… | |
… | |
16 | cede; # yield to coro |
16 | cede; # yield to coro |
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; |
|
|
22 | my $lock = new Coro::Semaphore; |
21 | my $lock = new Coro::Semaphore; |
23 | my $locked; |
22 | my $locked; |
24 | |
23 | |
25 | $lock->down; |
24 | $lock->down; |
26 | $locked = 1; |
25 | $locked = 1; |
… | |
… | |
90 | } 1, 2, 3; |
89 | } 1, 2, 3; |
91 | |
90 | |
92 | This creates a new coro thread and puts it into the ready queue, meaning |
91 | This creates a new coro thread and puts it into the ready queue, meaning |
93 | it will run as soon as the CPU is free for it. |
92 | it will run as soon as the CPU is free for it. |
94 | |
93 | |
95 | C<async> will return a coro object - you can store this for future |
94 | C<async> will return a Coro object - you can store this for future |
96 | reference or ignore it, the thread itself will keep a reference to it's |
95 | reference or ignore it - a thread that is running, ready to run or waiting |
97 | thread object - threads are alive on their own. |
96 | for some event is alive on it's own. |
98 | |
97 | |
99 | Another way to create a thread is to call the C<new> constructor with a |
98 | Another way to create a thread is to call the C<new> constructor with a |
100 | code-reference: |
99 | code-reference: |
101 | |
100 | |
102 | new Coro sub { |
101 | new Coro sub { |
… | |
… | |
131 | A lot can happen after the coro thread has started running. Quite usually, |
130 | A lot can happen after the coro thread has started running. Quite usually, |
132 | it will not run to the end in one go (because you could use a function |
131 | it will not run to the end in one go (because you could use a function |
133 | instead), but it will give up the CPU regularly because it waits for |
132 | instead), but it will give up the CPU regularly because it waits for |
134 | external events. |
133 | external events. |
135 | |
134 | |
136 | As long as a coro thread runs, it's coro object is available in the global |
135 | As long as a coro thread runs, its Coro object is available in the global |
137 | variable C<$Coro::current>. |
136 | variable C<$Coro::current>. |
138 | |
137 | |
139 | The low-level way to give up the CPU is to call the scheduler, which |
138 | The low-level way to give up the CPU is to call the scheduler, which |
140 | selects a new coro thread to run: |
139 | selects a new coro thread to run: |
141 | |
140 | |
… | |
… | |
196 | |
195 | |
197 | async { |
196 | async { |
198 | Coro::terminate "return value 1", "return value 2"; |
197 | Coro::terminate "return value 1", "return value 2"; |
199 | }; |
198 | }; |
200 | |
199 | |
201 | And yet another way is to C<< ->cancel >> the coro thread from another |
200 | Yet another way is to C<< ->cancel >> (or C<< ->safe_cancel >>) the coro |
202 | thread: |
201 | thread from another thread: |
203 | |
202 | |
204 | my $coro = async { |
203 | my $coro = async { |
205 | exit 1; |
204 | exit 1; |
206 | }; |
205 | }; |
207 | |
206 | |
208 | $coro->cancel; # an also accept values for ->join to retrieve |
207 | $coro->cancel; # also accepts values for ->join to retrieve |
209 | |
208 | |
210 | Cancellation I<can> be dangerous - it's a bit like calling C<exit> without |
209 | Cancellation I<can> be dangerous - it's a bit like calling C<exit> without |
211 | actually exiting, and might leave C libraries and XS modules in a weird |
210 | actually exiting, and might leave C libraries and XS modules in a weird |
212 | state. Unlike other thread implementations, however, Coro is exceptionally |
211 | state. Unlike other thread implementations, however, Coro is exceptionally |
213 | safe with regards to cancellation, as perl will always be in a consistent |
212 | safe with regards to cancellation, as perl will always be in a consistent |
214 | state. |
213 | state, and for those cases where you want to do truly marvellous things |
|
|
