… | |
… | |
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; |
… | |
… | |
35 | parallel access are rarely an issue, making coroutine programming much |
36 | parallel access are rarely an issue, making coroutine programming much |
36 | safer and easier than threads programming. |
37 | safer and easier than threads programming. |
37 | |
38 | |
38 | Unlike a normal perl program, however, coroutines allow you to have |
39 | Unlike a normal perl program, however, coroutines allow you to have |
39 | multiple running interpreters that share data, which is especially useful |
40 | multiple running interpreters that share data, which is especially useful |
40 | to code pseudo-parallel processes, such as multiple HTTP-GET requests |
41 | to code pseudo-parallel processes and for event-based programming, such as |
41 | running concurrently. |
42 | multiple HTTP-GET requests running concurrently. See L<Coro::AnyEvent> to |
|
|
43 | learn more. |
42 | |
44 | |
43 | Coroutines are also useful because Perl has no support for threads (the so |
45 | Coroutines are also useful because Perl has no support for threads (the so |
44 | called "threads" that perl offers are nothing more than the (bad) process |
46 | called "threads" that perl offers are nothing more than the (bad) process |
45 | emulation coming from the Windows platform: On standard operating systems |
47 | emulation coming from the Windows platform: On standard operating systems |
46 | they serve no purpose whatsoever, except by making your programs slow and |
48 | they serve no purpose whatsoever, except by making your programs slow and |
… | |
… | |
54 | |
56 | |
55 | =cut |
57 | =cut |
56 | |
58 | |
57 | package Coro; |
59 | package Coro; |
58 | |
60 | |
59 | use strict; |
61 | use strict qw(vars subs); |
60 | no warnings "uninitialized"; |
62 | no warnings "uninitialized"; |
61 | |
63 | |
62 | use Coro::State; |
64 | use Coro::State; |
63 | |
65 | |
64 | use base qw(Coro::State Exporter); |
66 | use base qw(Coro::State Exporter); |
65 | |
67 | |
66 | our $idle; # idle handler |
68 | our $idle; # idle handler |
67 | our $main; # main coroutine |
69 | our $main; # main coroutine |
68 | our $current; # current coroutine |
70 | our $current; # current coroutine |
69 | |
71 | |
70 | our $VERSION = 4.6; |
72 | our $VERSION = 5.0; |
71 | |
73 | |
72 | 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); |
73 | our %EXPORT_TAGS = ( |
75 | our %EXPORT_TAGS = ( |
74 | 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)], |
75 | ); |
77 | ); |
… | |
… | |
80 | =item $Coro::main |
82 | =item $Coro::main |
81 | |
83 | |
82 | This variable stores the coroutine object that represents the main |
84 | This variable stores the coroutine object that represents the main |
83 | program. While you cna C<ready> it and do most other things you can do to |
85 | program. While you cna C<ready> it and do most other things you can do to |
84 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
86 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
85 | wether you are running in the main program or not. |
87 | whether you are running in the main program or not. |
86 | |
88 | |
87 | =cut |
89 | =cut |
88 | |
90 | |
89 | $main = new Coro; |
91 | # $main is now being initialised by Coro::State |
90 | |
92 | |
91 | =item $Coro::current |
93 | =item $Coro::current |
92 | |
94 | |
93 | The coroutine object representing the current coroutine (the last |
95 | The coroutine object representing the current coroutine (the last |
94 | coroutine that the Coro scheduler switched to). The initial value is |
96 | coroutine that the Coro scheduler switched to). The initial value is |
95 | C<$main> (of course). |
97 | C<$Coro::main> (of course). |
96 | |
98 | |
97 | 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 |
98 | 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 |
99 | not otherwise modify the variable itself. |
101 | not otherwise modify the variable itself. |
100 | |
102 | |
101 | =cut |
103 | =cut |
102 | |
|
|
103 | $main->{desc} = "[main::]"; |
|
|
104 | |
|
|
105 | # maybe some other module used Coro::Specific before... |
|
|
106 | $main->{_specific} = $current->{_specific} |
|
|
107 | if $current; |
|
|
108 | |
|
|
109 | _set_current $main; |
|
|
110 | |
104 | |
111 | sub current() { $current } # [DEPRECATED] |
105 | sub current() { $current } # [DEPRECATED] |
112 | |
106 | |
113 | =item $Coro::idle |
107 | =item $Coro::idle |
114 | |
108 | |
… | |
… | |
150 | $self->_destroy |
144 | $self->_destroy |
151 | or return; |
145 | or return; |
152 | |
