… | |
… | |
58 | This module provides an interface to libev |
58 | This module provides an interface to libev |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
60 | below is comprehensive, one might also consult the documentation of libev |
60 | below is comprehensive, one might also consult the documentation of libev |
61 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
61 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
62 | watcher semantics or some discussion on the available backends, or how to |
62 | watcher semantics or some discussion on the available backends, or how to |
63 | force a specific backend with C<LIBEV_FLAGS>. |
63 | force a specific backend with C<LIBEV_FLAGS>, or just about in any case |
|
|
64 | because it has much more detailed information. |
64 | |
65 | |
65 | =cut |
66 | =cut |
66 | |
67 | |
67 | package EV; |
68 | package EV; |
68 | |
69 | |
69 | use strict; |
70 | use strict; |
70 | |
71 | |
71 | BEGIN { |
72 | BEGIN { |
72 | our $VERSION = '1.4'; |
73 | our $VERSION = '1.8'; |
73 | use XSLoader; |
74 | use XSLoader; |
74 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
75 | } |
76 | } |
76 | |
77 | |
77 | @EV::IO::ISA = |
78 | @EV::IO::ISA = |
78 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
79 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
80 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
|
|
82 | @EV::Child::ISA = |
|
|
83 | @EV::Stat::ISA = |
81 | @EV::Idle::ISA = |
84 | @EV::Idle::ISA = |
82 | @EV::Prepare::ISA = |
85 | @EV::Prepare::ISA = |
83 | @EV::Check::ISA = |
86 | @EV::Check::ISA = |
84 | @EV::Child::ISA = |
|
|
85 | @EV::Embed::ISA = |
87 | @EV::Embed::ISA = |
86 | @EV::Stat::ISA = "EV::Watcher"; |
88 | @EV::Fork::ISA = |
|
|
89 | "EV::Watcher"; |
87 | |
90 | |
88 | =head1 BASIC INTERFACE |
91 | =head1 BASIC INTERFACE |
89 | |
92 | |
90 | =over 4 |
93 | =over 4 |
91 | |
94 | |
… | |
… | |
128 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
131 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
129 | innermost call to EV::loop return. |
132 | innermost call to EV::loop return. |
130 | |
133 | |
131 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
134 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
132 | fast as possible. |
135 | fast as possible. |
|
|
136 | |
|
|
137 | =item $count = EV::loop_count |
|
|
138 | |
|
|
139 | Return the number of times the event loop has polled for new |
|
|
140 | events. Sometiems useful as a generation counter. |
133 | |
141 | |
134 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
142 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
135 | |
143 | |
136 | This function rolls together an I/O and a timer watcher for a single |
144 | This function rolls together an I/O and a timer watcher for a single |
137 | one-shot event without the need for managing a watcher object. |
145 | one-shot event without the need for managing a watcher object. |
… | |
… | |
173 | events. |
181 | events. |
174 | |
182 | |
175 | Each watcher type has its associated bit in revents, so you can use the |
183 | Each watcher type has its associated bit in revents, so you can use the |
176 | same callback for multiple watchers. The event mask is named after the |
184 | same callback for multiple watchers. The event mask is named after the |
177 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
185 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
178 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
186 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
179 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
187 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
180 | uses EV::TIMEOUT). |
188 | uses EV::TIMEOUT). |
181 | |
189 | |
182 | In the rare case where one wants to create a watcher but not start it at |
190 | In the rare case where one wants to create a watcher but not start it at |
183 | the same time, each constructor has a variant with a trailing C<_ns> in |
191 | the same time, each constructor has a variant with a trailing C<_ns> in |
… | |
… | |
205 | |
213 | |
206 | =item $w->stop |
214 | =item $w->stop |
207 | |
215 | |
208 | Stop a watcher if it is active. Also clear any pending events (events that |
216 | Stop a watcher if it is active. Also clear any pending events (events that |
209 | have been received but that didn't yet result in a callback invocation), |
217 | have been received but that didn't yet result in a callback invocation), |
210 | regardless of wether the watcher was active or not. |
218 | regardless of whether the watcher was active or not. |
211 | |
219 | |
212 | =item $bool = $w->is_active |
220 | =item $bool = $w->is_active |
213 | |
221 | |
214 | Returns true if the watcher is active, false otherwise. |
222 | Returns true if the watcher is active, false otherwise. |
215 | |
223 | |
… | |
… | |
270 | though your watcher is active, it won't keep C<EV::loop> from returning. |
278 | though your watcher is active, it won't keep C<EV::loop> from returning. |
271 | |
279 | |
272 | The initial value for keepalive is true (enabled), and you cna change it |
280 | The initial value for keepalive is true (enabled), and you cna change it |
273 | any time. |
281 | any time. |
274 | |
282 | |
275 | Example: Register an IO watcher for some UDP socket but do not keep the |
283 | Example: Register an I/O watcher for some UDP socket but do not keep the |
276 | event loop from running just because of that watcher. |
284 | event loop from running just because of that watcher. |
277 | |
285 | |