214 | with your coro while it is being cancelled - that is, make sure all |
|
|
215 | cleanup code is executed from the thread being cancelled - there is even a |
|
|
216 | C<< ->safe_cancel >> method. |
215 | |
217 | |
216 | So, cancelling a thread that runs in an XS event loop might not be the |
218 | So, cancelling a thread that runs in an XS event loop might not be the |
217 | best idea, but any other combination that deals with perl only (cancelling |
219 | best idea, but any other combination that deals with perl only (cancelling |
218 | when a thread is in a C<tie> method or an C<AUTOLOAD> for example) is |
220 | when a thread is in a C<tie> method or an C<AUTOLOAD> for example) is |
219 | safe. |
221 | safe. |
220 | |
222 | |
|
|
223 | Last not least, a coro thread object that isn't referenced is C<< |
|
|
224 | ->cancel >>'ed automatically - just like other objects in Perl. This |
|
|
225 | is not such a common case, however - a running thread is referencedy by |
|
|
226 | C<$Coro::current>, a thread ready to run is referenced by the ready queue, |
|
|
227 | a thread waiting on a lock or semaphore is referenced by being in some |
|
|
228 | wait list and so on. But a thread that isn't in any of those queues gets |
|
|
229 | cancelled: |
|
|
230 | |
|
|
231 | async { |
|
|
232 | schedule; # cede to other coros, don't go into the ready queue |
|
|
233 | }; |
|
|
234 | |
|
|
235 | cede; |
|
|
236 | # now the async above is destroyed, as it is not referenced by anything. |
|
|
237 | |
|
|
238 | A slightly embellished example might make it clearer: |
|
|
239 | |
|
|
240 | async { |
|
|
241 | my $guard = Guard::guard { print "destroyed\n" }; |
|
|
242 | schedule while 1; |
|
|
243 | }; |
|
|
244 | |
|
|
245 | cede; |
|
|
246 | |
|
|
247 | Superficially one might not expect any output - since the C<async> |
|
|
248 | implements an endless loop, the C<$guard> will not be cleaned up. However, |
|
|
249 | since the thread object returned by C<async> is not stored anywhere, the |
|
|
250 | thread is initially referenced because it is in the ready queue, when it |
|
|
251 | runs it is referenced by C<$Coro::current>, but when it calls C<schedule>, |
|
|
252 | it gets C<cancel>ed causing the guard object to be destroyed (see the next |
|
|
253 | section), and printing it's message. |
|
|
254 | |
|
|
255 | If this seems a bit drastic, remember that this only happens when nothing |
|
|
256 | references the thread anymore, which means there is no way to further |
|
|
257 | execute it, ever. The only options at this point are leaking the thread, |
|
|
258 | or cleaning it up, which brings us to... |
|
|
259 | |
221 | =item 5. Cleanup |
260 | =item 5. Cleanup |
222 | |
261 | |
223 | Threads will allocate various resources. Most but not all will be returned |
262 | Threads will allocate various resources. Most but not all will be returned |
224 | when a thread terminates, during clean-up. |
263 | when a thread terminates, during clean-up. |
225 | |
264 | |
… | |
… | |
243 | |
282 | |
244 | my $sem = new Coro::Semaphore; |
283 | my $sem = new Coro::Semaphore; |
245 | |
284 | |
246 | async { |
285 | async { |
247 | my $lock_guard = $sem->guard; |
286 | my $lock_guard = $sem->guard; |
248 | # if we reutrn, or die or get cancelled, here, |
287 | # if we return, or die or get cancelled, here, |
249 | # then the semaphore will be "up"ed. |
288 | # then the semaphore will be "up"ed. |
250 | }; |
289 | }; |
251 | |
290 | |
252 | The C<Guard::guard> function comes in handy for any custom cleanup you |
291 | The C<Guard::guard> function comes in handy for any custom cleanup you |
253 | might want to do: |
292 | might want to do (but you cannot switch to other coroutines from those |
|
|
293 | code blocks): |
254 | |
294 | |
255 | async { |
295 | async { |
256 | my $window = new Gtk2::Window "toplevel"; |
296 | my $window = new Gtk2::Window "toplevel"; |
257 | # The window will not be cleaned up automatically, even when $window |
