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Revision 1.101 by root, Sat Jul 12 22:19:22 2008 UTC vs.
Revision 1.117 by root, Tue Jul 14 00:09:59 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; 81use common::sense;
77use strict;
78 82
79BEGIN { 83BEGIN {
80 our $VERSION = '3.431'; 84 our $VERSION = '3.6';
81 use XSLoader; 85 use XSLoader;
82 XSLoader::load "EV", $VERSION; 86 XSLoader::load "EV", $VERSION;
83} 87}
84 88
85@EV::IO::ISA = 89@EV::IO::ISA =
112default loop as this is fastest (perl-wise), best supported by other 116default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 117modules (e.g. AnyEvent or Coro) and most portable event loop.
114 118
115For specific programs you can create additional event loops dynamically. 119For specific programs you can create additional event loops dynamically.
116 120
117If you want to take avdantage of kqueue (which often works properly for 121If 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 122sockets 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 123I<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 124will 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. 125the section about embed watchers for an example on how to achieve that.
122 126
123=over 4 127=over 4
124 128
125=item $loop = new EV::loop [$flags] 129=item $loop = new EV::Loop [$flags]
126 130
127Create a new event loop as per the specified flags. Please refer to the 131Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 132the 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>) 133(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 134or locally-installed as F<EV::libev> manpage) for more info.
131 135
132The loop will automatically be destroyed when it is no longer referenced 136The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 137by any watcher and the loop object goes out of scope.
134 138
135Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 139If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
136is protected by this module. 140is recommended, as only the default event loop is protected by this
141module. If you I<are> embedding this loop in the default loop, this is not
142necessary, as C<EV::embed> automatically does the right thing on fork.
137 143
138=item $loop->loop_fork 144=item $loop->loop_fork
139 145
140Must be called after a fork in the child, before entering or continuing 146Must 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 147the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
192=item $time = EV::now 198=item $time = EV::now
193 199
194=item $time = $loop->now 200=item $time = $loop->now
195 201
196Returns the time the last event loop iteration has been started. This 202Returns 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 203is the time that (relative) timers are based on, and referring to it is
198usually faster then calling EV::time. 204usually faster then calling EV::time.
199 205
206=item EV::now_update
207
208=item $loop->now_update
209
210Establishes the current time by querying the kernel, updating the time
211returned by C<EV::now> in the progress. This is a costly operation and
212is usually done automatically within C<EV::loop>.
213
214This function is rarely useful, but when some event callback runs for a
215very long time without entering the event loop, updating libev's idea of
216the current time is a good idea.
217
218=item EV::suspend
219
220=item $loop->suspend
221
222=item EV::resume
223
224=item $loop->resume
225
226These two functions suspend and resume a loop, for use when the loop is
227not used for a while and timeouts should not be processed.
228
229A typical use case would be an interactive program such as a game: When
230the user presses C<^Z> to suspend the game and resumes it an hour later it
231would be best to handle timeouts as if no time had actually passed while
232the program was suspended. This can be achieved by calling C<suspend>
233in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
234C<resume> directly afterwards to resume timer processing.
235
236Effectively, all C<timer> watchers will be delayed by the time spend
237between C<suspend> and C<resume>, and all C<periodic> watchers
238will be rescheduled (that is, they will lose any events that would have
239occured while suspended).
240
241After calling C<suspend> you B<must not> call I<any> function on the given
242loop other than C<resume>, and you B<must not> call C<resume>
243without a previous call to C<suspend>.
244
245Calling C<suspend>/C<resume> has the side effect of updating the event
246loop time (see C<now_update>).
247
200=item $backend = EV::backend 248=item $backend = EV::backend
201 249
202=item $backend = $loop->backend 250=item $backend = $loop->backend
203 251
204Returns an integer describing the backend used by libev (EV::METHOD_SELECT 252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
205or EV::METHOD_EPOLL). 253or EV::BACKEND_EPOLL).
206 254
207=item EV::loop [$flags] 255=item EV::loop [$flags]
208 256
209=item $loop->loop ([$flags]) 257=item $loop->loop ([$flags])
210 258
230=item $count = EV::loop_count 278=item $count = EV::loop_count
231 279
232=item $count = $loop->loop_count 280=item $count = $loop->loop_count
233 281
234Return the number of times the event loop has polled for new 282Return the number of times the event loop has polled for new
235events. Sometiems useful as a generation counter. 283events. Sometimes useful as a generation counter.
