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Revision 1.126 by root, Tue Mar 16 17:11:48 2010 UTC vs.
Revision 1.154 by root, Fri Dec 21 07:06:51 2018 UTC

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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
56=head1 BEFORE YOU START USING THIS MODULE
57
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,
60specifically the simplified API described in L<AE>.
61
62When used with EV as backend, the L<AE> API is as fast as the native L<EV>
63API, but your programs/modules will still run with many other event loops.
55 64
56=head1 DESCRIPTION 65=head1 DESCRIPTION
57 66
58This module provides an interface to libev 67This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 68(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
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68can 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
69loops (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)
70and 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
71Perl. 80Perl.
72 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
73=head2 MODULE EXPORTS 113=head2 MODULE EXPORTS
74 114
75This module does not export any symbols. 115This module does not export any symbols.
76 116
77=cut 117=cut
… …
79package EV; 119package EV;
80 120
81use common::sense; 121use common::sense;
82 122
83BEGIN { 123BEGIN {
84 our $VERSION = '4.00'; 124 our $VERSION = 4.25;
85 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
86 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
87} 128}
88 129
89@EV::IO::ISA = 130@EV::IO::ISA =
90@EV::Timer::ISA = 131@EV::Timer::ISA =
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146Must 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
147the 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
148this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
149documentation). 190documentation).
150 191
151=item $loop->loop_verify 192=item $loop->verify
152 193
153Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
154libev) 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
155corrupted. 196corrupted.
156 197
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250=item $backend = $loop->backend 291=item $backend = $loop->backend
251 292
252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
253or EV::BACKEND_EPOLL). 294or EV::BACKEND_EPOLL).
254 295
255=item EV::loop [$flags] 296=item $active = EV::run [$flags]
256 297
257=item $loop->loop ([$flags]) 298=item $active = $loop->run ([$flags])
258 299
259Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
260callback 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".
261 306
262The $flags argument can be one of the following: 307The $flags argument can be one of the following:
263 308
264 0 as above 309 0 as above
265 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
266 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
267 312
268=item EV::unloop [$how] 313=item EV::break [$how]
269 314
270=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
271 316
272When 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
273innermost call to EV::loop return. 318innermost call to EV::loop return.
274 319
275When 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::loop will
276fast as possible. 321return as fast as possible.
277 322
278=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
279 325
326=item $count = EV::iteration
327
280=item $count = $loop->loop_count 328=item $count = $loop->iteration
281 329
282Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
283events. Sometimes useful as a generation counter. 331events. Sometimes useful as a generation counter.
284 332
285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
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294| 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
295you 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
296C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
297 345
298If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
299timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
300 348
301When 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
302the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
303you 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>,
304C<EV::WRITE> and C<EV::TIMER>). 352C<EV::WRITE> and C<EV::TIMER>).
305 353
306EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
307of 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
308invoked. 356invoked.
309 357
310=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
311 359
312=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
313 361
314Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
315if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
316C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
317 365
318=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
319 367
320Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
321specified by C<$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
375fro custom signal implementations.
322 376
323=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
324 378
325=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
326 380
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544 598
545=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
546 600
547=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
548 602
549Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
550C<$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
551value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
552 606
553This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
554seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
555to 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
556loop 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,
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560in 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
561clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
562 616
563The 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.
564 618
565=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
566 620
567Reconfigures 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
568any time. 622any time.
569 623
570=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
571 627
572Similar 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:
573 629
574If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
575 631
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582 638
583This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
584operation. 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
585C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
586on 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 = $w->remaining
648
649Calculates and returns the remaining time till the timer will fire.
587 650
588=back 651=back
589 652
590 653
591=head3 PERIODIC WATCHERS - to cron or not to cron? 654=head3 PERIODIC WATCHERS - to cron or not to cron?
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619surpasses this time. 682surpasses this time.
620 683
621=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 684=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
622 685
623In this mode the watcher will always be scheduled to time out at the 686In this mode the watcher will always be scheduled to time out at the
624next C<$at + N * $interval> time (for some integer N) and then repeat, 687next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
625regardless of any time jumps. 688regardless of any time jumps. Note that, since C<N> can be negative, the
689first trigger can happen before C<$at>.
626 690
627This 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
628time: 692time:
629 693
630 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 694 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
631 695
632That doesn't mean there will always be 3600 seconds in between triggers, 696That doesn't mean there will always be 3600 seconds in between triggers,
633but only that the the clalback will be called when the system time shows a 697but only that the the callback will be called when the system time shows a
634full hour (UTC). 698full hour (UTC).
