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Revision 1.125 by root, Fri Apr 27 19:35:58 2007 UTC vs.
Revision 1.165 by root, Thu Dec 20 07:29:14 2007 UTC

6 6
7 use Coro; 7 use Coro;
8 8
9 async { 9 async {
10 # some asynchronous thread of execution 10 # some asynchronous thread of execution
11 print "2\n";
12 cede; # yield back to main
13 print "4\n";
11 }; 14 };
15 print "1\n";
16 cede; # yield to coroutine
17 print "3\n";
18 cede; # and again
12 19
13 # alternatively create an async coroutine like this: 20 # use locking
21 my $lock = new Coro::Semaphore;
22 my $locked;
14 23
15 sub some_func : Coro { 24 $lock->down;
16 # some more async code 25 $locked = 1;
17 } 26 $lock->up;
18
19 cede;
20 27
21=head1 DESCRIPTION 28=head1 DESCRIPTION
22 29
23This module collection manages coroutines. Coroutines are similar 30This module collection manages coroutines. Coroutines are similar
24to threads but don't run in parallel at the same time even on SMP 31to threads but don't run in parallel at the same time even on SMP
33is a performance win on Windows machines, and a loss everywhere else). 40is a performance win on Windows machines, and a loss everywhere else).
34 41
35In this module, coroutines are defined as "callchain + lexical variables + 42In this module, coroutines are defined as "callchain + lexical variables +
36@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, 43@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
37its own set of lexicals and its own set of perls most important global 44its own set of lexicals and its own set of perls most important global
38variables. 45variables (see L<Coro::State> for more configuration).
39 46
40=cut 47=cut
41 48
42package Coro; 49package Coro;
43 50
50 57
51our $idle; # idle handler 58our $idle; # idle handler
52our $main; # main coroutine 59our $main; # main coroutine
53our $current; # current coroutine 60our $current; # current coroutine
54 61
55our $VERSION = '3.62'; 62our $VERSION = '4.34';
56 63
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 64our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 65our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 66 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 67);
113reasons. If performance is not essential you are encouraged to use the 120reasons. If performance is not essential you are encouraged to use the
114C<Coro::current> function instead. 121C<Coro::current> function instead.
115 122
116=cut 123=cut
117 124
125$main->{desc} = "[main::]";
126
118# maybe some other module used Coro::Specific before... 127# maybe some other module used Coro::Specific before...
119$main->{specific} = $current->{specific} 128$main->{_specific} = $current->{_specific}
120 if $current; 129 if $current;
121 130
122_set_current $main; 131_set_current $main;
123 132
124sub current() { $current } 133sub current() { $current }
132This hook is overwritten by modules such as C<Coro::Timer> and 141This hook is overwritten by modules such as C<Coro::Timer> and
133C<Coro::Event> to wait on an external event that hopefully wake up a 142C<Coro::Event> to wait on an external event that hopefully wake up a
134coroutine so the scheduler can run it. 143coroutine so the scheduler can run it.
135 144
136Please note that if your callback recursively invokes perl (e.g. for event 145Please note that if your callback recursively invokes perl (e.g. for event
137handlers), then it must be prepared to be called recursively. 146handlers), then it must be prepared to be called recursively itself.
138 147
139=cut 148=cut
140 149
141$idle = sub { 150$idle = sub {
142 require Carp; 151 require Carp;
149 # free coroutine data and mark as destructed 158 # free coroutine data and mark as destructed
150 $self->_destroy 159 $self->_destroy
151 or return; 160 or return;
152 161
153 # call all destruction callbacks 162 # call all destruction callbacks
154 $_->(@{$self->{status}}) 163 $_->(@{$self->{_status}})
155 for @{(delete $self->{destroy_cb}) || []}; 164 for @{(delete $self->{_on_destroy}) || []};
156} 165}
157 166
158# this coroutine is necessary because a coroutine 167# this coroutine is necessary because a coroutine
159# cannot destroy itself. 168# cannot destroy itself.
