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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 = '4.34';
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
135If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> 180If you are not embedding the loop, then using C<EV::FLAG_FORKCHECK>
136is recommended, as only the default event loop is protected by this 181is recommended, as only the default event loop is protected by this
137module. If you I<are> embedding this loop in the default loop, this is not 182module. If you I<are> embedding this loop in the default loop, this is not
138necessary, as C<EV::embed> automatically does the right thing on fork. 183necessary, as C<EV::embed> automatically does the right thing on fork.
139 184
140=item $loop->loop_fork 185=item $loop->loop_fork
… …
142Must 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
143the 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
144this function automatically, at some performance loss (refer to the libev 189this function automatically, at some performance loss (refer to the libev
145documentation). 190documentation).
146 191
147=item $loop->loop_verify 192=item $loop->verify
148 193
149Calls C<ev_verify> to make internal consistency checks (for debugging 194Calls C<ev_verify> to make internal consistency checks (for debugging
150libev) 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
151corrupted. 196corrupted.
152 197
… …
194=item $time = EV::now 239=item $time = EV::now
195 240
196=item $time = $loop->now 241=item $time = $loop->now
197 242
198Returns the time the last event loop iteration has been started. This 243Returns 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 244is the time that (relative) timers are based on, and referring to it is
200usually faster then calling EV::time. 245usually faster then calling EV::time.
201 246
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::run>.
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
202=item $backend = EV::backend 289=item $backend = EV::backend
203 290
204=item $backend = $loop->backend 291=item $backend = $loop->backend
205 292
206Returns an integer describing the backend used by libev (EV::METHOD_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
207or EV::METHOD_EPOLL). 294or EV::BACKEND_EPOLL).
208 295
209=item EV::loop [$flags] 296=item $active = EV::run [$flags]
210 297
211=item $loop->loop ([$flags]) 298=item $active = $loop->run ([$flags])
212 299
213Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
214callback 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".
215 306
216The $flags argument can be one of the following: 307The $flags argument can be one of the following:
217 308
218 0 as above 309 0 as above
219 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
220 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
221 312
222=item EV::unloop [$how] 313=item EV::break [$how]
223 314
224=item $loop->unloop ([$how]) 315=item $loop->break ([$how])
225 316
226When 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
227innermost call to EV::loop return. 318innermost call to EV::run return.
228 319
229When 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::run will
230fast as possible. 321return as fast as possible.
231 322
232=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
233 325
326=item $count = EV::iteration
327
234=item $count = $loop->loop_count 328=item $count = $loop->iteration
235 329
236Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
237events. Sometiems useful as a generation counter. 331events. Sometimes useful as a generation counter.
238 332
239=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
240 334
241=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 335=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
242 336
… …
248| EV::WRITE>, indicating the type of I/O event you want to wait for. If 342| EV::WRITE>, indicating the type of I/O event you want to wait for. If
249you do not want to wait for some I/O event, specify C<undef> for 343you do not want to wait for some I/O event, specify C<undef> for
250C<$fh_or_undef> and C<0> for C<$events>). 344C<$fh_or_undef> and C<0> for C<$events>).
251 345
252If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
253timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise an C<EV::timer> with this value will be started.
254 348
255When 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
256the callback will be called with the received event set (in general 350the 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>, 351you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
258C<EV::WRITE> and C<EV::TIMEOUT>). 352C<EV::WRITE> and C<EV::TIMER>).
259 353
260EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
261of 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
262invoked. 356invoked.
263 357
264=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
265 359
266=item $loop->feed_fd_event ($fd, $revents) 360=item $loop->feed_fd_event ($fd, $revents)
267 361
268Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
269if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
270C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
271 365
272=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
273 367
274Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
275specified by C<$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
375for custom signal implementations.
276 376
277=item EV::set_io_collect_interval $time 377=item EV::set_io_collect_interval $time
278 378
279=item $loop->set_io_collect_interval ($time) 379=item $loop->set_io_collect_interval ($time)
280 380
… …
282 382
283=item $loop->set_timeout_collect_interval ($time) 383=item $loop->set_timeout_collect_interval ($time)
284 384
285These 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
286wait interval for timer events. See the libev documentation at 386wait 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 387L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
288a 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 $loop->invoke_pending
399
400Invoke all currently pending watchers.
