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Revision 1.101 by root, Sat Jul 12 22:19:22 2008 UTC vs.
Revision 1.127 by root, Sun Mar 28 15:48:21 2010 UTC

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 MODULE EXPORTS
83
84This module does not export any symbols.
85
72=cut 86=cut
73 87
74package EV; 88package EV;
75 89
76no warnings; 90use common::sense;
77use strict;
78 91
79BEGIN { 92BEGIN {
80 our $VERSION = '3.431'; 93 our $VERSION = '4.00';
81 use XSLoader; 94 use XSLoader;
82 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
83} 96}
84 97
85@EV::IO::ISA = 98@EV::IO::ISA =
112default loop as this is fastest (perl-wise), best supported by other 125default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 126modules (e.g. AnyEvent or Coro) and most portable event loop.
114 127
115For specific programs you can create additional event loops dynamically. 128For specific programs you can create additional event loops dynamically.
116 129
117If you want to take avdantage of kqueue (which often works properly for 130If 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 131sockets 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 132I<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 133will 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. 134the section about embed watchers for an example on how to achieve that.
122 135
123=over 4 136=over 4
124 137
125=item $loop = new EV::loop [$flags] 138=item $loop = new EV::Loop [$flags]
126 139
127Create a new event loop as per the specified flags. Please refer to the 140Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 141the 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>) 142(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 143or locally-installed as F<EV::libev> manpage) for more info.
131 144
132The loop will automatically be destroyed when it is no longer referenced 145The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 146by any watcher and the loop object goes out of scope.
134 147
135Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 148If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
136is protected by this module. 149is recommended, as only the default event loop is protected by this
150module. If you I<are> embedding this loop in the default loop, this is not
151necessary, as C<EV::embed> automatically does the right thing on fork.
137 152
138=item $loop->loop_fork 153=item $loop->loop_fork
139 154
140Must be called after a fork in the child, before entering or continuing 155Must be called after a fork in the child, before entering or continuing
141the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls 156the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
192=item $time = EV::now 207=item $time = EV::now
193 208
194=item $time = $loop->now 209=item $time = $loop->now
195 210
196Returns the time the last event loop iteration has been started. This 211Returns the time the last event loop iteration has been started. This
197is the time that (relative) timers are based on, and refering to it is 212is the time that (relative) timers are based on, and referring to it is
198usually faster then calling EV::time. 213usually faster then calling EV::time.
199 214
215=item EV::now_update
216
217=item $loop->now_update
218
219Establishes the current time by querying the kernel, updating the time
220returned by C<EV::now> in the progress. This is a costly operation and
221is usually done automatically within C<EV::loop>.
222
223This function is rarely useful, but when some event callback runs for a
224very long time without entering the event loop, updating libev's idea of
225the current time is a good idea.
226
227=item EV::suspend
228
229=item $loop->suspend
230
231=item EV::resume
232
233=item $loop->resume
234
235These two functions suspend and resume a loop, for use when the loop is
236not used for a while and timeouts should not be processed.
237
238A typical use case would be an interactive program such as a game: When
239the user presses C<^Z> to suspend the game and resumes it an hour later it
240would be best to handle timeouts as if no time had actually passed while
241the program was suspended. This can be achieved by calling C<suspend>
242in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
243C<resume> directly afterwards to resume timer processing.
244
245Effectively, all C<timer> watchers will be delayed by the time spend
246between C<suspend> and C<resume>, and all C<periodic> watchers
247will be rescheduled (that is, they will lose any events that would have
248occured while suspended).
249
250After calling C<suspend> you B<must not> call I<any> function on the given
251loop other than C<resume>, and you B<must not> call C<resume>
252without a previous call to C<suspend>.
253
254Calling C<suspend>/C<resume> has the side effect of updating the event
255loop time (see C<now_update>).
256
200=item $backend = EV::backend 257=item $backend = EV::backend
201 258
202=item $backend = $loop->backend 259=item $backend = $loop->backend
203 260
204Returns an integer describing the backend used by libev (EV::METHOD_SELECT 261Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
205or EV::METHOD_EPOLL). 262or EV::BACKEND_EPOLL).
