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Revision 1.114 by root, Wed Apr 15 19:35:53 2009 UTC vs.
Revision 1.136 by root, Thu Jan 19 17:55:23 2012 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 = '4.10';
86 use XSLoader; 125 use XSLoader;
87 XSLoader::load "EV", $VERSION; 126 XSLoader::load "EV", $VERSION;
88} 127}
89 128
90@EV::IO::ISA = 129@EV::IO::ISA =
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147Must be called after a fork in the child, before entering or continuing 186Must 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 187the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
149this function automatically, at some performance loss (refer to the libev 188this function automatically, at some performance loss (refer to the libev
150documentation). 189documentation).
151 190
152=item $loop->loop_verify 191=item $loop->verify
153 192
154Calls C<ev_verify> to make internal consistency checks (for debugging 193Calls C<ev_verify> to make internal consistency checks (for debugging
155libev) and abort the program if any data structures were found to be 194libev) and abort the program if any data structures were found to be
156corrupted. 195corrupted.
157 196
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251=item $backend = $loop->backend 290=item $backend = $loop->backend
252 291
253Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 292Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
254or EV::BACKEND_EPOLL). 293or EV::BACKEND_EPOLL).
255 294
256=item EV::loop [$flags] 295=item EV::run [$flags]
257 296
258=item $loop->loop ([$flags]) 297=item $loop->run ([$flags])
259 298
260Begin checking for events and calling callbacks. It returns when a 299Begin checking for events and calling callbacks. It returns when a
261callback calls EV::unloop. 300callback calls EV::unloop.
262 301
263The $flags argument can be one of the following: 302The $flags argument can be one of the following:
264 303
265 0 as above 304 0 as above
266 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 305 EV::RUN_ONCE block at most once (wait, but do not loop)
267 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 306 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
268 307
269=item EV::unloop [$how] 308=item EV::break [$how]
270 309
271=item $loop->unloop ([$how]) 310=item $loop->break ([$how])
272 311
273When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 312When called with no arguments or an argument of EV::BREAK_ONE, makes the
274innermost call to EV::loop return. 313innermost call to EV::loop return.
275 314
276When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 315When called with an argument of EV::BREAK_ALL, all calls to EV::loop will
277fast as possible. 316return as fast as possible.
278 317
279=item $count = EV::loop_count 318When called with an argument of EV::BREAK_CANCEL, any pending break will
319be cancelled.
280 320
321=item $count = EV::iteration
322
281=item $count = $loop->loop_count 323=item $count = $loop->iteration
282 324
283Return the number of times the event loop has polled for new 325Return the number of times the event loop has polled for new
284events. Sometimes useful as a generation counter. 326events. Sometimes useful as a generation counter.
285 327
286=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 328=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. 342timeout. Otherwise a EV::timer with this value will be started.
301 343
302When an error occurs or either the timeout or I/O watcher triggers, then 344When 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 345the 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>, 346you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
305C<EV::WRITE> and C<EV::TIMEOUT>). 347C<EV::WRITE> and C<EV::TIMER>).
306 348
307EV::once doesn't return anything: the watchers stay active till either 349EV::once doesn't return anything: the watchers stay active till either
308of them triggers, then they will be stopped and freed, and the callback 350of them triggers, then they will be stopped and freed, and the callback
309invoked. 351invoked.
310 352
311=item EV::feed_fd_event ($fd, $revents) 353=item EV::feed_fd_event $fd, $revents
312 354
313=item $loop->feed_fd_event ($fd, $revents) 355=item $loop->feed_fd_event ($fd, $revents)
314 356
315Feed an event on a file descriptor into EV. EV will react to this call as 357Feed an event on a file descriptor into EV. EV will react to this call as
316if the readyness notifications specified by C<$revents> (a combination of 358if the readyness notifications specified by C<$revents> (a combination of
317C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 359C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
318 360
319=item EV::feed_signal_event ($signal) 361=item EV::feed_signal_event $signal
320 362
321Feed a signal event into EV. EV will react to this call as if the signal 363Feed a signal event into the default loop. EV will react to this call as
322specified by C<$signal> had occured. 364if the signal specified by C<$signal> had occured.
365
366=item EV::feed_signal $signal
367
368Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
369regardless of which loop has registered the signal, and is mainly useful
370fro custom signal implementations.
323 371
324=item EV::set_io_collect_interval $time 372=item EV::set_io_collect_interval $time
325 373
326=item $loop->set_io_collect_interval ($time) 374=item $loop->set_io_collect_interval ($time)
327 375
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332These advanced functions set the minimum block interval when polling for I/O events and the minimum 380These 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 381wait 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> 382L<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. 383(locally installed as F<EV::libev>) for a more detailed discussion.
336 384
385=item $count = EV::pending_count
386
387=item $count = $loop->pending_count
388
389Returns the number of currently pending watchers.
390
391=item EV::invoke_pending
392
393=item $loop->invoke_pending
394
395Invoke all currently pending watchers.
396
337=back 397=back
338 398
339 399
340=head1 WATCHER OBJECTS 400=head1 WATCHER OBJECTS
341 401
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355 415
356Each watcher type has its associated bit in revents, so you can use the 416Each 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 417same callback for multiple watchers. The event mask is named after the
358type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 418type, 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 419EV::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 420(which can set both EV::READ and EV::WRITE bits).
361uses EV::TIMEOUT).
