… | |
… | |
16 | cede; # yield to coroutine |
16 | cede; # yield to coroutine |
17 | print "3\n"; |
17 | print "3\n"; |
18 | cede; # and again |
18 | cede; # and again |
19 | |
19 | |
20 | # use locking |
20 | # use locking |
|
|
21 | use Coro::Semaphore; |
21 | my $lock = new Coro::Semaphore; |
22 | my $lock = new Coro::Semaphore; |
22 | my $locked; |
23 | my $locked; |
23 | |
24 | |
24 | $lock->down; |
25 | $lock->down; |
25 | $locked = 1; |
26 | $locked = 1; |
… | |
… | |
55 | |
56 | |
56 | =cut |
57 | =cut |
57 | |
58 | |
58 | package Coro; |
59 | package Coro; |
59 | |
60 | |
60 | use strict; |
61 | use strict qw(vars subs); |
61 | no warnings "uninitialized"; |
62 | no warnings "uninitialized"; |
62 | |
63 | |
63 | use Coro::State; |
64 | use Coro::State; |
64 | |
65 | |
65 | use base qw(Coro::State Exporter); |
66 | use base qw(Coro::State Exporter); |
66 | |
67 | |
67 | our $idle; # idle handler |
68 | our $idle; # idle handler |
68 | our $main; # main coroutine |
69 | our $main; # main coroutine |
69 | our $current; # current coroutine |
70 | our $current; # current coroutine |
70 | |
71 | |
71 | our $VERSION = '4.71'; |
72 | our $VERSION = 5.0; |
72 | |
73 | |
73 | 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); |
74 | our %EXPORT_TAGS = ( |
75 | our %EXPORT_TAGS = ( |
75 | 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)], |
76 | ); |
77 | ); |
… | |
… | |
81 | =item $Coro::main |
82 | =item $Coro::main |
82 | |
83 | |
83 | This variable stores the coroutine object that represents the main |
84 | This variable stores the coroutine object that represents the main |
84 | program. While you cna C<ready> it and do most other things you can do to |
85 | program. While you cna C<ready> it and do most other things you can do to |
85 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
86 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
86 | wether you are running in the main program or not. |
87 | whether you are running in the main program or not. |
87 | |
88 | |
88 | =cut |
89 | =cut |
89 | |
90 | |
90 | $main = new Coro; |
91 | # $main is now being initialised by Coro::State |
91 | |
92 | |
92 | =item $Coro::current |
93 | =item $Coro::current |
93 | |
94 | |
94 | The coroutine object representing the current coroutine (the last |
95 | The coroutine object representing the current coroutine (the last |
95 | coroutine that the Coro scheduler switched to). The initial value is |
96 | coroutine that the Coro scheduler switched to). The initial value is |
96 | C<$main> (of course). |
97 | C<$Coro::main> (of course). |
97 | |
98 | |
98 | 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 |
99 | 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 |
100 | not otherwise modify the variable itself. |
101 | not otherwise modify the variable itself. |
101 | |
102 | |
102 | =cut |
103 | =cut |
103 | |
|
|
104 | $main->{desc} = "[main::]"; |
|
|
105 | |
|
|
106 | # maybe some other module used Coro::Specific before... |
|
|
107 | $main->{_specific} = $current->{_specific} |
|
|
108 | if $current; |
|
|
109 | |
|
|
110 | _set_current $main; |
|
|
111 | |
104 | |
112 | sub current() { $current } # [DEPRECATED] |
105 | sub current() { $current } # [DEPRECATED] |
113 | |
106 | |
114 | =item $Coro::idle |
107 | =item $Coro::idle |
115 | |
108 | |
… | |
… | |
151 | $self->_destroy |
144 | $self->_destroy |
152 | or return; |
145 | or return; |
153 | |
146 | |
154 | # call all destruction callbacks |
147 | # call all destruction callbacks |
155 | $_->(@{$self->{_status}}) |
148 | $_->(@{$self->{_status}}) |
156 | for @{(delete $self->{_on_destroy}) || []}; |
149 | for @{ delete $self->{_on_destroy} || [] }; |
157 | } |
150 | } |
158 | |
151 | |
159 | # this coroutine is necessary because a coroutine |
152 | # this coroutine is necessary because a coroutine |
160 | # cannot destroy itself. |
153 | # cannot destroy itself. |
161 | my @destroy; |
154 | our @destroy; |
162 | my $manager; |
155 | our $manager; |
163 | |
156 | |
164 | $manager = new Coro sub { |
157 | $manager = new Coro sub { |
165 | while () { |
158 | while () { |
166 | (shift @destroy)->_cancel |
159 | (shift @destroy)->_cancel |