206 263
207=item EV::loop [$flags] 264=item EV::loop [$flags]
208 265
209=item $loop->loop ([$flags]) 266=item $loop->loop ([$flags])
210 267
230=item $count = EV::loop_count 287=item $count = EV::loop_count
231 288
232=item $count = $loop->loop_count 289=item $count = $loop->loop_count
233 290
234Return the number of times the event loop has polled for new 291Return the number of times the event loop has polled for new
235events. Sometiems useful as a generation counter. 292events. Sometimes useful as a generation counter.
236 293
237=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 294=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
238 295
239=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 296=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
240 297
251timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
252 309
253When an error occurs or either the timeout or I/O watcher triggers, then 310When an error occurs or either the timeout or I/O watcher triggers, then
254the callback will be called with the received event set (in general 311the callback will be called with the received event set (in general
255you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, 312you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
256C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
257 314
258EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
259of them triggers, then they will be stopped and freed, and the callback 316of them triggers, then they will be stopped and freed, and the callback
260invoked. 317invoked.
261 318
280 337
281=item $loop->set_timeout_collect_interval ($time) 338=item $loop->set_timeout_collect_interval ($time)
282 339
283These advanced functions set the minimum block interval when polling for I/O events and the minimum 340These advanced functions set the minimum block interval when polling for I/O events and the minimum
284wait interval for timer events. See the libev documentation at 341wait interval for timer events. See the libev documentation at
285L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for 342L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
286a more detailed discussion. 343(locally installed as F<EV::libev>) for a more detailed discussion.
344
345=item $count = EV::pending_count
346
347=item $count = $loop->pending_count
348
349Returns the number of currently pending watchers.
350
351=item EV::invoke_pending
352
353=item $loop->invoke_pending
354
355Invoke all currently pending watchers.
287 356
288=back 357=back
289 358
290 359
291=head1 WATCHER OBJECTS 360=head1 WATCHER OBJECTS
304called with at least two arguments: the watcher and a bitmask of received 373called with at least two arguments: the watcher and a bitmask of received
305events. 374events.
306 375
307Each watcher type has its associated bit in revents, so you can use the 376Each watcher type has its associated bit in revents, so you can use the
308same callback for multiple watchers. The event mask is named after the 377same callback for multiple watchers. The event mask is named after the
309type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 378type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
310EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 379EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
311(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 380(which can set both EV::READ and EV::WRITE bits).
312uses EV::TIMEOUT).
313 381
314In the rare case where one wants to create a watcher but not start it at 382In the rare case where one wants to create a watcher but not start it at
315the same time, each constructor has a variant with a trailing C<_ns> in 383the same time, each constructor has a variant with a trailing C<_ns> in
316its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 384its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
317 385
396 464
397=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
398 466
399Normally, C<EV::loop> will return when there are no active watchers 467Normally, C<EV::loop> will return when there are no active watchers
400(which is a "deadlock" because no progress can be made anymore). This is 468(which is a "deadlock" because no progress can be made anymore). This is
401convinient because it allows you to start your watchers (and your jobs), 469convenient because it allows you to start your watchers (and your jobs),
402call C<EV::loop> once and when it returns you know that all your jobs are 470call C<EV::loop> once and when it returns you know that all your jobs are
403finished (or they forgot to register some watchers for their task :). 471finished (or they forgot to register some watchers for their task :).
404 472
405Sometimes, however, this gets in your way, for example when the module 473Sometimes, however, this gets in your way, for example when the module
406that calls C<EV::loop> (usually the main program) is not the same module 474that calls C<EV::loop> (usually the main program) is not the same module
410because you happen to have this long-running UDP port watcher. 478because you happen to have this long-running UDP port watcher.
411 479
412In this case you can clear the keepalive status, which means that even 480In this case you can clear the keepalive status, which means that even
413though your watcher is active, it won't keep C<EV::loop> from returning. 481though your watcher is active, it won't keep C<EV::loop> from returning.
414 482
415The initial value for keepalive is true (enabled), and you cna change it 483The initial value for keepalive is true (enabled), and you can change it
416any time. 484any time.