297 | # The window will not be cleaned up automatically, even when $window |
258 | # gets freed, so use a guard to ensure it's destruction |
298 | # gets freed, so use a guard to ensure it's destruction |
… | |
… | |
271 | # if we return or die here, the description will be restored |
311 | # if we return or die here, the description will be restored |
272 | } |
312 | } |
273 | |
313 | |
274 | =item 6. Viva La Zombie Muerte |
314 | =item 6. Viva La Zombie Muerte |
275 | |
315 | |
276 | Even after a thread has terminated and cleaned up it's resources, the coro |
316 | Even after a thread has terminated and cleaned up its resources, the Coro |
277 | object still is there and stores the return values of the thread. Only in |
317 | object still is there and stores the return values of the thread. |
278 | this state will the coro object be "reference counted" in the normal perl |
|
|
279 | sense: the thread code keeps a reference to it when it is active, but not |
|
|
280 | after it has terminated. |
|
|
281 | |
318 | |
282 | The means the coro object gets freed automatically when the thread has |
319 | When there are no other references, it will simply be cleaned up and |
283 | terminated and cleaned up and there arenot other references. |
320 | freed. |
284 | |
321 | |
285 | If there are, the coro object will stay around, and you can call C<< |
322 | If there areany references, the Coro object will stay around, and you |
286 | ->join >> as many times as you wish to retrieve the result values: |
323 | can call C<< ->join >> as many times as you wish to retrieve the result |
|
|
324 | values: |
287 | |
325 | |
288 | async { |
326 | async { |
289 | print "hi\n"; |
327 | print "hi\n"; |
290 | 1 |
328 | 1 |
291 | }; |
329 | }; |
… | |
… | |
328 | |
366 | |
329 | our $idle; # idle handler |
367 | our $idle; # idle handler |
330 | our $main; # main coro |
368 | our $main; # main coro |
331 | our $current; # current coro |
369 | our $current; # current coro |
332 | |
370 | |
333 | our $VERSION = 5.372; |
371 | our $VERSION = 6.41; |
334 | |
372 | |
335 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub rouse_cb rouse_wait); |
373 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub rouse_cb rouse_wait); |
336 | our %EXPORT_TAGS = ( |
374 | our %EXPORT_TAGS = ( |
337 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
375 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
338 | ); |
376 | ); |
… | |
… | |
343 | =over 4 |
381 | =over 4 |
344 | |
382 | |
345 | =item $Coro::main |
383 | =item $Coro::main |
346 | |
384 | |
347 | This variable stores the Coro object that represents the main |
385 | This variable stores the Coro object that represents the main |
348 | program. While you cna C<ready> it and do most other things you can do to |
386 | program. While you can C<ready> it and do most other things you can do to |
349 | coro, it is mainly useful to compare again C<$Coro::current>, to see |
387 | coro, it is mainly useful to compare again C<$Coro::current>, to see |
350 | whether you are running in the main program or not. |
388 | whether you are running in the main program or not. |
351 | |
389 | |
352 | =cut |
390 | =cut |
353 | |
391 | |
… | |
… | |
399 | our @destroy; |
437 | our @destroy; |
400 | our $manager; |
438 | our $manager; |
401 | |
439 | |
402 | $manager = new Coro sub { |
440 | $manager = new Coro sub { |
403 | while () { |
441 | while () { |
404 | Coro::State::cancel shift @destroy |
442 | _destroy shift @destroy |
405 | while @destroy; |
443 | while @destroy; |
406 | |
444 | |
407 | &schedule; |
445 | &schedule; |
408 | } |
446 | } |
409 | }; |
447 | }; |
… | |
… | |
543 | coro, regardless of priority. This is useful sometimes to ensure |
581 | coro, regardless of priority. This is useful sometimes to ensure |
544 | progress is made. |
582 | progress is made. |
545 | |
583 | |
546 | =item terminate [arg...] |