160my @destroy; 169my @destroy;
166 while @destroy; 175 while @destroy;
167 176
168 &schedule; 177 &schedule;
169 } 178 }
170}; 179};
171 180$manager->desc ("[coro manager]");
172$manager->prio (PRIO_MAX); 181$manager->prio (PRIO_MAX);
173 182
174# static methods. not really. 183# static methods. not really.
175 184
176=back 185=back
184=item async { ... } [@args...] 193=item async { ... } [@args...]
185 194
186Create a new asynchronous coroutine and return it's coroutine object 195Create a new asynchronous coroutine and return it's coroutine object
187(usually unused). When the sub returns the new coroutine is automatically 196(usually unused). When the sub returns the new coroutine is automatically
188terminated. 197terminated.
198
199See the C<Coro::State::new> constructor for info about the coroutine
200environment in which coroutines run.
189 201
190Calling C<exit> in a coroutine will do the same as calling exit outside 202Calling C<exit> in a coroutine will do the same as calling exit outside
191the coroutine. Likewise, when the coroutine dies, the program will exit, 203the coroutine. Likewise, when the coroutine dies, the program will exit,
192just as it would in the main program. 204just as it would in the main program.
193 205
214issued in case of an exception instead of terminating the program, as 226issued in case of an exception instead of terminating the program, as
215C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 227C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
216will not work in the expected way, unless you call terminate or cancel, 228will not work in the expected way, unless you call terminate or cancel,
217which somehow defeats the purpose of pooling. 229which somehow defeats the purpose of pooling.
218 230
219The priority will be reset to C<0> after each job, otherwise the coroutine 231The priority will be reset to C<0> after each job, tracing will be
220will be re-used "as-is". 232disabled, the description will be reset and the default output filehandle
233gets restored, so you can change alkl these. Otherwise the coroutine will
234be re-used "as-is": most notably if you change other per-coroutine global
235stuff such as C<$/> you need to revert that change, which is most simply
236done by using local as in C< local $/ >.
221 237
222The pool size is limited to 8 idle coroutines (this can be adjusted by 238The pool size is limited to 8 idle coroutines (this can be adjusted by
223changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 239changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
224required. 240required.
225 241
226If you are concerned about pooled coroutines growing a lot because a 242If you are concerned about pooled coroutines growing a lot because a
227single C<async_pool> used a lot of stackspace you can e.g. C<async_pool { 243single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
228terminate }> once per second or so to slowly replenish the pool. 244{ terminate }> once per second or so to slowly replenish the pool. In
245addition to that, when the stacks used by a handler grows larger than 16kb
246(adjustable with $Coro::POOL_RSS) it will also exit.
229 247
230=cut 248=cut
231 249
232our $POOL_SIZE = 8; 250our $POOL_SIZE = 8;
251our $POOL_RSS = 16 * 1024;
233our @pool; 252our @async_pool;
234 253
235sub pool_handler { 254sub pool_handler {
255 my $cb;
256
236 while () { 257 while () {
237 eval { 258 eval {
238 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 259 while () {
239 $cb->(@arg); 260 _pool_1 $cb;
261 &$cb;
262 _pool_2 $cb;
263 &schedule;
264 }
240 }; 265 };
266
267 last if $@ eq "\3async_pool terminate\2\n";
241 warn $@ if $@; 268 warn $@ if $@;
242
243 last if @pool >= $POOL_SIZE;
244 push @pool, $current;
245
246 $current->save (Coro::State::SAVE_DEF);
247 $current->prio (0);
248 schedule;
249 } 269 }
250} 270}
251 271
252sub async_pool(&@) { 272sub async_pool(&@) {
253 # this is also inlined into the unlock_scheduler 273 # this is also inlined into the unlock_scheduler
254 my $coro = (pop @pool or new Coro \&pool_handler); 274 my $coro = (pop @async_pool) || new Coro \&pool_handler;
255 275
256 $coro->{_invoke} = [@_]; 276 $coro->{_invoke} = [@_];
257 $coro->ready; 277 $coro->ready;
258 278
259 $coro 279 $coro
289 309
290"Cede" to other coroutines. This function puts the current coroutine into the 310"Cede" to other coroutines. This function puts the current coroutine into the
291ready queue and calls C<schedule>, which has the effect of giving up the 311ready queue and calls C<schedule>, which has the effect of giving up the
292current "timeslice" to other coroutines of the same or higher priority. 312current "timeslice" to other coroutines of the same or higher priority.
