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Revision 1.110 by root, Wed Dec 24 22:05:58 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
76 85
77=cut 86=cut
78 87
79package EV; 88package EV;
80 89
81no warnings; 90use common::sense;
82use strict;
83 91
84BEGIN { 92BEGIN {
85 our $VERSION = '3.51'; 93 our $VERSION = '4.00';
86 use XSLoader; 94 use XSLoader;
87 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
88} 96}
89 97
90@EV::IO::ISA = 98@EV::IO::ISA =
125will 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
126the 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.
127 135
128=over 4 136=over 4
129 137
130=item $loop = new EV::loop [$flags] 138=item $loop = new EV::Loop [$flags]
131 139
132Create 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
133the C<ev_loop_new ()> function description in the libev documentation 141the 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>, 142(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. 143or locally-installed as F<EV::libev> manpage) for more info.
202 210
203Returns the time the last event loop iteration has been started. This 211Returns the time the last event loop iteration has been started. This
204is the time that (relative) timers are based on, and referring to it is 212is the time that (relative) timers are based on, and referring to it is
205usually faster then calling EV::time. 213usually faster then calling EV::time.
206 214
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
207=item $backend = EV::backend 257=item $backend = EV::backend
208 258
209=item $backend = $loop->backend 259=item $backend = $loop->backend
210 260
211Returns an integer describing the backend used by libev (EV::BACKEND_SELECT 261Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
258timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
259 309
260When 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
261the callback will be called with the received event set (in general 311the callback will be called with the received event set (in general
262you 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>,
263C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
264 314
265EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
266of 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
267invoked. 317invoked.
268 318
290These 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
291wait interval for timer events. See the libev documentation at 341wait 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> 342L<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. 343(locally installed as F<EV::libev>) for a more detailed discussion.
294 344
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
295=back 357=back
296 358
297 359
298=head1 WATCHER OBJECTS 360=head1 WATCHER OBJECTS
299 361
313 375
314Each 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
315same callback for multiple watchers. The event mask is named after the 377same callback for multiple watchers. The event mask is named after the
316type, 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,
317EV::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
318(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).
319uses EV::TIMEOUT).
320 381
321In 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
322the 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
323its 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.
324 385
403 464
404=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
405 466
406Normally, C<EV::loop> will return when there are no active watchers 467Normally, C<EV::loop> will return when there are no active watchers
407(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
408convinient because it allows you to start your watchers (and your jobs), 469convenient because it allows you to start your watchers (and your jobs),
409call 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
410finished (or they forgot to register some watchers for their task :). 471finished (or they forgot to register some watchers for their task :).
411 472
412Sometimes, however, this gets in your way, for example when the module 473Sometimes, however, this gets in your way, for example when the module
413that 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
645 706
646=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
647 708
648=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
649 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
650Call 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
651number 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.
652 721
653EV 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
654component 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,
655and 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
656add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
1002 1071
1003=back 1072=back
1004 1073
1005=head3 ASYNC WATCHERS - how to wake up another event loop 1074=head3 ASYNC WATCHERS - how to wake up another event loop
1006 1075
1007Async 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,
1008neither supports threads nor direct access to signal handlers or other 1077as perl neither supports threads running in parallel nor direct access to
1009contexts where they could be of value. 1078signal handlers or other contexts where they could be of value.
1010 1079
1011It is, however, possible to use them from the XS level. 1080It is, however, possible to use them from the XS level.
1012 1081
1013Please see the libev documentation for further details. 1082Please see the libev documentation for further details.
1014 1083
1042 my $async_check = EV::check sub { }; 1111 my $async_check = EV::check sub { };
1043 1112
1044This 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
1045pending signals, and also ensures (slightly) slower overall operation. 1114pending signals, and also ensures (slightly) slower overall operation.
1046 1115
1047=head1 THREADS 1116=head1 ITHREADS
1048 1117
1049Threads 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
1050is 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
1051on thread support for it. 1120supported (and enhanced support is available via L<Coro::EV>).
1052 1121
1053=head1 FORK 1122=head1 FORK
1054 1123
1055Most of the "improved" event delivering mechanisms of modern operating 1124Most of the "improved" event delivering mechanisms of modern operating
1056systems 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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