584 | =item terminate [arg...] |
547 | |
585 | |
548 | Terminates the current coro with the given status values (see L<cancel>). |
586 | Terminates the current coro with the given status values (see |
|
|
587 | L<cancel>). The values will not be copied, but referenced directly. |
549 | |
588 | |
550 | =item Coro::on_enter BLOCK, Coro::on_leave BLOCK |
589 | =item Coro::on_enter BLOCK, Coro::on_leave BLOCK |
551 | |
590 | |
552 | These function install enter and leave winders in the current scope. The |
591 | These function install enter and leave winders in the current scope. The |
553 | enter block will be executed when on_enter is called and whenever the |
592 | enter block will be executed when on_enter is called and whenever the |
… | |
… | |
613 | Coro::on_enter { |
652 | Coro::on_enter { |
614 | # on entering the thread, we set an VTALRM handler to cede |
653 | # on entering the thread, we set an VTALRM handler to cede |
615 | $SIG{VTALRM} = sub { cede }; |
654 | $SIG{VTALRM} = sub { cede }; |
616 | # and then start the interval timer |
655 | # and then start the interval timer |
617 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01; |
656 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01; |
618 | }; |
657 | }; |
619 | Coro::on_leave { |
658 | Coro::on_leave { |
620 | # on leaving the thread, we stop the interval timer again |
659 | # on leaving the thread, we stop the interval timer again |
621 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0; |
660 | Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0; |
622 | }; |
661 | }; |
623 | |
662 | |
624 | &{+shift}; |
663 | &{+shift}; |
625 | } |
664 | } |
626 | |
665 | |
627 | # use like this: |
666 | # use like this: |
628 | timeslice { |
667 | timeslice { |
629 | # The following is an endless loop that would normally |
668 | # The following is an endless loop that would normally |
630 | # monopolise the process. Since it runs in a timesliced |
669 | # monopolise the process. Since it runs in a timesliced |
631 | # environment, it will regularly cede to other threads. |
670 | # environment, it will regularly cede to other threads. |
632 | while () { } |
671 | while () { } |
633 | }; |
672 | }; |
634 | |
673 | |
635 | |
674 | |
636 | =item killall |
675 | =item killall |
637 | |
676 | |
638 | Kills/terminates/cancels all coros except the currently running one. |
677 | Kills/terminates/cancels all coros except the currently running one. |
… | |
… | |
709 | To avoid this, it is best to put a suspended coro into the ready queue |
748 | To avoid this, it is best to put a suspended coro into the ready queue |
710 | unconditionally, as every synchronisation mechanism must protect itself |
749 | unconditionally, as every synchronisation mechanism must protect itself |
711 | against spurious wakeups, and the one in the Coro family certainly do |
750 | against spurious wakeups, and the one in the Coro family certainly do |
712 | that. |
751 | that. |
713 | |
752 | |
|
|
753 | =item $state->is_new |
|
|
754 | |
|
|
755 | Returns true iff this Coro object is "new", i.e. has never been run |
|
|
756 | yet. Those states basically consist of only the code reference to call and |
|
|
757 | the arguments, but consumes very little other resources. New states will |
|
|
758 | automatically get assigned a perl interpreter when they are transfered to. |
|
|
759 | |
|
|
760 | =item $state->is_zombie |
|
|
761 | |
|
|
762 | Returns true iff the Coro object has been cancelled, i.e. |
|
|
763 | it's resources freed because they were C<cancel>'ed, C<terminate>'d, |
|
|
764 | C<safe_cancel>'ed or simply went out of scope. |
|
|
765 | |
|
|
766 | The name "zombie" stems from UNIX culture, where a process that has |
|
|
767 | exited and only stores and exit status and no other resources is called a |
|
|
768 | "zombie". |
|
|
769 | |
714 | =item $is_ready = $coro->is_ready |
770 | =item $is_ready = $coro->is_ready |
715 | |
771 | |
