really.
140
141=back
118 142
119=head2 STATIC METHODS 143=head2 STATIC METHODS
120 144
121Static methods are actually functions that operate on the current process only. 145Static methods are actually functions that operate on the current process only.
122 146
… …
138 162
139=cut 163=cut
140 164
141sub async(&@) { 165sub async(&@) {
142 my $pid = new Coro @_; 166 my $pid = new Coro @_;
167 $manager->ready; # this ensures that the stack is cloned from the manager
143 $pid->ready; 168 $pid->ready;
144 $pid; 169 $pid;
145} 170}
146 171
147=item schedule 172=item schedule
… …
150into the ready queue, so calling this function usually means you will 175into the ready queue, so calling this function usually means you will
151never be called again. 176never be called again.
152 177
153=cut 178=cut
154 179
155my $prev;
156
157sub schedule {
158 # should be done using priorities :(
159 ($prev, $current) = ($current, shift @ready || $idle);
160 Coro::State::transfer($prev, $current);
161}
162
163=item yield 180=item cede
164 181
165Yield to other processes. This function puts the current process into the 182"Cede" to other processes. This function puts the current process into the
166ready queue and calls C<schedule>. 183ready queue and calls C<schedule>, which has the effect of giving up the
184current "timeslice" to other coroutines of the same or higher priority.
167 185
168=cut 186=cut
169 187
170sub yield { 188=item terminate [arg...]
189
190Terminates the current process.
191
192Future versions of this function will allow result arguments.
193
194=cut
195
196sub terminate {
197 $current->{status} = [@_];
171 $current->ready; 198 $current->cancel;
172 &schedule; 199 &schedule;
173} 200 die; # NORETURN
174
175=item terminate
176
177Terminates the current process.
178
179Future versions of this function will allow result arguments.
180
181=cut
182
183sub terminate {
184 $current->{_results} = [@_];
185 delete $current->{_coro_state};
186 &schedule;
187} 201}
188 202
189=back 203=back
190 204
191# dynamic methods 205# dynamic methods
… …
197=over 4 211=over 4
198 212
199=item new Coro \&sub [, @args...] 213=item new Coro \&sub [, @args...]
200 214
201Create a new process and return it. When the sub returns the process 215Create a new process and return it. When the sub returns the process
202automatically terminates. To start the process you must first put it into 216automatically terminates as if C<terminate> with the returned values were
217called. To make the process run you must first put it into the ready queue
203the ready queue by calling the ready method. 218by calling the ready method.
204
205The coderef you submit MUST NOT be a closure that refers to variables
206in an outer scope. This does NOT work. Pass arguments into it instead.
207 219
208=cut 220=cut
209 221
210sub _newcoro { 222sub _newcoro {
211 terminate &{+shift}; 223 terminate &{+shift};
… …
218 }, $class; 230 }, $class;
219} 231}
220 232
221=item $process->ready 233=item $process->ready
222 234
223Put the current process into the ready queue. 235Put the given process into the ready queue.
224 236
225=cut 237=cut
226 238
227sub ready { 239=item $process->cancel
240
241Like C<terminate>, but terminates the specified process instead.
242
243=cut
244
245sub cancel {
228 push @ready, $_[0]; 246 push @destroy, $_[0];
247 $manager->ready;
248 &schedule if $current == $_[0];
249}
250
251=item $process->join
252
253Wait until the coroutine terminates and return any values given to the
254C<terminate> function. C<join> can be called multiple times from multiple
255processes.
256
257=cut
258
259sub join {
260 my $self = shift;
261 unless ($self->{status}) {
262 push @{$self->{join}}, $current;
263 &schedule;
264 }
265 wantarray ? @{$self->{status}} : $self->{status}[0];
266}
267
268=item $oldprio = $process->prio($newprio)
269
270Sets (or gets, if the argument is missing) the priority of the
271process. Higher priority processes get run before lower priority
272processes. Priorities are small signed integers (currently -4 .. +3),
273that you can refer to using PRIO_xxx constants (use the import tag :prio
274to get then):
275
276 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
277 3 > 1 > 0 > -1 > -3 > -4
278
279 # set priority to HIGH
280 current->prio(PRIO_HIGH);
281
282The idle coroutine ($Coro::idle) always has a lower priority than any
283existing coroutine.
284
285Changing the priority of the current process will take effect immediately,
286but changing the priority of processes in the ready queue (but not
287running) will only take effect after the next schedule (of that
288process). This is a bug that will be fixed in some future version.
289
290=cut
291
292sub prio {
293 my $old = $_[0]{prio};
294 $_[0]{prio} = $_[1] if @_ > 1;
295 $old;
296}
297
298=item $newprio = $process->nice($change)
299
300Similar to C<prio>, but subtract the given value from the priority (i.e.
301higher values mean lower priority, just as in unix).
302
303=cut
304
305sub nice {
306 $_[0]{prio} -= $_[1];
307}
308
309=item $olddesc = $process->desc($newdesc)
310
311Sets (or gets in case the argument is missing) the description for this
312process. This is just a free-form string you can associate with a process.
313
314=cut
315
316sub desc {
317 my $old = $_[0]{desc};
318 $_[0]{desc} = $_[1] if @_ > 1;
319 $old;
229} 320}
230 321
231=back 322=back
232 323
233=cut 324=cut
234 325
2351; 3261;
236 327
237=head1 BUGS/LIMITATIONS 328=head1 BUGS/LIMITATIONS
238 329
239 - could be faster, especially when the core would introduce special 330 - you must make very sure that no coro is still active on global
240 support for coroutines (like it does for threads). 331 destruction. very bad things might happen otherwise (usually segfaults).
241 - there is still a memleak on coroutine termination that I could not 332
242 identify. Could be as small as a single SV.
243 - this module is not well-tested.
244 - if variables or arguments "disappear" (become undef) or become
245 corrupted please contact the author so he cen iron out the
246 remaining bugs.
247 - this module is not thread-safe. You must only ever use this module from 333 - this module is not thread-safe. You should only ever use this module
248 the same thread (this requirement might be loosened in the future to 334 from the same thread (this requirement might be losened in the future
249 allow per-thread schedulers, but Coro::State does not yet allow this). 335 to allow per-thread schedulers, but Coro::State does not yet allow
336 this).
250 337
251=head1 SEE ALSO 338=head1 SEE ALSO
252 339
253L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 340L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
254L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 341L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
342L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
255 343
256=head1 AUTHOR 344=head1 AUTHOR
257 345
258 Marc Lehmann <pcg@goof.com> 346 Marc Lehmann <pcg@goof.com>
259 http://www.goof.com/pcg/marc/ 347 http://www.goof.com/pcg/marc/

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