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Revision 1.136 by root, Thu Jan 19 17:55:23 2012 UTC vs.
Revision 1.155 by root, Sun May 12 21:58:31 2019 UTC

47 my ($w, $revents) = @_; 47 my ($w, $revents) = @_;
48 warn $w->path, " has changed somehow.\n"; 48 warn $w->path, " has changed somehow.\n";
49 }; 49 };
50 50
51 # MAINLOOP 51 # MAINLOOP
52 EV::run; # loop until EV::unloop is called or all watchers stop 52 EV::run; # loop until EV::break is called or all watchers stop
53 EV::run EV::RUN_ONCE; # block until at least one event could be handled 53 EV::run EV::RUN_ONCE; # block until at least one event could be handled
54 EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block 54 EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block
55 55
56=head1 BEFORE YOU START USING THIS MODULE 56=head1 BEFORE YOU START USING THIS MODULE
57 57
119package EV; 119package EV;
120 120
121use common::sense; 121use common::sense;
122 122
123BEGIN { 123BEGIN {
124 our $VERSION = '4.10'; 124 our $VERSION = 4.25;
125 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
126 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
127} 128}
128 129
129@EV::IO::ISA = 130@EV::IO::ISA =
130@EV::Timer::ISA = 131@EV::Timer::ISA =
247 248
248=item $loop->now_update 249=item $loop->now_update
249 250
250Establishes the current time by querying the kernel, updating the time 251Establishes the current time by querying the kernel, updating the time
251returned by C<EV::now> in the progress. This is a costly operation and 252returned by C<EV::now> in the progress. This is a costly operation and
252is usually done automatically within C<EV::loop>. 253is usually done automatically within C<EV::run>.
253 254
254This function is rarely useful, but when some event callback runs for a 255This function is rarely useful, but when some event callback runs for a
255very long time without entering the event loop, updating libev's idea of 256very long time without entering the event loop, updating libev's idea of
256the current time is a good idea. 257the current time is a good idea.
257 258
290=item $backend = $loop->backend 291=item $backend = $loop->backend
291 292
292Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
293or EV::BACKEND_EPOLL). 294or EV::BACKEND_EPOLL).
294 295
295=item EV::run [$flags] 296=item $active = EV::run [$flags]
296 297
297=item $loop->run ([$flags]) 298=item $active = $loop->run ([$flags])
298 299
299Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
300callback calls EV::unloop. 301callback calls EV::break or the flags are nonzero (in which case the
302return value is true) or when there are no active watchers which reference
303the loop (keepalive is true), in which case the return value will be
304false. The return value can generally be interpreted as "if true, there is
305more work left to do".
301 306
302The $flags argument can be one of the following: 307The $flags argument can be one of the following:
303 308
304 0 as above 309 0 as above
305 EV::RUN_ONCE block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
308=item EV::break [$how] 313=item EV::break [$how]
309 314
310=item $loop->break ([$how]) 315=item $loop->break ([$how])
311 316
312When called with no arguments or an argument of EV::BREAK_ONE, makes the 317When called with no arguments or an argument of EV::BREAK_ONE, makes the
313innermost call to EV::loop return. 318innermost call to EV::run return.
314 319
315When called with an argument of EV::BREAK_ALL, all calls to EV::loop will 320When called with an argument of EV::BREAK_ALL, all calls to EV::run will
316return as fast as possible. 321return as fast as possible.
317 322
318When called with an argument of EV::BREAK_CANCEL, any pending break will 323When called with an argument of EV::BREAK_CANCEL, any pending break will
319be cancelled. 324be cancelled.
320 325
337| EV::WRITE>, indicating the type of I/O event you want to wait for. If 342| EV::WRITE>, indicating the type of I/O event you want to wait for. If
338you do not want to wait for some I/O event, specify C<undef> for 343you do not want to wait for some I/O event, specify C<undef> for
339C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
340 345
341If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
342timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
343 348
344When an error occurs or either the timeout or I/O watcher triggers, then 349When an error occurs or either the timeout or I/O watcher triggers, then
345the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
346you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, 351you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
347C<EV::WRITE> and C<EV::TIMER>). 352C<EV::WRITE> and C<EV::TIMER>).
502returns its C<$revents> bitset (as if its callback was invoked). If the 507returns its C<$revents> bitset (as if its callback was invoked). If the
503watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
504 509
505=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
506 511
507Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::run> will return when there are no active watchers
508(which is a "deadlock" because no progress can be made anymore). This is 513(which is a "deadlock" because no progress can be made anymore). This is
509convenient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
510call C<EV::loop> once and when it returns you know that all your jobs are 515call C<EV::run> once and when it returns you know that all your jobs are
511finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
512 517
513Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
514that calls C<EV::loop> (usually the main program) is not the same module 519that calls C<EV::run> (usually the main program) is not the same module
515as a long-living watcher (for example a DNS client module written by 520as a long-living watcher (for example a DNS client module written by
516somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
517handled, but you would not want to keep C<EV::loop> from returning just 522handled, but you would not want to keep C<EV::run> from returning just
518because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
519 524
520In this case you can clear the keepalive status, which means that even 525In this case you can clear the keepalive status, which means that even
521though your watcher is active, it won't keep C<EV::loop> from returning. 526though your watcher is active, it won't keep C<EV::run> from returning.
522 527
523The initial value for keepalive is true (enabled), and you can change it 528The initial value for keepalive is true (enabled), and you can change it
524any time. 529any time.
