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Revision 1.114 by root, Wed Apr 15 19:35:53 2009 UTC vs.
Revision 1.142 by root, Sat Mar 8 15:51:23 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
78 118
79package EV; 119package EV;
80 120
81no warnings; 121use common::sense;
82use strict;
83 122
84BEGIN { 123BEGIN {
85 our $VERSION = '3.53'; 124 our $VERSION = '4.16';
86 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
87 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
88} 128}
89 129
90@EV::IO::ISA = 130@EV::IO::ISA =
91@EV::Timer::ISA = 131@EV::Timer::ISA =
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147Must 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
148the 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
149this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
150documentation). 190documentation).
151 191
152=item $loop->loop_verify 192=item $loop->verify
153 193
154Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
155libev) 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
156corrupted. 196corrupted.
157 197
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251=item $backend = $loop->backend 291=item $backend = $loop->backend
252 292
253Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
254or EV::BACKEND_EPOLL). 294or EV::BACKEND_EPOLL).
255 295
256=item EV::loop [$flags] 296=item $active = EV::run [$flags]
257 297
258=item $loop->loop ([$flags]) 298=item $active = $loop->run ([$flags])
259 299
260Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
261callback 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".
262 306
263The $flags argument can be one of the following: 307The $flags argument can be one of the following:
264 308
265 0 as above 309 0 as above
266 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
267 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
268 312
269=item EV::unloop [$how] 313=item EV::break [$how]
270 314
271=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
272 316
273When 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
274innermost call to EV::loop return. 318innermost call to EV::loop return.
275 319
276When 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
277fast as possible. 321return as fast as possible.
278 322
279=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
280 325
326=item $count = EV::iteration
327
281=item $count = $loop->loop_count 328=item $count = $loop->iteration
282 329
283Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
284events. Sometimes useful as a generation counter. 331events. Sometimes useful as a generation counter.
285 332
286=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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300timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise a EV::timer with this value will be started.
301 348
302When 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
303the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
304you 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>,
305C<EV::WRITE> and C<EV::TIMEOUT>). 352C<EV::WRITE> and C<EV::TIMER>).
306 353
307EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
308of 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
309invoked. 356invoked.
310 357
311=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
312 359
313=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
314 361
315Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
316if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
317C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
318 365
319=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
320 367
321Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
322specified by C<$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.
323 376
324=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
325 378
326=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
327 380
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332These advanced functions set the minimum block interval when polling for I/O events and the minimum 385These advanced functions set the minimum block interval when polling for I/O events and the minimum
333wait interval for timer events. See the libev documentation at 386wait interval for timer events. See the libev documentation at
334L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> 387L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
335(locally installed as F<EV::libev>) for a more detailed discussion. 388(locally installed as F<EV::libev>) for a more detailed discussion.
336 389
390=item $count = EV::pending_count
391
392=item $count = $loop->pending_count
393
394Returns the number of currently pending watchers.
395
396=item EV::invoke_pending
397
398=item $loop->invoke_pending
399
400Invoke all currently pending watchers.
401
337=back 402=back
338 403
339 404
340=head1 WATCHER OBJECTS 405=head1 WATCHER OBJECTS
341 406
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355 420
356Each 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
357same callback for multiple watchers. The event mask is named after the 422same callback for multiple watchers. The event mask is named after the
358type, 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,
359EV::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
360(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).
361uses EV::TIMEOUT).
362 426
363In 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
364the 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
365its 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.
366 430
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445 509
446=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
447 511
448Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::loop> will return when there are no active watchers
449(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
450convinient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
451call C<EV::loop> once and when it returns you know that all your jobs are 515call C<EV::loop> once and when it returns you know that all your jobs are
452finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
453 517
454Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
455that calls C<EV::loop> (usually the main program) is not the same module 519that calls C<EV::loop> (usually the main program) is not the same module
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618time: 682time:
619 683
620 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 684 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
621 685
622That doesn't mean there will always be 3600 seconds in between triggers, 686That doesn't mean there will always be 3600 seconds in between triggers,
623but only that the the clalback will be called when the system time shows a 687but only that the the callback will be called when the system time shows a
624full hour (UTC). 688full hour (UTC).
625 689
626Another way to think about it (for the mathematically inclined) is that 690Another way to think about it (for the mathematically inclined) is that
627EV::periodic will try to run the callback in this mode at the next 691EV::periodic will try to run the callback in this mode at the next
628possible time where C<$time = $at (mod $interval)>, regardless of any time 692possible time where C<$time = $at (mod $interval)>, regardless of any time
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687 751
688=item $w = EV::signal $signal, $callback 752=item $w = EV::signal $signal, $callback
689 753
690=item $w = EV::signal_ns $signal, $callback 754=item $w = EV::signal_ns $signal, $callback
691 755
756=item $w = $loop->signal ($signal, $callback)
757
758=item $w = $loop->signal_ns ($signal, $callback)
759
692Call the callback when $signal is received (the signal can be specified by 760Call the callback when $signal is received (the signal can be specified by
693number or by name, just as with C<kill> or C<%SIG>). 761number or by name, just as with C<kill> or C<%SIG>).
