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Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC vs.
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… …
51 # MAINLOOP 51 # MAINLOOP
52 EV::loop; # loop until EV::unloop is called or all watchers stop 52 EV::loop; # 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::loop EV::LOOP_ONESHOT; # 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::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55 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.
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
60below is comprehensive, one might also consult the documentation of libev 69below is comprehensive, one might also consult the documentation of
61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more 70libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62subtle details on watcher semantics or some discussion on the available 71F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just 72discussion on the available backends, or how to force a specific backend
64about in any case because it has much more detailed information. 73with C<LIBEV_FLAGS>, or just about in any case because it has much more
74detailed information.
65 75
66This module is very fast and scalable. It is actually so fast that you 76This module is very fast and scalable. It is actually so fast that you
67can 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
68loops (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)
69and 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
70Perl. 80Perl.
71 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
113=head2 MODULE EXPORTS
114
115This module does not export any symbols.
116
72=cut 117=cut
73 118
74package EV; 119package EV;
75 120
76no warnings; 121use common::sense;
77use strict;
78 122
79BEGIN { 123BEGIN {
80 our $VERSION = '3.44'; 124 our $VERSION = '4.03';
81 use XSLoader; 125 use XSLoader;
82 XSLoader::load "EV", $VERSION; 126 XSLoader::load "EV", $VERSION;
83} 127}
84 128
85@EV::IO::ISA = 129@EV::IO::ISA =
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112default loop as this is fastest (perl-wise), best supported by other 156default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 157modules (e.g. AnyEvent or Coro) and most portable event loop.
114 158
115For specific programs you can create additional event loops dynamically. 159For specific programs you can create additional event loops dynamically.
116 160
117If you want to take avdantage of kqueue (which often works properly for 161If you want to take advantage of kqueue (which often works properly for
118sockets only) even though the default loop doesn't enable it, you can 162sockets only) even though the default loop doesn't enable it, you can
119I<embed> a kqueue loop into the default loop: running the default loop 163I<embed> a kqueue loop into the default loop: running the default loop
120will then also service the kqueue loop to some extent. See the example in 164will then also service the kqueue loop to some extent. See the example in
121the section about embed watchers for an example on how to achieve that. 165the section about embed watchers for an example on how to achieve that.
122 166
123=over 4 167=over 4
124 168
125=item $loop = new EV::loop [$flags] 169=item $loop = new EV::Loop [$flags]
126 170
127Create a new event loop as per the specified flags. Please refer to the 171Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 172the C<ev_loop_new ()> function description in the libev documentation
129(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) 173(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 174or locally-installed as F<EV::libev> manpage) for more info.
131 175
132The loop will automatically be destroyed when it is no longer referenced 176The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 177by any watcher and the loop object goes out of scope.
134 178
135If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> 179If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
… …
194=item $time = EV::now 238=item $time = EV::now
195 239
196=item $time = $loop->now 240=item $time = $loop->now
197 241
198Returns the time the last event loop iteration has been started. This 242Returns the time the last event loop iteration has been started. This
199is the time that (relative) timers are based on, and refering to it is 243is the time that (relative) timers are based on, and referring to it is
200usually faster then calling EV::time. 244usually faster then calling EV::time.
201 245
246=item EV::now_update
247
248=item $loop->now_update
249
250Establishes the current time by querying the kernel, updating the time
251returned by C<EV::now> in the progress. This is a costly operation and
252is usually done automatically within C<EV::loop>.
253
254This function is rarely useful, but when some event callback runs for a
255very long time without entering the event loop, updating libev's idea of
256the current time is a good idea.
257
258=item EV::suspend
259
260=item $loop->suspend
261
262=item EV::resume
263
264=item $loop->resume
265
266These two functions suspend and resume a loop, for use when the loop is
267not used for a while and timeouts should not be processed.
268
269A typical use case would be an interactive program such as a game: When
270the user presses C<^Z> to suspend the game and resumes it an hour later it
271would be best to handle timeouts as if no time had actually passed while
272the program was suspended. This can be achieved by calling C<suspend>
273in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
274C<resume> directly afterwards to resume timer processing.
275
276Effectively, all C<timer> watchers will be delayed by the time spend
277between C<suspend> and C<resume>, and all C<periodic> watchers
278will be rescheduled (that is, they will lose any events that would have
279occured while suspended).
280
281After calling C<suspend> you B<must not> call I<any> function on the given
282loop other than C<resume>, and you B<must not> call C<resume>
283without a previous call to C<suspend>.
284
285Calling C<suspend>/C<resume> has the side effect of updating the event
286loop time (see C<now_update>).
287
202=item $backend = EV::backend 288=item $backend = EV::backend
203 289
204=item $backend = $loop->backend 290=item $backend = $loop->backend
205 291
206Returns an integer describing the backend used by libev (EV::METHOD_SELECT 292Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
207or EV::METHOD_EPOLL). 293or EV::BACKEND_EPOLL).