167 | while @destroy; |
160 | while @destroy; |
168 | |
161 | |
169 | &schedule; |
162 | &schedule; |
170 | } |
163 | } |
171 | }; |
164 | }; |
172 | $manager->desc ("[coro manager]"); |
165 | $manager->{desc} = "[coro manager]"; |
173 | $manager->prio (PRIO_MAX); |
166 | $manager->prio (PRIO_MAX); |
174 | |
167 | |
175 | =back |
168 | =back |
176 | |
169 | |
177 | =head2 SIMPLE COROUTINE CREATION |
170 | =head2 SIMPLE COROUTINE CREATION |
… | |
… | |
219 | Similar to C<async>, but uses a coroutine pool, so you should not call |
212 | Similar to C<async>, but uses a coroutine pool, so you should not call |
220 | 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 |
221 | 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 |
222 | or bad :). |
215 | or bad :). |
223 | |
216 | |
224 | On the plus side, this function is faster than creating (and destroying) |
217 | On the plus side, this function is about twice as fast as creating (and |
225 | a completely new coroutine, so if you need a lot of generic coroutines in |
218 | destroying) a completely new coroutine, so if you need a lot of generic |
226 | quick successsion, use C<async_pool>, not C<async>. |
219 | coroutines in quick successsion, use C<async_pool>, not C<async>. |
227 | |
220 | |
228 | 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 |
229 | 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 |
230 | 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> |
231 | will not work in the expected way, unless you call terminate or cancel, |
224 | will not work in the expected way, unless you call terminate or cancel, |
… | |
… | |
234 | |
227 | |
235 | 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 |
236 | disabled, the description will be reset and the default output filehandle |
229 | disabled, the description will be reset and the default output filehandle |
237 | 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 |
238 | 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 |
239 | 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 |
240 | simply done by using local as in: C< local $/ >. |
233 | simply done by using local as in: C<< local $/ >>. |
241 | |
234 | |
242 | 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 |
243 | 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 |
244 | required. |
237 | coros as required. |
245 | |
238 | |
246 | 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 |
247 | 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 |
248 | { 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 |
249 | 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 |
… | |
… | |
254 | our $POOL_SIZE = 8; |
247 | our $POOL_SIZE = 8; |
255 | our $POOL_RSS = 16 * 1024; |
248 | our $POOL_RSS = 16 * 1024; |
256 | our @async_pool; |
249 | our @async_pool; |
257 | |
250 | |
258 | sub pool_handler { |
251 | sub pool_handler { |
259 | my $cb; |
|
|
260 | |
|
|
261 | while () { |
252 | while () { |
262 | eval { |
253 | eval { |
263 | while () { |
254 | &{&_pool_handler} while 1; |
264 | _pool_1 $cb; |
|
|
265 | &$cb; |
|
|
266 | _pool_2 $cb; |
|
|
267 | &schedule; |
|
|
268 | } |
|
|
269 | }; |
255 | }; |
270 | |
256 | |
271 | last if $@ eq "\3async_pool terminate\2\n"; |
|
|
272 | warn $@ if $@; |
257 | warn $@ if $@; |
273 | } |
258 | } |
274 | } |
|
|
275 | |
|
|
276 | sub async_pool(&@) { |
|
|
277 | # this is also inlined into the unlock_scheduler |
|
|
278 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
|
|
279 | |
|
|
280 | $coro->{_invoke} = [@_]; |
|
|
281 | $coro->ready; |
|
|
282 | |
|
|
283 | $coro |
|
|
284 | } |
259 | } |
285 | |
260 | |
286 | =back |
261 | =back |
287 | |
262 | |
288 | =head2 STATIC METHODS |
263 | =head2 STATIC METHODS |
… | |
… | |
307 | This makes C<schedule> I<the> generic method to use to block the current |
282 | This makes C<schedule> I<the> generic method to use to block the current |
308 | coroutine and wait for events: first you remember the current coroutine in |
283 | coroutine and wait for events: first you remember the current coroutine in |
309 | a variable, then arrange for some callback of yours to call C<< ->ready |
284 | a variable, then arrange for some callback of yours to call C<< ->ready |
