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Revision 1.37 by root, Sat Oct 23 22:25:44 2010 UTC vs.
Revision 1.46 by root, Mon Jun 24 22:33:39 2019 UTC

46 my ($w, $revents) = @_; 46 my ($w, $revents) = @_;
47 warn $w->path, " has changed somehow.\n"; 47 warn $w->path, " has changed somehow.\n";
48 }; 48 };
49 49
50 # MAINLOOP 50 # MAINLOOP
51 EV::loop; # loop until EV::unloop is called or all watchers stop 51 EV::run; # loop until EV::break is called or all watchers stop
52 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 52 EV::run EV::RUN_ONCE; # block until at least one event could be handled
53 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 53 EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block
54 54
55BEFORE YOU START USING THIS MODULE 55BEFORE YOU START USING THIS MODULE
56 If you only need timer, I/O, signal, child and idle watchers and not the 56 If you only need timer, I/O, signal, child and idle watchers and not the
57 advanced functionality of this module, consider using AnyEvent instead, 57 advanced functionality of this module, consider using AnyEvent instead,
58 specifically the simplified API described in AE. 58 specifically the simplified API described in AE.
151 Must be called after a fork in the child, before entering or 151 Must be called after a fork in the child, before entering or
152 continuing the event loop. An alternative is to use 152 continuing the event loop. An alternative is to use
153 "EV::FLAG_FORKCHECK" which calls this function automatically, at 153 "EV::FLAG_FORKCHECK" which calls this function automatically, at
154 some performance loss (refer to the libev documentation). 154 some performance loss (refer to the libev documentation).
155 155
156 $loop->loop_verify 156 $loop->verify
157 Calls "ev_verify" to make internal consistency checks (for debugging 157 Calls "ev_verify" to make internal consistency checks (for debugging
158 libev) and abort the program if any data structures were found to be 158 libev) and abort the program if any data structures were found to be
159 corrupted. 159 corrupted.
160 160
161 $loop = EV::default_loop [$flags] 161 $loop = EV::default_loop [$flags]
195 195
196 EV::now_update 196 EV::now_update
197 $loop->now_update 197 $loop->now_update
198 Establishes the current time by querying the kernel, updating the 198 Establishes the current time by querying the kernel, updating the
199 time returned by "EV::now" in the progress. This is a costly 199 time returned by "EV::now" in the progress. This is a costly
200 operation and is usually done automatically within "EV::loop". 200 operation and is usually done automatically within "EV::run".
201 201
202 This function is rarely useful, but when some event callback runs 202 This function is rarely useful, but when some event callback runs
203 for a very long time without entering the event loop, updating 203 for a very long time without entering the event loop, updating
204 libev's idea of the current time is a good idea. 204 libev's idea of the current time is a good idea.
205 205
233 $backend = EV::backend 233 $backend = EV::backend
234 $backend = $loop->backend 234 $backend = $loop->backend
235 Returns an integer describing the backend used by libev 235 Returns an integer describing the backend used by libev
236 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL). 236 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
237 237
238 EV::loop [$flags] 238 $active = EV::run [$flags]
239 $loop->loop ([$flags]) 239 $active = $loop->run ([$flags])
240 Begin checking for events and calling callbacks. It returns when a 240 Begin checking for events and calling callbacks. It returns when a
241 callback calls EV::unloop. 241 callback calls EV::break or the flags are nonzero (in which case the
242 return value is true) or when there are no active watchers which
243 reference the loop (keepalive is true), in which case the return
244 value will be false. The return value can generally be interpreted
245 as "if true, there is more work left to do".
242 246
243 The $flags argument can be one of the following: 247 The $flags argument can be one of the following:
244 248
245 0 as above 249 0 as above
246 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 250 EV::RUN_ONCE block at most once (wait, but do not loop)
247 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 251 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
248 252
249 EV::unloop [$how] 253 EV::break [$how]
250 $loop->unloop ([$how]) 254 $loop->break ([$how])
251 When called with no arguments or an argument of EV::UNLOOP_ONE, 255 When called with no arguments or an argument of EV::BREAK_ONE, makes
252 makes the innermost call to EV::loop return. 256 the innermost call to EV::run return.
253 257
254 When called with an argument of EV::UNLOOP_ALL, all calls to 258 When called with an argument of EV::BREAK_ALL, all calls to EV::run
255 EV::loop will return as fast as possible. 259 will return as fast as possible.
256 260
257 $count = EV::loop_count 261 When called with an argument of EV::BREAK_CANCEL, any pending break
258 $count = $loop->loop_count 262 will be cancelled.
263
264 $count = EV::iteration
265 $count = $loop->iteration
259 Return the number of times the event loop has polled for new events. 266 Return the number of times the event loop has polled for new events.
260 Sometimes useful as a generation counter. 267 Sometimes useful as a generation counter.
261 268
262 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 269 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
263 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 270 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
269 "EV::READ | EV::WRITE", indicating the type of I/O event you want to 276 "EV::READ | EV::WRITE", indicating the type of I/O event you want to
270 wait for. If you do not want to wait for some I/O event, specify 277 wait for. If you do not want to wait for some I/O event, specify
271 "undef" for $fh_or_undef and 0 for $events). 278 "undef" for $fh_or_undef and 0 for $events).
272 279
273 If timeout is "undef" or negative, then there will be no timeout. 280 If timeout is "undef" or negative, then there will be no timeout.
274 Otherwise a EV::timer with this value will be started. 281 Otherwise an "EV::timer" with this value will be started.
275 282
276 When an error occurs or either the timeout or I/O watcher triggers, 283 When an error occurs or either the timeout or I/O watcher triggers,
277 then the callback will be called with the received event set (in 284 then the callback will be called with the received event set (in
278 general you can expect it to be a combination of "EV::ERROR", 285 general you can expect it to be a combination of "EV::ERROR",
279 "EV::READ", "EV::WRITE" and "EV::TIMER"). 286 "EV::READ", "EV::WRITE" and "EV::TIMER").
280 287
281 EV::once doesn't return anything: the watchers stay active till 288 EV::once doesn't return anything: the watchers stay active till
282 either of them triggers, then they will be stopped and freed, and 289 either of them triggers, then they will be stopped and freed, and
283 the callback invoked. 290 the callback invoked.
284 291
285 EV::feed_fd_event ($fd, $revents) 292 EV::feed_fd_event $fd, $revents
286 $loop->feed_fd_event ($fd, $revents) 293 $loop->feed_fd_event ($fd, $revents)
287 Feed an event on a file descriptor into EV. EV will react to this 294 Feed an event on a file descriptor into EV. EV will react to this
288 call as if the readyness notifications specified by $revents (a 295 call as if the readyness notifications specified by $revents (a
289 combination of "EV::READ" and "EV::WRITE") happened on the file 296 combination of "EV::READ" and "EV::WRITE") happened on the file
290 descriptor $fd. 297 descriptor $fd.
291 298
292 EV::feed_signal_event ($signal) 299 EV::feed_signal_event $signal
293 Feed a signal event into EV. EV will react to this call as if the 300 Feed a signal event into the default loop. EV will react to this
294 signal specified by $signal had occured. 301 call as if the signal specified by $signal had occured.
302
303 EV::feed_signal $signal
304 Feed a signal event into EV - unlike "EV::feed_signal_event", this
305 works regardless of which loop has registered the signal, and is
306 mainly useful fro custom signal implementations.
295 307
296 EV::set_io_collect_interval $time 308 EV::set_io_collect_interval $time
297 $loop->set_io_collect_interval ($time) 309 $loop->set_io_collect_interval ($time)
298 EV::set_timeout_collect_interval $time 310 EV::set_timeout_collect_interval $time
299 $loop->set_timeout_collect_interval ($time) 311 $loop->set_timeout_collect_interval ($time)
402 If the watcher is pending, this function clears its pending status 414 If the watcher is pending, this function clears its pending status
403 and returns its $revents bitset (as if its callback was invoked). If 415 and returns its $revents bitset (as if its callback was invoked). If
404 the watcher isn't pending it does nothing and returns 0. 416 the watcher isn't pending it does nothing and returns 0.
405 417
406 $previous_state = $w->keepalive ($bool) 418 $previous_state = $w->keepalive ($bool)
407 Normally, "EV::loop" will return when there are no active watchers 419 Normally, "EV::run" will return when there are no active watchers
408 (which is a "deadlock" because no progress can be made anymore). 420 (which is a "deadlock" because no progress can be made anymore).
409 This is convenient because it allows you to start your watchers (and 421 This is convenient because it allows you to start your watchers (and
410 your jobs), call "EV::loop" once and when it returns you know that 422 your jobs), call "EV::run" once and when it returns you know that
411 all your jobs are finished (or they forgot to register some watchers 423 all your jobs are finished (or they forgot to register some watchers
412 for their task :). 424 for their task :).
413 425
414 Sometimes, however, this gets in your way, for example when the 426 Sometimes, however, this gets in your way, for example when the
415 module that calls "EV::loop" (usually the main program) is not the 427 module that calls "EV::run" (usually the main program) is not the
416 same module as a long-living watcher (for example a DNS client 428 same module as a long-living watcher (for example a DNS client
417 module written by somebody else even). Then you might want any 429 module written by somebody else even). Then you might want any
418 outstanding requests to be handled, but you would not want to keep 430 outstanding requests to be handled, but you would not want to keep
419 "EV::loop" from returning just because you happen to have this 431 "EV::run" from returning just because you happen to have this
420 long-running UDP port watcher. 432 long-running UDP port watcher.