208 294
209=item EV::loop [$flags] 295=item EV::loop [$flags]
210 296
211=item $loop->loop ([$flags]) 297=item $loop->loop ([$flags])
212 298
213Begin checking for events and calling callbacks. It returns when a 299Begin checking for events and calling callbacks. It returns when a
214callback calls EV::unloop. 300callback calls EV::unloop.
215 301
216The $flags argument can be one of the following: 302The $flags argument can be one of the following:
217 303
218 0 as above 304 0 as above
219 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 305 EV::LOOP_ONCE block at most once (wait, but do not loop)
220 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 306 EV::LOOP_NOWAIT do not block at all (fetch/handle events but do not wait)
221 307
222=item EV::unloop [$how] 308=item EV::break [$how]
223 309
224=item $loop->unloop ([$how]) 310=item $loop->break ([$how])
225 311
226When 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
227innermost call to EV::loop return. 313innermost call to EV::loop return.
228 314
229When 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
230fast as possible. 316return as fast as possible.
317
318When called with an argument of EV::BREAK_CANCEL, any pending break will
319be cancelled.
231 320
232=item $count = EV::loop_count 321=item $count = EV::loop_count
233 322
234=item $count = $loop->loop_count 323=item $count = $loop->loop_count
235 324
236Return the number of times the event loop has polled for new 325Return the number of times the event loop has polled for new
237events. Sometiems useful as a generation counter. 326events. Sometimes useful as a generation counter.
238 327
239=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 328=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
240 329
241=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 330=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
242 331
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253timeout. Otherwise a EV::timer with this value will be started. 342timeout. Otherwise a EV::timer with this value will be started.
254 343
255When 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
256the callback will be called with the received event set (in general 345the callback will be called with the received event set (in general
257you 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>,
258C<EV::WRITE> and C<EV::TIMEOUT>). 347C<EV::WRITE> and C<EV::TIMER>).
259 348
260EV::once doesn't return anything: the watchers stay active till either 349EV::once doesn't return anything: the watchers stay active till either
261of 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
262invoked. 351invoked.
263 352
264=item EV::feed_fd_event ($fd, $revents) 353=item EV::feed_fd_event $fd, $revents
265 354
266=item $loop->feed_fd_event ($fd, $revents) 355=item $loop->feed_fd_event ($fd, $revents)
267 356
268Feed an event on a file descriptor into EV. EV will react to this call as 357Feed an event on a file descriptor into EV. EV will react to this call as
269if the readyness notifications specified by C<$revents> (a combination of 358if the readyness notifications specified by C<$revents> (a combination of
270C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 359C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
271 360
272=item EV::feed_signal_event ($signal) 361=item EV::feed_signal_event $signal
273 362
274Feed a signal event into EV. EV will react to this call as if the signal 363Feed a signal event into the default loop. EV will react to this call as
275specified by C<$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.
276 371
277=item EV::set_io_collect_interval $time 372=item EV::set_io_collect_interval $time
278 373
279=item $loop->set_io_collect_interval ($time) 374=item $loop->set_io_collect_interval ($time)
280 375
… …
282 377
283=item $loop->set_timeout_collect_interval ($time) 378=item $loop->set_timeout_collect_interval ($time)
284 379
285These 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
286wait interval for timer events. See the libev documentation at 381wait interval for timer events. See the libev documentation at
287L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for 382L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
288a more detailed discussion. 383(locally installed as F<EV::libev>) for a more detailed discussion.
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.
289 396
290=back 397=back
291 398
292 399
293=head1 WATCHER OBJECTS 400=head1 WATCHER OBJECTS
… …
306called with at least two arguments: the watcher and a bitmask of received 413called with at least two arguments: the watcher and a bitmask of received
307events. 414events.
308 415
309Each 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
310same callback for multiple watchers. The event mask is named after the 417same callback for multiple watchers. The event mask is named after the
311type, 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,
312EV::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
313(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).
314uses EV::TIMEOUT).
315 421
316In 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
317the 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
318its 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.
319 425
… …
398 504
399=item $previous_state = $w->keepalive ($bool) 505=item $previous_state = $w->keepalive ($bool)
400 506
401Normally, C<EV::loop> will return when there are no active watchers 507Normally, C<EV::loop> will return when there are no active watchers
402(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
403convinient because it allows you to start your watchers (and your jobs), 509convenient because it allows you to start your watchers (and your jobs),
404call 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
405finished (or they forgot to register some watchers for their task :). 511finished (or they forgot to register some watchers for their task :).
406 512
407Sometimes, however, this gets in your way, for example when the module 513Sometimes, however, this gets in your way, for example when the module
408that 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
… …
412because you happen to have this long-running UDP port watcher. 518because you happen to have this long-running UDP port watcher.
