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… …
47 my ($w, $revents) = @_; 47 my ($w, $revents) = @_;
48 warn $w->path, " has changed somehow.\n"; 48 warn $w->path, " has changed somehow.\n";
49 }; 49 };
50 50
51 # MAINLOOP 51 # MAINLOOP
52 EV::loop; # loop until EV::unloop is called or all watchers stop 52 EV::run; # loop until EV::break is called or all watchers stop
53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 53 EV::run EV::RUN_ONCE; # 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::run EV::RUN_NOWAIT; # try to handle same events, but do not block
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.
55 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 PORTING FROM EV 3.X to 4.X
83
84EV version 4 introduces a number of incompatible changes summarised
85here. According to the depreciation strategy used by libev, there is a
86compatibility layer in place so programs should continue to run unchanged
87(the XS interface lacks this layer, so programs using that one need to be
88updated).
89
90This compatibility layer will be switched off in some future release.
91
92All changes relevant to Perl are renames of symbols, functions and
93methods:
94
95 EV::loop => EV::run
96 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
97 EV::LOOP_ONESHOT => EV::RUN_ONCE
98
99 EV::unloop => EV::break
100 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
101 EV::UNLOOP_ONE => EV::BREAK_ONE
102 EV::UNLOOP_ALL => EV::BREAK_ALL
103
104 EV::TIMEOUT => EV::TIMER
105
106 EV::loop_count => EV::iteration
107 EV::loop_depth => EV::depth
108 EV::loop_verify => EV::verify
109
110The loop object methods corresponding to the functions above have been
111similarly renamed.
112
113=head2 MODULE EXPORTS
114
115This module does not export any symbols.
116
72=cut 117=cut
73 118
74package EV; 119package EV;
75 120
76no warnings; 121use common::sense;
77use strict;
78 122
79BEGIN { 123BEGIN {
80 our $VERSION = '3.44'; 124 our $VERSION = 4.22;
81 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
82 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
83} 128}
84 129
85@EV::IO::ISA = 130@EV::IO::ISA =
86@EV::Timer::ISA = 131@EV::Timer::ISA =
… …
112default loop as this is fastest (perl-wise), best supported by other 157default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop. 158modules (e.g. AnyEvent or Coro) and most portable event loop.
114 159
115For specific programs you can create additional event loops dynamically. 160For specific programs you can create additional event loops dynamically.
116 161
117If you want to take avdantage of kqueue (which often works properly for 162If 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 163sockets 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 164I<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 165will 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. 166the section about embed watchers for an example on how to achieve that.
122 167
123=over 4 168=over 4
124 169
125=item $loop = new EV::loop [$flags] 170=item $loop = new EV::Loop [$flags]
126 171
127Create a new event loop as per the specified flags. Please refer to the 172Create a new event loop as per the specified flags. Please refer to
128C<ev_loop_new ()> function description in the libev documentation 173the 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>) 174(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
130for more info. 175or locally-installed as F<EV::libev> manpage) for more info.
131 176
132The loop will automatically be destroyed when it is no longer referenced 177The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope. 178by any watcher and the loop object goes out of scope.
134 179
135Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 180If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
136is protected by this module. 181is recommended, as only the default event loop is protected by this
182module. If you I<are> embedding this loop in the default loop, this is not
183necessary, as C<EV::embed> automatically does the right thing on fork.
137 184
138=item $loop->loop_fork 185=item $loop->loop_fork
139 186
140Must be called after a fork in the child, before entering or continuing 187Must 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 188the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
142this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
143documentation). 190documentation).
144 191
145=item $loop->loop_verify 192=item $loop->verify
146 193
147Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
148libev) and abort the program if any data structures were found to be 195libev) and abort the program if any data structures were found to be
149corrupted. 196corrupted.
150 197
… …
192=item $time = EV::now 239=item $time = EV::now
193 240
194=item $time = $loop->now 241=item $time = $loop->now
195 242
196Returns the time the last event loop iteration has been started. This 243Returns 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 244is the time that (relative) timers are based on, and referring to it is
198usually faster then calling EV::time. 245usually faster then calling EV::time.
