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Revision 1.124 by root, Tue Dec 1 13:56:33 2009 UTC vs.
Revision 1.144 by root, Sat Sep 6 18:42:18 2014 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::unloop 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
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79package EV; 119package EV;
80 120
81use common::sense; 121use common::sense;
82 122
83BEGIN { 123BEGIN {
84 our $VERSION = '3.8'; 124 our $VERSION = '4.18';
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::unloop or the flasg 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 returnv alue 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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299timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise a 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::TIMEOUT>). 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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366 420
367Each watcher type has its associated bit in revents, so you can use the 421Each watcher type has its associated bit in revents, so you can use the
368same callback for multiple watchers. The event mask is named after the 422same callback for multiple watchers. The event mask is named after the
369type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 423type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
370EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 424EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
371(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 425(which can set both EV::READ and EV::WRITE bits).
372uses EV::TIMEOUT).
373 426
374In the rare case where one wants to create a watcher but not start it at 427In the rare case where one wants to create a watcher but not start it at
375the same time, each constructor has a variant with a trailing C<_ns> in 428the same time, each constructor has a variant with a trailing C<_ns> in
376its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 429its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
377 430
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629time: 682time:
630 683
631 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 684 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
632 685
633That doesn't mean there will always be 3600 seconds in between triggers, 686That doesn't mean there will always be 3600 seconds in between triggers,
634but only that the the clalback will be called when the system time shows a 687but only that the the callback will be called when the system time shows a
635full hour (UTC). 688full hour (UTC).
636 689
637Another way to think about it (for the mathematically inclined) is that 690Another way to think about it (for the mathematically inclined) is that
638EV::periodic will try to run the callback in this mode at the next 691EV::periodic will try to run the callback in this mode at the next
639possible time where C<$time = $at (mod $interval)>, regardless of any time 692possible time where C<$time = $at (mod $interval)>, regardless of any time
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942=item $w = $loop->check_ns ($callback) 995=item $w = $loop->check_ns ($callback)
943 996
944Call the callback just after the process wakes up again (after it has 997Call the callback just after the process wakes up again (after it has
945gathered events), but before any other callbacks have been invoked. 998gathered events), but before any other callbacks have been invoked.
946 999
947This is used to integrate other event-based software into the EV 1000This can be used to integrate other event-based software into the EV
948mainloop: You register a prepare callback and in there, you create io and 1001mainloop: You register a prepare callback and in there, you create io and
949timer watchers as required by the other software. Here is a real-world 1002timer watchers as required by the other software. Here is a real-world
950example of integrating Net::SNMP (with some details left out): 1003example of integrating Net::SNMP (with some details left out):
951 1004
952 our @snmp_watcher; 1005 our @snmp_watcher;
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986The callbacks of the created watchers will not be called as the watchers 1039The callbacks of the created watchers will not be called as the watchers
987are destroyed before this can happen (remember EV::check gets called 1040are destroyed before this can happen (remember EV::check gets called
988first). 1041first).
989 1042
990The C<check_ns> variant doesn't start (activate) the newly created watcher. 1043The C<check_ns> variant doesn't start (activate) the newly created watcher.
1044
1045=item EV::CHECK constant issues
1046
1047Like all other watcher types, there is a bitmask constant for use in
1048C<$revents> and other places. The C<EV::CHECK> is special as it has
1049the same name as the C<CHECK> sub called by Perl. This doesn't cause
1050big issues on newer perls (beginning with 5.8.9), but it means thatthe
1051constant must be I<inlined>, i.e. runtime calls will not work. That means
1052that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1053safe side.
991 1054
992=back 1055=back
993 1056
994 1057
995=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1058=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
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1077 1140
1078=item $w = EV::async $callback 1141=item $w = EV::async $callback
1079 1142
1080=item $w = EV::async_ns $callback 1143=item $w = EV::async_ns $callback
1081 1144
1145=item $w = $loop->async ($callback)
1146
1147=item $w = $loop->async_ns ($callback)
1148
1082=item $w->send 1149=item $w->send
1083 1150
1084=item $bool = $w->async_pending 1151=item $bool = $w->async_pending
1085 1152
1086=back 1153=back
1154
1155=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1156
1157Cleanup watchers are not supported on the Perl level, they can only be
1158used via XS currently.
1087 1159
1088 1160
1089=head1 PERL SIGNALS 1161=head1 PERL SIGNALS
1090 1162
1091While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1163While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
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1139 1211
11401; 12121;
1141 1213
1142=head1 SEE ALSO 1214=head1 SEE ALSO
1143 1215
1216L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1144L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1217(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1145event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1218loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1146coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1219integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1147event-loop agnostic and portable event driven programming. 1220event-loop agnostic and portable event driven programming.
1148 1221
1149=head1 AUTHOR 1222=head1 AUTHOR
1150 1223
1151 Marc Lehmann <schmorp@schmorp.de> 1224 Marc Lehmann <schmorp@schmorp.de>

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