… | |
… | |
56 | |
56 | |
57 | =cut |
57 | =cut |
58 | |
58 | |
59 | package Coro; |
59 | package Coro; |
60 | |
60 | |
61 | use strict; |
61 | use strict qw(vars subs); |
62 | no warnings "uninitialized"; |
62 | no warnings "uninitialized"; |
63 | |
63 | |
64 | use Coro::State; |
64 | use Coro::State; |
65 | |
65 | |
66 | use base qw(Coro::State Exporter); |
66 | use base qw(Coro::State Exporter); |
67 | |
67 | |
68 | our $idle; # idle handler |
68 | our $idle; # idle handler |
69 | our $main; # main coroutine |
69 | our $main; # main coroutine |
70 | our $current; # current coroutine |
70 | our $current; # current coroutine |
71 | |
71 | |
72 | our $VERSION = 4.749; |
72 | our $VERSION = 5.0; |
73 | |
73 | |
74 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
74 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
75 | our %EXPORT_TAGS = ( |
75 | our %EXPORT_TAGS = ( |
76 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
76 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
77 | ); |
77 | ); |
… | |
… | |
86 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
86 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
87 | whether you are running in the main program or not. |
87 | whether you are running in the main program or not. |
88 | |
88 | |
89 | =cut |
89 | =cut |
90 | |
90 | |
91 | $main = new Coro; |
91 | # $main is now being initialised by Coro::State |
92 | |
92 | |
93 | =item $Coro::current |
93 | =item $Coro::current |
94 | |
94 | |
95 | The coroutine object representing the current coroutine (the last |
95 | The coroutine object representing the current coroutine (the last |
96 | coroutine that the Coro scheduler switched to). The initial value is |
96 | coroutine that the Coro scheduler switched to). The initial value is |
97 | C<$main> (of course). |
97 | C<$Coro::main> (of course). |
98 | |
98 | |
99 | This variable is B<strictly> I<read-only>. You can take copies of the |
99 | This variable is B<strictly> I<read-only>. You can take copies of the |
100 | value stored in it and use it as any other coroutine object, but you must |
100 | value stored in it and use it as any other coroutine object, but you must |
101 | not otherwise modify the variable itself. |
101 | not otherwise modify the variable itself. |
102 | |
102 | |
103 | =cut |
103 | =cut |
104 | |
|
|
105 | $main->{desc} = "[main::]"; |
|
|
106 | |
|
|
107 | # maybe some other module used Coro::Specific before... |
|
|
108 | $main->{_specific} = $current->{_specific} |
|
|
109 | if $current; |
|
|
110 | |
|
|
111 | _set_current $main; |
|
|
112 | |
104 | |
113 | sub current() { $current } # [DEPRECATED] |
105 | sub current() { $current } # [DEPRECATED] |
114 | |
106 | |
115 | =item $Coro::idle |
107 | =item $Coro::idle |
116 | |
108 | |
… | |
… | |
152 | $self->_destroy |
144 | $self->_destroy |
153 | or return; |
145 | or return; |
154 | |
146 | |
155 | # call all destruction callbacks |
147 | # call all destruction callbacks |
156 | $_->(@{$self->{_status}}) |
148 | $_->(@{$self->{_status}}) |
157 | for @{(delete $self->{_on_destroy}) || []}; |
149 | for @{ delete $self->{_on_destroy} || [] }; |
158 | } |
150 | } |
159 | |
151 | |
160 | # this coroutine is necessary because a coroutine |
152 | # this coroutine is necessary because a coroutine |
161 | # cannot destroy itself. |
153 | # cannot destroy itself. |
162 | my @destroy; |
154 | my @destroy; |
… | |
… | |
168 | while @destroy; |
160 | while @destroy; |
169 | |
161 | |
170 | &schedule; |
162 | &schedule; |
171 | } |
163 | } |
172 | }; |
164 | }; |
173 | $manager->desc ("[coro manager]"); |
165 | $manager->{desc} = "[coro manager]"; |
174 | $manager->prio (PRIO_MAX); |
166 | $manager->prio (PRIO_MAX); |
175 | |
167 | |
176 | =back |
168 | =back |
177 | |
169 | |
178 | =head2 SIMPLE COROUTINE CREATION |
170 | =head2 SIMPLE COROUTINE CREATION |
… | |
… | |
221 | terminate or join on it (although you are allowed to), and you get a |
213 | terminate or join on it (although you are allowed to), and you get a |