278 | my $udp_socket = ... |
286 | my $udp_socket = ... |
279 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
287 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
280 | $udp_watcher->keepalive (0); |
288 | $udp_watcher->keepalive (0); |
… | |
… | |
284 | |
292 | |
285 | =head2 WATCHER TYPES |
293 | =head2 WATCHER TYPES |
286 | |
294 | |
287 | Each of the following subsections describes a single watcher type. |
295 | Each of the following subsections describes a single watcher type. |
288 | |
296 | |
289 | =head3 IO WATCHERS - is this file descriptor readable or writable? |
297 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
290 | |
298 | |
291 | =over 4 |
299 | =over 4 |
292 | |
300 | |
293 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
301 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
294 | |
302 | |
… | |
… | |
551 | watcher for all pids). |
559 | watcher for all pids). |
552 | |
560 | |
553 | =back |
561 | =back |
554 | |
562 | |
555 | |
563 | |
|
|
564 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
565 | |
|
|
566 | =over 4 |
|
|
567 | |
|
|
568 | =item $w = EV::stat $path, $interval, $callback |
|
|
569 | |
|
|
570 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
571 | |
|
|
572 | Call the callback when a file status change has been detected on |
|
|
573 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
574 | to "path does not exist" is a status change like any other. |
|
|
575 | |
|
|
576 | The C<$interval> is a recommended polling interval for systems where |
|
|
577 | OS-supported change notifications don't exist or are not supported. If |
|
|
578 | you use C<0> then an unspecified default is used (which is highly |
|
|
579 | recommended!), which is to be expected to be around five seconds usually. |
|
|
580 | |
|
|
581 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
582 | as even with OS-supported change notifications, this can be |
|
|
583 | resource-intensive. |
|
|
584 | |
|
|
585 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
586 | |
|
|
587 | =item ... = $w->stat |
|
|
588 | |
|
|
589 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
590 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
591 | well as EV's idea of the current stat values) to the values found. |
|
|
592 | |
|
|
593 | In scalar context, a boolean is return indicating success or failure of |
|
|
594 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
595 | (except that the blksize and blocks fields are not reliable). |
|
|
596 | |
|
|
597 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
598 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
599 | was successful then nlink is guaranteed to be non-zero). |
|
|
600 | |
|
|
601 | See also the next two entries for more info. |
|
|
602 | |
|
|
603 | =item ... = $w->attr |
|
|
604 | |
|
|
605 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
606 | the values most recently detected by EV. See the next entry for more info. |
|
|
607 | |
|
|
608 | =item ... = $w->prev |
|
|
609 | |
|
|
610 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
611 | the previous set of values, before the change. |
|
|
612 | |
|
|
613 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
614 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
615 | returns the values found leading to the change detection. The difference (if any) |
|
|
616 | between C<prev> and C<attr> is what triggered the callback. |
|
|
617 | |
|
|
618 | If you did something to the filesystem object and do not want to trigger |
|
|
619 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
620 | current attributes are. |
|
|
621 | |
|
|
622 | =item $w->set ($path, $interval) |
|
|
623 | |
|
|
624 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
625 | called at any time. |
|
|
626 | |
|
|
627 | =item $current_path = $w->path |
|
|
628 | |
|
|
629 | =item $old_path = $w->path ($new_path) |
|
|
630 | |
|
|
631 | Returns the previously set path and optionally set a new one. |
|
|
632 | |
|
|
633 | =item $current_interval = $w->interval |
|
|
634 | |
|
|
635 | =item $old_interval = $w->interval ($new_interval) |
|
|
636 | |
|
|
637 | Returns the previously set interval and optionally set a new one. Can be |
|
|
638 | used to query the actual interval used. |
|
|
639 | |
|
|
640 | =back |
|
|
641 | |
|
|
642 | |
556 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
643 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
557 | |
644 | |
558 | =over 4 |
645 | =over 4 |
559 | |
646 | |
560 | =item $w = EV::idle $callback |
647 | =item $w = EV::idle $callback |
561 | |
648 | |
562 | =item $w = EV::idle_ns $callback |
649 | =item $w = EV::idle_ns $callback |
563 | |
650 | |
564 | Call the callback when there are no pending io, timer/periodic, signal or |
651 | Call the callback when there are no other pending watchers of the same or |
565 | child events, i.e. when the process is idle. |
652 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
653 | same or lower priority, of course). They are called idle watchers because |
|
|
654 | when the watcher is the highest priority pending event in the process, the |
|
|
655 | process is considered to be idle at that priority. |
|
|
656 | |
|
|
657 | If you want a watcher that is only ever called when I<no> other events are |
|
|
658 | outstanding you have to set the priority to C<EV::MINPRI>. |
566 | |
659 | |
567 | The process will not block as long as any idle watchers are active, and |
660 | The process will not block as long as any idle watchers are active, and |