293 313
294Returns true if at least one coroutine switch has happened.
295
296=item Coro::cede_notself 314=item Coro::cede_notself
297 315
298Works like cede, but is not exported by default and will cede to any 316Works like cede, but is not exported by default and will cede to any
299coroutine, regardless of priority, once. 317coroutine, regardless of priority, once.
300 318
301Returns true if at least one coroutine switch has happened.
302
303=item terminate [arg...] 319=item terminate [arg...]
304 320
305Terminates the current coroutine with the given status values (see L<cancel>). 321Terminates the current coroutine with the given status values (see L<cancel>).
322
323=item killall
324
325Kills/terminates/cancels all coroutines except the currently running
326one. This is useful after a fork, either in the child or the parent, as
327usually only one of them should inherit the running coroutines.
306 328
307=cut 329=cut
308 330
309sub terminate { 331sub terminate {
310 $current->cancel (@_); 332 $current->cancel (@_);
333}
334
335sub killall {
336 for (Coro::State::list) {
337 $_->cancel
338 if $_ != $current && UNIVERSAL::isa $_, "Coro";
339 }
311} 340}
312 341
313=back 342=back
314 343
315# dynamic methods 344# dynamic methods
325Create a new coroutine and return it. When the sub returns the coroutine 354Create a new coroutine and return it. When the sub returns the coroutine
326automatically terminates as if C<terminate> with the returned values were 355automatically terminates as if C<terminate> with the returned values were
327called. To make the coroutine run you must first put it into the ready queue 356called. To make the coroutine run you must first put it into the ready queue
328by calling the ready method. 357by calling the ready method.
329 358
330See C<async> for additional discussion. 359See C<async> and C<Coro::State::new> for additional info about the
360coroutine environment.
331 361
332=cut 362=cut
333 363
334sub _run_coro { 364sub _run_coro {
335 terminate &{+shift}; 365 terminate &{+shift};
359 389
360=cut 390=cut
361 391
362sub cancel { 392sub cancel {
363 my $self = shift; 393 my $self = shift;
364 $self->{status} = [@_]; 394 $self->{_status} = [@_];
365 395
366 if ($current == $self) { 396 if ($current == $self) {
367 push @destroy, $self; 397 push @destroy, $self;
368 $manager->ready; 398 $manager->ready;
369 &schedule while 1; 399 &schedule while 1;
373} 403}
374 404
375=item $coroutine->join 405=item $coroutine->join
376 406
377Wait until the coroutine terminates and return any values given to the 407Wait until the coroutine terminates and return any values given to the
378C<terminate> or C<cancel> functions. C<join> can be called multiple times 408C<terminate> or C<cancel> functions. C<join> can be called concurrently
379from multiple coroutine. 409from multiple coroutines.
380 410
381=cut 411=cut
382 412
383sub join { 413sub join {
384 my $self = shift; 414 my $self = shift;
385 415
386 unless ($self->{status}) { 416 unless ($self->{_status}) {
387 my $current = $current; 417 my $current = $current;
388 418
389 push @{$self->{destroy_cb}}, sub { 419 push @{$self->{_on_destroy}}, sub {
390 $current->ready; 420 $current->ready;
391 undef $current; 421 undef $current;
392 }; 422 };
393 423
394 &schedule while $current; 424 &schedule while $current;
395 } 425 }
396 426
397 wantarray ? @{$self->{status}} : $self->{status}[0]; 427 wantarray ? @{$self->{_status}} : $self->{_status}[0];
398} 428}
399 429
400=item $coroutine->on_destroy (\&cb) 430=item $coroutine->on_destroy (\&cb)
401 431
402Registers a callback that is called when this coroutine gets destroyed, 432Registers a callback that is called when this coroutine gets destroyed,
406=cut 436=cut
407 437
408sub on_destroy { 438sub on_destroy {
409 my ($self, $cb) = @_; 439 my ($self, $cb) = @_;
410 440
411 push @{ $self->{destroy_cb} }, $cb; 441 push @{ $self->{_on_destroy} }, $cb;
412} 442}
413 443
414=item $oldprio = $coroutine->prio ($newprio) 444=item $oldprio = $coroutine->prio ($newprio)
415 445
416Sets (or gets, if the argument is missing) the priority of the 446Sets (or gets, if the argument is missing) the priority of the
440 470
441=item $olddesc = $coroutine->desc ($newdesc) 471=item $olddesc = $coroutine->desc ($newdesc)
442 472
443Sets (or gets in case the argument is missing) the description for this 473Sets (or gets in case the argument is missing) the description for this
444coroutine. This is just a free-form string you can associate with a coroutine. 474coroutine. This is just a free-form string you can associate with a coroutine.
