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Revision 1.133 by root, Fri Sep 21 01:23:58 2007 UTC vs.
Revision 1.178 by root, Thu Apr 17 22:33:10 2008 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 = '3.7'; 62our $VERSION = '4.51';
56 63
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 64our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 65our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 66 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 67);
116=cut 123=cut
117 124
118$main->{desc} = "[main::]"; 125$main->{desc} = "[main::]";
119 126
120# maybe some other module used Coro::Specific before... 127# maybe some other module used Coro::Specific before...
121$main->{specific} = $current->{specific} 128$main->{_specific} = $current->{_specific}
122 if $current; 129 if $current;
123 130
124_set_current $main; 131_set_current $main;
125 132
126sub current() { $current } 133sub current() { $current }
134This hook is overwritten by modules such as C<Coro::Timer> and 141This hook is overwritten by modules such as C<Coro::Timer> and
135C<Coro::Event> to wait on an external event that hopefully wake up a 142C<Coro::Event> to wait on an external event that hopefully wake up a
136coroutine so the scheduler can run it. 143coroutine so the scheduler can run it.
137 144
138Please note that if your callback recursively invokes perl (e.g. for event 145Please note that if your callback recursively invokes perl (e.g. for event
139handlers), then it must be prepared to be called recursively. 146handlers), then it must be prepared to be called recursively itself.
140 147
141=cut 148=cut
142 149
143$idle = sub { 150$idle = sub {
144 require Carp; 151 require Carp;
151 # free coroutine data and mark as destructed 158 # free coroutine data and mark as destructed
152 $self->_destroy 159 $self->_destroy
153 or return; 160 or return;
154 161
155 # call all destruction callbacks 162 # call all destruction callbacks
156 $_->(@{$self->{status}}) 163 $_->(@{$self->{_status}})
157 for @{(delete $self->{destroy_cb}) || []}; 164 for @{(delete $self->{_on_destroy}) || []};
158} 165}
159 166
160# this coroutine is necessary because a coroutine 167# this coroutine is necessary because a coroutine
161# cannot destroy itself. 168# cannot destroy itself.
162my @destroy; 169my @destroy;
171 } 178 }
172}; 179};
173$manager->desc ("[coro manager]"); 180$manager->desc ("[coro manager]");
174$manager->prio (PRIO_MAX); 181$manager->prio (PRIO_MAX);
175 182
176# static methods. not really.
177
178=back 183=back
179 184
180=head2 STATIC METHODS 185=head2 STATIC METHODS
181 186
182Static methods are actually functions that operate on the current coroutine only. 187Static methods are actually functions that operate on the current coroutine only.
186=item async { ... } [@args...] 191=item async { ... } [@args...]
187 192
188Create a new asynchronous coroutine and return it's coroutine object 193Create a new asynchronous coroutine and return it's coroutine object
189(usually unused). When the sub returns the new coroutine is automatically 194(usually unused). When the sub returns the new coroutine is automatically
190terminated. 195terminated.
196
197See the C<Coro::State::new> constructor for info about the coroutine
198environment in which coroutines run.
191 199
192Calling C<exit> in a coroutine will do the same as calling exit outside 200Calling C<exit> in a coroutine will do the same as calling exit outside
193the coroutine. Likewise, when the coroutine dies, the program will exit, 201the coroutine. Likewise, when the coroutine dies, the program will exit,
194just as it would in the main program. 202just as it would in the main program.
195 203
216issued in case of an exception instead of terminating the program, as 224issued in case of an exception instead of terminating the program, as
217C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 225C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
218will not work in the expected way, unless you call terminate or cancel, 226will not work in the expected way, unless you call terminate or cancel,
219which somehow defeats the purpose of pooling. 227which somehow defeats the purpose of pooling.
220 228
221The priority will be reset to C<0> after each job, otherwise the coroutine 229The priority will be reset to C<0> after each job, tracing will be
222will be re-used "as-is". 230disabled, the description will be reset and the default output filehandle
231gets restored, so you can change alkl these. Otherwise the coroutine will
232be re-used "as-is": most notably if you change other per-coroutine global
233stuff such as C<$/> you need to revert that change, which is most simply
234done by using local as in C< local $/ >.
223 235
224The pool size is limited to 8 idle coroutines (this can be adjusted by 236The pool size is limited to 8 idle coroutines (this can be adjusted by
225changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 237changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
226required. 238required.
227 239
228If you are concerned about pooled coroutines growing a lot because a 240If you are concerned about pooled coroutines growing a lot because a
229single C<async_pool> used a lot of stackspace you can e.g. C<async_pool 241single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
230{ terminate }> once per second or so to slowly replenish the pool. In 242{ terminate }> once per second or so to slowly replenish the pool. In
231addition to that, when the stacks used by a handler grows larger than 16kb 243addition to that, when the stacks used by a handler grows larger than 16kb
232(adjustable with $Coro::MAX_POOL_RSS) it will also exit. 244(adjustable with $Coro::POOL_RSS) it will also exit.