310 | >> on that once some event happens, and last you call C<schedule> to put |
285 | >> on that once some event happens, and last you call C<schedule> to put |
311 | yourself to sleep. Note that a lot of things can wake your coroutine up, |
286 | yourself to sleep. Note that a lot of things can wake your coroutine up, |
312 | so you need to check wether the event indeed happened, e.g. by storing the |
287 | so you need to check whether the event indeed happened, e.g. by storing the |
313 | status in a variable. |
288 | status in a variable. |
314 | |
289 | |
315 | The canonical way to wait on external events is this: |
290 | See B<HOW TO WAIT FOR A CALLBACK>, below, for some ways to wait for callbacks. |
316 | |
|
|
317 | { |
|
|
318 | # remember current coroutine |
|
|
319 | my $current = $Coro::current; |
|
|
320 | |
|
|
321 | # register a hypothetical event handler |
|
|
322 | on_event_invoke sub { |
|
|
323 | # wake up sleeping coroutine |
|
|
324 | $current->ready; |
|
|
325 | undef $current; |
|
|
326 | }; |
|
|
327 | |
|
|
328 | # call schedule until event occurred. |
|
|
329 | # in case we are woken up for other reasons |
|
|
330 | # (current still defined), loop. |
|
|
331 | Coro::schedule while $current; |
|
|
332 | } |
|
|
333 | |
291 | |
334 | =item cede |
292 | =item cede |
335 | |
293 | |
336 | "Cede" to other coroutines. This function puts the current coroutine into |
294 | "Cede" to other coroutines. This function puts the current coroutine into |
337 | the ready queue and calls C<schedule>, which has the effect of giving |
295 | the ready queue and calls C<schedule>, which has the effect of giving |
… | |
… | |
356 | Kills/terminates/cancels all coroutines except the currently running |
314 | Kills/terminates/cancels all coroutines except the currently running |
357 | one. This is useful after a fork, either in the child or the parent, as |
315 | one. This is useful after a fork, either in the child or the parent, as |
358 | usually only one of them should inherit the running coroutines. |
316 | usually only one of them should inherit the running coroutines. |
359 | |
317 | |
360 | Note that while this will try to free some of the main programs resources, |
318 | Note that while this will try to free some of the main programs resources, |
361 | you cnanot free all of them, so if a coroutine that is not the main |
319 | you cannot free all of them, so if a coroutine that is not the main |
362 | program calls this function, there will be some one-time resource leak. |
320 | program calls this function, there will be some one-time resource leak. |
363 | |
321 | |
364 | =cut |
322 | =cut |
365 | |
323 | |
366 | sub terminate { |
324 | sub terminate { |
367 | $current->cancel (@_); |
325 | $current->{_status} = [@_]; |
|
|
326 | push @destroy, $current; |
|
|
327 | $manager->ready; |
|
|
328 | do { &schedule } while 1; |
368 | } |
329 | } |
369 | |
330 | |
370 | sub killall { |
331 | sub killall { |
371 | for (Coro::State::list) { |
332 | for (Coro::State::list) { |
372 | $_->cancel |
333 | $_->cancel |
… | |
… | |
393 | See C<async> and C<Coro::State::new> for additional info about the |
354 | See C<async> and C<Coro::State::new> for additional info about the |
394 | coroutine environment. |
355 | coroutine environment. |
395 | |
356 | |
396 | =cut |
357 | =cut |
397 | |
358 | |
398 | sub _run_coro { |
359 | sub _terminate { |
399 | terminate &{+shift}; |
360 | terminate &{+shift}; |
400 | } |
|
|
401 | |
|
|
402 | sub new { |
|
|
403 | my $class = shift; |
|
|
404 | |
|
|
405 | $class->SUPER::new (\&_run_coro, @_) |
|
|
406 | } |
361 | } |
407 | |
362 | |
408 | =item $success = $coroutine->ready |
363 | =item $success = $coroutine->ready |
409 | |
364 | |
410 | Put the given coroutine into the end of its ready queue (there is one |
365 | Put the given coroutine into the end of its ready queue (there is one |
… | |
… | |
415 | once all the coroutines of higher priority and all coroutines of the same |
370 | once all the coroutines of higher priority and all coroutines of the same |
416 | priority that were put into the ready queue earlier have been resumed. |