236 284
237=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
238 286
239=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 287=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
240 288
280 328
281=item $loop->set_timeout_collect_interval ($time) 329=item $loop->set_timeout_collect_interval ($time)
282 330
283These advanced functions set the minimum block interval when polling for I/O events and the minimum 331These 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 332wait 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 333L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
286a more detailed discussion. 334(locally installed as F<EV::libev>) for a more detailed discussion.
287 335
288=back 336=back
289 337
290 338
291=head1 WATCHER OBJECTS 339=head1 WATCHER OBJECTS
304called with at least two arguments: the watcher and a bitmask of received 352called with at least two arguments: the watcher and a bitmask of received
305events. 353events.
306 354
307Each watcher type has its associated bit in revents, so you can use the 355Each 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 356same callback for multiple watchers. The event mask is named after the
309type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 357type, 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 358EV::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 359(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
312uses EV::TIMEOUT). 360uses EV::TIMEOUT).
313 361
314In the rare case where one wants to create a watcher but not start it at 362In the rare case where one wants to create a watcher but not start it at
410because you happen to have this long-running UDP port watcher. 458because you happen to have this long-running UDP port watcher.
411 459
412In this case you can clear the keepalive status, which means that even 460In 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. 461though your watcher is active, it won't keep C<EV::loop> from returning.
414 462
415The initial value for keepalive is true (enabled), and you cna change it 463The initial value for keepalive is true (enabled), and you can change it
416any time. 464any time.
417 465
418Example: Register an I/O watcher for some UDP socket but do not keep the 466Example: Register an I/O watcher for some UDP socket but do not keep the
419event loop from running just because of that watcher. 467event loop from running just because of that watcher.
420 468
914 # make the dispatcher handle any new stuff 962 # make the dispatcher handle any new stuff
915 ... not shown 963 ... not shown
916 }; 964 };
917 965
918The callbacks of the created watchers will not be called as the watchers 966The callbacks of the created watchers will not be called as the watchers
919are destroyed before this cna happen (remember EV::check gets called 967are destroyed before this can happen (remember EV::check gets called
920first). 968first).
921 969
922The C<check_ns> variant doesn't start (activate) the newly created watcher. 970The C<check_ns> variant doesn't start (activate) the newly created watcher.
923 971
924=back 972=back
955loop, other types of watchers might be handled in a delayed or incorrect 1003loop, other types of watchers might be handled in a delayed or incorrect
956fashion and must not be used). 1004fashion and must not be used).
957 1005
958See the libev documentation at 1006See the libev documentation at
959L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1007L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
960for more details. 1008(locally installed as F<EV::libev>) for more details.
961 1009
962In short, this watcher is most useful on BSD systems without working 1010In short, this watcher is most useful on BSD systems without working
963kqueue to still be able to handle a large number of sockets: 1011kqueue to still be able to handle a large number of sockets:
964 1012
965 my $socket_loop; 1013 my $socket_loop;
995 1043
996=back 1044=back
997 1045
998=head3 ASYNC WATCHERS - how to wake up another event loop 1046=head3 ASYNC WATCHERS - how to wake up another event loop
999 1047
1000Async watchers are provided by EV, but have little use in perl directly, as perl 1048Async watchers are provided by EV, but have little use in perl directly,
1001neither supports threads nor direct access to signal handlers or other 1049as perl neither supports threads running in parallel nor direct access to
1002contexts where they could be of value. 1050signal handlers or other contexts where they could be of value.
1003 1051
1004It is, however, possible to use them from the XS level. 1052It is, however, possible to use them from the XS level.
1005 1053
1006Please see the libev documentation for further details. 1054Please see the libev documentation for further details.
1007 1055
1035 my $async_check = EV::check sub { }; 1083 my $async_check = EV::check sub { };
1036 1084
1037This ensures that perl gets into control for a short time to handle any 1085This ensures that perl gets into control for a short time to handle any
1038pending signals, and also ensures (slightly) slower overall operation. 1086pending signals, and also ensures (slightly) slower overall operation.
1039 1087
1040=head1 THREADS 1088=head1 ITHREADS
1041 1089
1042Threads are not supported by this module in any way. Perl pseudo-threads 1090Ithreads 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 1091is evil stuff and must die. Real threads as provided by Coro are fully
1044on thread support for it. 1092supported (and enhanced support is available via L<Coro::EV>).
1045 1093
1046=head1 FORK 1094=head1 FORK
1047 1095
1048Most of the "improved" event delivering mechanisms of modern operating 1096Most of the "improved" event delivering mechanisms of modern operating
1049systems have quite a few problems with fork(2) (to put it bluntly: it is 1097systems have quite a few problems with fork(2) (to put it bluntly: it is

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