289 401
290=back 402=back
291 403
292 404
293=head1 WATCHER OBJECTS 405=head1 WATCHER OBJECTS
… …
306called with at least two arguments: the watcher and a bitmask of received 418called with at least two arguments: the watcher and a bitmask of received
307events. 419events.
308 420
309Each watcher type has its associated bit in revents, so you can use the 421Each watcher type has its associated bit in revents, so you can use the
310same callback for multiple watchers. The event mask is named after the 422same callback for multiple watchers. The event mask is named after the
311type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 423type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
312EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 424EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
313(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 425(which can set both EV::READ and EV::WRITE bits).
314uses EV::TIMEOUT).
315 426
316In the rare case where one wants to create a watcher but not start it at 427In the rare case where one wants to create a watcher but not start it at
317the same time, each constructor has a variant with a trailing C<_ns> in 428the same time, each constructor has a variant with a trailing C<_ns> in
318its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 429its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
319 430
… …
396returns its C<$revents> bitset (as if its callback was invoked). If the 507returns its C<$revents> bitset (as if its callback was invoked). If the
397watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
398 509
399=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
400 511
401Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::run> will return when there are no active watchers
402(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
403convinient because it allows you to start your watchers (and your jobs), 514convenient 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 515call C<EV::run> once and when it returns you know that all your jobs are
405finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
406 517
407Sometimes, however, this gets in your way, for example when the module 518Sometimes, 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 519that calls C<EV::run> (usually the main program) is not the same module
409as a long-living watcher (for example a DNS client module written by 520as a long-living watcher (for example a DNS client module written by
410somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
411handled, but you would not want to keep C<EV::loop> from returning just 522handled, but you would not want to keep C<EV::run> from returning just
412because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
413 524
414In 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
415though your watcher is active, it won't keep C<EV::loop> from returning. 526though your watcher is active, it won't keep C<EV::run> from returning.
416 527
417The 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
418any time. 529any time.
419 530
420Example: 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
421event loop from running just because of that watcher. 532event loop from running just because of that watcher.
422 533
… …
487 598
488=item $w = $loop->timer ($after, $repeat, $callback) 599=item $w = $loop->timer ($after, $repeat, $callback)
489 600
490=item $w = $loop->timer_ns ($after, $repeat, $callback) 601=item $w = $loop->timer_ns ($after, $repeat, $callback)
491 602
492Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional or
493C<$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
494value as $after) after the callback returns. 605the $repeat value as $after) after the callback returns.
495 606
496This means that the callback would be called roughly after C<$after> 607This means that the callback would be called roughly after C<$after>
497seconds, and then every C<$repeat> seconds. The timer does his best not 608seconds, and then every C<$repeat> seconds. The timer does his best not
498to 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
499loop 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,
… …
503in 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
504clock, the timer will nevertheless run (roughly) the same time. 615clock, the timer will nevertheless run (roughly) the same time.
505 616
506The 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.
507 618
508=item $w->set ($after, $repeat) 619=item $w->set ($after, $repeat = 0)
509 620
510Reconfigures 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
511any time. 622any time.
512 623
513=item $w->again 624=item $w->again
625
626=item $w->again ($repeat)
514 627
515Similar 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:
516 629
517If the timer is active and non-repeating, it will be stopped. 630If the timer is active and non-repeating, it will be stopped.
518 631
… …
525 638
526This behaviour is useful when you have a timeout for some IO 639This behaviour is useful when you have a timeout for some IO
527operation. 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
528C<$repeat>, and then, in the read/write watcher, run the C<again> method 641C<$repeat>, and then, in the read/write watcher, run the C<again> method
529on 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.
650
651=item $repeat = $w->repeat
652
653=item $old_repeat = $w->repeat ($new_repeat)
654
655Returns the current value of the repeat attribute and optionally sets a
656new one. Setting the new one will not restart the watcher - if the watcher
657is active, the new repeat value is used whenever it expires next.
