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Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC vs.
Revision 1.116 by root, Sat Jun 13 15:11:54 2009 UTC

55 55
56=head1 DESCRIPTION 56=head1 DESCRIPTION
57 57
58This module provides an interface to libev 58This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of libev 60below is comprehensive, one might also consult the documentation of
61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more 61libev 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 62F<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 63discussion on the available backends, or how to force a specific backend
64about in any case because it has much more detailed information. 64with C<LIBEV_FLAGS>, or just about in any case because it has much more
65detailed information.
65 66
66This module is very fast and scalable. It is actually so fast that you 67This 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 68can 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) 69loops (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 70and still be faster than with any other event loop currently supported in
70Perl. 71Perl.
71 72
73=head2 MODULE EXPORTS
74
75This module does not export any symbols.
76
72=cut 77=cut
73 78
74package EV; 79package EV;
75 80
76no warnings; 81no warnings;
77use strict; 82use strict;
78 83
79BEGIN { 84BEGIN {
80 our $VERSION = '3.44'; 85 our $VERSION = '3.6';
81 use XSLoader; 86 use XSLoader;
82 XSLoader::load "EV", $VERSION; 87 XSLoader::load "EV", $VERSION;
83} 88}
84 89
85@EV::IO::ISA = 90@EV::IO::ISA =
112default loop as this is fastest (perl-wise), best supported by other 117default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 118modules (e.g. AnyEvent or Coro) and most portable event loop.
114 119
115For specific programs you can create additional event loops dynamically. 120For specific programs you can create additional event loops dynamically.
116 121
117If you want to take avdantage of kqueue (which often works properly for 122If 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 123sockets 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 124I<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 125will 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. 126the section about embed watchers for an example on how to achieve that.
122 127
123=over 4 128=over 4
124 129
125=item $loop = new EV::loop [$flags] 130=item $loop = new EV::Loop [$flags]
126 131
127Create a new event loop as per the specified flags. Please refer to the 132Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 133the 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>) 134(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 135or locally-installed as F<EV::libev> manpage) for more info.
131 136
132The loop will automatically be destroyed when it is no longer referenced 137The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 138by any watcher and the loop object goes out of scope.
134 139
135If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> 140If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
194=item $time = EV::now 199=item $time = EV::now
195 200
196=item $time = $loop->now 201=item $time = $loop->now
197 202
198Returns the time the last event loop iteration has been started. This 203Returns 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 204is the time that (relative) timers are based on, and referring to it is
200usually faster then calling EV::time. 205usually faster then calling EV::time.
201 206
207=item EV::now_update
208
209=item $loop->now_update
210
211Establishes the current time by querying the kernel, updating the time
212returned by C<EV::now> in the progress. This is a costly operation and
213is usually done automatically within C<EV::loop>.
214
215This function is rarely useful, but when some event callback runs for a
216very long time without entering the event loop, updating libev's idea of
217the current time is a good idea.
218
219=item EV::suspend
220
221=item $loop->suspend
222
223=item EV::resume
224
225=item $loop->resume
226
227These two functions suspend and resume a loop, for use when the loop is
228not used for a while and timeouts should not be processed.
229
230A typical use case would be an interactive program such as a game: When
231the user presses C<^Z> to suspend the game and resumes it an hour later it
232would be best to handle timeouts as if no time had actually passed while
233the program was suspended. This can be achieved by calling C<suspend>
234in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
235C<resume> directly afterwards to resume timer processing.
236
237Effectively, all C<timer> watchers will be delayed by the time spend
238between C<suspend> and C<resume>, and all C<periodic> watchers
239will be rescheduled (that is, they will lose any events that would have
240occured while suspended).
241
242After calling C<suspend> you B<must not> call I<any> function on the given
243loop other than C<resume>, and you B<must not> call C<resume>
244without a previous call to C<suspend>.
245
246Calling C<suspend>/C<resume> has the side effect of updating the event
247loop time (see C<now_update>).
248
202=item $backend = EV::backend 249=item $backend = EV::backend
203 250
204=item $backend = $loop->backend 251=item $backend = $loop->backend
205 252
206Returns an integer describing the backend used by libev (EV::METHOD_SELECT 253Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
207or EV::METHOD_EPOLL). 254or EV::BACKEND_EPOLL).
208 255
209=item EV::loop [$flags] 256=item EV::loop [$flags]
210 257
211=item $loop->loop ([$flags]) 258=item $loop->loop ([$flags])
212 259
232=item $count = EV::loop_count 279=item $count = EV::loop_count
233 280
234=item $count = $loop->loop_count 281=item $count = $loop->loop_count
235 282
236Return the number of times the event loop has polled for new 283Return the number of times the event loop has polled for new
237events. Sometiems useful as a generation counter. 284events. Sometimes useful as a generation counter.