371 | priority that were put into the ready queue earlier have been resumed. |
417 | |
372 | |
418 | =item $is_ready = $coroutine->is_ready |
373 | =item $is_ready = $coroutine->is_ready |
419 | |
374 | |
420 | Return wether the coroutine is currently the ready queue or not, |
375 | Return whether the coroutine is currently the ready queue or not, |
421 | |
376 | |
422 | =item $coroutine->cancel (arg...) |
377 | =item $coroutine->cancel (arg...) |
423 | |
378 | |
424 | Terminates the given coroutine and makes it return the given arguments as |
379 | Terminates the given coroutine and makes it return the given arguments as |
425 | status (default: the empty list). Never returns if the coroutine is the |
380 | status (default: the empty list). Never returns if the coroutine is the |
… | |
… | |
427 | |
382 | |
428 | =cut |
383 | =cut |
429 | |
384 | |
430 | sub cancel { |
385 | sub cancel { |
431 | my $self = shift; |
386 | my $self = shift; |
432 | $self->{_status} = [@_]; |
|
|
433 | |
387 | |
434 | if ($current == $self) { |
388 | if ($current == $self) { |
435 | push @destroy, $self; |
389 | terminate @_; |
436 | $manager->ready; |
|
|
437 | &schedule while 1; |
|
|
438 | } else { |
390 | } else { |
|
|
391 | $self->{_status} = [@_]; |
439 | $self->_cancel; |
392 | $self->_cancel; |
440 | } |
393 | } |
441 | } |
394 | } |
|
|
395 | |
|
|
396 | =item $coroutine->throw ([$scalar]) |
|
|
397 | |
|
|
398 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
399 | inside the coroutine at the next convenient point in time. Otherwise |
|
|
400 | clears the exception object. |
|
|
401 | |
|
|
402 | Coro will check for the exception each time a schedule-like-function |
|
|
403 | returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down |
|
|
404 | >>, C<< Coro::Handle->readable >> and so on. Most of these functions |
|
|
405 | detect this case and return early in case an exception is pending. |
|
|
406 | |
|
|
407 | The exception object will be thrown "as is" with the specified scalar in |
|
|
408 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
409 | (unlike with C<die>). |
|
|
410 | |
|
|
411 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
412 | end itself, although there is no guarantee that the exception will lead to |
|
|
413 | termination, and if the exception isn't caught it might well end the whole |
|
|
414 | program. |
|
|
415 | |
|
|
416 | You might also think of C<throw> as being the moral equivalent of |
|
|
417 | C<kill>ing a coroutine with a signal (in this case, a scalar). |
442 | |
418 | |
443 | =item $coroutine->join |
419 | =item $coroutine->join |
444 | |
420 | |
445 | Wait until the coroutine terminates and return any values given to the |
421 | Wait until the coroutine terminates and return any values given to the |
446 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
422 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
… | |
… | |
508 | higher values mean lower priority, just as in unix). |
484 | higher values mean lower priority, just as in unix). |
509 | |
485 | |
510 | =item $olddesc = $coroutine->desc ($newdesc) |
486 | =item $olddesc = $coroutine->desc ($newdesc) |
511 | |
487 | |
512 | Sets (or gets in case the argument is missing) the description for this |
488 | Sets (or gets in case the argument is missing) the description for this |
513 | coroutine. This is just a free-form string you can associate with a coroutine. |
489 | coroutine. This is just a free-form string you can associate with a |
|
|
490 | coroutine. |
514 | |
491 | |
515 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
492 | This method simply sets the C<< $coroutine->{desc} >> member to the given |
516 | can modify this member directly if you wish. |
493 | string. You can modify this member directly if you wish. |
517 | |
|
|
518 | =item $coroutine->throw ([$scalar]) |
|
|
519 | |
|
|
520 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
521 | inside the coroutine at the next convinient point in time (usually after |
|
|
522 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
523 | exception object. |
|
|
524 | |
|
|
525 | The exception object will be thrown "as is" with the specified scalar in |
