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

Comparing EV/EV.pm (file contents):
Revision 1.103 by root, Thu Oct 2 07:49:09 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 libev 69below is comprehensive, one might also consult the documentation of
61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more 70libev 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 71F<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 72discussion on the available backends, or how to force a specific backend
64about in any case because it has much more detailed information. 73with C<LIBEV_FLAGS>, or just about in any case because it has much more
74detailed information.
65 75
66This module is very fast and scalable. It is actually so fast that you 76This 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 77can 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) 78loops (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 79and still be faster than with any other event loop currently supported in
70Perl. 80Perl.
71 81
82=head2 MODULE EXPORTS
83
84This module does not export any symbols.
85
72=cut 86=cut
73 87
74package EV; 88package EV;
75 89
76no warnings; 90use common::sense;
77use strict;
78 91
79BEGIN { 92BEGIN {
80 our $VERSION = '3.44'; 93 our $VERSION = '4.00';
81 use XSLoader; 94 use XSLoader;
82 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
83} 96}
84 97
85@EV::IO::ISA = 98@EV::IO::ISA =
112default loop as this is fastest (perl-wise), best supported by other 125default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 126modules (e.g. AnyEvent or Coro) and most portable event loop.
114 127
115For specific programs you can create additional event loops dynamically. 128For specific programs you can create additional event loops dynamically.
116 129
117If you want to take avdantage of kqueue (which often works properly for 130If 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 131sockets 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 132I<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 133will 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. 134the section about embed watchers for an example on how to achieve that.
122 135
123=over 4 136=over 4
124 137
125=item $loop = new EV::loop [$flags] 138=item $loop = new EV::Loop [$flags]
126 139
127Create a new event loop as per the specified flags. Please refer to the 140Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 141the 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>) 142(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 143or locally-installed as F<EV::libev> manpage) for more info.
131 144
132The loop will automatically be destroyed when it is no longer referenced 145The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 146by any watcher and the loop object goes out of scope.
134 147
135If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> 148If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
194=item $time = EV::now 207=item $time = EV::now
195 208
196=item $time = $loop->now 209=item $time = $loop->now
197 210
198Returns the time the last event loop iteration has been started. This 211Returns 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 212is the time that (relative) timers are based on, and referring to it is
200usually faster then calling EV::time. 213usually faster then calling EV::time.
201 214
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
202=item $backend = EV::backend 257=item $backend = EV::backend
203 258
204=item $backend = $loop->backend 259=item $backend = $loop->backend
205 260
206Returns an integer describing the backend used by libev (EV::METHOD_SELECT 261Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
207or EV::METHOD_EPOLL). 262or EV::BACKEND_EPOLL).
208 263
209=item EV::loop [$flags] 264=item EV::loop [$flags]
210 265
211=item $loop->loop ([$flags]) 266=item $loop->loop ([$flags])
212 267
232=item $count = EV::loop_count 287=item $count = EV::loop_count
233 288
234=item $count = $loop->loop_count 289=item $count = $loop->loop_count
235 290
236Return the number of times the event loop has polled for new 291Return the number of times the event loop has polled for new
237events. Sometiems useful as a generation counter. 292events. Sometimes useful as a generation counter.
238 293
239=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 294=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
240 295
241=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 296=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
242 297
253timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
254 309
255When 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
256the callback will be called with the received event set (in general 311the callback will be called with the received event set (in general
257you 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>,
258C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
259 314
260EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
261of 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
262invoked. 317invoked.
263 318
282 337
283=item $loop->set_timeout_collect_interval ($time) 338=item $loop->set_timeout_collect_interval ($time)
284 339
285These 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
286wait interval for timer events. See the libev documentation at 341wait 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 342L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
288a more detailed discussion. 343(locally installed as F<EV::libev>) for a more detailed discussion.
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.
289 356
290=back 357=back
291 358
292 359
293=head1 WATCHER OBJECTS 360=head1 WATCHER OBJECTS
306called with at least two arguments: the watcher and a bitmask of received 373called with at least two arguments: the watcher and a bitmask of received
307events. 374events.