762
763Only one event loop can grab a given signal - attempting to grab the same
764signal from two EV loops will crash the program immediately or cause data
765corruption.
694 766
695EV will grab the signal for the process (the kernel only allows one 767EV will grab the signal for the process (the kernel only allows one
696component to receive a signal at a time) when you start a signal watcher, 768component to receive a signal at a time) when you start a signal watcher,
697and removes it again when you stop it. Perl does the same when you 769and removes it again when you stop it. Perl does the same when you
698add/remove callbacks to C<%SIG>, so watch out. 770add/remove callbacks to C<%SIG>, so watch out.
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923=item $w = $loop->check_ns ($callback) 995=item $w = $loop->check_ns ($callback)
924 996
925Call 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
926gathered events), but before any other callbacks have been invoked. 998gathered events), but before any other callbacks have been invoked.
927 999
928This is used to integrate other event-based software into the EV 1000This can be used to integrate other event-based software into the EV
929mainloop: 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
930timer 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
931example of integrating Net::SNMP (with some details left out): 1003example of integrating Net::SNMP (with some details left out):
932 1004
933 our @snmp_watcher; 1005 our @snmp_watcher;
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967The 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
968are destroyed before this can happen (remember EV::check gets called 1040are destroyed before this can happen (remember EV::check gets called
969first). 1041first).
970 1042
971The 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.
972 1054
973=back 1055=back
974 1056
975 1057
976=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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1044 1126
1045=back 1127=back
1046 1128
1047=head3 ASYNC WATCHERS - how to wake up another event loop 1129=head3 ASYNC WATCHERS - how to wake up another event loop
1048 1130
1049Async watchers are provided by EV, but have little use in perl directly, as perl 1131Async watchers are provided by EV, but have little use in perl directly,
1050neither supports threads nor direct access to signal handlers or other 1132as perl neither supports threads running in parallel nor direct access to
1051contexts where they could be of value. 1133signal handlers or other contexts where they could be of value.
1052 1134
1053It is, however, possible to use them from the XS level. 1135It is, however, possible to use them from the XS level.
1054 1136
1055Please see the libev documentation for further details. 1137Please see the libev documentation for further details.
1056 1138
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1058 1140
1059=item $w = EV::async $callback 1141=item $w = EV::async $callback
1060 1142
1061=item $w = EV::async_ns $callback 1143=item $w = EV::async_ns $callback
1062 1144
1145=item $w = $loop->async ($callback)
1146
1147=item $w = $loop->async_ns ($callback)
1148
1063=item $w->send 1149=item $w->send
1064 1150
1065=item $bool = $w->async_pending 1151=item $bool = $w->async_pending
1066 1152
1067=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.
1068 1159
1069 1160
1070=head1 PERL SIGNALS 1161=head1 PERL SIGNALS
1071 1162
1072While 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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1084 my $async_check = EV::check sub { }; 1175 my $async_check = EV::check sub { };
1085 1176
1086This ensures that perl gets into control for a short time to handle any 1177This ensures that perl gets into control for a short time to handle any
1087pending signals, and also ensures (slightly) slower overall operation. 1178pending signals, and also ensures (slightly) slower overall operation.
1088 1179
1089=head1 THREADS 1180=head1 ITHREADS
1090 1181
1091Threads are not supported by this module in any way. Perl pseudo-threads 1182Ithreads are not supported by this module in any way. Perl pseudo-threads
1092is evil stuff and must die. As soon as Perl gains real threads I will work 1183is evil stuff and must die. Real threads as provided by Coro are fully
1093on thread support for it. 1184supported (and enhanced support is available via L<Coro::EV>).
1094 1185
1095=head1 FORK 1186=head1 FORK
1096 1187
1097Most of the "improved" event delivering mechanisms of modern operating 1188Most of the "improved" event delivering mechanisms of modern operating
1098systems have quite a few problems with fork(2) (to put it bluntly: it is 1189systems have quite a few problems with fork(2) (to put it bluntly: it is
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1120 1211
11211; 12121;
1122 1213
1123=head1 SEE ALSO 1214=head1 SEE ALSO
1124 1215
1216L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1125L<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
1126event 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
1127coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1219integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1128event-loop agnostic and portable event driven programming. 1220event-loop agnostic and portable event driven programming.
1129 1221
1130=head1 AUTHOR 1222=head1 AUTHOR
1131 1223
1132 Marc Lehmann <schmorp@schmorp.de> 1224 Marc Lehmann <schmorp@schmorp.de>

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