199 246
247=item EV::now_update
248
249=item $loop->now_update
250
251Establishes the current time by querying the kernel, updating the time
252returned by C<EV::now> in the progress. This is a costly operation and
253is usually done automatically within C<EV::loop>.
254
255This function is rarely useful, but when some event callback runs for a
256very long time without entering the event loop, updating libev's idea of
257the current time is a good idea.
258
259=item EV::suspend
260
261=item $loop->suspend
262
263=item EV::resume
264
265=item $loop->resume
266
267These two functions suspend and resume a loop, for use when the loop is
268not used for a while and timeouts should not be processed.
269
270A typical use case would be an interactive program such as a game: When
271the user presses C<^Z> to suspend the game and resumes it an hour later it
272would be best to handle timeouts as if no time had actually passed while
273the program was suspended. This can be achieved by calling C<suspend>
274in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
275C<resume> directly afterwards to resume timer processing.
276
277Effectively, all C<timer> watchers will be delayed by the time spend
278between C<suspend> and C<resume>, and all C<periodic> watchers
279will be rescheduled (that is, they will lose any events that would have
280occured while suspended).
281
282After calling C<suspend> you B<must not> call I<any> function on the given
283loop other than C<resume>, and you B<must not> call C<resume>
284without a previous call to C<suspend>.
285
286Calling C<suspend>/C<resume> has the side effect of updating the event
287loop time (see C<now_update>).
288
200=item $backend = EV::backend 289=item $backend = EV::backend
201 290
202=item $backend = $loop->backend 291=item $backend = $loop->backend
203 292
204Returns an integer describing the backend used by libev (EV::METHOD_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
205or EV::METHOD_EPOLL). 294or EV::BACKEND_EPOLL).
206 295
207=item EV::loop [$flags] 296=item $active = EV::run [$flags]
208 297
209=item $loop->loop ([$flags]) 298=item $active = $loop->run ([$flags])
210 299
211Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
212callback calls EV::unloop. 301callback calls EV::break or the flags are nonzero (in which case the
302return value is true) or when there are no active watchers which reference
303the loop (keepalive is true), in which case the return value will be
304false. The return value can generally be interpreted as "if true, there is
305more work left to do".
213 306
214The $flags argument can be one of the following: 307The $flags argument can be one of the following:
215 308
216 0 as above 309 0 as above
217 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
218 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
219 312
220=item EV::unloop [$how] 313=item EV::break [$how]
221 314
222=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
223 316
224When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 317When called with no arguments or an argument of EV::BREAK_ONE, makes the
225innermost call to EV::loop return. 318innermost call to EV::loop return.
226 319
227When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 320When called with an argument of EV::BREAK_ALL, all calls to EV::loop will
228fast as possible. 321return as fast as possible.
229 322
230=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
231 325
326=item $count = EV::iteration
327
232=item $count = $loop->loop_count 328=item $count = $loop->iteration
233 329
234Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
235events. Sometiems useful as a generation counter. 331events. Sometimes useful as a generation counter.
236 332
237=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
238 334
239=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 335=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
240 336
… …
251timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise a EV::timer with this value will be started.
252 348
253When an error occurs or either the timeout or I/O watcher triggers, then 349When an error occurs or either the timeout or I/O watcher triggers, then
254the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
255you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, 351you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
256C<EV::WRITE> and C<EV::TIMEOUT>). 352C<EV::WRITE> and C<EV::TIMER>).
257 353
258EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
259of them triggers, then they will be stopped and freed, and the callback 355of them triggers, then they will be stopped and freed, and the callback
260invoked. 356invoked.
261 357
262=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
263 359
264=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
265 361
266Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
267if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
268C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
269 365
270=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
271 367
272Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
273specified by C<$signal> had occured. 369if the signal specified by C<$signal> had occured.
370
371=item EV::feed_signal $signal
372
373Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
374regardless of which loop has registered the signal, and is mainly useful
375fro custom signal implementations.