146 | |
153 | # call all destruction callbacks |
147 | # call all destruction callbacks |
154 | $_->(@{$self->{_status}}) |
148 | $_->(@{$self->{_status}}) |
155 | for @{(delete $self->{_on_destroy}) || []}; |
149 | for @{ delete $self->{_on_destroy} || [] }; |
156 | } |
150 | } |
157 | |
151 | |
158 | # this coroutine is necessary because a coroutine |
152 | # this coroutine is necessary because a coroutine |
159 | # cannot destroy itself. |
153 | # cannot destroy itself. |
160 | my @destroy; |
154 | my @destroy; |
… | |
… | |
166 | while @destroy; |
160 | while @destroy; |
167 | |
161 | |
168 | &schedule; |
162 | &schedule; |
169 | } |
163 | } |
170 | }; |
164 | }; |
171 | $manager->desc ("[coro manager]"); |
165 | $manager->{desc} = "[coro manager]"; |
172 | $manager->prio (PRIO_MAX); |
166 | $manager->prio (PRIO_MAX); |
173 | |
167 | |
174 | =back |
168 | =back |
175 | |
169 | |
176 | =head2 SIMPLE COROUTINE CREATION |
170 | =head2 SIMPLE COROUTINE CREATION |
… | |
… | |
219 | 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 |
220 | 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 |
221 | or bad :). |
215 | or bad :). |
222 | |
216 | |
223 | 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) |
224 | 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 |
225 | quick successsion, use C<async_pool>, not C<async>. |
219 | quick successsion, use C<async_pool>, not C<async>. |
226 | |
220 | |
227 | 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 |
228 | 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 |
229 | 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> |
… | |
… | |
233 | |
227 | |
234 | 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 |
235 | disabled, the description will be reset and the default output filehandle |
229 | disabled, the description will be reset and the default output filehandle |
236 | 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 |
237 | 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 |
238 | 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 |
239 | simply done by using local as in: C< local $/ >. |
233 | simply done by using local as in: C<< local $/ >>. |
240 | |
234 | |
241 | 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 |
242 | 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 |
243 | required. |
237 | coros as required. |
244 | |
238 | |
245 | 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 |
246 | 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 |
247 | { 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 |
248 | 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 |
… | |
… | |
265 | _pool_2 $cb; |
259 | _pool_2 $cb; |
266 | &schedule; |
260 | &schedule; |
267 | } |
261 | } |
268 | }; |
262 | }; |
269 | |
263 | |
|
|
264 | if ($@) { |
270 | last if $@ eq "\3async_pool terminate\2\n"; |
265 | last if $@ eq "\3async_pool terminate\2\n"; |
271 | warn $@ if $@; |
266 | warn $@; |
|
|
267 | } |
272 | } |
268 | } |
273 | } |
269 | } |
274 | |
270 | |
275 | sub async_pool(&@) { |
271 | sub async_pool(&@) { |
276 | # this is also inlined into the unlock_scheduler |
272 | # this is also inlined into the unblock_scheduler |
277 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
273 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
278 | |
274 | |
279 | $coro->{_invoke} = [@_]; |
275 | $coro->{_invoke} = [@_]; |
280 | $coro->ready; |
276 | $coro->ready; |
281 | |
277 | |
… | |
… | |
306 | This makes C<schedule> I<the> generic method to use to block the current |
302 | This makes C<schedule> I<the> generic method to use to block the current |
307 | coroutine and wait for events: first you remember the current coroutine in |
303 | coroutine and wait for events: first you remember the current coroutine in |
308 | a variable, then arrange for some callback of yours to call C<< ->ready |
304 | a variable, then arrange for some callback of yours to call C<< ->ready |
309 | >> 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 |
310 | 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, |
311 | so you need to check wether 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 |
312 | status in a variable. |
308 | status in a variable. |
313 | |
309 | |
314 | The canonical way to wait on external events is this: |
310 | The canonical way to wait on external events is this: |
315 | |
311 | |
316 | { |
312 | { |
… | |
… | |
355 | Kills/terminates/cancels all coroutines except the currently running |
351 | Kills/terminates/cancels all coroutines except the currently running |