530 658
531=back 659=back
532 660
533 661
534=head3 PERIODIC WATCHERS - to cron or not to cron? 662=head3 PERIODIC WATCHERS - to cron or not to cron?
… …
562surpasses this time. 690surpasses this time.
563 691
564=item * repeating interval timer ($interval > 0, $reschedule_cb = 0) 692=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
565 693
566In this mode the watcher will always be scheduled to time out at the 694In this mode the watcher will always be scheduled to time out at the
567next C<$at + N * $interval> time (for some integer N) and then repeat, 695next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
568regardless of any time jumps. 696regardless of any time jumps. Note that, since C<N> can be negative, the
697first trigger can happen before C<$at>.
569 698
570This can be used to create timers that do not drift with respect to system 699This can be used to create timers that do not drift with respect to system
571time: 700time:
572 701
573 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 702 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
574 703
575That doesn't mean there will always be 3600 seconds in between triggers, 704That doesn't mean there will always be 3600 seconds in between triggers,
576but only that the the clalback will be called when the system time shows a 705but only that the the callback will be called when the system time shows a
577full hour (UTC). 706full hour (UTC).
578 707
579Another way to think about it (for the mathematically inclined) is that 708Another way to think about it (for the mathematically inclined) is that
580EV::periodic will try to run the callback in this mode at the next 709EV::periodic will try to run the callback in this mode at the next
581possible time where C<$time = $at (mod $interval)>, regardless of any time 710possible time where C<$time = $at (mod $interval)>, regardless of any time
… …
589time as second argument. 718time as second argument.
590 719
591I<This callback MUST NOT stop or destroy this or any other periodic 720I<This callback MUST NOT stop or destroy this or any other periodic
592watcher, ever, and MUST NOT call any event loop functions or methods>. If 721watcher, ever, and MUST NOT call any event loop functions or methods>. If
593you need to stop it, return 1e30 and stop it afterwards. You may create 722you need to stop it, return 1e30 and stop it afterwards. You may create
594and start a C<EV::prepare> watcher for this task. 723and start an C<EV::prepare> watcher for this task.
595 724
596It must return the next time to trigger, based on the passed time value 725It must return the next time to trigger, based on the passed time value
597(that is, the lowest time value larger than or equal to to the second 726(that is, the lowest time value larger than or equal to to the second
598argument). It will usually be called just before the callback will be 727argument). It will usually be called just before the callback will be
599triggered, but might be called at other times, too. 728triggered, but might be called at other times, too.
600 729
601This can be used to create very complex timers, such as a timer that 730This can be used to create very complex timers, such as a timer that
602triggers on each midnight, local time (actually 24 hours after the last 731triggers on each midnight, local time (actually one day after the last
603midnight, to keep the example simple. If you know a way to do it correctly 732midnight, to keep the example simple):
604in about the same space (without requiring elaborate modules), drop me a
605note :):
606 733
607 my $daily = EV::periodic 0, 0, sub { 734 my $daily = EV::periodic 0, 0, sub {
608 my ($w, $now) = @_; 735 my ($w, $now) = @_;
609 736
610 use Time::Local (); 737 use Time::Local ();
611 my (undef, undef, undef, $d, $m, $y) = localtime $now; 738 my (undef, undef, undef, $d, $m, $y) = localtime $now;
612 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 739 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
613 }, sub { 740 }, sub {
614 print "it's midnight or likely shortly after, now\n"; 741 print "it's midnight or likely shortly after, now\n";
615 }; 742 };
616 743
617=back 744=back
… …
629 756
630=item $time = $w->at 757=item $time = $w->at
631 758
632Return the time that the watcher is expected to trigger next. 759Return the time that the watcher is expected to trigger next.
633 760
761=item $offset = $w->offset
762
763=item $old_offset = $w->offset ($new_offset)
764
765Returns the current value of the offset attribute and optionally sets a
766new one. Setting the new one will not restart the watcher - if the watcher
767is active, the new offset value is used whenever it expires next.