308 375
309Each 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
310same callback for multiple watchers. The event mask is named after the 377same callback for multiple watchers. The event mask is named after the
311type, 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,
312EV::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
313(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).
314uses EV::TIMEOUT).
315 381
316In 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
317the 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
318its 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.
319 385
398 464
399=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
400 466
401Normally, C<EV::loop> will return when there are no active watchers 467Normally, C<EV::loop> will return when there are no active watchers
402(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
403convinient because it allows you to start your watchers (and your jobs), 469convenient because it allows you to start your watchers (and your jobs),
404call 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
405finished (or they forgot to register some watchers for their task :). 471finished (or they forgot to register some watchers for their task :).
406 472
407Sometimes, however, this gets in your way, for example when the module 473Sometimes, however, this gets in your way, for example when the module
408that 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
412because you happen to have this long-running UDP port watcher. 478because you happen to have this long-running UDP port watcher.
413 479
414In this case you can clear the keepalive status, which means that even 480In 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. 481though your watcher is active, it won't keep C<EV::loop> from returning.
416 482
417The initial value for keepalive is true (enabled), and you cna change it 483The initial value for keepalive is true (enabled), and you can change it
418any time. 484any time.
419 485
420Example: Register an I/O watcher for some UDP socket but do not keep the 486Example: Register an I/O watcher for some UDP socket but do not keep the
421event loop from running just because of that watcher. 487event loop from running just because of that watcher.
422 488
640 706
641=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
642 708
643=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
644 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
645Call 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
646number 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.
647 721
648EV 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
649component 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,
650and 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
651add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
916 # make the dispatcher handle any new stuff 990 # make the dispatcher handle any new stuff
917 ... not shown 991 ... not shown
918 }; 992 };
919 993
920The callbacks of the created watchers will not be called as the watchers 994The callbacks of the created watchers will not be called as the watchers
921are destroyed before this cna happen (remember EV::check gets called 995are destroyed before this can happen (remember EV::check gets called
922first). 996first).
923 997
924The C<check_ns> variant doesn't start (activate) the newly created watcher. 998The C<check_ns> variant doesn't start (activate) the newly created watcher.
925 999
926=back 1000=back
957loop, other types of watchers might be handled in a delayed or incorrect 1031loop, other types of watchers might be handled in a delayed or incorrect
958fashion and must not be used). 1032fashion and must not be used).
959 1033
960See the libev documentation at 1034See the libev documentation at
961L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1035L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
962for more details. 1036(locally installed as F<EV::libev>) for more details.
963 1037
964In short, this watcher is most useful on BSD systems without working 1038In short, this watcher is most useful on BSD systems without working
965kqueue to still be able to handle a large number of sockets: 1039kqueue to still be able to handle a large number of sockets:
966 1040
967 my $socket_loop; 1041 my $socket_loop;
997 1071
998=back 1072=back
999 1073
1000=head3 ASYNC WATCHERS - how to wake up another event loop 1074=head3 ASYNC WATCHERS - how to wake up another event loop
1001 1075
1002Async 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,
1003neither supports threads nor direct access to signal handlers or other 1077as perl neither supports threads running in parallel nor direct access to
1004contexts where they could be of value. 1078signal handlers or other contexts where they could be of value.
1005 1079
1006It is, however, possible to use them from the XS level. 1080It is, however, possible to use them from the XS level.
1007 1081
1008Please see the libev documentation for further details. 1082Please see the libev documentation for further details.
1009 1083
1037 my $async_check = EV::check sub { }; 1111 my $async_check = EV::check sub { };
1038 1112
1039This 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
1040pending signals, and also ensures (slightly) slower overall operation. 1114pending signals, and also ensures (slightly) slower overall operation.
1041 1115
1042=head1 THREADS 1116=head1 ITHREADS
1043 1117
1044Threads 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
1045is 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
1046on thread support for it. 1120supported (and enhanced support is available via L<Coro::EV>).
1047 1121
1048=head1 FORK 1122=head1 FORK
1049 1123
1050Most of the "improved" event delivering mechanisms of modern operating 1124Most of the "improved" event delivering mechanisms of modern operating
1051systems 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

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines