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Revision 1.128 by root, Thu Oct 21 02:46:59 2010 UTC vs.
Revision 1.167 by root, Thu Oct 19 18:02:42 2023 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,
77can use it through the L<AnyEvent> module, stay portable to other event 77can use it through the L<AnyEvent> module, stay portable to other event
78loops (if you don't rely on any watcher types not available through it) 78loops (if you don't rely on any watcher types not available through it)
79and still be faster than with any other event loop currently supported in 79and still be faster than with any other event loop currently supported in
80Perl. 80Perl.
81 81
82=head2 PORTING FROM EV 3.X to 4.X
83
84EV version 4 introduces a number of incompatible changes summarised
85here. According to the depreciation strategy used by libev, there is a
86compatibility layer in place so programs should continue to run unchanged
87(the XS interface lacks this layer, so programs using that one need to be
88updated).
89
90This compatibility layer will be switched off in some future release.
91
92All changes relevant to Perl are renames of symbols, functions and
93methods:
94
95 EV::loop => EV::run
96 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
97 EV::LOOP_ONESHOT => EV::RUN_ONCE
98
99 EV::unloop => EV::break
100 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
101 EV::UNLOOP_ONE => EV::BREAK_ONE
102 EV::UNLOOP_ALL => EV::BREAK_ALL
103
104 EV::TIMEOUT => EV::TIMER
105
106 EV::loop_count => EV::iteration
107 EV::loop_depth => EV::depth
108 EV::loop_verify => EV::verify
109
110The loop object methods corresponding to the functions above have been
111similarly renamed.
112
82=head2 MODULE EXPORTS 113=head2 MODULE EXPORTS
83 114
84This module does not export any symbols. 115This module does not export any symbols.
85 116
86=cut 117=cut
88package EV; 119package EV;
89 120
90use common::sense; 121use common::sense;
91 122
92BEGIN { 123BEGIN {
93 our $VERSION = '4.00'; 124 our $VERSION = '4.34';
94 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
95 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
96} 128}
97 129
98@EV::IO::ISA = 130@EV::IO::ISA =
99@EV::Timer::ISA = 131@EV::Timer::ISA =
143or locally-installed as F<EV::libev> manpage) for more info. 175or locally-installed as F<EV::libev> manpage) for more info.
144 176
145The loop will automatically be destroyed when it is no longer referenced 177The loop will automatically be destroyed when it is no longer referenced
146by any watcher and the loop object goes out of scope. 178by any watcher and the loop object goes out of scope.
147 179
148If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> 180If you are not embedding the loop, then using C<EV::FLAG_FORKCHECK>
149is recommended, as only the default event loop is protected by this 181is recommended, as only the default event loop is protected by this
150module. If you I<are> embedding this loop in the default loop, this is not 182module. If you I<are> embedding this loop in the default loop, this is not
151necessary, as C<EV::embed> automatically does the right thing on fork. 183necessary, as C<EV::embed> automatically does the right thing on fork.
152 184
153=item $loop->loop_fork 185=item $loop->loop_fork
155Must 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
156the 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
157this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
158documentation). 190documentation).
159 191
160=item $loop->loop_verify 192=item $loop->verify
161 193
162Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
163libev) 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
164corrupted. 196corrupted.
165 197
216 248
217=item $loop->now_update 249=item $loop->now_update
218 250
219Establishes the current time by querying the kernel, updating the time 251Establishes the current time by querying the kernel, updating the time
220returned 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
221is usually done automatically within C<EV::loop>. 253is usually done automatically within C<EV::run>.
222 254
223This 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
224very 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
225the current time is a good idea. 257the current time is a good idea.
226 258
259=item $backend = $loop->backend 291=item $backend = $loop->backend
260 292
261Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
262or EV::BACKEND_EPOLL). 294or EV::BACKEND_EPOLL).
263 295
264=item EV::loop [$flags] 296=item $active = EV::run [$flags]
265 297
266=item $loop->loop ([$flags]) 298=item $active = $loop->run ([$flags])
267 299
268Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
269callback 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".
270 306
271The $flags argument can be one of the following: 307The $flags argument can be one of the following:
272 308
273 0 as above 309 0 as above
274 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
275 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
276 312
277=item EV::unloop [$how] 313=item EV::break [$how]
278 314
279=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
280 316
281When 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
282innermost call to EV::loop return. 318innermost call to EV::run return.