768
769=item $interval = $w->interval
770
771=item $old_interval = $w->interval ($new_interval)
772
773See above, for the interval attribute.
774
775=item $reschedule_cb = $w->reschedule_cb
776
777=item $old_reschedule_cb = $w->reschedule_cb ($new_reschedule_cb)
778
779See above, for the reschedule callback.
780
634=back 781=back
635 782
636 783
637=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 784=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
638 785
639=over 4 786=over 4
640 787
641=item $w = EV::signal $signal, $callback 788=item $w = EV::signal $signal, $callback
642 789
643=item $w = EV::signal_ns $signal, $callback 790=item $w = EV::signal_ns $signal, $callback
791
792=item $w = $loop->signal ($signal, $callback)
793
794=item $w = $loop->signal_ns ($signal, $callback)
644 795
645Call the callback when $signal is received (the signal can be specified by 796Call the callback when $signal is received (the signal can be specified by
646number or by name, just as with C<kill> or C<%SIG>). 797number or by name, just as with C<kill> or C<%SIG>).
798
799Only one event loop can grab a given signal - attempting to grab the same
800signal from two EV loops will crash the program immediately or cause data
801corruption.
647 802
648EV will grab the signal for the process (the kernel only allows one 803EV 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, 804component 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 805and removes it again when you stop it. Perl does the same when you
651add/remove callbacks to C<%SIG>, so watch out. 806add/remove callbacks to C<%SIG>, so watch out.
… …
718=item $pid = $w->rpid 873=item $pid = $w->rpid
719 874
720Return the pid of the awaited child (useful when you have installed a 875Return the pid of the awaited child (useful when you have installed a
721watcher for all pids). 876watcher for all pids).
722 877
878=item EV::Child::reinit [EXPERIMENTAL]
879
880Internally, libev installs a signal handler for C<SIGCHLD>. Unfortunately,
881a lot of Perl code does soemthing like C<< local $SIG{CHLD} >>, which,
882unfortunately, is broken and will not restore the signal handler.
883
884If this has happened, you can call this function to stop/rrestart the
885internal libev watcher, which will reset the signal handler.
886
887Note that this is an experimental function, whose interface might change.
888
723=back 889=back
724 890
725 891
726=head3 STAT WATCHERS - did the file attributes just change? 892=head3 STAT WATCHERS - did the file attributes just change?
727 893
… …
876=item $w = $loop->check_ns ($callback) 1042=item $w = $loop->check_ns ($callback)
877 1043
878Call the callback just after the process wakes up again (after it has 1044Call the callback just after the process wakes up again (after it has
879gathered events), but before any other callbacks have been invoked. 1045gathered events), but before any other callbacks have been invoked.
880 1046
881This is used to integrate other event-based software into the EV 1047This can be used to integrate other event-based software into the EV
882mainloop: You register a prepare callback and in there, you create io and 1048mainloop: You register a prepare callback and in there, you create io and
883timer watchers as required by the other software. Here is a real-world 1049timer watchers as required by the other software. Here is a real-world
884example of integrating Net::SNMP (with some details left out): 1050example of integrating Net::SNMP (with some details left out):
885 1051
886 our @snmp_watcher; 1052 our @snmp_watcher;
… …
916 # make the dispatcher handle any new stuff 1082 # make the dispatcher handle any new stuff
917 ... not shown 1083 ... not shown
918 }; 1084 };
919 1085
920The callbacks of the created watchers will not be called as the watchers 1086The callbacks of the created watchers will not be called as the watchers
921are destroyed before this cna happen (remember EV::check gets called 1087are destroyed before this can happen (remember EV::check gets called
922first). 1088first).
923 1089
924The C<check_ns> variant doesn't start (activate) the newly created watcher. 1090The C<check_ns> variant doesn't start (activate) the newly created watcher.