222 | coroutine that might have executed other code already (which can be good |
214 | coroutine that might have executed other code already (which can be good |
223 | or bad :). |
215 | or bad :). |
224 | |
216 | |
225 | On the plus side, this function is faster than creating (and destroying) |
217 | On the plus side, this function is faster than creating (and destroying) |
226 | a completely new coroutine, so if you need a lot of generic coroutines in |
218 | a completly new coroutine, so if you need a lot of generic coroutines in |
227 | quick successsion, use C<async_pool>, not C<async>. |
219 | quick successsion, use C<async_pool>, not C<async>. |
228 | |
220 | |
229 | The code block is executed in an C<eval> context and a warning will be |
221 | The code block is executed in an C<eval> context and a warning will be |
230 | issued in case of an exception instead of terminating the program, as |
222 | issued in case of an exception instead of terminating the program, as |
231 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
223 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
… | |
… | |
235 | |
227 | |
236 | The priority will be reset to C<0> after each run, tracing will be |
228 | The priority will be reset to C<0> after each run, tracing will be |
237 | disabled, the description will be reset and the default output filehandle |
229 | disabled, the description will be reset and the default output filehandle |
238 | gets restored, so you can change all these. Otherwise the coroutine will |
230 | gets restored, so you can change all these. Otherwise the coroutine will |
239 | be re-used "as-is": most notably if you change other per-coroutine global |
231 | be re-used "as-is": most notably if you change other per-coroutine global |
240 | stuff such as C<$/> you I<must needs> to revert that change, which is most |
232 | stuff such as C<$/> you I<must needs> revert that change, which is most |
241 | simply done by using local as in: C< local $/ >. |
233 | simply done by using local as in: C<< local $/ >>. |
242 | |
234 | |
243 | The pool size is limited to C<8> idle coroutines (this can be adjusted by |
235 | The idle pool size is limited to C<8> idle coroutines (this can be |
244 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
236 | adjusted by changing $Coro::POOL_SIZE), but there can be as many non-idle |
245 | required. |
237 | coros as required. |
246 | |
238 | |
247 | If you are concerned about pooled coroutines growing a lot because a |
239 | If you are concerned about pooled coroutines growing a lot because a |
248 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
240 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
249 | { terminate }> once per second or so to slowly replenish the pool. In |
241 | { terminate }> once per second or so to slowly replenish the pool. In |
250 | addition to that, when the stacks used by a handler grows larger than 16kb |
242 | addition to that, when the stacks used by a handler grows larger than 16kb |
… | |
… | |
275 | } |
267 | } |
276 | } |
268 | } |
277 | } |
269 | } |
278 | |
270 | |
279 | sub async_pool(&@) { |
271 | sub async_pool(&@) { |
280 | # this is also inlined into the unlock_scheduler |
272 | # this is also inlined into the unblock_scheduler |
281 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
273 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
282 | |
274 | |
283 | $coro->{_invoke} = [@_]; |
275 | $coro->{_invoke} = [@_]; |
284 | $coro->ready; |
276 | $coro->ready; |
285 | |
277 | |
… | |
… | |
313 | >> on that once some event happens, and last you call C<schedule> to put |
305 | >> on that once some event happens, and last you call C<schedule> to put |
314 | yourself to sleep. Note that a lot of things can wake your coroutine up, |
306 | yourself to sleep. Note that a lot of things can wake your coroutine up, |
315 | so you need to check whether the event indeed happened, e.g. by storing the |
307 | so you need to check whether the event indeed happened, e.g. by storing the |
316 | status in a variable. |
