ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/EV/EV.pm
(Generate patch)

Comparing EV/EV.pm (file contents):
Revision 1.106 by root, Thu Oct 23 04:56:49 2008 UTC vs.
Revision 1.123 by root, Sun Aug 9 13:30:41 2009 UTC

76 76
77=cut 77=cut
78 78
79package EV; 79package EV;
80 80
81no warnings; 81use common::sense;
82use strict;
83 82
84BEGIN { 83BEGIN {
85 our $VERSION = '3.45'; 84 our $VERSION = '3.8';
86 use XSLoader; 85 use XSLoader;
87 XSLoader::load "EV", $VERSION; 86 XSLoader::load "EV", $VERSION;
88} 87}
89 88
90@EV::IO::ISA = 89@EV::IO::ISA =
117default loop as this is fastest (perl-wise), best supported by other 116default loop as this is fastest (perl-wise), best supported by other
118modules (e.g. AnyEvent or Coro) and most portable event loop. 117modules (e.g. AnyEvent or Coro) and most portable event loop.
119 118
120For specific programs you can create additional event loops dynamically. 119For specific programs you can create additional event loops dynamically.
121 120
122If 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
123sockets 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
124I<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
125will 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
126the 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.
127 126
128=over 4 127=over 4
129 128
130=item $loop = new EV::loop [$flags] 129=item $loop = new EV::Loop [$flags]
131 130
132Create a new event loop as per the specified flags. Please refer to 131Create a new event loop as per the specified flags. Please refer to
133the C<ev_loop_new ()> function description in the libev documentation 132the C<ev_loop_new ()> function description in the libev documentation
134(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>,
135or locally-installed as F<EV::libev> manpage) for more info. 134or locally-installed as F<EV::libev> manpage) for more info.
199=item $time = EV::now 198=item $time = EV::now
200 199
201=item $time = $loop->now 200=item $time = $loop->now
202 201
203Returns the time the last event loop iteration has been started. This 202Returns the time the last event loop iteration has been started. This
204is 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
205usually faster then calling EV::time. 204usually faster then calling EV::time.
206 205
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
207=item $backend = EV::backend 248=item $backend = EV::backend
208 249
209=item $backend = $loop->backend 250=item $backend = $loop->backend
210 251
211Returns an integer describing the backend used by libev (EV::METHOD_SELECT 252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
212or EV::METHOD_EPOLL). 253or EV::BACKEND_EPOLL).
213 254
214=item EV::loop [$flags] 255=item EV::loop [$flags]
215 256
216=item $loop->loop ([$flags]) 257=item $loop->loop ([$flags])
217 258
237=item $count = EV::loop_count 278=item $count = EV::loop_count
238 279
239=item $count = $loop->loop_count 280=item $count = $loop->loop_count
240 281
241Return the number of times the event loop has polled for new 282Return the number of times the event loop has polled for new
242events. Sometiems useful as a generation counter. 283events. Sometimes useful as a generation counter.
243 284
244=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
245 286
246=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 287=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
247 288
290These 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
291wait interval for timer events. See the libev documentation at 332wait interval for timer events. See the libev documentation at
292L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> 333L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
293(locally installed as F<EV::libev>) for a more detailed discussion. 334(locally installed as F<EV::libev>) for a more detailed discussion.
294 335
336=item $count = EV::pending_count
337
338=item $count = $loop->pending_count
339
340Returns the number of currently pending watchers.
341
342=item EV::invoke_pending
343
344=item $loop->invoke_pending
345
346Invoke all currently pending watchers.
347
295=back 348=back
296 349
297 350
298=head1 WATCHER OBJECTS 351=head1 WATCHER OBJECTS
299 352
311called with at least two arguments: the watcher and a bitmask of received 364called with at least two arguments: the watcher and a bitmask of received
312events. 365events.
313 366
314Each watcher type has its associated bit in revents, so you can use the 367Each watcher type has its associated bit in revents, so you can use the
315same callback for multiple watchers. The event mask is named after the 368same callback for multiple watchers. The event mask is named after the
316type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 369type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
317EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 370EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
318(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 371(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
319uses EV::TIMEOUT). 372uses EV::TIMEOUT).
320 373