|
|
526 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
527 | (unlike with C<die>). |
|
|
528 | |
|
|
529 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
530 | end itself, although there is no guarentee that the exception will lead to |
|
|
531 | termination, and if the exception isn't caught it might well end the whole |
|
|
532 | program. |
|
|
533 | |
494 | |
534 | =cut |
495 | =cut |
535 | |
496 | |
536 | sub desc { |
497 | sub desc { |
537 | my $old = $_[0]{desc}; |
498 | my $old = $_[0]{desc}; |
… | |
… | |
629 | # return immediately and can be reused) and because we cannot cede |
590 | # return immediately and can be reused) and because we cannot cede |
630 | # inside an event callback. |
591 | # inside an event callback. |
631 | our $unblock_scheduler = new Coro sub { |
592 | our $unblock_scheduler = new Coro sub { |
632 | while () { |
593 | while () { |
633 | while (my $cb = pop @unblock_queue) { |
594 | while (my $cb = pop @unblock_queue) { |
634 | # this is an inlined copy of async_pool |
595 | &async_pool (@$cb); |
635 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
|
|
636 | |
596 | |
637 | $coro->{_invoke} = $cb; |
|
|
638 | $coro->ready; |
|
|
639 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
597 | # for short-lived callbacks, this reduces pressure on the coro pool |
|
|
598 | # as the chance is very high that the async_poll coro will be back |
|
|
599 | # in the idle state when cede returns |
|
|
600 | cede; |
640 | } |
601 | } |
641 | schedule; # sleep well |
602 | schedule; # sleep well |
642 | } |
603 | } |
643 | }; |
604 | }; |
644 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
605 | $unblock_scheduler->{desc} = "[unblock_sub scheduler]"; |
645 | |
606 | |
646 | sub unblock_sub(&) { |
607 | sub unblock_sub(&) { |
647 | my $cb = shift; |
608 | my $cb = shift; |
648 | |
609 | |
649 | sub { |
610 | sub { |
650 | unshift @unblock_queue, [$cb, @_]; |
611 | unshift @unblock_queue, [$cb, @_]; |
651 | $unblock_scheduler->ready; |
612 | $unblock_scheduler->ready; |
652 | } |
613 | } |
653 | } |
614 | } |
654 | |
615 | |
|
|
616 | =item $cb = Coro::rouse_cb |
|
|
617 | |
|
|
618 | Create and return a "rouse callback". That's a code reference that, when |
|
|
619 | called, will save its arguments and notify the owner coroutine of the |
|
|
620 | callback. |
|
|
621 | |
|
|
622 | See the next function. |
|
|
623 | |
|
|
624 | =item @args = Coro::rouse_wait [$cb] |
|
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625 | |
|
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626 | Wait for the specified rouse callback (or the last one tht was created in |
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627 | this coroutine). |
|
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628 | |
|
|
629 | As soon as the callback is invoked (or when the calback was invoked before |
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630 | C<rouse_wait>), it will return a copy of the arguments originally passed |
|
|
631 | to the rouse callback. |
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632 | |
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633 | See the section B<HOW TO WAIT FOR A CALLBACK> for an actual usage example. |
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634 | |
655 | =back |
635 | =back |
656 | |
636 | |
657 | =cut |
637 | =cut |
658 | |
638 | |
659 | 1; |
639 | 1; |
660 | |
640 | |
|
|
641 | =head1 HOW TO WAIT FOR A CALLBACK |
|
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642 | |
|
|
643 | It is very common for a coroutine to wait for some callback to be |
|
|
644 | called. This occurs naturally when you use coroutines in an otherwise |
|
|
645 | event-based program, or when you use event-based libraries. |
|
|
646 | |
|
|
647 | These typically register a callback for some event, and call that callback |
|
|
648 | when the event occured. In a coroutine, however, you typically want to |
|
|
649 | just wait for the event, simplyifying things. |
|
|
650 | |
|
|
651 | For example C<< AnyEvent->child >> registers a callback to be called when |
|
|
652 | a specific child has exited: |
|
|
653 | |
|
|