716 | Returns true iff the Coro object is in the ready queue. Unless the Coro |
772 | Returns true iff the Coro object is in the ready queue. Unless the Coro |
717 | object gets destroyed, it will eventually be scheduled by the scheduler. |
773 | object gets destroyed, it will eventually be scheduled by the scheduler. |
718 | |
774 | |
… | |
… | |
727 | Returns true iff this Coro object has been suspended. Suspended Coros will |
783 | Returns true iff this Coro object has been suspended. Suspended Coros will |
728 | not ever be scheduled. |
784 | not ever be scheduled. |
729 | |
785 | |
730 | =item $coro->cancel (arg...) |
786 | =item $coro->cancel (arg...) |
731 | |
787 | |
732 | Terminates the given Coro and makes it return the given arguments as |
788 | Terminates the given Coro thread and makes it return the given arguments as |
733 | status (default: an empty list). Never returns if the Coro is the |
789 | status (default: an empty list). Never returns if the Coro is the |
734 | current Coro. |
790 | current Coro. |
735 | |
791 | |
736 | =cut |
792 | This is a rather brutal way to free a coro, with some limitations - if |
|
|
793 | the thread is inside a C callback that doesn't expect to be canceled, |
|
|
794 | bad things can happen, or if the cancelled thread insists on running |
|
|
795 | complicated cleanup handlers that rely on its thread context, things will |
|
|
796 | not work. |
737 | |
797 | |
738 | sub cancel { |
798 | Any cleanup code being run (e.g. from C<guard> blocks, destructors and so |
739 | my $self = shift; |
799 | on) will be run without a thread context, and is not allowed to switch |
|
|
800 | to other threads. A common mistake is to call C<< ->cancel >> from a |
|
|
801 | destructor called by die'ing inside the thread to be cancelled for |
|
|
802 | example. |
740 | |
803 | |
741 | if ($current == $self) { |
804 | On the plus side, C<< ->cancel >> will always clean up the thread, no |
742 | terminate @_; |
805 | matter what. If your cleanup code is complex or you want to avoid |
743 | } else { |
806 | cancelling a C-thread that doesn't know how to clean up itself, it can be |
744 | $self->{_status} = [@_]; |
807 | better to C<< ->throw >> an exception, or use C<< ->safe_cancel >>. |
745 | Coro::State::cancel $self; |
808 | |
|
|
809 | The arguments to C<< ->cancel >> are not copied, but instead will |
|
|
810 | be referenced directly (e.g. if you pass C<$var> and after the call |
|
|
811 | change that variable, then you might change the return values passed to |
|
|
812 | e.g. C<join>, so don't do that). |
|
|
813 | |
|
|
814 | The resources of the Coro are usually freed (or destructed) before this |
|
|
815 | call returns, but this can be delayed for an indefinite amount of time, as |
|
|
816 | in some cases the manager thread has to run first to actually destruct the |
|
|
817 | Coro object. |
|
|
818 | |
|
|
819 | =item $coro->safe_cancel ($arg...) |
|
|
820 | |
|
|
821 | Works mostly like C<< ->cancel >>, but is inherently "safer", and |
|
|
822 | consequently, can fail with an exception in cases the thread is not in a |
|
|
823 | cancellable state. Essentially, C<< ->safe_cancel >> is a C<< ->cancel >> |
|
|
824 | with extra checks before canceling. |
|
|
825 | |
|
|
826 | It works a bit like throwing an exception that cannot be caught - |
|
|
827 | specifically, it will clean up the thread from within itself, so all |
|
|
828 | cleanup handlers (e.g. C<guard> blocks) are run with full thread |
|
|
829 | context and can block if they wish. The downside is that there is no |
|
|
830 | guarantee that the thread can be cancelled when you call this method, and |
|
|
831 | therefore, it might fail. It is also considerably slower than C<cancel> or |
|
|
832 | C<terminate>. |
|
|
833 | |
|
|
834 | A thread is in a safe-cancellable state if it either hasn't been run yet, |
|
|
835 | or it has no C context attached and is inside an SLF function. |