274 376
275=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
276 378
277=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
278 380
… …
280 382
281=item $loop->set_timeout_collect_interval ($time) 383=item $loop->set_timeout_collect_interval ($time)
282 384
283These advanced functions set the minimum block interval when polling for I/O events and the minimum 385These 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 386wait 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 387L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
286a more detailed discussion. 388(locally installed as F<EV::libev>) for a more detailed discussion.
389
390=item $count = EV::pending_count
391
392=item $count = $loop->pending_count
393
394Returns the number of currently pending watchers.
395
396=item EV::invoke_pending
397
398=item $loop->invoke_pending
399
400Invoke all currently pending watchers.
287 401
288=back 402=back
289 403
290 404
291=head1 WATCHER OBJECTS 405=head1 WATCHER OBJECTS
… …
304called with at least two arguments: the watcher and a bitmask of received 418called with at least two arguments: the watcher and a bitmask of received
305events. 419events.
306 420
307Each watcher type has its associated bit in revents, so you can use the 421Each 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 422same callback for multiple watchers. The event mask is named after the
309type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 423type, 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 424EV::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 425(which can set both EV::READ and EV::WRITE bits).
312uses EV::TIMEOUT).
313 426
314In the rare case where one wants to create a watcher but not start it at 427In the rare case where one wants to create a watcher but not start it at
315the same time, each constructor has a variant with a trailing C<_ns> in 428the same time, each constructor has a variant with a trailing C<_ns> in
316its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 429its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
317 430
… …
396 509
397=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
398 511
399Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::loop> will return when there are no active watchers
400(which is a "deadlock" because no progress can be made anymore). This is 513(which is a "deadlock" because no progress can be made anymore). This is
401convinient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
402call C<EV::loop> once and when it returns you know that all your jobs are 515call C<EV::loop> once and when it returns you know that all your jobs are
403finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
404 517
405Sometimes, however, this gets in your way, for example when the module 518Sometimes, however, this gets in your way, for example when the module
406that calls C<EV::loop> (usually the main program) is not the same module 519that calls C<EV::loop> (usually the main program) is not the same module
… …
410because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
411 524
412In this case you can clear the keepalive status, which means that even 525In 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. 526though your watcher is active, it won't keep C<EV::loop> from returning.
414 527
415The initial value for keepalive is true (enabled), and you cna change it 528The initial value for keepalive is true (enabled), and you can change it
416any time. 529any time.
417 530
418Example: Register an I/O watcher for some UDP socket but do not keep the 531Example: Register an I/O watcher for some UDP socket but do not keep the
419event loop from running just because of that watcher. 532event loop from running just because of that watcher.
420 533
… …
485 598
486=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
487 600
488=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
489 602
490Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
491C<$repeat> is non-zero, the timer will be restarted (with the $repeat 604negative). If C<$repeat> is non-zero, the timer will be restarted (with
492value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
493 606
494This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
495seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
496to drift, but it will not invoke the timer more often then once per event 609to drift, but it will not invoke the timer more often then once per event
497loop iteration, and might drift in other cases. If that isn't acceptable, 610loop iteration, and might drift in other cases. If that isn't acceptable,
… …
501in front of the machine while the timer is running and changes the system 614in front of the machine while the timer is running and changes the system
502clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
503 616
504The C<timer_ns> variant doesn't start (activate) the newly created watcher. 617The C<timer_ns> variant doesn't start (activate) the newly created watcher.
505 618
506=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
507 620
508Reconfigures the watcher, see the constructor above for details. Can be called at 621Reconfigures the watcher, see the constructor above for details. Can be called at
509any time. 622any time.
510 623
511=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
512 627
513Similar to the C<start> method, but has special semantics for repeating timers: 628Similar to the C<start> method, but has special semantics for repeating timers:
514 629
515If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
516 631
… …
523 638
524This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
525operation. You create a timer object with the same value for C<$after> and 640operation. You create a timer object with the same value for C<$after> and
526C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
527on the timeout. 642on the timeout.
643
644If called with a C<$repeat> argument, then it uses this a timer repeat
645value.
646
647=item $after = $w->remaining
648
649Calculates and returns the remaining time till the timer will fire.
528 650
529=back 651=back
530 652
531 653
532=head3 PERIODIC WATCHERS - to cron or not to cron? 654=head3 PERIODIC WATCHERS - to cron or not to cron?