1091
1092=item EV::CHECK constant issues
1093
1094Like all other watcher types, there is a bitmask constant for use in
1095C<$revents> and other places. The C<EV::CHECK> is special as it has
1096the same name as the C<CHECK> sub called by Perl. This doesn't cause
1097big issues on newer perls (beginning with 5.8.9), but it means thatthe
1098constant must be I<inlined>, i.e. runtime calls will not work. That means
1099that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1100safe side.
925 1101
926=back 1102=back
927 1103
928 1104
929=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1105=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
… …
957loop, other types of watchers might be handled in a delayed or incorrect 1133loop, other types of watchers might be handled in a delayed or incorrect
958fashion and must not be used). 1134fashion and must not be used).
959 1135
960See the libev documentation at 1136See the libev documentation at
961L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1137L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
962for more details. 1138(locally installed as F<EV::libev>) for more details.
963 1139
964In short, this watcher is most useful on BSD systems without working 1140In short, this watcher is most useful on BSD systems without working
965kqueue to still be able to handle a large number of sockets: 1141kqueue to still be able to handle a large number of sockets:
966 1142
967 my $socket_loop; 1143 my $socket_loop;
… …
997 1173
998=back 1174=back
999 1175
1000=head3 ASYNC WATCHERS - how to wake up another event loop 1176=head3 ASYNC WATCHERS - how to wake up another event loop
1001 1177
1002Async watchers are provided by EV, but have little use in perl directly, as perl 1178Async watchers are provided by EV, but have little use in perl directly,
1003neither supports threads nor direct access to signal handlers or other 1179as perl neither supports threads running in parallel nor direct access to
1004contexts where they could be of value. 1180signal handlers or other contexts where they could be of value.
1005 1181
1006It is, however, possible to use them from the XS level. 1182It is, however, possible to use them from the XS level.
1007 1183
1008Please see the libev documentation for further details. 1184Please see the libev documentation for further details.
1009 1185
… …
1011 1187
1012=item $w = EV::async $callback 1188=item $w = EV::async $callback
1013 1189
1014=item $w = EV::async_ns $callback 1190=item $w = EV::async_ns $callback
1015 1191
1192=item $w = $loop->async ($callback)
1193
1194=item $w = $loop->async_ns ($callback)
1195
1016=item $w->send 1196=item $w->send
1017 1197
1018=item $bool = $w->async_pending 1198=item $bool = $w->async_pending
1019 1199
1020=back 1200=back
1201
1202=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1203
1204Cleanup watchers are not supported on the Perl level, they can only be
1205used via XS currently.
1021 1206
1022 1207
1023=head1 PERL SIGNALS 1208=head1 PERL SIGNALS
1024 1209
1025While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1210While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
… …
1037 my $async_check = EV::check sub { }; 1222 my $async_check = EV::check sub { };
1038 1223
1039This ensures that perl gets into control for a short time to handle any 1224This ensures that perl gets into control for a short time to handle any
1040pending signals, and also ensures (slightly) slower overall operation. 1225pending signals, and also ensures (slightly) slower overall operation.
1041 1226
1042=head1 THREADS 1227=head1 ITHREADS
1043 1228
1044Threads are not supported by this module in any way. Perl pseudo-threads 1229Ithreads 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 1230is evil stuff and must die. Real threads as provided by Coro are fully
1046on thread support for it. 1231supported (and enhanced support is available via L<Coro::EV>).
1047 1232
1048=head1 FORK 1233=head1 FORK
1049 1234
1050Most of the "improved" event delivering mechanisms of modern operating 1235Most of the "improved" event delivering mechanisms of modern operating
1051systems have quite a few problems with fork(2) (to put it bluntly: it is 1236systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
1073 1258
10741; 12591;
1075 1260
1076=head1 SEE ALSO 1261=head1 SEE ALSO
1077 1262
1263L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1078L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1264(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1079event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1265loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1080coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1266integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1081event-loop agnostic and portable event driven programming. 1267event-loop agnostic and portable event driven programming.
1082 1268
1083=head1 AUTHOR 1269=head1 AUTHOR
1084 1270
1085 Marc Lehmann <schmorp@schmorp.de> 1271 Marc Lehmann <schmorp@schmorp.de>

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