308 | status in a variable. |
317 | |
309 | |
318 | The canonical way to wait on external events is this: |
310 | See B<HOW TO WAIT FOR A CALLBACK>, below, for some ways to wait for callbacks. |
319 | |
|
|
320 | { |
|
|
321 | # remember current coroutine |
|
|
322 | my $current = $Coro::current; |
|
|
323 | |
|
|
324 | # register a hypothetical event handler |
|
|
325 | on_event_invoke sub { |
|
|
326 | # wake up sleeping coroutine |
|
|
327 | $current->ready; |
|
|
328 | undef $current; |
|
|
329 | }; |
|
|
330 | |
|
|
331 | # call schedule until event occurred. |
|
|
332 | # in case we are woken up for other reasons |
|
|
333 | # (current still defined), loop. |
|
|
334 | Coro::schedule while $current; |
|
|
335 | } |
|
|
336 | |
311 | |
337 | =item cede |
312 | =item cede |
338 | |
313 | |
339 | "Cede" to other coroutines. This function puts the current coroutine into |
314 | "Cede" to other coroutines. This function puts the current coroutine into |
340 | the ready queue and calls C<schedule>, which has the effect of giving |
315 | the ready queue and calls C<schedule>, which has the effect of giving |
… | |
… | |
396 | See C<async> and C<Coro::State::new> for additional info about the |
371 | See C<async> and C<Coro::State::new> for additional info about the |
397 | coroutine environment. |
372 | coroutine environment. |
398 | |
373 | |
399 | =cut |
374 | =cut |
400 | |
375 | |
401 | sub _run_coro { |
376 | sub _terminate { |
402 | terminate &{+shift}; |
377 | terminate &{+shift}; |
403 | } |
|
|
404 | |
|
|
405 | sub new { |
|
|
406 | my $class = shift; |
|
|
407 | |
|
|
408 | $class->SUPER::new (\&_run_coro, @_) |
|
|
409 | } |
378 | } |
410 | |
379 | |
411 | =item $success = $coroutine->ready |
380 | =item $success = $coroutine->ready |
412 | |
381 | |
413 | Put the given coroutine into the end of its ready queue (there is one |
382 | Put the given coroutine into the end of its ready queue (there is one |
… | |
… | |
441 | } else { |
410 | } else { |
442 | $self->_cancel; |
411 | $self->_cancel; |
443 | } |
412 | } |
444 | } |
413 | } |
445 | |
414 | |
|
|
415 | =item $coroutine->throw ([$scalar]) |
|
|
416 | |
|
|
417 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
418 | inside the coroutine at the next convenient point in time. Otherwise |
|
|
419 | clears the exception object. |
|
|
420 | |
|
|
421 | Coro will check for the exception each time a schedule-like-function |
|
|
422 | returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down |
|
|
423 | >>, C<< Coro::Handle->readable >> and so on. Most of these functions |
|
|
424 | detect this case and return early in case an exception is pending. |
|
|
425 | |
|
|
426 | The exception object will be thrown "as is" with the specified scalar in |
|
|
427 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
428 | (unlike with C<die>). |
|
|
429 | |
|
|
430 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
431 | end itself, although there is no guarantee that the exception will lead to |
|
|
432 | termination, and if the exception isn't caught it might well end the whole |
|
|
433 | program. |
|
|
434 | |
|
|
435 | You might also think of C<throw> as being the moral equivalent of |
|
|
436 | C<kill>ing a coroutine with a signal (in this case, a scalar). |
|
|
437 | |
446 | =item $coroutine->join |
438 | =item $coroutine->join |
447 | |
439 | |
448 | Wait until the coroutine terminates and return any values given to the |
440 | Wait until the coroutine terminates and return any values given to the |
449 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
441 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
450 | from multiple coroutines, and all will be resumed and given the status |
442 | from multiple coroutines, and all will be resumed and given the status |
… | |
… | |
511 | higher values mean lower priority, just as in unix). |
503 | higher values mean lower priority, just as in unix). |
512 | |
504 | |
513 | =item $olddesc = $coroutine->desc ($newdesc) |
505 | =item $olddesc = $coroutine->desc ($newdesc) |