… …
560surpasses this time. 682surpasses this time.
561 683
562=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 684=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
563 685
564In this mode the watcher will always be scheduled to time out at the 686In this mode the watcher will always be scheduled to time out at the
565next C<$at + N * $interval> time (for some integer N) and then repeat, 687next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
566regardless of any time jumps. 688regardless of any time jumps. Note that, since C<N> can be negative, the
689first trigger can happen before C<$at>.
567 690
568This can be used to create timers that do not drift with respect to system 691This can be used to create timers that do not drift with respect to system
569time: 692time:
570 693
571 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 694 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
572 695
573That doesn't mean there will always be 3600 seconds in between triggers, 696That doesn't mean there will always be 3600 seconds in between triggers,
574but only that the the clalback will be called when the system time shows a 697but only that the the callback will be called when the system time shows a
575full hour (UTC). 698full hour (UTC).
576 699
577Another way to think about it (for the mathematically inclined) is that 700Another way to think about it (for the mathematically inclined) is that
578EV::periodic will try to run the callback in this mode at the next 701EV::periodic will try to run the callback in this mode at the next
579possible time where C<$time = $at (mod $interval)>, regardless of any time 702possible time where C<$time = $at (mod $interval)>, regardless of any time
… …
638 761
639=item $w = EV::signal $signal, $callback 762=item $w = EV::signal $signal, $callback
640 763
641=item $w = EV::signal_ns $signal, $callback 764=item $w = EV::signal_ns $signal, $callback
642 765
766=item $w = $loop->signal ($signal, $callback)
767
768=item $w = $loop->signal_ns ($signal, $callback)
769
643Call the callback when $signal is received (the signal can be specified by 770Call the callback when $signal is received (the signal can be specified by
644number or by name, just as with C<kill> or C<%SIG>). 771number or by name, just as with C<kill> or C<%SIG>).
772
773Only one event loop can grab a given signal - attempting to grab the same
774signal from two EV loops will crash the program immediately or cause data
775corruption.
645 776
646EV will grab the signal for the process (the kernel only allows one 777EV will grab the signal for the process (the kernel only allows one
647component to receive a signal at a time) when you start a signal watcher, 778component to receive a signal at a time) when you start a signal watcher,
648and removes it again when you stop it. Perl does the same when you 779and removes it again when you stop it. Perl does the same when you
649add/remove callbacks to C<%SIG>, so watch out. 780add/remove callbacks to C<%SIG>, so watch out.
… …
874=item $w = $loop->check_ns ($callback) 1005=item $w = $loop->check_ns ($callback)
875 1006
876Call the callback just after the process wakes up again (after it has 1007Call the callback just after the process wakes up again (after it has
877gathered events), but before any other callbacks have been invoked. 1008gathered events), but before any other callbacks have been invoked.
878 1009
879This is used to integrate other event-based software into the EV 1010This can be used to integrate other event-based software into the EV
880mainloop: You register a prepare callback and in there, you create io and 1011mainloop: You register a prepare callback and in there, you create io and
881timer watchers as required by the other software. Here is a real-world 1012timer watchers as required by the other software. Here is a real-world
882example of integrating Net::SNMP (with some details left out): 1013example of integrating Net::SNMP (with some details left out):
883 1014
884 our @snmp_watcher; 1015 our @snmp_watcher;
… …
914 # make the dispatcher handle any new stuff 1045 # make the dispatcher handle any new stuff
915 ... not shown 1046 ... not shown
916 }; 1047 };
917 1048
918The callbacks of the created watchers will not be called as the watchers 1049The callbacks of the created watchers will not be called as the watchers
919are destroyed before this cna happen (remember EV::check gets called 1050are destroyed before this can happen (remember EV::check gets called
920first). 1051first).
921 1052
922The C<check_ns> variant doesn't start (activate) the newly created watcher. 1053The C<check_ns> variant doesn't start (activate) the newly created watcher.
