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Revision 1.138 by root, Sun May 6 16:30:27 2012 UTC vs.
Revision 1.159 by root, Tue Nov 19 20:09:38 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 = '4.11'; 124 our $VERSION = 4.28;
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
295=item $active = EV::run [$flags] 296=item $active = EV::run [$flags]
296 297
297=item $active = $loop->run ([$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 or the flasg are nonzero (in which case the 301callback calls EV::break or the flags are nonzero (in which case the
301return value is true) or when there are no active watchers which reference 302return value is true) or when there are no active watchers which reference
302the loop (keepalive is true), in which case the return value will be 303the loop (keepalive is true), in which case the return value will be
303false. The returnv alue can generally be interpreted as "if true, there is 304false. The return value can generally be interpreted as "if true, there is
304more work left to do". 305more work left to do".
305 306
306The $flags argument can be one of the following: 307The $flags argument can be one of the following:
307 308
308 0 as above 309 0 as above
312=item EV::break [$how] 313=item EV::break [$how]
313 314
314=item $loop->break ([$how]) 315=item $loop->break ([$how])
315 316
316When 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
317innermost call to EV::loop return. 318innermost call to EV::run return.
318 319
319When 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
320return as fast as possible. 321return as fast as possible.
321 322
322When 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
323be cancelled. 324be cancelled.
324 325
341| 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
342you 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
343C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
344 345
345If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
346timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
347 348
348When 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
349the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
350you 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>,
351C<EV::WRITE> and C<EV::TIMER>). 352C<EV::WRITE> and C<EV::TIMER>).
369 370
370=item EV::feed_signal $signal 371=item EV::feed_signal $signal
371 372
372Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works 373Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
373regardless of which loop has registered the signal, and is mainly useful 374regardless of which loop has registered the signal, and is mainly useful
374fro custom signal implementations. 375for custom signal implementations.
375 376
376=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
377 378
378=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
379 380
506returns 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
507watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
508 509
509=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
510 511
511Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::run> will return when there are no active watchers
512(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
513convenient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
514call 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
515finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
516 517
517Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
518that 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
519as 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
520somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
521handled, 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
522because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
523 524
524In 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
525though 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.
526 527
527The 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
528any time. 529any time.
529 530
530Example: 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
597 598
598=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
599 600
600=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
601 602
602Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
603C<$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
604value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
605 606
606This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
607seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
608to 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
609loop 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,
613in 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
614clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
615 616
616The 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.
617 618
618=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
619 620
620Reconfigures 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
621any time. 622any time.
622 623
623=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
624 627
625Similar 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:
626 629
627If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
628 631
635 638
636This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
637operation. 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
638C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
639on 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 = $w->remaining
648
649Calculates and returns the remaining time till the timer will fire.
640 650
641=back 651=back
642 652
643 653
644=head3 PERIODIC WATCHERS - to cron or not to cron? 654=head3 PERIODIC WATCHERS - to cron or not to cron?
672surpasses this time. 682surpasses this time.
673 683
674=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 684=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
675 685
676In this mode the watcher will always be scheduled to time out at the 686In this mode the watcher will always be scheduled to time out at the
677next C<$at + N * $interval> time (for some integer N) and then repeat, 687next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
678regardless of any time jumps. 688regardless of any time jumps. Note that, since C<N> can be negative, the
689first trigger can happen before C<$at>.
679 690
680This 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
681time: 692time:
682 693
683 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 694 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
684 695
685That doesn't mean there will always be 3600 seconds in between triggers, 696That doesn't mean there will always be 3600 seconds in between triggers,
686but only that the the clalback will be called when the system time shows a 697but only that the the callback will be called when the system time shows a
687full hour (UTC). 698full hour (UTC).
688 699
689Another way to think about it (for the mathematically inclined) is that 700Another way to think about it (for the mathematically inclined) is that
690EV::periodic will try to run the callback in this mode at the next 701EV::periodic will try to run the callback in this mode at the next
691possible time where C<$time = $at (mod $interval)>, regardless of any time 702possible time where C<$time = $at (mod $interval)>, regardless of any time
699time as second argument. 710time as second argument.
700 711
701I<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
702watcher, 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
703you 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
704and start a C<EV::prepare> watcher for this task. 715and start an C<EV::prepare> watcher for this task.
705 716
706It 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
707(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
708argument). It will usually be called just before the callback will be 719argument). It will usually be called just before the callback will be
709triggered, but might be called at other times, too. 720triggered, but might be called at other times, too.
710 721
711This 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
712triggers on each midnight, local time (actually 24 hours after the last 723triggers on each midnight, local time (actually one day after the last
713midnight, to keep the example simple. If you know a way to do it correctly 724midnight, to keep the example simple):
714in about the same space (without requiring elaborate modules), drop me a
715note :):
716 725
717 my $daily = EV::periodic 0, 0, sub { 726 my $daily = EV::periodic 0, 0, sub {
718 my ($w, $now) = @_; 727 my ($w, $now) = @_;
719 728
720 use Time::Local (); 729 use Time::Local ();
721 my (undef, undef, undef, $d, $m, $y) = localtime $now; 730 my (undef, undef, undef, $d, $m, $y) = localtime $now;
722 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 731 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
723 }, sub { 732 }, sub {
724 print "it's midnight or likely shortly after, now\n"; 733 print "it's midnight or likely shortly after, now\n";
725 }; 734 };
726 735
727=back 736=back

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