417 485
418Example: Register an I/O watcher for some UDP socket but do not keep the 486Example: Register an I/O watcher for some UDP socket but do not keep the
419event loop from running just because of that watcher. 487event loop from running just because of that watcher.
420 488
638 706
639=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
640 708
641=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
642 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
643Call the callback when $signal is received (the signal can be specified by 715Call the callback when $signal is received (the signal can be specified by
644number or by name, just as with C<kill> or C<%SIG>). 716number or by name, just as with C<kill> or C<%SIG>).
717
718Only one event loop can grab a given signal - attempting to grab the same
719signal from two EV loops will crash the program immediately or cause data
720corruption.
645 721
646EV will grab the signal for the process (the kernel only allows one 722EV will grab the signal for the process (the kernel only allows one
647component to receive a signal at a time) when you start a signal watcher, 723component to receive a signal at a time) when you start a signal watcher,
648and removes it again when you stop it. Perl does the same when you 724and removes it again when you stop it. Perl does the same when you
649add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
914 # make the dispatcher handle any new stuff 990 # make the dispatcher handle any new stuff
915 ... not shown 991 ... not shown
916 }; 992 };
917 993
918The callbacks of the created watchers will not be called as the watchers 994The callbacks of the created watchers will not be called as the watchers
919are destroyed before this cna happen (remember EV::check gets called 995are destroyed before this can happen (remember EV::check gets called
920first). 996first).
921 997
922The C<check_ns> variant doesn't start (activate) the newly created watcher. 998The C<check_ns> variant doesn't start (activate) the newly created watcher.
923 999
924=back 1000=back
955loop, other types of watchers might be handled in a delayed or incorrect 1031loop, other types of watchers might be handled in a delayed or incorrect
956fashion and must not be used). 1032fashion and must not be used).
957 1033
958See the libev documentation at 1034See the libev documentation at
959L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1035L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
960for more details. 1036(locally installed as F<EV::libev>) for more details.
961 1037
962In short, this watcher is most useful on BSD systems without working 1038In short, this watcher is most useful on BSD systems without working
963kqueue to still be able to handle a large number of sockets: 1039kqueue to still be able to handle a large number of sockets:
964 1040
965 my $socket_loop; 1041 my $socket_loop;
995 1071
996=back 1072=back
997 1073
998=head3 ASYNC WATCHERS - how to wake up another event loop 1074=head3 ASYNC WATCHERS - how to wake up another event loop
999 1075
1000Async watchers are provided by EV, but have little use in perl directly, as perl 1076Async watchers are provided by EV, but have little use in perl directly,
1001neither supports threads nor direct access to signal handlers or other 1077as perl neither supports threads running in parallel nor direct access to
1002contexts where they could be of value. 1078signal handlers or other contexts where they could be of value.
1003 1079
1004It is, however, possible to use them from the XS level. 1080It is, however, possible to use them from the XS level.
1005 1081
1006Please see the libev documentation for further details. 1082Please see the libev documentation for further details.
1007 1083
1035 my $async_check = EV::check sub { }; 1111 my $async_check = EV::check sub { };
1036 1112
1037This ensures that perl gets into control for a short time to handle any 1113This ensures that perl gets into control for a short time to handle any
1038pending signals, and also ensures (slightly) slower overall operation. 1114pending signals, and also ensures (slightly) slower overall operation.
1039 1115
1040=head1 THREADS 1116=head1 ITHREADS
1041 1117
1042Threads are not supported by this module in any way. Perl pseudo-threads 1118Ithreads are not supported by this module in any way. Perl pseudo-threads
1043is evil stuff and must die. As soon as Perl gains real threads I will work 1119is evil stuff and must die. Real threads as provided by Coro are fully
1044on thread support for it. 1120supported (and enhanced support is available via L<Coro::EV>).
1045 1121
1046=head1 FORK 1122=head1 FORK
1047 1123
1048Most of the "improved" event delivering mechanisms of modern operating 1124Most of the "improved" event delivering mechanisms of modern operating
1049systems have quite a few problems with fork(2) (to put it bluntly: it is 1125systems have quite a few problems with fork(2) (to put it bluntly: it is

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