475
476This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
477can modify this member directly if you wish.
478
479=item $coroutine->throw ([$scalar])
480
481If C<$throw> is specified and defined, it will be thrown as an exception
482inside the coroutine at the next convinient point in time (usually after
483it gains control at the next schedule/transfer/cede). Otherwise clears the
484exception object.
485
486The exception object will be thrown "as is" with the specified scalar in
487C<$@>, i.e. if it is a string, no line number or newline will be appended
488(unlike with C<die>).
489
490This can be used as a softer means than C<cancel> to ask a coroutine to
491end itself, although there is no guarentee that the exception will lead to
492termination, and if the exception isn't caught it might well end the whole
493program.
445 494
446=cut 495=cut
447 496
448sub desc { 497sub desc {
449 my $old = $_[0]{desc}; 498 my $old = $_[0]{desc};
525 574
526# we create a special coro because we want to cede, 575# we create a special coro because we want to cede,
527# to reduce pressure on the coro pool (because most callbacks 576# to reduce pressure on the coro pool (because most callbacks
528# return immediately and can be reused) and because we cannot cede 577# return immediately and can be reused) and because we cannot cede
529# inside an event callback. 578# inside an event callback.
530our $unblock_scheduler = async { 579our $unblock_scheduler = new Coro sub {
531 while () { 580 while () {
532 while (my $cb = pop @unblock_queue) { 581 while (my $cb = pop @unblock_queue) {
533 # this is an inlined copy of async_pool 582 # this is an inlined copy of async_pool
534 my $coro = (pop @pool or new Coro \&pool_handler); 583 my $coro = (pop @async_pool) || new Coro \&pool_handler;
535 584
536 $coro->{_invoke} = $cb; 585 $coro->{_invoke} = $cb;
537 $coro->ready; 586 $coro->ready;
538 cede; # for short-lived callbacks, this reduces pressure on the coro pool 587 cede; # for short-lived callbacks, this reduces pressure on the coro pool
539 } 588 }
540 schedule; # sleep well 589 schedule; # sleep well
541 } 590 }
542}; 591};
592$unblock_scheduler->desc ("[unblock_sub scheduler]");
543 593
544sub unblock_sub(&) { 594sub unblock_sub(&) {
545 my $cb = shift; 595 my $cb = shift;
546 596
547 sub { 597 sub {
566 to allow per-thread schedulers, but Coro::State does not yet allow 616 to allow per-thread schedulers, but Coro::State does not yet allow
567 this). 617 this).
568 618
569=head1 SEE ALSO 619=head1 SEE ALSO
570 620
621Lower level Configuration, Coroutine Environment: L<Coro::State>.
622
623Debugging: L<Coro::Debug>.
624
571Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. 625Support/Utility: L<Coro::Specific>, L<Coro::Util>.
572 626
573Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. 627Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
574 628
575Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. 629Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
576 630
631Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
632
577Embedding: L<Coro:MakeMaker> 633Embedding: L<Coro::MakeMaker>.
578 634
579=head1 AUTHOR 635=head1 AUTHOR
580 636
581 Marc Lehmann <schmorp@schmorp.de> 637 Marc Lehmann <schmorp@schmorp.de>
582 http://home.schmorp.de/ 638 http://home.schmorp.de/

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