568 | they will be called repeatedly until stopped. |
661 | they will be called repeatedly until stopped. |
|
|
662 | |
|
|
663 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
664 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
665 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
666 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
667 | pending with the C<0>-priority idle watcher be invoked. |
569 | |
668 | |
570 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
669 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
571 | |
670 | |
572 | =back |
671 | =back |
573 | |
672 | |
… | |
… | |
614 | or return; |
713 | or return; |
615 | |
714 | |
616 | # make the dispatcher handle any outstanding stuff |
715 | # make the dispatcher handle any outstanding stuff |
617 | ... not shown |
716 | ... not shown |
618 | |
717 | |
619 | # create an IO watcher for each and every socket |
718 | # create an I/O watcher for each and every socket |
620 | @snmp_watcher = ( |
719 | @snmp_watcher = ( |
621 | (map { EV::io $_, EV::READ, sub { } } |
720 | (map { EV::io $_, EV::READ, sub { } } |
622 | keys %{ $dispatcher->{_descriptors} }), |
721 | keys %{ $dispatcher->{_descriptors} }), |
623 | |
722 | |
624 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
723 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
646 | |
745 | |
647 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
746 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
648 | |
747 | |
649 | =back |
748 | =back |
650 | |
749 | |
651 | =head3 STAT WATCHERS - did the file stats just change? |
|
|
652 | |
750 | |
653 | =over 4 |
751 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
654 | |
752 | |
655 | =item $w = EV::stat $path, $interval, $callback |
753 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
754 | is done before the event loop blocks next and before C<check> watchers |
|
|
755 | are being called, and only in the child after the fork. |
656 | |
756 | |
657 | =item $w = EV::stat_ns $path, $interval, $callback |
757 | =over 4 |
658 | |
758 | |
659 | Call the callback when a file status change has been detected on |
759 | =item $w = EV::fork $callback |
660 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
661 | to "path does not exist" is a status change like any other. |
|
|
662 | |
760 | |
663 | The C<$interval> is a recommended polling interval for systems where |
761 | =item $w = EV::fork_ns $callback |
664 | OS-supported change notifications don't exist or are not supported. If |
|
|
665 | you use C<0> then an unspecified default is used (which is highly |
|
|
666 | recommended!), which is to be expected to be around five seconds usually. |
|
|
667 | |
762 | |
668 | This watcher type is not meant for massive numbers of stat watchers, |
763 | Call the callback before the event loop is resumed in the child process |
669 | as even with OS-supported change notifications, this can be |
764 | after a fork. |
670 | resource-intensive. |
|
|
671 | |
765 | |
672 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
766 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
673 | |
767 | |
674 | =item $w->set ($path, $interval) |
|
|
675 | |
|
|
676 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
677 | called at any time. |
|
|
678 | |
|
|
679 | =item $current_path = $w->path |
|
|
680 | |
|
|
681 | =item $old_path = $w->path ($new_path) |
|
|
682 | |
|
|
683 | Returns the previously set path and optionally set a new one. |
|
|
684 | |
|
|
685 | =item $current_interval = $w->interval |
|
|
686 | |
|
|
687 | =item $old_interval = $w->interval ($new_interval) |
|
|
688 | |
|
|
689 | Returns the previously set interval and optionally set a new one. Can be |
|
|
690 | used to query the actual interval used. |
|
|
691 | |
|
|
692 | =back |
768 | =back |
693 | |
769 | |
|
|
770 | |
|
|
771 | =head1 PERL SIGNALS |
|
|
772 | |
|
|
773 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
774 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
775 | handled when Perl runs, which means your signal handler might be invoked |
|
|
776 | only the next time an event callback is invoked. |
|
|
777 | |
|
|
778 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
779 | ensure proper operations with regards to other event watchers. |
|
|
780 | |
|
|
781 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
782 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
783 | watcher: |
|
|
784 | |
|
|
785 | my $async_check = EV::check sub { }; |
|
|
786 | |
|
|
787 | This ensures that perl shortly gets into control for a short time, and |
|
|
788 | also ensures slower overall operation. |
694 | |
789 | |
695 | =head1 THREADS |
790 | =head1 THREADS |
696 | |
791 | |
697 | Threads are not supported by this module in any way. Perl pseudo-threads |
792 | Threads are not supported by this module in any way. Perl pseudo-threads |
698 | is evil stuff and must die. As soon as Perl gains real threads I will work |
793 | is evil stuff and must die. As soon as Perl gains real threads I will work |
… | |
… | |
726 | |
821 | |
727 | 1; |
822 | 1; |
728 | |
823 | |
729 | =head1 SEE ALSO |
824 | =head1 SEE ALSO |
730 | |
825 | |
731 | L<EV::DNS>. |
826 | L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
827 | event loop), L<Coro::EV> (efficient coroutines with EV). |
732 | |
828 | |
733 | =head1 AUTHOR |
829 | =head1 AUTHOR |
734 | |
830 | |
735 | Marc Lehmann <schmorp@schmorp.de> |
831 | Marc Lehmann <schmorp@schmorp.de> |
736 | http://home.schmorp.de/ |
832 | http://home.schmorp.de/ |