|
|
836 | |
|
|
837 | The latter two basically mean that the thread isn't currently inside a |
|
|
838 | perl callback called from some C function (usually via some XS modules) |
|
|
839 | and isn't currently executing inside some C function itself (via Coro's XS |
|
|
840 | API). |
|
|
841 | |
|
|
842 | This call returns true when it could cancel the thread, or croaks with an |
|
|
843 | error otherwise (i.e. it either returns true or doesn't return at all). |
|
|
844 | |
|
|
845 | Why the weird interface? Well, there are two common models on how and |
|
|
846 | when to cancel things. In the first, you have the expectation that your |
|
|
847 | coro thread can be cancelled when you want to cancel it - if the thread |
|
|
848 | isn't cancellable, this would be a bug somewhere, so C<< ->safe_cancel >> |
|
|
849 | croaks to notify of the bug. |
|
|
850 | |
|
|
851 | In the second model you sometimes want to ask nicely to cancel a thread, |
|
|
852 | but if it's not a good time, well, then don't cancel. This can be done |
|
|
853 | relatively easy like this: |
|
|
854 | |
|
|
855 | if (! eval { $coro->safe_cancel }) { |
|
|
856 | warn "unable to cancel thread: $@"; |
746 | } |
857 | } |
747 | } |
858 | |
|
|
859 | However, what you never should do is first try to cancel "safely" and |
|
|
860 | if that fails, cancel the "hard" way with C<< ->cancel >>. That makes |
|
|
861 | no sense: either you rely on being able to execute cleanup code in your |
|
|
862 | thread context, or you don't. If you do, then C<< ->safe_cancel >> is the |
|
|
863 | only way, and if you don't, then C<< ->cancel >> is always faster and more |
|
|
864 | direct. |
748 | |
865 | |
749 | =item $coro->schedule_to |
866 | =item $coro->schedule_to |
750 | |
867 | |
751 | Puts the current coro to sleep (like C<Coro::schedule>), but instead |
868 | Puts the current coro to sleep (like C<Coro::schedule>), but instead |
752 | of continuing with the next coro from the ready queue, always switch to |
869 | of continuing with the next coro from the ready queue, always switch to |
… | |
… | |
771 | inside the coro at the next convenient point in time. Otherwise |
888 | inside the coro at the next convenient point in time. Otherwise |
772 | clears the exception object. |
889 | clears the exception object. |
773 | |
890 | |
774 | Coro will check for the exception each time a schedule-like-function |
891 | Coro will check for the exception each time a schedule-like-function |
775 | returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down |
892 | returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down |
776 | >>, C<< Coro::Handle->readable >> and so on. Most of these functions |
893 | >>, C<< Coro::Handle->readable >> and so on. Most of those functions (all |
777 | detect this case and return early in case an exception is pending. |
894 | that are part of Coro itself) detect this case and return early in case an |
|
|
895 | exception is pending. |
778 | |
896 | |
779 | The exception object will be thrown "as is" with the specified scalar in |
897 | The exception object will be thrown "as is" with the specified scalar in |
780 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
898 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
781 | (unlike with C<die>). |
899 | (unlike with C<die>). |
782 | |
900 | |
783 | This can be used as a softer means than C<cancel> to ask a coro to |
901 | This can be used as a softer means than either C<cancel> or C<safe_cancel |
784 | end itself, although there is no guarantee that the exception will lead to |
902 | >to ask a coro to end itself, although there is no guarantee that the |
785 | termination, and if the exception isn't caught it might well end the whole |
903 | exception will lead to termination, and if the exception isn't caught it |
786 | program. |
904 | might well end the whole program. |
787 | |
905 | |
788 | You might also think of C<throw> as being the moral equivalent of |
