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Revision 1.129 by root, Thu Oct 21 15:13:42 2010 UTC vs.
Revision 1.161 by root, Fri Dec 20 21:02:34 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::loop; # 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::loop EV::LOOP_ONESHOT; # 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::loop EV::LOOP_NONBLOCK; # 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
58If you only need timer, I/O, signal, child and idle watchers and not the 58If you only need timer, I/O, signal, child and idle watchers and not the
59advanced functionality of this module, consider using L<AnyEvent> instead, 59advanced functionality of this module, consider using L<AnyEvent> instead,
119package EV; 119package EV;
120 120
121use common::sense; 121use common::sense;
122 122
123BEGIN { 123BEGIN {
124 our $VERSION = '4.00'; 124 our $VERSION = '4.31';
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 =
186Must be called after a fork in the child, before entering or continuing 187Must be called after a fork in the child, before entering or continuing
187the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls 188the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
188this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
189documentation). 190documentation).
190 191
191=item $loop->loop_verify 192=item $loop->verify
192 193
193Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
194libev) and abort the program if any data structures were found to be 195libev) and abort the program if any data structures were found to be
195corrupted. 196corrupted.
196 197
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 = $loop->backend
291 292
292Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
293or EV::BACKEND_EPOLL). 294or EV::BACKEND_EPOLL).
294 295
295=item EV::loop [$flags] 296=item $active = EV::run [$flags]
296 297
297=item $loop->loop ([$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 $flags argument can be one of the following:
303 308
304 0 as above 309 0 as above
305 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
306 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
307 312
308=item EV::unloop [$how] 313=item EV::break [$how]
309 314
310=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
311 316
312When called with no arguments or an argument of EV::UNLOOP_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::UNLOOP_ALL, all calls to EV::loop will return as 320When called with an argument of EV::BREAK_ALL, all calls to EV::run will
316fast as possible. 321return as fast as possible.
317 322
318=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
319 325
326=item $count = EV::iteration
327
320=item $count = $loop->loop_count 328=item $count = $loop->iteration
321 329
322Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
323events. Sometimes useful as a generation counter. 331events. Sometimes useful as a generation counter.
324 332
325=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
334| 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
335you 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
336C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
337 345
338If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
339timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
340 348
341When 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
342the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
343you 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>,
344C<EV::WRITE> and C<EV::TIMER>). 352C<EV::WRITE> and C<EV::TIMER>).
345 353
346EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
347of them triggers, then they will be stopped and freed, and the callback 355of them triggers, then they will be stopped and freed, and the callback
348invoked. 356invoked.
349 357
350=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
351 359
352=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
353 361
354Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
355if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
356C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
357 365
358=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
359 367
360Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
361specified by C<$signal> had occured. 369if the signal specified by C<$signal> had occured.
370
371=item EV::feed_signal $signal
372
373Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
374regardless of which loop has registered the signal, and is mainly useful
375for custom signal implementations.
362 376
363=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
364 378
365=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
366 380
493returns 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
494watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
495 509
496=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
497 511
498Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::run> will return when there are no active watchers
499(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
500convenient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
501call 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
502finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
503 517
504Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
505that 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
506as 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
507somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
508handled, 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
509because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
510 524
511In 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
512though 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.
513 527
514The 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
515any time. 529any time.
516 530
517Example: 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
584 598
585=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
586 600
587=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
588 602
589Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
590C<$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
591value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
592 606
593This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
594seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
595to 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
596loop 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,
600in 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
601clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
602 616
603The 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.
604 618
605=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
606 620
607Reconfigures 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
608any time. 622any time.
609 623
610=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
611 627
612Similar 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:
613 629
614If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
615 631
622 638
623This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
624operation. 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
625C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
626on 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 = $w->remaining
648
649Calculates and returns the remaining time till the timer will fire.
627 650
628=back 651=back
629 652
630 653
631=head3 PERIODIC WATCHERS - to cron or not to cron? 654=head3 PERIODIC WATCHERS - to cron or not to cron?
659surpasses this time. 682surpasses this time.
660 683
661=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 684=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
662 685
663In this mode the watcher will always be scheduled to time out at the 686In this mode the watcher will always be scheduled to time out at the
664next C<$at + N * $interval> time (for some integer N) and then repeat, 687next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
665regardless of any time jumps. 688regardless of any time jumps. Note that, since C<N> can be negative, the
689first trigger can happen before C<$at>.
666 690
667This 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
668time: 692time:
669 693
670 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 694 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
671 695
672That doesn't mean there will always be 3600 seconds in between triggers, 696That doesn't mean there will always be 3600 seconds in between triggers,
673but only that the the clalback will be called when the system time shows a 697but only that the the callback will be called when the system time shows a
674full hour (UTC). 698full hour (UTC).
675 699
676Another way to think about it (for the mathematically inclined) is that 700Another way to think about it (for the mathematically inclined) is that
677EV::periodic will try to run the callback in this mode at the next 701EV::periodic will try to run the callback in this mode at the next
678possible time where C<$time = $at (mod $interval)>, regardless of any time 702possible time where C<$time = $at (mod $interval)>, regardless of any time
686time as second argument. 710time as second argument.
687 711
688I<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
689watcher, 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
690you 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
691and start a C<EV::prepare> watcher for this task. 715and start an C<EV::prepare> watcher for this task.
692 716
693It 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
694(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
695argument). It will usually be called just before the callback will be 719argument). It will usually be called just before the callback will be
696triggered, but might be called at other times, too. 720triggered, but might be called at other times, too.
697 721
698This 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
699triggers on each midnight, local time (actually 24 hours after the last 723triggers on each midnight, local time (actually one day after the last
700midnight, to keep the example simple. If you know a way to do it correctly 724midnight, to keep the example simple):
701in about the same space (without requiring elaborate modules), drop me a
702note :):
703 725
704 my $daily = EV::periodic 0, 0, sub { 726 my $daily = EV::periodic 0, 0, sub {
705 my ($w, $now) = @_; 727 my ($w, $now) = @_;
706 728
707 use Time::Local (); 729 use Time::Local ();
708 my (undef, undef, undef, $d, $m, $y) = localtime $now; 730 my (undef, undef, undef, $d, $m, $y) = localtime $now;
709 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 731 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
710 }, sub { 732 }, sub {
711 print "it's midnight or likely shortly after, now\n"; 733 print "it's midnight or likely shortly after, now\n";
712 }; 734 };
713 735
714=back 736=back
1126 1148
1127=item $w = EV::async $callback 1149=item $w = EV::async $callback
1128 1150
1129=item $w = EV::async_ns $callback 1151=item $w = EV::async_ns $callback
1130 1152
1153=item $w = $loop->async ($callback)
1154
1155=item $w = $loop->async_ns ($callback)
1156
1131=item $w->send 1157=item $w->send
1132 1158
1133=item $bool = $w->async_pending 1159=item $bool = $w->async_pending
1134 1160
1135=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.
1136 1167
1137 1168
1138=head1 PERL SIGNALS 1169=head1 PERL SIGNALS
1139 1170
1140While 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
1188 1219
11891; 12201;
1190 1221
1191=head1 SEE ALSO 1222=head1 SEE ALSO
1192 1223
1224L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1193L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1225(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1194event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1226loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1195coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1227integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1196event-loop agnostic and portable event driven programming. 1228event-loop agnostic and portable event driven programming.
1197 1229
1198=head1 AUTHOR 1230=head1 AUTHOR
1199 1231
1200 Marc Lehmann <schmorp@schmorp.de> 1232 Marc Lehmann <schmorp@schmorp.de>

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