514 | |
506 | |
515 | Sets (or gets in case the argument is missing) the description for this |
507 | Sets (or gets in case the argument is missing) the description for this |
516 | coroutine. This is just a free-form string you can associate with a coroutine. |
508 | coroutine. This is just a free-form string you can associate with a |
|
|
509 | coroutine. |
517 | |
510 | |
518 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
511 | This method simply sets the C<< $coroutine->{desc} >> member to the given |
519 | can modify this member directly if you wish. |
512 | string. You can modify this member directly if you wish. |
520 | |
|
|
521 | =item $coroutine->throw ([$scalar]) |
|
|
522 | |
|
|
523 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
524 | inside the coroutine at the next convinient point in time (usually after |
|
|
525 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
526 | exception object. |
|
|
527 | |
|
|
528 | The exception object will be thrown "as is" with the specified scalar in |
|
|
529 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
530 | (unlike with C<die>). |
|
|
531 | |
|
|
532 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
533 | end itself, although there is no guarentee that the exception will lead to |
|
|
534 | termination, and if the exception isn't caught it might well end the whole |
|
|
535 | program. |
|
|
536 | |
513 | |
537 | =cut |
514 | =cut |
538 | |
515 | |
539 | sub desc { |
516 | sub desc { |
540 | my $old = $_[0]{desc}; |
517 | my $old = $_[0]{desc}; |
… | |
… | |
642 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
619 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
643 | } |
620 | } |
644 | schedule; # sleep well |
621 | schedule; # sleep well |
645 | } |
622 | } |
646 | }; |
623 | }; |
647 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
624 | $unblock_scheduler->{desc} = "[unblock_sub scheduler]"; |
648 | |
625 | |
649 | sub unblock_sub(&) { |
626 | sub unblock_sub(&) { |
650 | my $cb = shift; |
627 | my $cb = shift; |
651 | |
628 | |
652 | sub { |
629 | sub { |
653 | unshift @unblock_queue, [$cb, @_]; |
630 | unshift @unblock_queue, [$cb, @_]; |
654 | $unblock_scheduler->ready; |
631 | $unblock_scheduler->ready; |
655 | } |
632 | } |
656 | } |
633 | } |
657 | |
634 | |
|
|
635 | =item $cb = Coro::rouse_cb |
|
|
636 | |
|
|
637 | Create and return a "rouse callback". That's a code reference that, when |
|
|
638 | called, will save its arguments and notify the owner coroutine of the |
|
|
639 | callback. |
|
|
640 | |
|
|
641 | See the next function. |
|
|
642 | |
|
|
643 | =item @args = Coro::rouse_wait [$cb] |
|
|
644 | |
|
|
645 | Wait for the specified rouse callback (or the last one tht was created in |
|
|
646 | this coroutine). |
|
|
647 | |
|
|
648 | As soon as the callback is invoked (or when the calback was invoked before |
|
|
649 | C<rouse_wait>), it will return a copy of the arguments originally passed |
|
|
650 | to the rouse callback. |
|
|
651 | |
|
|
652 | See the section B<HOW TO WAIT FOR A CALLBACK> for an actual usage example. |
|
|
653 | |
658 | =back |
654 | =back |
659 | |
655 | |
660 | =cut |
656 | =cut |
661 | |
657 | |
662 | 1; |
658 | 1; |
663 | |
659 | |
|
|
660 | =head1 HOW TO WAIT FOR A CALLBACK |
|
|
661 | |
|
|
662 | It is very common for a coroutine to wait for some callback to be |
|
|
663 | called. This occurs naturally when you use coroutines in an otherwise |
|
|
664 | event-based program, or when you use event-based libraries. |
|
|
665 | |
|
|
666 | These typically register a callback for some event, and call that callback |
|
|
667 | when the event occured. In a coroutine, however, you typically want to |
|
|
668 | just wait for the event, simplyifying things. |
|
|
669 | |
|
|
670 | For example C<< AnyEvent->child >> registers a callback to be called when |
|
|
671 | a specific child has exited: |
|
|
672 | |
|
|
673 | my $child_watcher = AnyEvent->child (pid => $pid, cb => sub { ... }); |
|
|
674 | |
|
|