233 245
234=cut 246=cut
235 247
236our $POOL_SIZE = 8; 248our $POOL_SIZE = 8;
237our $MAX_POOL_RSS = 16 * 1024; 249our $POOL_RSS = 16 * 1024;
238our @pool; 250our @async_pool;
239 251
240sub pool_handler { 252sub pool_handler {
253 my $cb;
254
241 while () { 255 while () {
242 $current->{desc} = "[async_pool]";
243
244 eval { 256 eval {
245 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 257 while () {
246 $cb->(@arg); 258 _pool_1 $cb;
259 &$cb;
260 _pool_2 $cb;
261 &schedule;
262 }
247 }; 263 };
264
265 last if $@ eq "\3async_pool terminate\2\n";
248 warn $@ if $@; 266 warn $@ if $@;
249
250 last if @pool >= $POOL_SIZE || $current->rss >= $MAX_POOL_RSS;
251
252 push @pool, $current;
253 $current->{desc} = "[async_pool idle]";
254 $current->save (Coro::State::SAVE_DEF);
255 $current->prio (0);
256 schedule;
257 } 267 }
258} 268}
259 269
260sub async_pool(&@) { 270sub async_pool(&@) {
261 # this is also inlined into the unlock_scheduler 271 # this is also inlined into the unlock_scheduler
262 my $coro = (pop @pool) || new Coro \&pool_handler;; 272 my $coro = (pop @async_pool) || new Coro \&pool_handler;
263 273
264 $coro->{_invoke} = [@_]; 274 $coro->{_invoke} = [@_];
265 $coro->ready; 275 $coro->ready;
266 276
267 $coro 277 $coro
297 307
298"Cede" to other coroutines. This function puts the current coroutine into the 308"Cede" to other coroutines. This function puts the current coroutine into the
299ready queue and calls C<schedule>, which has the effect of giving up the 309ready queue and calls C<schedule>, which has the effect of giving up the
300current "timeslice" to other coroutines of the same or higher priority. 310current "timeslice" to other coroutines of the same or higher priority.
301 311
302Returns true if at least one coroutine switch has happened.
303
304=item Coro::cede_notself 312=item Coro::cede_notself
305 313
306Works like cede, but is not exported by default and will cede to any 314Works like cede, but is not exported by default and will cede to any
307coroutine, regardless of priority, once. 315coroutine, regardless of priority, once.
308 316
309Returns true if at least one coroutine switch has happened.
310
311=item terminate [arg...] 317=item terminate [arg...]
312 318
313Terminates the current coroutine with the given status values (see L<cancel>). 319Terminates the current coroutine with the given status values (see L<cancel>).
320
321=item killall
322
323Kills/terminates/cancels all coroutines except the currently running
324one. This is useful after a fork, either in the child or the parent, as
325usually only one of them should inherit the running coroutines.
314 326
315=cut 327=cut
316 328
317sub terminate { 329sub terminate {
318 $current->cancel (@_); 330 $current->cancel (@_);
319} 331}
320 332
333sub killall {
334 for (Coro::State::list) {
335 $_->cancel
336 if $_ != $current && UNIVERSAL::isa $_, "Coro";
337 }
338}
339
321=back 340=back
322
323# dynamic methods
324 341
325=head2 COROUTINE METHODS 342=head2 COROUTINE METHODS
326 343
327These are the methods you can call on coroutine objects. 344These are the methods you can call on coroutine objects.
328 345
333Create a new coroutine and return it. When the sub returns the coroutine 350Create a new coroutine and return it. When the sub returns the coroutine
334automatically terminates as if C<terminate> with the returned values were 351automatically terminates as if C<terminate> with the returned values were
335called. To make the coroutine run you must first put it into the ready queue 352called. To make the coroutine run you must first put it into the ready queue
336by calling the ready method. 353by calling the ready method.
337 354
338See C<async> for additional discussion. 355See C<async> and C<Coro::State::new> for additional info about the
356coroutine environment.
339 357
340=cut 358=cut
341 359
342sub _run_coro { 360sub _run_coro {
343 terminate &{+shift}; 361 terminate &{+shift};
367 385
368=cut 386=cut
369 387
370sub cancel { 388sub cancel {
371 my $self = shift; 389 my $self = shift;
372 $self->{status} = [@_]; 390 $self->{_status} = [@_];
373 391
374 if ($current == $self) { 392 if ($current == $self) {
375 push @destroy, $self; 393 push @destroy, $self;
376 $manager->ready; 394 $manager->ready;
377 &schedule while 1; 395 &schedule while 1;
381} 399}
382 400
383=item $coroutine->join 401=item $coroutine->join
384 402
385Wait until the coroutine terminates and return any values given to the 403Wait until the coroutine terminates and return any values given to the
386C<terminate> or C<cancel> functions. C<join> can be called multiple times 404C<terminate> or C<cancel> functions. C<join> can be called concurrently
387from multiple coroutine. 405from multiple coroutines.