283 319
284When 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
285fast as possible. 321return as fast as possible.
286 322
287=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
288 325
326=item $count = EV::iteration
327
289=item $count = $loop->loop_count 328=item $count = $loop->iteration
290 329
291Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
292events. Sometimes useful as a generation counter. 331events. Sometimes useful as a generation counter.
293 332
294=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
303| 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
304you 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
305C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
306 345
307If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
308timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
309 348
310When 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
311the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
312you 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>,
313C<EV::WRITE> and C<EV::TIMER>). 352C<EV::WRITE> and C<EV::TIMER>).
314 353
315EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
316of 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
317invoked. 356invoked.
318 357
319=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
320 359
321=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
322 361
323Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
324if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
325C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
326 365
327=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
328 367
329Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
330specified by C<$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.
331 376
332=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
333 378
334=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
335 380
462returns 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
463watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
464 509
465=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
466 511
467Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::run> will return when there are no active watchers
468(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
469convenient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
470call 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
471finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
472 517
473Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
474that 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
475as 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
476somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
477handled, 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
478because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
479 524
480In 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
481though 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.
482 527
483The 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
484any time. 529any time.
485 530
486Example: 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
553 598
554=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
555 600
556=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
557 602
558Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
559C<$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
560value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
561 606
562This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
563seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
564to 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
565loop 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,
569in 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
570clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
571 616
572The 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.
573 618
574=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
575 620
576Reconfigures 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
577any time. 622any time.
578 623
579=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
580 627
581Similar 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:
582 629
583If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
584 631
591 638
592This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
593operation. 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
594C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
595on 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.
650
651=item $repeat = $w->repeat
652
653=item $old_repeat = $w->repeat ($new_repeat)
654
655Returns the current value of the repeat attribute and optionally sets a
656new one. Setting the new one will not restart the watcher - if the watcher
657is active, the new repeat value is used whenever it expires next.
596 658
597=back 659=back
598 660
599 661
600=head3 PERIODIC WATCHERS - to cron or not to cron? 662=head3 PERIODIC WATCHERS - to cron or not to cron?
628surpasses this time. 690surpasses this time.
629 691
630=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 692=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
631 693
632In this mode the watcher will always be scheduled to time out at the 694In this mode the watcher will always be scheduled to time out at the
633next C<$at + N * $interval> time (for some integer N) and then repeat, 695next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
634regardless of any time jumps. 696regardless of any time jumps. Note that, since C<N> can be negative, the
697first trigger can happen before C<$at>.
635 698
636This can be used to create timers that do not drift with respect to system 699This can be used to create timers that do not drift with respect to system
637time: 700time:
638 701
639 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 702 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
640 703
641That doesn't mean there will always be 3600 seconds in between triggers, 704That doesn't mean there will always be 3600 seconds in between triggers,
642but only that the the clalback will be called when the system time shows a 705but only that the the callback will be called when the system time shows a
643full hour (UTC). 706full hour (UTC).
644 707
645Another way to think about it (for the mathematically inclined) is that 708Another way to think about it (for the mathematically inclined) is that
646EV::periodic will try to run the callback in this mode at the next 709EV::periodic will try to run the callback in this mode at the next
647possible time where C<$time = $at (mod $interval)>, regardless of any time 710possible time where C<$time = $at (mod $interval)>, regardless of any time
655time as second argument. 718time as second argument.
656 719
657I<This callback MUST NOT stop or destroy this or any other periodic 720I<This callback MUST NOT stop or destroy this or any other periodic
658watcher, ever, and MUST NOT call any event loop functions or methods>. If 721watcher, ever, and MUST NOT call any event loop functions or methods>. If
659you need to stop it, return 1e30 and stop it afterwards. You may create 722you need to stop it, return 1e30 and stop it afterwards. You may create
660and start a C<EV::prepare> watcher for this task. 723and start an C<EV::prepare> watcher for this task.
661 724
662It must return the next time to trigger, based on the passed time value 725It must return the next time to trigger, based on the passed time value
663(that is, the lowest time value larger than or equal to to the second 726(that is, the lowest time value larger than or equal to to the second
664argument). It will usually be called just before the callback will be 727argument). It will usually be called just before the callback will be
665triggered, but might be called at other times, too. 728triggered, but might be called at other times, too.