356 | one. This is useful after a fork, either in the child or the parent, as |
352 | one. This is useful after a fork, either in the child or the parent, as |
357 | usually only one of them should inherit the running coroutines. |
353 | usually only one of them should inherit the running coroutines. |
358 | |
354 | |
359 | Note that while this will try to free some of the main programs resources, |
355 | Note that while this will try to free some of the main programs resources, |
360 | you cnanot free all of them, so if a coroutine that is not the main |
356 | you cannot free all of them, so if a coroutine that is not the main |
361 | program calls this function, there will be some one-time resource leak. |
357 | program calls this function, there will be some one-time resource leak. |
362 | |
358 | |
363 | =cut |
359 | =cut |
364 | |
360 | |
365 | sub terminate { |
361 | sub terminate { |
… | |
… | |
414 | once all the coroutines of higher priority and all coroutines of the same |
410 | once all the coroutines of higher priority and all coroutines of the same |
415 | priority that were put into the ready queue earlier have been resumed. |
411 | priority that were put into the ready queue earlier have been resumed. |
416 | |
412 | |
417 | =item $is_ready = $coroutine->is_ready |
413 | =item $is_ready = $coroutine->is_ready |
418 | |
414 | |
419 | Return wether the coroutine is currently the ready queue or not, |
415 | Return whether the coroutine is currently the ready queue or not, |
420 | |
416 | |
421 | =item $coroutine->cancel (arg...) |
417 | =item $coroutine->cancel (arg...) |
422 | |
418 | |
423 | Terminates the given coroutine and makes it return the given arguments as |
419 | Terminates the given coroutine and makes it return the given arguments as |
424 | status (default: the empty list). Never returns if the coroutine is the |
420 | status (default: the empty list). Never returns if the coroutine is the |
… | |
… | |
437 | } else { |
433 | } else { |
438 | $self->_cancel; |
434 | $self->_cancel; |
439 | } |
435 | } |
440 | } |
436 | } |
441 | |
437 | |
|
|
438 | =item $coroutine->throw ([$scalar]) |
|
|
439 | |
|
|
440 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
441 | inside the coroutine at the next convenient point in time (usually after |
|
|
442 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
443 | exception object. |
|
|
444 | |
|
|
445 | The exception object will be thrown "as is" with the specified scalar in |
|
|
446 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
447 | (unlike with C<die>). |
|
|
448 | |
|
|
449 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
450 | end itself, although there is no guarantee that the exception will lead to |
|
|
451 | termination, and if the exception isn't caught it might well end the whole |
|
|
452 | program. |
|
|
453 | |
|
|
454 | You might also think of C<throw> as being the moral equivalent of |
|
|
455 | C<kill>ing a coroutine with a signal (in this case, a scalar). |
|
|
456 | |
442 | =item $coroutine->join |
457 | =item $coroutine->join |
443 | |
458 | |
444 | Wait until the coroutine terminates and return any values given to the |
459 | Wait until the coroutine terminates and return any values given to the |
445 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
460 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
446 | from multiple coroutines, and all will be resumed and given the status |
461 | from multiple coroutines, and all will be resumed and given the status |
… | |
… | |
507 | higher values mean lower priority, just as in unix). |
522 | higher values mean lower priority, just as in unix). |
508 | |
523 | |
509 | =item $olddesc = $coroutine->desc ($newdesc) |
524 | =item $olddesc = $coroutine->desc ($newdesc) |
510 | |
525 | |
511 | Sets (or gets in case the argument is missing) the description for this |
526 | Sets (or gets in case the argument is missing) the description for this |
512 | coroutine. This is just a free-form string you can associate with a coroutine. |
527 | coroutine. This is just a free-form string you can associate with a |
|
|
528 | coroutine. |
513 | |
529 | |
514 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
530 | This method simply sets the C<< $coroutine->{desc} >> member to the given |
515 | can modify this member directly if you wish. |
531 | string. You can modify this member directly if you wish. |
516 | |
|
|
517 | =item $coroutine->throw ([$scalar]) |
|
|
518 | |
|
|
519 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