238 285
239=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 286=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
240 287
241=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 288=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
242 289
282 329
283=item $loop->set_timeout_collect_interval ($time) 330=item $loop->set_timeout_collect_interval ($time)
284 331
285These advanced functions set the minimum block interval when polling for I/O events and the minimum 332These 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 333wait 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 334L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
288a more detailed discussion. 335(locally installed as F<EV::libev>) for a more detailed discussion.
289 336
290=back 337=back
291 338
292 339
293=head1 WATCHER OBJECTS 340=head1 WATCHER OBJECTS
306called with at least two arguments: the watcher and a bitmask of received 353called with at least two arguments: the watcher and a bitmask of received
307events. 354events.
308 355
309Each watcher type has its associated bit in revents, so you can use the 356Each 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 357same callback for multiple watchers. The event mask is named after the
311type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 358type, 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 359EV::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 360(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
314uses EV::TIMEOUT). 361uses EV::TIMEOUT).
315 362
316In the rare case where one wants to create a watcher but not start it at 363In the rare case where one wants to create a watcher but not start it at
412because you happen to have this long-running UDP port watcher. 459because you happen to have this long-running UDP port watcher.
413 460
414In this case you can clear the keepalive status, which means that even 461In 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. 462though your watcher is active, it won't keep C<EV::loop> from returning.
416 463
417The initial value for keepalive is true (enabled), and you cna change it 464The initial value for keepalive is true (enabled), and you can change it
418any time. 465any time.
419 466
420Example: Register an I/O watcher for some UDP socket but do not keep the 467Example: Register an I/O watcher for some UDP socket but do not keep the
421event loop from running just because of that watcher. 468event loop from running just because of that watcher.
422 469
916 # make the dispatcher handle any new stuff 963 # make the dispatcher handle any new stuff
917 ... not shown 964 ... not shown
918 }; 965 };
919 966
920The callbacks of the created watchers will not be called as the watchers 967The callbacks of the created watchers will not be called as the watchers
921are destroyed before this cna happen (remember EV::check gets called 968are destroyed before this can happen (remember EV::check gets called
922first). 969first).
923 970
924The C<check_ns> variant doesn't start (activate) the newly created watcher. 971The C<check_ns> variant doesn't start (activate) the newly created watcher.
925 972
926=back 973=back
957loop, other types of watchers might be handled in a delayed or incorrect 1004loop, other types of watchers might be handled in a delayed or incorrect
958fashion and must not be used). 1005fashion and must not be used).
959 1006
960See the libev documentation at 1007See the libev documentation at
961L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1008L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
962for more details. 1009(locally installed as F<EV::libev>) for more details.
963 1010
964In short, this watcher is most useful on BSD systems without working 1011In short, this watcher is most useful on BSD systems without working
965kqueue to still be able to handle a large number of sockets: 1012kqueue to still be able to handle a large number of sockets:
966 1013
967 my $socket_loop; 1014 my $socket_loop;
997 1044
998=back 1045=back
999 1046
1000=head3 ASYNC WATCHERS - how to wake up another event loop 1047=head3 ASYNC WATCHERS - how to wake up another event loop
1001 1048
1002Async watchers are provided by EV, but have little use in perl directly, as perl 1049Async watchers are provided by EV, but have little use in perl directly,
1003neither supports threads nor direct access to signal handlers or other 1050as perl neither supports threads running in parallel nor direct access to
1004contexts where they could be of value. 1051signal handlers or other contexts where they could be of value.
1005 1052
1006It is, however, possible to use them from the XS level. 1053It is, however, possible to use them from the XS level.
1007 1054
1008Please see the libev documentation for further details. 1055Please see the libev documentation for further details.
1009 1056
1037 my $async_check = EV::check sub { }; 1084 my $async_check = EV::check sub { };
1038 1085
1039This ensures that perl gets into control for a short time to handle any 1086This ensures that perl gets into control for a short time to handle any
1040pending signals, and also ensures (slightly) slower overall operation. 1087pending signals, and also ensures (slightly) slower overall operation.
1041 1088
1042=head1 THREADS 1089=head1 ITHREADS
1043 1090
1044Threads are not supported by this module in any way. Perl pseudo-threads 1091Ithreads 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 1092is evil stuff and must die. Real threads as provided by Coro are fully
1046on thread support for it. 1093supported (and enhanced support is available via L<Coro::EV>).
1047 1094
1048=head1 FORK 1095=head1 FORK
1049 1096
1050Most of the "improved" event delivering mechanisms of modern operating 1097Most of the "improved" event delivering mechanisms of modern operating
1051systems have quite a few problems with fork(2) (to put it bluntly: it is 1098systems have quite a few problems with fork(2) (to put it bluntly: it is

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