654 | my $child_watcher = AnyEvent->child (pid => $pid, cb => sub { ... }); |
|
|
655 | |
|
|
656 | But from withina coroutine, you often just want to write this: |
|
|
657 | |
|
|
658 | my $status = wait_for_child $pid; |
|
|
659 | |
|
|
660 | Coro offers two functions specifically designed to make this easy, |
|
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661 | C<Coro::rouse_cb> and C<Coro::rouse_wait>. |
|
|
662 | |
|
|
663 | The first function, C<rouse_cb>, generates and returns a callback that, |
|
|
664 | when invoked, will save it's arguments and notify the coroutine that |
|
|
665 | created the callback. |
|
|
666 | |
|
|
667 | The second function, C<rouse_wait>, waits for the callback to be called |
|
|
668 | (by calling C<schedule> to go to sleep) and returns the arguments |
|
|
669 | originally passed to the callback. |
|
|
670 | |
|
|
671 | Using these functions, it becomes easy to write the C<wait_for_child> |
|
|
672 | function mentioned above: |
|
|
673 | |
|
|
674 | sub wait_for_child($) { |
|
|
675 | my ($pid) = @_; |
|
|
676 | |
|
|
677 | my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb); |
|
|
678 | |
|
|
679 | my ($rpid, $rstatus) = Coro::rouse_wait; |
|
|
680 | $rstatus |
|
|
681 | } |
|
|
682 | |
|
|
683 | In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough, |
|
|
684 | you can roll your own, using C<schedule>: |
|
|
685 | |
|
|
686 | sub wait_for_child($) { |
|
|
687 | my ($pid) = @_; |
|
|
688 | |
|
|
689 | # store the current coroutine in $current, |
|
|
690 | # and provide result variables for the closure passed to ->child |
|
|
691 | my $current = $Coro::current; |
|
|
692 | my ($done, $rstatus); |
|
|
693 | |
|
|
694 | # pass a closure to ->child |
|
|
695 | my $watcher = AnyEvent->child (pid => $pid, cb => sub { |
|
|
696 | $rstatus = $_[1]; # remember rstatus |
|
|
697 | $done = 1; # mark $rstatus as valud |
|
|
698 | }); |
|
|
699 | |
|
|
700 | # wait until the closure has been called |
|
|
701 | schedule while !$done; |
|
|
702 | |
|
|
703 | $rstatus |
|
|
704 | } |
|
|
705 | |
|
|
706 | |
661 | =head1 BUGS/LIMITATIONS |
707 | =head1 BUGS/LIMITATIONS |
|
|
708 | |
|
|
709 | =over 4 |
|
|
710 | |
|
|
711 | =item fork with pthread backend |
|
|
712 | |
|
|
713 | When Coro is compiled using the pthread backend (which isn't recommended |
|
|
714 | but required on many BSDs as their libcs are completely broken), then |
|
|
715 | coroutines will not survive a fork. There is no known workaround except to |
|
|
716 | fix your libc and use a saner backend. |
|
|
717 | |
|
|
718 | =item perl process emulation ("threads") |
662 | |
719 | |
663 | This module is not perl-pseudo-thread-safe. You should only ever use this |
720 | This module is not perl-pseudo-thread-safe. You should only ever use this |
664 | module from the same thread (this requirement might be removed in the |
721 | module from the same thread (this requirement might be removed in the |
665 | future to allow per-thread schedulers, but Coro::State does not yet allow |
722 | future to allow per-thread schedulers, but Coro::State does not yet allow |
666 | this). I recommend disabling thread support and using processes, as this |
723 | this). I recommend disabling thread support and using processes, as having |
667 | is much faster and uses less memory. |
724 | the windows process emulation enabled under unix roughly halves perl |
|
|
725 | performance, even when not used. |
|
|
726 | |
|
|
727 | =item coroutine switching not signal safe |
|
|
728 | |
|
|
729 | You must not switch to another coroutine from within a signal handler |
|
|
730 | (only relevant with %SIG - most event libraries provide safe signals). |
|
|
731 | |
|
|
732 | That means you I<MUST NOT> call any function that might "block" the |
|
|
733 | current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or |
|
|
734 | anything that calls those. Everything else, including calling C<ready>, |
|
|
735 | works. |
|
|
736 | |
|
|
737 | =back |
|
|
738 | |
668 | |
739 | |
669 | =head1 SEE ALSO |
740 | =head1 SEE ALSO |
670 | |
741 | |
671 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
742 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
672 | |
743 | |