388 406
389=cut 407=cut
390 408
391sub join { 409sub join {
392 my $self = shift; 410 my $self = shift;
393 411
394 unless ($self->{status}) { 412 unless ($self->{_status}) {
395 my $current = $current; 413 my $current = $current;
396 414
397 push @{$self->{destroy_cb}}, sub { 415 push @{$self->{_on_destroy}}, sub {
398 $current->ready; 416 $current->ready;
399 undef $current; 417 undef $current;
400 }; 418 };
401 419
402 &schedule while $current; 420 &schedule while $current;
403 } 421 }
404 422
405 wantarray ? @{$self->{status}} : $self->{status}[0]; 423 wantarray ? @{$self->{_status}} : $self->{_status}[0];
406} 424}
407 425
408=item $coroutine->on_destroy (\&cb) 426=item $coroutine->on_destroy (\&cb)
409 427
410Registers a callback that is called when this coroutine gets destroyed, 428Registers a callback that is called when this coroutine gets destroyed,
414=cut 432=cut
415 433
416sub on_destroy { 434sub on_destroy {
417 my ($self, $cb) = @_; 435 my ($self, $cb) = @_;
418 436
419 push @{ $self->{destroy_cb} }, $cb; 437 push @{ $self->{_on_destroy} }, $cb;
420} 438}
421 439
422=item $oldprio = $coroutine->prio ($newprio) 440=item $oldprio = $coroutine->prio ($newprio)
423 441
424Sets (or gets, if the argument is missing) the priority of the 442Sets (or gets, if the argument is missing) the priority of the
448 466
449=item $olddesc = $coroutine->desc ($newdesc) 467=item $olddesc = $coroutine->desc ($newdesc)
450 468
451Sets (or gets in case the argument is missing) the description for this 469Sets (or gets in case the argument is missing) the description for this
452coroutine. This is just a free-form string you can associate with a coroutine. 470coroutine. This is just a free-form string you can associate with a coroutine.
471
472This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
473can modify this member directly if you wish.
474
475=item $coroutine->throw ([$scalar])
476
477If C<$throw> is specified and defined, it will be thrown as an exception
478inside the coroutine at the next convinient point in time (usually after
479it gains control at the next schedule/transfer/cede). Otherwise clears the
480exception object.
481
482The exception object will be thrown "as is" with the specified scalar in
483C<$@>, i.e. if it is a string, no line number or newline will be appended
484(unlike with C<die>).
485
486This can be used as a softer means than C<cancel> to ask a coroutine to
487end itself, although there is no guarentee that the exception will lead to
488termination, and if the exception isn't caught it might well end the whole
489program.
453 490
454=cut 491=cut
455 492
456sub desc { 493sub desc {
457 my $old = $_[0]{desc}; 494 my $old = $_[0]{desc};
537# inside an event callback. 574# inside an event callback.
538our $unblock_scheduler = new Coro sub { 575our $unblock_scheduler = new Coro sub {
539 while () { 576 while () {
540 while (my $cb = pop @unblock_queue) { 577 while (my $cb = pop @unblock_queue) {
541 # this is an inlined copy of async_pool 578 # this is an inlined copy of async_pool
542 my $coro = (pop @pool or new Coro \&pool_handler); 579 my $coro = (pop @async_pool) || new Coro \&pool_handler;
543 580
544 $coro->{_invoke} = $cb; 581 $coro->{_invoke} = $cb;
545 $coro->ready; 582 $coro->ready;
546 cede; # for short-lived callbacks, this reduces pressure on the coro pool 583 cede; # for short-lived callbacks, this reduces pressure on the coro pool
547 } 584 }
575 to allow per-thread schedulers, but Coro::State does not yet allow 612 to allow per-thread schedulers, but Coro::State does not yet allow
576 this). 613 this).
577 614
578=head1 SEE ALSO 615=head1 SEE ALSO
579 616
617Lower level Configuration, Coroutine Environment: L<Coro::State>.
618
619Debugging: L<Coro::Debug>.
620
580Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. 621Support/Utility: L<Coro::Specific>, L<Coro::Util>.
581 622
582Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. 623Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
583 624
584Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. 625Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
585 626
627Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
628
586Embedding: L<Coro:MakeMaker> 629Embedding: L<Coro::MakeMaker>.
587 630
588=head1 AUTHOR 631=head1 AUTHOR
589 632
590 Marc Lehmann <schmorp@schmorp.de> 633 Marc Lehmann <schmorp@schmorp.de>
591 http://home.schmorp.de/ 634 http://home.schmorp.de/

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