1054
1055=item EV::CHECK constant issues
1056
1057Like all other watcher types, there is a bitmask constant for use in
1058C<$revents> and other places. The C<EV::CHECK> is special as it has
1059the same name as the C<CHECK> sub called by Perl. This doesn't cause
1060big issues on newer perls (beginning with 5.8.9), but it means thatthe
1061constant must be I<inlined>, i.e. runtime calls will not work. That means
1062that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1063safe side.
923 1064
924=back 1065=back
925 1066
926 1067
927=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1068=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
… …
955loop, other types of watchers might be handled in a delayed or incorrect 1096loop, other types of watchers might be handled in a delayed or incorrect
956fashion and must not be used). 1097fashion and must not be used).
957 1098
958See the libev documentation at 1099See the libev documentation at
959L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1100L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
960for more details. 1101(locally installed as F<EV::libev>) for more details.
961 1102
962In short, this watcher is most useful on BSD systems without working 1103In short, this watcher is most useful on BSD systems without working
963kqueue to still be able to handle a large number of sockets: 1104kqueue to still be able to handle a large number of sockets:
964 1105
965 my $socket_loop; 1106 my $socket_loop;
… …
995 1136
996=back 1137=back
997 1138
998=head3 ASYNC WATCHERS - how to wake up another event loop 1139=head3 ASYNC WATCHERS - how to wake up another event loop
999 1140
1000Async watchers are provided by EV, but have little use in perl directly, as perl 1141Async watchers are provided by EV, but have little use in perl directly,
1001neither supports threads nor direct access to signal handlers or other 1142as perl neither supports threads running in parallel nor direct access to
1002contexts where they could be of value. 1143signal handlers or other contexts where they could be of value.
1003 1144
1004It is, however, possible to use them from the XS level. 1145It is, however, possible to use them from the XS level.
1005 1146
1006Please see the libev documentation for further details. 1147Please see the libev documentation for further details.
1007 1148
… …
1009 1150
1010=item $w = EV::async $callback 1151=item $w = EV::async $callback
1011 1152
1012=item $w = EV::async_ns $callback 1153=item $w = EV::async_ns $callback
1013 1154
1155=item $w = $loop->async ($callback)
1156
1157=item $w = $loop->async_ns ($callback)
1158
1014=item $w->send 1159=item $w->send
1015 1160
1016=item $bool = $w->async_pending 1161=item $bool = $w->async_pending
1017 1162
1018=back 1163=back
1164
1165=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1166
1167Cleanup watchers are not supported on the Perl level, they can only be
1168used via XS currently.
1019 1169
1020 1170
1021=head1 PERL SIGNALS 1171=head1 PERL SIGNALS
1022 1172
1023While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1173While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
… …
1035 my $async_check = EV::check sub { }; 1185 my $async_check = EV::check sub { };
1036 1186
1037This ensures that perl gets into control for a short time to handle any 1187This ensures that perl gets into control for a short time to handle any
1038pending signals, and also ensures (slightly) slower overall operation. 1188pending signals, and also ensures (slightly) slower overall operation.
1039 1189
1040=head1 THREADS 1190=head1 ITHREADS
1041 1191
1042Threads are not supported by this module in any way. Perl pseudo-threads 1192Ithreads 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 1193is evil stuff and must die. Real threads as provided by Coro are fully
1044on thread support for it. 1194supported (and enhanced support is available via L<Coro::EV>).
1045 1195
1046=head1 FORK 1196=head1 FORK
1047 1197
1048Most of the "improved" event delivering mechanisms of modern operating 1198Most of the "improved" event delivering mechanisms of modern operating
1049systems have quite a few problems with fork(2) (to put it bluntly: it is 1199systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
1071 1221
10721; 12221;
1073 1223
1074=head1 SEE ALSO 1224=head1 SEE ALSO
1075 1225
1226L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1076L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1227(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1077event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1228loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1078coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1229integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1079event-loop agnostic and portable event driven programming. 1230event-loop agnostic and portable event driven programming.
1080 1231
1081=head1 AUTHOR 1232=head1 AUTHOR
1082 1233
1083 Marc Lehmann <schmorp@schmorp.de> 1234 Marc Lehmann <schmorp@schmorp.de>

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