362 421
363In the rare case where one wants to create a watcher but not start it at 422In 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 423the 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. 424its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
366 425
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445 504
446=item $previous_state = $w->keepalive ($bool) 505=item $previous_state = $w->keepalive ($bool)
447 506
448Normally, C<EV::loop> will return when there are no active watchers 507Normally, 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 508(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), 509convenient 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 510call 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 :). 511finished (or they forgot to register some watchers for their task :).
453 512
454Sometimes, however, this gets in your way, for example when the module 513Sometimes, 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 514that calls C<EV::loop> (usually the main program) is not the same module
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687 746
688=item $w = EV::signal $signal, $callback 747=item $w = EV::signal $signal, $callback
689 748
690=item $w = EV::signal_ns $signal, $callback 749=item $w = EV::signal_ns $signal, $callback
691 750
751=item $w = $loop->signal ($signal, $callback)
752
753=item $w = $loop->signal_ns ($signal, $callback)
754
692Call the callback when $signal is received (the signal can be specified by 755Call the callback when $signal is received (the signal can be specified by
693number or by name, just as with C<kill> or C<%SIG>). 756number or by name, just as with C<kill> or C<%SIG>).
757
758Only one event loop can grab a given signal - attempting to grab the same
759signal from two EV loops will crash the program immediately or cause data
760corruption.
694 761
695EV will grab the signal for the process (the kernel only allows one 762EV 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, 763component 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 764and removes it again when you stop it. Perl does the same when you
698add/remove callbacks to C<%SIG>, so watch out. 765add/remove callbacks to C<%SIG>, so watch out.
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923=item $w = $loop->check_ns ($callback) 990=item $w = $loop->check_ns ($callback)
924 991
925Call the callback just after the process wakes up again (after it has 992Call the callback just after the process wakes up again (after it has
926gathered events), but before any other callbacks have been invoked. 993gathered events), but before any other callbacks have been invoked.
927 994
928This is used to integrate other event-based software into the EV 995This 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 996mainloop: 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 997timer watchers as required by the other software. Here is a real-world
931example of integrating Net::SNMP (with some details left out): 998example of integrating Net::SNMP (with some details left out):
932 999
933 our @snmp_watcher; 1000 our @snmp_watcher;
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967The callbacks of the created watchers will not be called as the watchers 1034The callbacks of the created watchers will not be called as the watchers
968are destroyed before this can happen (remember EV::check gets called 1035are destroyed before this can happen (remember EV::check gets called
969first). 1036first).
970 1037
971The C<check_ns> variant doesn't start (activate) the newly created watcher. 1038The C<check_ns> variant doesn't start (activate) the newly created watcher.
1039
1040=item EV::CHECK constant issues
1041
1042Like all other watcher types, there is a bitmask constant for use in
1043C<$revents> and other places. The C<EV::CHECK> is special as it has
1044the same name as the C<CHECK> sub called by Perl. This doesn't cause
1045big issues on newer perls (beginning with 5.8.9), but it means thatthe
1046constant must be I<inlined>, i.e. runtime calls will not work. That means
1047that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1048safe side.
972 1049
973=back 1050=back
974 1051
975 1052
976=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1053=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
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1044 1121
1045=back 1122=back
1046 1123
1047=head3 ASYNC WATCHERS - how to wake up another event loop 1124=head3 ASYNC WATCHERS - how to wake up another event loop
1048 1125
1049Async watchers are provided by EV, but have little use in perl directly, as perl 1126Async watchers are provided by EV, but have little use in perl directly,
1050neither supports threads nor direct access to signal handlers or other 1127as perl neither supports threads running in parallel nor direct access to
1051contexts where they could be of value. 1128signal handlers or other contexts where they could be of value.
1052 1129
1053It is, however, possible to use them from the XS level. 1130It is, however, possible to use them from the XS level.
1054 1131
1055Please see the libev documentation for further details. 1132Please see the libev documentation for further details.
1056 1133
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1084 my $async_check = EV::check sub { }; 1161 my $async_check = EV::check sub { };
1085 1162
1086This ensures that perl gets into control for a short time to handle any 1163This ensures that perl gets into control for a short time to handle any
1087pending signals, and also ensures (slightly) slower overall operation. 1164pending signals, and also ensures (slightly) slower overall operation.
1088 1165
1089=head1 THREADS 1166=head1 ITHREADS
1090 1167
1091Threads are not supported by this module in any way. Perl pseudo-threads 1168Ithreads 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 1169is evil stuff and must die. Real threads as provided by Coro are fully
1093on thread support for it. 1170supported (and enhanced support is available via L<Coro::EV>).
1094 1171
1095=head1 FORK 1172=head1 FORK
1096 1173
1097Most of the "improved" event delivering mechanisms of modern operating 1174Most of the "improved" event delivering mechanisms of modern operating
1098systems have quite a few problems with fork(2) (to put it bluntly: it is 1175systems have quite a few problems with fork(2) (to put it bluntly: it is
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1120 1197
11211; 11981;
1122 1199
1123=head1 SEE ALSO 1200=head1 SEE ALSO
1124 1201
1202L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1125L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1203(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 1204loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1127coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1205integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1128event-loop agnostic and portable event driven programming. 1206event-loop agnostic and portable event driven programming.
1129 1207
1130=head1 AUTHOR 1208=head1 AUTHOR
1131 1209
1132 Marc Lehmann <schmorp@schmorp.de> 1210 Marc Lehmann <schmorp@schmorp.de>

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