321In the rare case where one wants to create a watcher but not start it at 374In the rare case where one wants to create a watcher but not start it at
417because you happen to have this long-running UDP port watcher. 470because you happen to have this long-running UDP port watcher.
418 471
419In this case you can clear the keepalive status, which means that even 472In this case you can clear the keepalive status, which means that even
420though your watcher is active, it won't keep C<EV::loop> from returning. 473though your watcher is active, it won't keep C<EV::loop> from returning.
421 474
422The initial value for keepalive is true (enabled), and you cna change it 475The initial value for keepalive is true (enabled), and you can change it
423any time. 476any time.
424 477
425Example: Register an I/O watcher for some UDP socket but do not keep the 478Example: Register an I/O watcher for some UDP socket but do not keep the
426event loop from running just because of that watcher. 479event loop from running just because of that watcher.
427 480
645 698
646=item $w = EV::signal $signal, $callback 699=item $w = EV::signal $signal, $callback
647 700
648=item $w = EV::signal_ns $signal, $callback 701=item $w = EV::signal_ns $signal, $callback
649 702
703=item $w = $loop->signal ($signal, $callback)
704
705=item $w = $loop->signal_ns ($signal, $callback)
706
650Call the callback when $signal is received (the signal can be specified by 707Call the callback when $signal is received (the signal can be specified by
651number or by name, just as with C<kill> or C<%SIG>). 708number or by name, just as with C<kill> or C<%SIG>).
709
710Only one event loop can grab a given signal - attempting to grab the same
711signal from two EV loops will crash the program immediately or cause data
712corruption.
652 713
653EV will grab the signal for the process (the kernel only allows one 714EV will grab the signal for the process (the kernel only allows one
654component to receive a signal at a time) when you start a signal watcher, 715component to receive a signal at a time) when you start a signal watcher,
655and removes it again when you stop it. Perl does the same when you 716and removes it again when you stop it. Perl does the same when you
656add/remove callbacks to C<%SIG>, so watch out. 717add/remove callbacks to C<%SIG>, so watch out.
921 # make the dispatcher handle any new stuff 982 # make the dispatcher handle any new stuff
922 ... not shown 983 ... not shown
923 }; 984 };
924 985
925The callbacks of the created watchers will not be called as the watchers 986The callbacks of the created watchers will not be called as the watchers
926are destroyed before this cna happen (remember EV::check gets called 987are destroyed before this can happen (remember EV::check gets called
927first). 988first).
928 989
929The C<check_ns> variant doesn't start (activate) the newly created watcher. 990The C<check_ns> variant doesn't start (activate) the newly created watcher.
930 991
931=back 992=back
1002 1063
1003=back 1064=back
1004 1065
1005=head3 ASYNC WATCHERS - how to wake up another event loop 1066=head3 ASYNC WATCHERS - how to wake up another event loop
1006 1067
1007Async watchers are provided by EV, but have little use in perl directly, as perl 1068Async watchers are provided by EV, but have little use in perl directly,
1008neither supports threads nor direct access to signal handlers or other 1069as perl neither supports threads running in parallel nor direct access to
1009contexts where they could be of value. 1070signal handlers or other contexts where they could be of value.
1010 1071
1011It is, however, possible to use them from the XS level. 1072It is, however, possible to use them from the XS level.
1012 1073
1013Please see the libev documentation for further details. 1074Please see the libev documentation for further details.
1014 1075
1042 my $async_check = EV::check sub { }; 1103 my $async_check = EV::check sub { };
1043 1104
1044This ensures that perl gets into control for a short time to handle any 1105This ensures that perl gets into control for a short time to handle any
1045pending signals, and also ensures (slightly) slower overall operation. 1106pending signals, and also ensures (slightly) slower overall operation.
1046 1107
1047=head1 THREADS 1108=head1 ITHREADS
1048 1109
1049Threads are not supported by this module in any way. Perl pseudo-threads 1110Ithreads are not supported by this module in any way. Perl pseudo-threads
1050is evil stuff and must die. As soon as Perl gains real threads I will work 1111is evil stuff and must die. Real threads as provided by Coro are fully
1051on thread support for it. 1112supported (and enhanced support is available via L<Coro::EV>).
1052 1113
1053=head1 FORK 1114=head1 FORK
1054 1115
1055Most of the "improved" event delivering mechanisms of modern operating 1116Most of the "improved" event delivering mechanisms of modern operating
1056systems have quite a few problems with fork(2) (to put it bluntly: it is 1117systems have quite a few problems with fork(2) (to put it bluntly: it is

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines