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Revision 1.99 by root, Tue Jul 8 09:37:37 2008 UTC vs.
Revision 1.117 by root, Tue Jul 14 00:09:59 2009 UTC

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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
76use strict; 81use common::sense;
77 82
78BEGIN { 83BEGIN {
79 our $VERSION = '3.42'; 84 our $VERSION = '3.6';
80 use XSLoader; 85 use XSLoader;
81 XSLoader::load "EV", $VERSION; 86 XSLoader::load "EV", $VERSION;
82} 87}
83 88
84@EV::IO::ISA = 89@EV::IO::ISA =
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111default loop as this is fastest (perl-wise), best supported by other 116default loop as this is fastest (perl-wise), best supported by other
112modules (e.g. AnyEvent or Coro) and most portable event loop. 117modules (e.g. AnyEvent or Coro) and most portable event loop.
113 118
114For specific programs you can create additional event loops dynamically. 119For specific programs you can create additional event loops dynamically.
115 120
116If 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
117sockets 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
118I<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
119will 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
120the 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.
121 126
122=over 4 127=over 4
123 128
124=item $loop = new EV::loop [$flags] 129=item $loop = new EV::Loop [$flags]
125 130
126Create 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
127C<ev_loop_new ()> function description in the libev documentation 132the C<ev_loop_new ()> function description in the libev documentation
128(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>,
129for more info. 134or locally-installed as F<EV::libev> manpage) for more info.
130 135
131The loop will automatically be destroyed when it is no longer referenced 136The loop will automatically be destroyed when it is no longer referenced
132by any watcher and the loop object goes out of scope. 137by any watcher and the loop object goes out of scope.
133 138
134Using 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>
135is 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.
136 143
137=item $loop->loop_fork 144=item $loop->loop_fork
138 145
139Must 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
140the 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
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191=item $time = EV::now 198=item $time = EV::now
192 199
193=item $time = $loop->now 200=item $time = $loop->now
194 201
195Returns the time the last event loop iteration has been started. This 202Returns the time the last event loop iteration has been started. This
196is 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
197usually faster then calling EV::time. 204usually faster then calling EV::time.
198 205
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
199=item $backend = EV::backend 248=item $backend = EV::backend
200 249
201=item $backend = $loop->backend 250=item $backend = $loop->backend
202 251
203Returns an integer describing the backend used by libev (EV::METHOD_SELECT 252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
204or EV::METHOD_EPOLL). 253or EV::BACKEND_EPOLL).
205 254
206=item EV::loop [$flags] 255=item EV::loop [$flags]
207 256
208=item $loop->loop ([$flags]) 257=item $loop->loop ([$flags])
209 258
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229=item $count = EV::loop_count 278=item $count = EV::loop_count
230 279
231=item $count = $loop->loop_count 280=item $count = $loop->loop_count
232 281
233Return the number of times the event loop has polled for new 282Return the number of times the event loop has polled for new
234events. Sometiems useful as a generation counter. 283events. Sometimes useful as a generation counter.
235 284
236=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
237 286
238=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 287=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
239 288
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279 328
280=item $loop->set_timeout_collect_interval ($time) 329=item $loop->set_timeout_collect_interval ($time)
281 330
282These 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
283wait interval for timer events. See the libev documentation at 332wait interval for timer events. See the libev documentation at
284L<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>
285a more detailed discussion. 334(locally installed as F<EV::libev>) for a more detailed discussion.
286 335
287=back 336=back
288 337
289 338
290=head1 WATCHER OBJECTS 339=head1 WATCHER OBJECTS
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303called 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
304events. 353events.
305 354
306Each 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
307same callback for multiple watchers. The event mask is named after the 356same callback for multiple watchers. The event mask is named after the
308type, 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,
309EV::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
310(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
311uses EV::TIMEOUT). 360uses EV::TIMEOUT).
312 361
313In 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
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409because you happen to have this long-running UDP port watcher. 458because you happen to have this long-running UDP port watcher.
410 459
411In 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
412though 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.
413 462
414The 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
415any time. 464any time.
416 465
417Example: 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
418event loop from running just because of that watcher. 467event loop from running just because of that watcher.
419 468
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913 # make the dispatcher handle any new stuff 962 # make the dispatcher handle any new stuff
914 ... not shown 963 ... not shown
915 }; 964 };
916 965
917The 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
918are destroyed before this cna happen (remember EV::check gets called 967are destroyed before this can happen (remember EV::check gets called
919first). 968first).
920 969
921The 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.
922 971
923=back 972=back
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954loop, 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
955fashion and must not be used). 1004fashion and must not be used).
956 1005
957See the libev documentation at 1006See the libev documentation at
958L<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_>
959for more details. 1008(locally installed as F<EV::libev>) for more details.
960 1009
961In short, this watcher is most useful on BSD systems without working 1010In short, this watcher is most useful on BSD systems without working
962kqueue to still be able to handle a large number of sockets: 1011kqueue to still be able to handle a large number of sockets:
963 1012
964 my $socket_loop; 1013 my $socket_loop;
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975 # use the default loop otherwise 1024 # use the default loop otherwise
976 $socket_loop ||= EV::default_loop; 1025 $socket_loop ||= EV::default_loop;
977 1026
978=over 4 1027=over 4
979 1028
980=item $w = EV::embed $otherloop, $callback 1029=item $w = EV::embed $otherloop[, $callback]
981 1030
982=item $w = EV::embed_ns $otherloop, $callback 1031=item $w = EV::embed_ns $otherloop[, $callback]
983 1032
984=item $w = $loop->embed ($otherloop, $callback) 1033=item $w = $loop->embed ($otherloop[, $callback])
985 1034
986=item $w = $loop->embed_ns ($otherloop, $callback) 1035=item $w = $loop->embed_ns ($otherloop[, $callback])
987 1036
988Call the callback when the embedded event loop (C<$otherloop>) has any 1037Call the callback when the embedded event loop (C<$otherloop>) has any
989I/O activity. The C<$callback> should alwas be specified as C<undef> in 1038I/O activity. The C<$callback> is optional: if it is missing, then the
990this version of EV, which means the embedded event loop will be managed 1039embedded event loop will be managed automatically (which is recommended),
991automatically. 1040otherwise you have to invoke C<sweep> yourself.
992 1041
993The C<embed_ns> variant doesn't start (activate) the newly created watcher. 1042The C<embed_ns> variant doesn't start (activate) the newly created watcher.
994 1043
995=back 1044=back
996 1045
997=head3 ASYNC WATCHERS - how to wake up another event loop 1046=head3 ASYNC WATCHERS - how to wake up another event loop
998 1047
999Async 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,
1000neither supports threads nor direct access to signal handlers or other 1049as perl neither supports threads running in parallel nor direct access to
1001contexts where they could be of value. 1050signal handlers or other contexts where they could be of value.
1002 1051
1003It is, however, possible to use them from the XS level. 1052It is, however, possible to use them from the XS level.
1004 1053
1005Please see the libev documentation for further details. 1054Please see the libev documentation for further details.
1006 1055
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1034 my $async_check = EV::check sub { }; 1083 my $async_check = EV::check sub { };
1035 1084
1036This 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
1037pending signals, and also ensures (slightly) slower overall operation. 1086pending signals, and also ensures (slightly) slower overall operation.
1038 1087
1039=head1 THREADS 1088=head1 ITHREADS
1040 1089
1041Threads 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
1042is 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
1043on thread support for it. 1092supported (and enhanced support is available via L<Coro::EV>).
1044 1093
1045=head1 FORK 1094=head1 FORK
1046 1095
1047Most of the "improved" event delivering mechanisms of modern operating 1096Most of the "improved" event delivering mechanisms of modern operating
1048systems 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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