635 699
636Another way to think about it (for the mathematically inclined) is that 700Another way to think about it (for the mathematically inclined) is that
637EV::periodic will try to run the callback in this mode at the next 701EV::periodic will try to run the callback in this mode at the next
638possible time where C<$time = $at (mod $interval)>, regardless of any time 702possible time where C<$time = $at (mod $interval)>, regardless of any time
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646time as second argument. 710time as second argument.
647 711
648I<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
649watcher, 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
650you 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
651and start a C<EV::prepare> watcher for this task. 715and start an C<EV::prepare> watcher for this task.
652 716
653It 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
654(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
655argument). It will usually be called just before the callback will be 719argument). It will usually be called just before the callback will be
656triggered, but might be called at other times, too. 720triggered, but might be called at other times, too.
657 721
658This 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
659triggers on each midnight, local time (actually 24 hours after the last 723triggers on each midnight, local time (actually one day after the last
660midnight, to keep the example simple. If you know a way to do it correctly 724midnight, to keep the example simple):
661in about the same space (without requiring elaborate modules), drop me a
662note :):
663 725
664 my $daily = EV::periodic 0, 0, sub { 726 my $daily = EV::periodic 0, 0, sub {
665 my ($w, $now) = @_; 727 my ($w, $now) = @_;
666 728
667 use Time::Local (); 729 use Time::Local ();
668 my (undef, undef, undef, $d, $m, $y) = localtime $now; 730 my (undef, undef, undef, $d, $m, $y) = localtime $now;
669 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 731 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
670 }, sub { 732 }, sub {
671 print "it's midnight or likely shortly after, now\n"; 733 print "it's midnight or likely shortly after, now\n";
672 }; 734 };
673 735
674=back 736=back
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941=item $w = $loop->check_ns ($callback) 1003=item $w = $loop->check_ns ($callback)
942 1004
943Call the callback just after the process wakes up again (after it has 1005Call the callback just after the process wakes up again (after it has
944gathered events), but before any other callbacks have been invoked. 1006gathered events), but before any other callbacks have been invoked.
945 1007
946This is used to integrate other event-based software into the EV 1008This can be used to integrate other event-based software into the EV
947mainloop: You register a prepare callback and in there, you create io and 1009mainloop: You register a prepare callback and in there, you create io and
948timer watchers as required by the other software. Here is a real-world 1010timer watchers as required by the other software. Here is a real-world
949example of integrating Net::SNMP (with some details left out): 1011example of integrating Net::SNMP (with some details left out):
950 1012
951 our @snmp_watcher; 1013 our @snmp_watcher;
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985The callbacks of the created watchers will not be called as the watchers 1047The callbacks of the created watchers will not be called as the watchers
986are destroyed before this can happen (remember EV::check gets called 1048are destroyed before this can happen (remember EV::check gets called
987first). 1049first).
988 1050
989The C<check_ns> variant doesn't start (activate) the newly created watcher. 1051The C<check_ns> variant doesn't start (activate) the newly created watcher.
1052
1053=item EV::CHECK constant issues
1054
1055Like all other watcher types, there is a bitmask constant for use in
1056C<$revents> and other places. The C<EV::CHECK> is special as it has
1057the same name as the C<CHECK> sub called by Perl. This doesn't cause
1058big issues on newer perls (beginning with 5.8.9), but it means thatthe
1059constant must be I<inlined>, i.e. runtime calls will not work. That means
1060that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1061safe side.
990 1062
991=back 1063=back
992 1064
993 1065
994=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1066=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
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1076 1148
1077=item $w = EV::async $callback 1149=item $w = EV::async $callback
1078 1150
1079=item $w = EV::async_ns $callback 1151=item $w = EV::async_ns $callback
1080 1152
1153=item $w = $loop->async ($callback)
1154
1155=item $w = $loop->async_ns ($callback)
1156
1081=item $w->send 1157=item $w->send
1082 1158
1083=item $bool = $w->async_pending 1159=item $bool = $w->async_pending
1084 1160
1085=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.
1086 1167
1087 1168
1088=head1 PERL SIGNALS 1169=head1 PERL SIGNALS
1089 1170
1090While 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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1138 1219
11391; 12201;
1140 1221
1141=head1 SEE ALSO 1222=head1 SEE ALSO
1142 1223
1224L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1143L<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
1144event 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
1145coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1227integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1146event-loop agnostic and portable event driven programming. 1228event-loop agnostic and portable event driven programming.
1147 1229
1148=head1 AUTHOR 1230=head1 AUTHOR
1149 1231
1150 Marc Lehmann <schmorp@schmorp.de> 1232 Marc Lehmann <schmorp@schmorp.de>

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