520 | inside the coroutine at the next convinient point in time (usually after |
|
|
521 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
522 | exception object. |
|
|
523 | |
|
|
524 | The exception object will be thrown "as is" with the specified scalar in |
|
|
525 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
526 | (unlike with C<die>). |
|
|
527 | |
|
|
528 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
529 | end itself, although there is no guarentee that the exception will lead to |
|
|
530 | termination, and if the exception isn't caught it might well end the whole |
|
|
531 | program. |
|
|
532 | |
532 | |
533 | =cut |
533 | =cut |
534 | |
534 | |
535 | sub desc { |
535 | sub desc { |
536 | my $old = $_[0]{desc}; |
536 | my $old = $_[0]{desc}; |
… | |
… | |
610 | creating event callbacks that want to block. |
610 | creating event callbacks that want to block. |
611 | |
611 | |
612 | If your handler does not plan to block (e.g. simply sends a message to |
612 | If your handler does not plan to block (e.g. simply sends a message to |
613 | another coroutine, or puts some other coroutine into the ready queue), |
613 | another coroutine, or puts some other coroutine into the ready queue), |
614 | there is no reason to use C<unblock_sub>. |
614 | there is no reason to use C<unblock_sub>. |
|
|
615 | |
|
|
616 | Note that you also need to use C<unblock_sub> for any other callbacks that |
|
|
617 | are indirectly executed by any C-based event loop. For example, when you |
|
|
618 | use a module that uses L<AnyEvent> (and you use L<Coro::AnyEvent>) and it |
|
|
619 | provides callbacks that are the result of some event callback, then you |
|
|
620 | must not block either, or use C<unblock_sub>. |
615 | |
621 | |
616 | =cut |
622 | =cut |
617 | |
623 | |
618 | our @unblock_queue; |
624 | our @unblock_queue; |
619 | |
625 | |
… | |
… | |
632 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
638 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
633 | } |
639 | } |
634 | schedule; # sleep well |
640 | schedule; # sleep well |
635 | } |
641 | } |
636 | }; |
642 | }; |
637 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
643 | $unblock_scheduler->{desc} = "[unblock_sub scheduler]"; |
638 | |
644 | |
639 | sub unblock_sub(&) { |
645 | sub unblock_sub(&) { |
640 | my $cb = shift; |
646 | my $cb = shift; |
641 | |
647 | |
642 | sub { |
648 | sub { |
… | |
… | |
651 | |
657 | |
652 | 1; |
658 | 1; |
653 | |
659 | |
654 | =head1 BUGS/LIMITATIONS |
660 | =head1 BUGS/LIMITATIONS |
655 | |
661 | |
|
|
662 | =over 4 |
|
|
663 | |
|
|
664 | =item fork with pthread backend |
|
|
665 | |
|
|
666 | When Coro is compiled using the pthread backend (which isn't recommended |
|
|
667 | but required on many BSDs as their libcs are completely broken), then |
|
|
668 | coroutines will not survive a fork. There is no known workaround except to |
|
|
669 | fix your libc and use a saner backend. |
|
|
670 | |
|
|
671 | =item perl process emulation ("threads") |
|
|
672 | |
656 | This module is not perl-pseudo-thread-safe. You should only ever use this |
673 | This module is not perl-pseudo-thread-safe. You should only ever use this |
657 | module from the same thread (this requirement might be removed in the |
674 | module from the same thread (this requirement might be removed in the |
658 | future to allow per-thread schedulers, but Coro::State does not yet allow |
675 | future to allow per-thread schedulers, but Coro::State does not yet allow |
659 | this). I recommend disabling thread support and using processes, as this |
676 | this). I recommend disabling thread support and using processes, as having |
660 | is much faster and uses less memory. |
677 | the windows process emulation enabled under unix roughly halves perl |
|
|
678 | performance, even when not used. |
|
|
679 | |
|
|
680 | =item coroutine switching not signal safe |
|
|
681 | |
|
|
682 | You must not switch to another coroutine from within a signal handler |
|
|
683 | (only relevant with %SIG - most event libraries provide safe signals). |
|
|
684 | |
|
|
685 | That means you I<MUST NOT> call any function that might "block" the |
|
|
686 | current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or |
|
|
687 | anything that calls those. Everything else, including calling C<ready>, |
|
|
688 | works. |
|
|
689 | |
|
|
690 | =back |
|
|
691 | |
661 | |
692 | |
662 | =head1 SEE ALSO |
693 | =head1 SEE ALSO |
663 | |
694 | |
664 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
695 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
665 | |
696 | |