675 | But from withina coroutine, you often just want to write this: |
|
|
676 | |
|
|
677 | my $status = wait_for_child $pid; |
|
|
678 | |
|
|
679 | Coro offers two functions specifically designed to make this easy, |
|
|
680 | C<Coro::rouse_cb> and C<Coro::rouse_wait>. |
|
|
681 | |
|
|
682 | The first function, C<rouse_cb>, generates and returns a callback that, |
|
|
683 | when invoked, will save it's arguments and notify the coroutine that |
|
|
684 | created the callback. |
|
|
685 | |
|
|
686 | The second function, C<rouse_wait>, waits for the callback to be called |
|
|
687 | (by calling C<schedule> to go to sleep) and returns the arguments |
|
|
688 | originally passed to the callback. |
|
|
689 | |
|
|
690 | Using these functions, it becomes easy to write the C<wait_for_child> |
|
|
691 | function mentioned above: |
|
|
692 | |
|
|
693 | sub wait_for_child($) { |
|
|
694 | my ($pid) = @_; |
|
|
695 | |
|
|
696 | my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb); |
|
|
697 | |
|
|
698 | my ($rpid, $rstatus) = Coro::rouse_wait; |
|
|
699 | $rstatus |
|
|
700 | } |
|
|
701 | |
|
|
702 | In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough, |
|
|
703 | you can roll your own, using C<schedule>: |
|
|
704 | |
|
|
705 | sub wait_for_child($) { |
|
|
706 | my ($pid) = @_; |
|
|
707 | |
|
|
708 | # store the current coroutine in $current, |
|
|
709 | # and provide result variables for the closure passed to ->child |
|
|
710 | my $current = $Coro::current; |
|
|
711 | my ($done, $rstatus); |
|
|
712 | |
|
|
713 | # pass a closure to ->child |
|
|
714 | my $watcher = AnyEvent->child (pid => $pid, cb => sub { |
|
|
715 | $rstatus = $_[1]; # remember rstatus |
|
|
716 | $done = 1; # mark $rstatus as valud |
|
|
717 | }); |
|
|
718 | |
|
|
719 | # wait until the closure has been called |
|
|
720 | schedule while !$done; |
|
|
721 | |
|
|
722 | $rstatus |
|
|
723 | } |
|
|
724 | |
|
|
725 | |
664 | =head1 BUGS/LIMITATIONS |
726 | =head1 BUGS/LIMITATIONS |
|
|
727 | |
|
|
728 | =over 4 |
|
|
729 | |
|
|
730 | =item fork with pthread backend |
|
|
731 | |
|
|
732 | When Coro is compiled using the pthread backend (which isn't recommended |
|
|
733 | but required on many BSDs as their libcs are completely broken), then |
|
|
734 | coroutines will not survive a fork. There is no known workaround except to |
|
|
735 | fix your libc and use a saner backend. |
|
|
736 | |
|
|
737 | =item perl process emulation ("threads") |
665 | |
738 | |
666 | This module is not perl-pseudo-thread-safe. You should only ever use this |
739 | This module is not perl-pseudo-thread-safe. You should only ever use this |
667 | module from the same thread (this requirement might be removed in the |
740 | module from the same thread (this requirement might be removed in the |
668 | future to allow per-thread schedulers, but Coro::State does not yet allow |
741 | future to allow per-thread schedulers, but Coro::State does not yet allow |
669 | this). I recommend disabling thread support and using processes, as this |
742 | this). I recommend disabling thread support and using processes, as having |
670 | is much faster and uses less memory. |
743 | the windows process emulation enabled under unix roughly halves perl |
|
|
744 | performance, even when not used. |
|
|
745 | |
|
|
746 | =item coroutine switching not signal safe |
|
|
747 | |
|
|
748 | You must not switch to another coroutine from within a signal handler |
|
|
749 | (only relevant with %SIG - most event libraries provide safe signals). |
|
|
750 | |
|
|
751 | That means you I<MUST NOT> call any function that might "block" the |
|
|
752 | current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or |
|
|
753 | anything that calls those. Everything else, including calling C<ready>, |
|
|
754 | works. |
|
|
755 | |
|
|
756 | =back |
|
|
757 | |
671 | |
758 | |
672 | =head1 SEE ALSO |
759 | =head1 SEE ALSO |
673 | |
760 | |
674 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
761 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
675 | |
762 | |