666 729
667This can be used to create very complex timers, such as a timer that 730This can be used to create very complex timers, such as a timer that
668triggers on each midnight, local time (actually 24 hours after the last 731triggers on each midnight, local time (actually one day after the last
669midnight, to keep the example simple. If you know a way to do it correctly 732midnight, to keep the example simple):
670in about the same space (without requiring elaborate modules), drop me a
671note :):
672 733
673 my $daily = EV::periodic 0, 0, sub { 734 my $daily = EV::periodic 0, 0, sub {
674 my ($w, $now) = @_; 735 my ($w, $now) = @_;
675 736
676 use Time::Local (); 737 use Time::Local ();
677 my (undef, undef, undef, $d, $m, $y) = localtime $now; 738 my (undef, undef, undef, $d, $m, $y) = localtime $now;
678 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 739 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
679 }, sub { 740 }, sub {
680 print "it's midnight or likely shortly after, now\n"; 741 print "it's midnight or likely shortly after, now\n";
681 }; 742 };
682 743
683=back 744=back
694Simply stops and starts the watcher again. 755Simply stops and starts the watcher again.
695 756
696=item $time = $w->at 757=item $time = $w->at
697 758
698Return the time that the watcher is expected to trigger next. 759Return the time that the watcher is expected to trigger next.
760
761=item $offset = $w->offset
762
763=item $old_offset = $w->offset ($new_offset)
764
765Returns the current value of the offset attribute and optionally sets a
766new one. Setting the new one will not restart the watcher - if the watcher
767is active, the new offset value is used whenever it expires next.
768
769=item $interval = $w->interval
770
771=item $old_interval = $w->interval ($new_interval)
772
773See above, for the interval attribute.
774
775=item $reschedule_cb = $w->reschedule_cb
776
777=item $old_reschedule_cb = $w->reschedule_cb ($new_reschedule_cb)
778
779See above, for the reschedule callback.
699 780
700=back 781=back
701 782
702 783
703=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 784=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
791 872
792=item $pid = $w->rpid 873=item $pid = $w->rpid
793 874
794Return the pid of the awaited child (useful when you have installed a 875Return the pid of the awaited child (useful when you have installed a
795watcher for all pids). 876watcher for all pids).
877
878=item EV::Child::reinit [EXPERIMENTAL]
879
880Internally, libev installs a signal handler for C<SIGCHLD>. Unfortunately,
881a lot of Perl code does soemthing like C<< local $SIG{CHLD} >>, which,
882unfortunately, is broken and will not restore the signal handler.
883
884If this has happened, you can call this function to stop/rrestart the
885internal libev watcher, which will reset the signal handler.
886
887Note that this is an experimental function, whose interface might change.
796 888
797=back 889=back
798 890
799 891
800=head3 STAT WATCHERS - did the file attributes just change? 892=head3 STAT WATCHERS - did the file attributes just change?
1095 1187
1096=item $w = EV::async $callback 1188=item $w = EV::async $callback
1097 1189
1098=item $w = EV::async_ns $callback 1190=item $w = EV::async_ns $callback
1099 1191
1192=item $w = $loop->async ($callback)
1193
1194=item $w = $loop->async_ns ($callback)
1195
1100=item $w->send 1196=item $w->send
1101 1197
1102=item $bool = $w->async_pending 1198=item $bool = $w->async_pending
1103 1199
1104=back 1200=back
1201
1202=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1203
1204Cleanup watchers are not supported on the Perl level, they can only be
1205used via XS currently.
1105 1206
1106 1207
1107=head1 PERL SIGNALS 1208=head1 PERL SIGNALS
1108 1209
1109While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1210While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
1157 1258
11581; 12591;
1159 1260
1160=head1 SEE ALSO 1261=head1 SEE ALSO
1161 1262
1263L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1162L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1264(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1163event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1265loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1164coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1266integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1165event-loop agnostic and portable event driven programming. 1267event-loop agnostic and portable event driven programming.
1166 1268
1167=head1 AUTHOR 1269=head1 AUTHOR
1168 1270
1169 Marc Lehmann <schmorp@schmorp.de> 1271 Marc Lehmann <schmorp@schmorp.de>

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