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Revision 1.105 by root, Thu Oct 2 12:27:55 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 69below is comprehensive, one might also consult the documentation of
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 MODULE EXPORTS
83
84This module does not export any symbols.
85
73=cut 86=cut
74 87
75package EV; 88package EV;
76 89
77no warnings; 90use common::sense;
78use strict;
79 91
80BEGIN { 92BEGIN {
81 our $VERSION = '3.44'; 93 our $VERSION = '4.00';
82 use XSLoader; 94 use XSLoader;
83 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
84} 96}
85 97
86@EV::IO::ISA = 98@EV::IO::ISA =
113default loop as this is fastest (perl-wise), best supported by other 125default loop as this is fastest (perl-wise), best supported by other
114modules (e.g. AnyEvent or Coro) and most portable event loop. 126modules (e.g. AnyEvent or Coro) and most portable event loop.
115 127
116For specific programs you can create additional event loops dynamically. 128For specific programs you can create additional event loops dynamically.
117 129
118If 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
119sockets 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
120I<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
121will 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
122the 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.
123 135
124=over 4 136=over 4
125 137
126=item $loop = new EV::loop [$flags] 138=item $loop = new EV::Loop [$flags]
127 139
128Create a new event loop as per the specified flags. Please refer to 140Create a new event loop as per the specified flags. Please refer to
129the C<ev_loop_new ()> function description in the libev documentation 141the C<ev_loop_new ()> function description in the libev documentation
130(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>,
131or locally-installed as F<EV::libev> manpage) for more info. 143or locally-installed as F<EV::libev> manpage) for more info.
195=item $time = EV::now 207=item $time = EV::now
196 208
197=item $time = $loop->now 209=item $time = $loop->now
198 210
199Returns the time the last event loop iteration has been started. This 211Returns the time the last event loop iteration has been started. This
200is 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
201usually faster then calling EV::time. 213usually faster then calling EV::time.
202 214
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
203=item $backend = EV::backend 257=item $backend = EV::backend
204 258
205=item $backend = $loop->backend 259=item $backend = $loop->backend
206 260
207Returns an integer describing the backend used by libev (EV::METHOD_SELECT 261Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
208or EV::METHOD_EPOLL). 262or EV::BACKEND_EPOLL).
209 263
210=item EV::loop [$flags] 264=item EV::loop [$flags]
211 265
212=item $loop->loop ([$flags]) 266=item $loop->loop ([$flags])
213 267
233=item $count = EV::loop_count 287=item $count = EV::loop_count
234 288
235=item $count = $loop->loop_count 289=item $count = $loop->loop_count
236 290
237Return the number of times the event loop has polled for new 291Return the number of times the event loop has polled for new
238events. Sometiems useful as a generation counter. 292events. Sometimes useful as a generation counter.
239 293
240=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 294=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
241 295
242=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 296=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
243 297
254timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
255 309
256When 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
257the callback will be called with the received event set (in general 311the callback will be called with the received event set (in general
258you 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>,
259C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
260 314
261EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
262of 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
263invoked. 317invoked.
264 318
286These 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
287wait interval for timer events. See the libev documentation at 341wait interval for timer events. See the libev documentation at
288L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> 342L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
289(locally installed as F<EV::libev>) for a more detailed discussion. 343(locally installed as F<EV::libev>) for a more detailed discussion.
290 344
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.
356
291=back 357=back
292 358
293 359
294=head1 WATCHER OBJECTS 360=head1 WATCHER OBJECTS
295 361
307called 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
308events. 374events.
309 375
310Each 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
311same callback for multiple watchers. The event mask is named after the 377same callback for multiple watchers. The event mask is named after the
312type, 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,
313EV::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
314(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).
315uses EV::TIMEOUT).
316 381
317In 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
318the 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
319its 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.
320 385
399 464
400=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
401 466
402Normally, C<EV::loop> will return when there are no active watchers 467Normally, C<EV::loop> will return when there are no active watchers
403(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
404convinient because it allows you to start your watchers (and your jobs), 469convenient because it allows you to start your watchers (and your jobs),
405call 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
406finished (or they forgot to register some watchers for their task :). 471finished (or they forgot to register some watchers for their task :).
407 472
408Sometimes, however, this gets in your way, for example when the module 473Sometimes, however, this gets in your way, for example when the module
409that 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
413because you happen to have this long-running UDP port watcher. 478because you happen to have this long-running UDP port watcher.
414 479
415In 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
416though 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.
417 482
418The 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
419any time. 484any time.
420 485
421Example: 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
422event loop from running just because of that watcher. 487event loop from running just because of that watcher.
423 488
641 706
642=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
643 708
644=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
645 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
646Call 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
647number 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.
648 721
649EV 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
650component 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,
651and 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
652add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
917 # make the dispatcher handle any new stuff 990 # make the dispatcher handle any new stuff
918 ... not shown 991 ... not shown
919 }; 992 };
920 993
921The 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
922are destroyed before this cna happen (remember EV::check gets called 995are destroyed before this can happen (remember EV::check gets called
923first). 996first).
924 997
925The 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.
926 999
927=back 1000=back
998 1071
999=back 1072=back
1000 1073
1001=head3 ASYNC WATCHERS - how to wake up another event loop 1074=head3 ASYNC WATCHERS - how to wake up another event loop
1002 1075
1003Async 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,
1004neither supports threads nor direct access to signal handlers or other 1077as perl neither supports threads running in parallel nor direct access to
1005contexts where they could be of value. 1078signal handlers or other contexts where they could be of value.
1006 1079
1007It is, however, possible to use them from the XS level. 1080It is, however, possible to use them from the XS level.
1008 1081
1009Please see the libev documentation for further details. 1082Please see the libev documentation for further details.
1010 1083
1038 my $async_check = EV::check sub { }; 1111 my $async_check = EV::check sub { };
1039 1112
1040This 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
1041pending signals, and also ensures (slightly) slower overall operation. 1114pending signals, and also ensures (slightly) slower overall operation.
1042 1115
1043=head1 THREADS 1116=head1 ITHREADS
1044 1117
1045Threads 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
1046is 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
1047on thread support for it. 1120supported (and enhanced support is available via L<Coro::EV>).
1048 1121
1049=head1 FORK 1122=head1 FORK
1050 1123
1051Most of the "improved" event delivering mechanisms of modern operating 1124Most of the "improved" event delivering mechanisms of modern operating
1052systems 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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