413 519
414In this case you can clear the keepalive status, which means that even 520In this case you can clear the keepalive status, which means that even
415though your watcher is active, it won't keep C<EV::loop> from returning. 521though your watcher is active, it won't keep C<EV::loop> from returning.
416 522
417The initial value for keepalive is true (enabled), and you cna change it 523The initial value for keepalive is true (enabled), and you can change it
418any time. 524any time.
419 525
420Example: Register an I/O watcher for some UDP socket but do not keep the 526Example: Register an I/O watcher for some UDP socket but do not keep the
421event loop from running just because of that watcher. 527event loop from running just because of that watcher.
422 528
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640 746
641=item $w = EV::signal $signal, $callback 747=item $w = EV::signal $signal, $callback
642 748
643=item $w = EV::signal_ns $signal, $callback 749=item $w = EV::signal_ns $signal, $callback
644 750
751=item $w = $loop->signal ($signal, $callback)
752
753=item $w = $loop->signal_ns ($signal, $callback)
754
645Call 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
646number 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.
647 761
648EV 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
649component 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,
650and 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
651add/remove callbacks to C<%SIG>, so watch out. 765add/remove callbacks to C<%SIG>, so watch out.
… …
876=item $w = $loop->check_ns ($callback) 990=item $w = $loop->check_ns ($callback)
877 991
878Call 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
879gathered events), but before any other callbacks have been invoked. 993gathered events), but before any other callbacks have been invoked.
880 994
881This is used to integrate other event-based software into the EV 995This can be used to integrate other event-based software into the EV
882mainloop: 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
883timer 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
884example of integrating Net::SNMP (with some details left out): 998example of integrating Net::SNMP (with some details left out):
885 999
886 our @snmp_watcher; 1000 our @snmp_watcher;
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916 # make the dispatcher handle any new stuff 1030 # make the dispatcher handle any new stuff
917 ... not shown 1031 ... not shown
918 }; 1032 };
919 1033
920The 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
921are destroyed before this cna happen (remember EV::check gets called 1035are destroyed before this can happen (remember EV::check gets called
922first). 1036first).
923 1037
924The 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.
925 1049
926=back 1050=back
927 1051
928 1052
929=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
… …
957loop, other types of watchers might be handled in a delayed or incorrect 1081loop, other types of watchers might be handled in a delayed or incorrect
958fashion and must not be used). 1082fashion and must not be used).
959 1083
960See the libev documentation at 1084See the libev documentation at
961L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1085L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
962for more details. 1086(locally installed as F<EV::libev>) for more details.
963 1087
964In short, this watcher is most useful on BSD systems without working 1088In short, this watcher is most useful on BSD systems without working
965kqueue to still be able to handle a large number of sockets: 1089kqueue to still be able to handle a large number of sockets:
966 1090
967 my $socket_loop; 1091 my $socket_loop;
… …
997 1121
998=back 1122=back
999 1123
1000=head3 ASYNC WATCHERS - how to wake up another event loop 1124=head3 ASYNC WATCHERS - how to wake up another event loop
1001 1125
1002Async 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,
1003neither supports threads nor direct access to signal handlers or other 1127as perl neither supports threads running in parallel nor direct access to
1004contexts where they could be of value. 1128signal handlers or other contexts where they could be of value.
1005 1129
1006It is, however, possible to use them from the XS level. 1130It is, however, possible to use them from the XS level.
1007 1131
1008Please see the libev documentation for further details. 1132Please see the libev documentation for further details.
1009 1133
… …
1037 my $async_check = EV::check sub { }; 1161 my $async_check = EV::check sub { };
1038 1162
1039This 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
1040pending signals, and also ensures (slightly) slower overall operation. 1164pending signals, and also ensures (slightly) slower overall operation.
1041 1165
1042=head1 THREADS 1166=head1 ITHREADS
1043 1167
1044Threads 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
1045is 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
1046on thread support for it. 1170supported (and enhanced support is available via L<Coro::EV>).
1047 1171
1048=head1 FORK 1172=head1 FORK
1049 1173
1050Most of the "improved" event delivering mechanisms of modern operating 1174Most of the "improved" event delivering mechanisms of modern operating
1051systems 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
… …
1073 1197
10741; 11981;
1075 1199
1076=head1 SEE ALSO 1200=head1 SEE ALSO
1077 1201
1202L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1078L<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
1079event 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
1080coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1205integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1081event-loop agnostic and portable event driven programming. 1206event-loop agnostic and portable event driven programming.
1082 1207
1083=head1 AUTHOR 1208=head1 AUTHOR
1084 1209
1085 Marc Lehmann <schmorp@schmorp.de> 1210 Marc Lehmann <schmorp@schmorp.de>

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