906 | You might also think of C<throw> as being the moral equivalent of |
789 | C<kill>ing a coro with a signal (in this case, a scalar). |
907 | C<kill>ing a coro with a signal (in this case, a scalar). |
790 | |
908 | |
791 | =item $coro->join |
909 | =item $coro->join |
792 | |
910 | |
793 | Wait until the coro terminates and return any values given to the |
911 | Wait until the coro terminates and return any values given to the |
794 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
912 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
795 | from multiple coro, and all will be resumed and given the status |
913 | from multiple threads, and all will be resumed and given the status |
796 | return once the C<$coro> terminates. |
914 | return once the C<$coro> terminates. |
797 | |
915 | |
798 | =cut |
|
|
799 | |
|
|
800 | sub join { |
|
|
801 | my $self = shift; |
|
|
802 | |
|
|
803 | unless ($self->{_status}) { |
|
|
804 | my $current = $current; |
|
|
805 | |
|
|
806 | push @{$self->{_on_destroy}}, sub { |
|
|
807 | $current->ready; |
|
|
808 | undef $current; |
|
|
809 | }; |
|
|
810 | |
|
|
811 | &schedule while $current; |
|
|
812 | } |
|
|
813 | |
|
|
814 | wantarray ? @{$self->{_status}} : $self->{_status}[0]; |
|
|
815 | } |
|
|
816 | |
|
|
817 | =item $coro->on_destroy (\&cb) |
916 | =item $coro->on_destroy (\&cb) |
818 | |
917 | |
819 | Registers a callback that is called when this coro thread gets destroyed, |
918 | Registers a callback that is called when this coro thread gets destroyed, |
820 | but before it is joined. The callback gets passed the terminate arguments, |
919 | that is, after it's resources have been freed but before it is joined. The |
|
|
920 | callback gets passed the terminate/cancel arguments, if any, and I<must |
821 | if any, and I<must not> die, under any circumstances. |
921 | not> die, under any circumstances. |
822 | |
922 | |
823 | There can be any number of C<on_destroy> callbacks per coro. |
923 | There can be any number of C<on_destroy> callbacks per coro, and there is |
824 | |
924 | currently no way to remove a callback once added. |
825 | =cut |
|
|
826 | |
|
|
827 | sub on_destroy { |
|
|
828 | my ($self, $cb) = @_; |
|
|
829 | |
|
|
830 | push @{ $self->{_on_destroy} }, $cb; |
|
|
831 | } |
|
|
832 | |
925 | |
833 | =item $oldprio = $coro->prio ($newprio) |
926 | =item $oldprio = $coro->prio ($newprio) |
834 | |
927 | |
835 | Sets (or gets, if the argument is missing) the priority of the |
928 | Sets (or gets, if the argument is missing) the priority of the |
836 | coro thread. Higher priority coro get run before lower priority |
929 | coro thread. Higher priority coro get run before lower priority |
… | |
… | |
863 | coro thread. This is just a free-form string you can associate with a |
956 | coro thread. This is just a free-form string you can associate with a |
864 | coro. |
957 | coro. |
865 | |
958 | |
866 | This method simply sets the C<< $coro->{desc} >> member to the given |
959 | This method simply sets the C<< $coro->{desc} >> member to the given |
867 | string. You can modify this member directly if you wish, and in fact, this |
960 | string. You can modify this member directly if you wish, and in fact, this |
868 | is often preferred to indicate major processing states that cna then be |
961 | is often preferred to indicate major processing states that can then be |
869 | seen for example in a L<Coro::Debug> session: |
962 | seen for example in a L<Coro::Debug> session: |
870 | |
963 | |
871 | sub my_long_function { |
964 | sub my_long_function { |
872 | local $Coro::current->{desc} = "now in my_long_function"; |
965 | local $Coro::current->{desc} = "now in my_long_function"; |
873 | ... |
966 | ... |
… | |
… | |
1042 | But from within a coro, you often just want to write this: |
1135 | But from within a coro, you often just want to write this: |
1043 | |
1136 | |