421 433
422 In this case you can clear the keepalive status, which means that 434 In this case you can clear the keepalive status, which means that
423 even though your watcher is active, it won't keep "EV::loop" from 435 even though your watcher is active, it won't keep "EV::run" from
424 returning. 436 returning.
425 437
426 The initial value for keepalive is true (enabled), and you can 438 The initial value for keepalive is true (enabled), and you can
427 change it any time. 439 change it any time.
428 440
470 TIMER WATCHERS - relative and optionally repeating timeouts 482 TIMER WATCHERS - relative and optionally repeating timeouts
471 $w = EV::timer $after, $repeat, $callback 483 $w = EV::timer $after, $repeat, $callback
472 $w = EV::timer_ns $after, $repeat, $callback 484 $w = EV::timer_ns $after, $repeat, $callback
473 $w = $loop->timer ($after, $repeat, $callback) 485 $w = $loop->timer ($after, $repeat, $callback)
474 $w = $loop->timer_ns ($after, $repeat, $callback) 486 $w = $loop->timer_ns ($after, $repeat, $callback)
475 Calls the callback after $after seconds (which may be fractional). 487 Calls the callback after $after seconds (which may be fractional or
476 If $repeat is non-zero, the timer will be restarted (with the 488 negative). If $repeat is non-zero, the timer will be restarted (with
477 $repeat value as $after) after the callback returns. 489 the $repeat value as $after) after the callback returns.
478 490
479 This means that the callback would be called roughly after $after 491 This means that the callback would be called roughly after $after
480 seconds, and then every $repeat seconds. The timer does his best not 492 seconds, and then every $repeat seconds. The timer does his best not
481 to drift, but it will not invoke the timer more often then once per 493 to drift, but it will not invoke the timer more often then once per
482 event loop iteration, and might drift in other cases. If that isn't 494 event loop iteration, and might drift in other cases. If that isn't
489 the same time. 501 the same time.
490 502
491 The "timer_ns" variant doesn't start (activate) the newly created 503 The "timer_ns" variant doesn't start (activate) the newly created
492 watcher. 504 watcher.
493 505
494 $w->set ($after, $repeat) 506 $w->set ($after, $repeat = 0)
495 Reconfigures the watcher, see the constructor above for details. Can 507 Reconfigures the watcher, see the constructor above for details. Can
496 be called at any time. 508 be called at any time.
497 509
498 $w->again 510 $w->again
511 $w->again ($repeat)
499 Similar to the "start" method, but has special semantics for 512 Similar to the "start" method, but has special semantics for
500 repeating timers: 513 repeating timers:
501 514
502 If the timer is active and non-repeating, it will be stopped. 515 If the timer is active and non-repeating, it will be stopped.
503 516
511 524
512 This behaviour is useful when you have a timeout for some IO 525 This behaviour is useful when you have a timeout for some IO
513 operation. You create a timer object with the same value for $after 526 operation. You create a timer object with the same value for $after
514 and $repeat, and then, in the read/write watcher, run the "again" 527 and $repeat, and then, in the read/write watcher, run the "again"
515 method on the timeout. 528 method on the timeout.
529
530 If called with a $repeat argument, then it uses this a timer repeat
531 value.
532
533 $after = $w->remaining
534 Calculates and returns the remaining time till the timer will fire.
516 535
517 PERIODIC WATCHERS - to cron or not to cron? 536 PERIODIC WATCHERS - to cron or not to cron?
518 $w = EV::periodic $at, $interval, $reschedule_cb, $callback 537 $w = EV::periodic $at, $interval, $reschedule_cb, $callback
519 $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 538 $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
520 $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) 539 $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
537 system time reaches or surpasses this time. 556 system time reaches or surpasses this time.
538 557
539 * repeating interval timer ($interval > 0, $reschedule_cb = 0) 558 * repeating interval timer ($interval > 0, $reschedule_cb = 0)
540 559
541 In this mode the watcher will always be scheduled to time out at 560 In this mode the watcher will always be scheduled to time out at
542 the next "$at + N * $interval" time (for some integer N) and 561 the next "$at + N * $interval" time (for the lowest integer N)
543 then repeat, regardless of any time jumps. 562 and then repeat, regardless of any time jumps. Note that, since
563 "N" can be negative, the first trigger can happen before $at.
544 564
545 This can be used to create timers that do not drift with respect 565 This can be used to create timers that do not drift with respect
546 to system time: 566 to system time:
547 567
548 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 568 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
549 569
550 That doesn't mean there will always be 3600 seconds in between 570 That doesn't mean there will always be 3600 seconds in between
551 triggers, but only that the the clalback will be called when the 571 triggers, but only that the the callback will be called when the
552 system time shows a full hour (UTC). 572 system time shows a full hour (UTC).
553 573
554 Another way to think about it (for the mathematically inclined) 574 Another way to think about it (for the mathematically inclined)
555 is that EV::periodic will try to run the callback in this mode 575 is that EV::periodic will try to run the callback in this mode
556 at the next possible time where "$time = $at (mod $interval)", 576 at the next possible time where "$time = $at (mod $interval)",
564 first, and the current time as second argument. 584 first, and the current time as second argument.
565 585
566 *This callback MUST NOT stop or destroy this or any other 586 *This callback MUST NOT stop or destroy this or any other
567 periodic watcher, ever, and MUST NOT call any event loop 587 periodic watcher, ever, and MUST NOT call any event loop
568 functions or methods*. If you need to stop it, return 1e30 and 588 functions or methods*. If you need to stop it, return 1e30 and
569 stop it afterwards. You may create and start a "EV::prepare" 589 stop it afterwards. You may create and start an "EV::prepare"
570 watcher for this task. 590 watcher for this task.
571 591
572 It must return the next time to trigger, based on the passed 592 It must return the next time to trigger, based on the passed
573 time value (that is, the lowest time value larger than or equal 593 time value (that is, the lowest time value larger than or equal
574 to to the second argument). It will usually be called just 594 to to the second argument). It will usually be called just
575 before the callback will be triggered, but might be called at 595 before the callback will be triggered, but might be called at
576 other times, too. 596 other times, too.
577 597
578 This can be used to create very complex timers, such as a timer 598 This can be used to create very complex timers, such as a timer
579 that triggers on each midnight, local time (actually 24 hours 599 that triggers on each midnight, local time (actually one day
580 after the last midnight, to keep the example simple. If you know 600 after the last midnight, to keep the example simple):
581 a way to do it correctly in about the same space (without
582 requiring elaborate modules), drop me a note :):
583 601
584 my $daily = EV::periodic 0, 0, sub { 602 my $daily = EV::periodic 0, 0, sub {
585 my ($w, $now) = @_; 603 my ($w, $now) = @_;
586 604
587 use Time::Local (); 605 use Time::Local ();
588 my (undef, undef, undef, $d, $m, $y) = localtime $now; 606 my (undef, undef, undef, $d, $m, $y) = localtime $now;
589 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 607 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
590 }, sub { 608 }, sub {
591 print "it's midnight or likely shortly after, now\n"; 609 print "it's midnight or likely shortly after, now\n";
592 }; 610 };
593 611
594 The "periodic_ns" variant doesn't start (activate) the newly created 612 The "periodic_ns" variant doesn't start (activate) the newly created
917 935
918 Please see the libev documentation for further details. 936 Please see the libev documentation for further details.
919 937
920 $w = EV::async $callback 938 $w = EV::async $callback
921 $w = EV::async_ns $callback 939 $w = EV::async_ns $callback
940 $w = $loop->async ($callback)
941 $w = $loop->async_ns ($callback)
922 $w->send 942 $w->send
923 $bool = $w->async_pending 943 $bool = $w->async_pending
944
945 CLEANUP WATCHERS - how to clean up when the event loop goes away
946 Cleanup watchers are not supported on the Perl level, they can only be
947 used via XS currently.
924 948
925PERL SIGNALS 949PERL SIGNALS
926 While Perl signal handling (%SIG) is not affected by EV, the behaviour 950 While Perl signal handling (%SIG) is not affected by EV, the behaviour
927 with EV is as the same as any other C library: Perl-signals will only be 951 with EV is as the same as any other C library: Perl-signals will only be
928 handled when Perl runs, which means your signal handler might be invoked 952 handled when Perl runs, which means your signal handler might be invoked
962 986
963 On win32, there is no notion of fork so all this doesn't apply, of 987 On win32, there is no notion of fork so all this doesn't apply, of
964 course. 988 course.
965 989
966SEE ALSO 990SEE ALSO
967 EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event 991 EV::MakeMaker - MakeMaker interface to XS API, EV::ADNS (asynchronous
968 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 992 DNS), Glib::EV (makes Glib/Gtk2 use EV as event loop), EV::Glib (embed
969 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 993 Glib into EV), Coro::EV (efficient thread integration), Net::SNMP::EV
970 agnostic and portable event driven programming. 994 (asynchronous SNMP), AnyEvent for event-loop agnostic and portable event
995 driven programming.
971 996
972AUTHOR 997AUTHOR
973 Marc Lehmann <schmorp@schmorp.de> 998 Marc Lehmann <schmorp@schmorp.de>
974 http://home.schmorp.de/ 999 http://home.schmorp.de/
975 1000

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