525 530
526Example: Register an I/O watcher for some UDP socket but do not keep the 531Example: Register an I/O watcher for some UDP socket but do not keep the
593 598
594=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
595 600
596=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
597 602
598Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
599C<$repeat> is non-zero, the timer will be restarted (with the $repeat 604negative). If C<$repeat> is non-zero, the timer will be restarted (with
600value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
601 606
602This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
603seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
604to drift, but it will not invoke the timer more often then once per event 609to drift, but it will not invoke the timer more often then once per event
605loop iteration, and might drift in other cases. If that isn't acceptable, 610loop iteration, and might drift in other cases. If that isn't acceptable,
609in front of the machine while the timer is running and changes the system 614in front of the machine while the timer is running and changes the system
610clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
611 616
612The C<timer_ns> variant doesn't start (activate) the newly created watcher. 617The C<timer_ns> variant doesn't start (activate) the newly created watcher.
613 618
614=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
615 620
616Reconfigures the watcher, see the constructor above for details. Can be called at 621Reconfigures the watcher, see the constructor above for details. Can be called at
617any time. 622any time.
618 623
619=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
620 627
621Similar to the C<start> method, but has special semantics for repeating timers: 628Similar to the C<start> method, but has special semantics for repeating timers:
622 629
623If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
624 631
631 638
632This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
633operation. You create a timer object with the same value for C<$after> and 640operation. You create a timer object with the same value for C<$after> and
634C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
635on the timeout. 642on the timeout.
643
644If called with a C<$repeat> argument, then it uses this a timer repeat
645value.
646
647=item $after = $w->remaining
648
649Calculates and returns the remaining time till the timer will fire.
636 650
637=back 651=back
638 652
639 653
640=head3 PERIODIC WATCHERS - to cron or not to cron? 654=head3 PERIODIC WATCHERS - to cron or not to cron?
668surpasses this time. 682surpasses this time.
669 683
670=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 684=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
671 685
672In this mode the watcher will always be scheduled to time out at the 686In this mode the watcher will always be scheduled to time out at the
673next C<$at + N * $interval> time (for some integer N) and then repeat, 687next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
674regardless of any time jumps. 688regardless of any time jumps. Note that, since C<N> can be negative, the
689first trigger can happen before C<$at>.
675 690
676This can be used to create timers that do not drift with respect to system 691This can be used to create timers that do not drift with respect to system
677time: 692time:
678 693
679 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 694 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
680 695
681That doesn't mean there will always be 3600 seconds in between triggers, 696That doesn't mean there will always be 3600 seconds in between triggers,
682but only that the the clalback will be called when the system time shows a 697but only that the the callback will be called when the system time shows a
683full hour (UTC). 698full hour (UTC).
684 699
685Another way to think about it (for the mathematically inclined) is that 700Another way to think about it (for the mathematically inclined) is that
686EV::periodic will try to run the callback in this mode at the next 701EV::periodic will try to run the callback in this mode at the next
687possible time where C<$time = $at (mod $interval)>, regardless of any time 702possible time where C<$time = $at (mod $interval)>, regardless of any time
695time as second argument. 710time as second argument.
696 711
697I<This callback MUST NOT stop or destroy this or any other periodic 712I<This callback MUST NOT stop or destroy this or any other periodic
698watcher, ever, and MUST NOT call any event loop functions or methods>. If 713watcher, ever, and MUST NOT call any event loop functions or methods>. If
699you need to stop it, return 1e30 and stop it afterwards. You may create 714you need to stop it, return 1e30 and stop it afterwards. You may create
700and start a C<EV::prepare> watcher for this task. 715and start an C<EV::prepare> watcher for this task.
701 716
702It must return the next time to trigger, based on the passed time value 717It must return the next time to trigger, based on the passed time value
703(that is, the lowest time value larger than or equal to to the second 718(that is, the lowest time value larger than or equal to to the second
704argument). It will usually be called just before the callback will be 719argument). It will usually be called just before the callback will be
705triggered, but might be called at other times, too. 720triggered, but might be called at other times, too.
706 721
707This can be used to create very complex timers, such as a timer that 722This can be used to create very complex timers, such as a timer that
708triggers on each midnight, local time (actually 24 hours after the last 723triggers on each midnight, local time (actually one day after the last
709midnight, to keep the example simple. If you know a way to do it correctly 724midnight, to keep the example simple):
710in about the same space (without requiring elaborate modules), drop me a
711note :):
712 725
713 my $daily = EV::periodic 0, 0, sub { 726 my $daily = EV::periodic 0, 0, sub {
714 my ($w, $now) = @_; 727 my ($w, $now) = @_;
715 728
716 use Time::Local (); 729 use Time::Local ();
717 my (undef, undef, undef, $d, $m, $y) = localtime $now; 730 my (undef, undef, undef, $d, $m, $y) = localtime $now;
718 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 731 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
719 }, sub { 732 }, sub {
720 print "it's midnight or likely shortly after, now\n"; 733 print "it's midnight or likely shortly after, now\n";
721 }; 734 };
722 735
723=back 736=back
1135 1148
1136=item $w = EV::async $callback 1149=item $w = EV::async $callback
1137 1150
1138=item $w = EV::async_ns $callback 1151=item $w = EV::async_ns $callback
1139 1152
1153=item $w = $loop->async ($callback)
1154
1155=item $w = $loop->async_ns ($callback)
1156
1140=item $w->send 1157=item $w->send
1141 1158
1142=item $bool = $w->async_pending 1159=item $bool = $w->async_pending
1143 1160
1144=back 1161=back
1162
1163=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1164
1165Cleanup watchers are not supported on the Perl level, they can only be
1166used via XS currently.
1145 1167
1146 1168
1147=head1 PERL SIGNALS 1169=head1 PERL SIGNALS
1148 1170
1149While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1171While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour

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