1044 | my $status = wait_for_child $pid; |
1137 | my $status = wait_for_child $pid; |
1045 | |
1138 | |
1046 | Coro offers two functions specifically designed to make this easy, |
1139 | Coro offers two functions specifically designed to make this easy, |
1047 | C<Coro::rouse_cb> and C<Coro::rouse_wait>. |
1140 | C<rouse_cb> and C<rouse_wait>. |
1048 | |
1141 | |
1049 | The first function, C<rouse_cb>, generates and returns a callback that, |
1142 | The first function, C<rouse_cb>, generates and returns a callback that, |
1050 | when invoked, will save its arguments and notify the coro that |
1143 | when invoked, will save its arguments and notify the coro that |
1051 | created the callback. |
1144 | created the callback. |
1052 | |
1145 | |
… | |
… | |
1058 | function mentioned above: |
1151 | function mentioned above: |
1059 | |
1152 | |
1060 | sub wait_for_child($) { |
1153 | sub wait_for_child($) { |
1061 | my ($pid) = @_; |
1154 | my ($pid) = @_; |
1062 | |
1155 | |
1063 | my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb); |
1156 | my $watcher = AnyEvent->child (pid => $pid, cb => rouse_cb); |
1064 | |
1157 | |
1065 | my ($rpid, $rstatus) = Coro::rouse_wait; |
1158 | my ($rpid, $rstatus) = rouse_wait; |
1066 | $rstatus |
1159 | $rstatus |
1067 | } |
1160 | } |
1068 | |
1161 | |
1069 | In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough, |
1162 | In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough, |
1070 | you can roll your own, using C<schedule>: |
1163 | you can roll your own, using C<schedule> and C<ready>: |
1071 | |
1164 | |
1072 | sub wait_for_child($) { |
1165 | sub wait_for_child($) { |
1073 | my ($pid) = @_; |
1166 | my ($pid) = @_; |
1074 | |
1167 | |
1075 | # store the current coro in $current, |
1168 | # store the current coro in $current, |
… | |
… | |
1078 | my ($done, $rstatus); |
1171 | my ($done, $rstatus); |
1079 | |
1172 | |
1080 | # pass a closure to ->child |
1173 | # pass a closure to ->child |
1081 | my $watcher = AnyEvent->child (pid => $pid, cb => sub { |
1174 | my $watcher = AnyEvent->child (pid => $pid, cb => sub { |
1082 | $rstatus = $_[1]; # remember rstatus |
1175 | $rstatus = $_[1]; # remember rstatus |
1083 | $done = 1; # mark $rstatus as valud |
1176 | $done = 1; # mark $rstatus as valid |
|
|
1177 | $current->ready; # wake up the waiting thread |
1084 | }); |
1178 | }); |
1085 | |
1179 | |
1086 | # wait until the closure has been called |
1180 | # wait until the closure has been called |
1087 | schedule while !$done; |
1181 | schedule while !$done; |
1088 | |
1182 | |
… | |
… | |
1107 | module from the first thread (this requirement might be removed in the |
1201 | module from the first thread (this requirement might be removed in the |
1108 | future to allow per-thread schedulers, but Coro::State does not yet allow |
1202 | future to allow per-thread schedulers, but Coro::State does not yet allow |
1109 | this). I recommend disabling thread support and using processes, as having |
1203 | this). I recommend disabling thread support and using processes, as having |
1110 | the windows process emulation enabled under unix roughly halves perl |
1204 | the windows process emulation enabled under unix roughly halves perl |
1111 | performance, even when not used. |
1205 | performance, even when not used. |
|
|
1206 | |
|
|
1207 | Attempts to use threads created in another emulated process will crash |
|
|
1208 | ("cleanly", with a null pointer exception). |
1112 | |
1209 | |
1113 | =item coro switching is not signal safe |
1210 | =item coro switching is not signal safe |
1114 | |
1211 | |
1115 | You must not switch to another coro from within a signal handler (only |
1212 | You must not switch to another coro from within a signal handler (only |
1116 | relevant with %SIG - most event libraries provide safe signals), I<unless> |
1213 | relevant with %SIG - most event libraries provide safe signals), I<unless> |