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Revision 1.39 by root, Tue Jan 11 13:45:28 2011 UTC vs.
Revision 1.47 by root, Tue Nov 19 20:11:01 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 $flags argument can be one of the following:
244 248
245 0 as above 249 0 as above
246 EV::LOOP_ONCE block at most once (wait, but do not loop) 250 EV::RUN_ONCE block at most once (wait, but do not loop)
247 EV::LOOP_NOWAIT do not block at all (fetch/handle events but do not wait) 251 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
248 252
249 EV::break [$how] 253 EV::break [$how]
250 $loop->break ([$how]) 254 $loop->break ([$how])
251 When called with no arguments or an argument of EV::BREAK_ONE, makes 255 When called with no arguments or an argument of EV::BREAK_ONE, makes
252 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::BREAK_ALL, all calls to EV::loop 258 When called with an argument of EV::BREAK_ALL, all calls to EV::run
255 will return as fast as possible. 259 will return as fast as possible.
256 260
257 When called with an argument of EV::BREAK_CANCEL, any pending break 261 When called with an argument of EV::BREAK_CANCEL, any pending break
258 will be cancelled. 262 will be cancelled.
259 263
260 $count = EV::loop_count 264 $count = EV::iteration
261 $count = $loop->loop_count 265 $count = $loop->iteration
262 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.
263 Sometimes useful as a generation counter. 267 Sometimes useful as a generation counter.
264 268
265 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 269 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
266 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 270 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
272 "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
273 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
274 "undef" for $fh_or_undef and 0 for $events). 278 "undef" for $fh_or_undef and 0 for $events).
275 279
276 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.
277 Otherwise a EV::timer with this value will be started. 281 Otherwise an "EV::timer" with this value will be started.
278 282
279 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,
280 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
281 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",
282 "EV::READ", "EV::WRITE" and "EV::TIMER"). 286 "EV::READ", "EV::WRITE" and "EV::TIMER").
297 call as if the signal specified by $signal had occured. 301 call as if the signal specified by $signal had occured.
298 302
299 EV::feed_signal $signal 303 EV::feed_signal $signal
300 Feed a signal event into EV - unlike "EV::feed_signal_event", this 304 Feed a signal event into EV - unlike "EV::feed_signal_event", this
301 works regardless of which loop has registered the signal, and is 305 works regardless of which loop has registered the signal, and is
302 mainly useful fro custom signal implementations. 306 mainly useful for custom signal implementations.
303 307
304 EV::set_io_collect_interval $time 308 EV::set_io_collect_interval $time
305 $loop->set_io_collect_interval ($time) 309 $loop->set_io_collect_interval ($time)
306 EV::set_timeout_collect_interval $time 310 EV::set_timeout_collect_interval $time
307 $loop->set_timeout_collect_interval ($time) 311 $loop->set_timeout_collect_interval ($time)
410 If the watcher is pending, this function clears its pending status 414 If the watcher is pending, this function clears its pending status
411 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
412 the watcher isn't pending it does nothing and returns 0. 416 the watcher isn't pending it does nothing and returns 0.
413 417
414 $previous_state = $w->keepalive ($bool) 418 $previous_state = $w->keepalive ($bool)
415 Normally, "EV::loop" will return when there are no active watchers 419 Normally, "EV::run" will return when there are no active watchers
416 (which is a "deadlock" because no progress can be made anymore). 420 (which is a "deadlock" because no progress can be made anymore).
417 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
418 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
419 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
420 for their task :). 424 for their task :).
421 425
422 Sometimes, however, this gets in your way, for example when the 426 Sometimes, however, this gets in your way, for example when the
423 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
424 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
425 module written by somebody else even). Then you might want any 429 module written by somebody else even). Then you might want any
426 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
427 "EV::loop" from returning just because you happen to have this 431 "EV::run" from returning just because you happen to have this
428 long-running UDP port watcher. 432 long-running UDP port watcher.
429 433
430 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
431 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
432 returning. 436 returning.
433 437
434 The initial value for keepalive is true (enabled), and you can 438 The initial value for keepalive is true (enabled), and you can
435 change it any time. 439 change it any time.
436 440
478 TIMER WATCHERS - relative and optionally repeating timeouts 482 TIMER WATCHERS - relative and optionally repeating timeouts
479 $w = EV::timer $after, $repeat, $callback 483 $w = EV::timer $after, $repeat, $callback
480 $w = EV::timer_ns $after, $repeat, $callback 484 $w = EV::timer_ns $after, $repeat, $callback
481 $w = $loop->timer ($after, $repeat, $callback) 485 $w = $loop->timer ($after, $repeat, $callback)
482 $w = $loop->timer_ns ($after, $repeat, $callback) 486 $w = $loop->timer_ns ($after, $repeat, $callback)
483 Calls the callback after $after seconds (which may be fractional). 487 Calls the callback after $after seconds (which may be fractional or
484 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
485 $repeat value as $after) after the callback returns. 489 the $repeat value as $after) after the callback returns.
486 490
487 This means that the callback would be called roughly after $after 491 This means that the callback would be called roughly after $after
488 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
489 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
490 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
497 the same time. 501 the same time.
498 502
499 The "timer_ns" variant doesn't start (activate) the newly created 503 The "timer_ns" variant doesn't start (activate) the newly created
500 watcher. 504 watcher.
501 505
502 $w->set ($after, $repeat) 506 $w->set ($after, $repeat = 0)
503 Reconfigures the watcher, see the constructor above for details. Can 507 Reconfigures the watcher, see the constructor above for details. Can
504 be called at any time. 508 be called at any time.
505 509
506 $w->again 510 $w->again
511 $w->again ($repeat)
507 Similar to the "start" method, but has special semantics for 512 Similar to the "start" method, but has special semantics for
508 repeating timers: 513 repeating timers:
509 514
510 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.
511 516
519 524
520 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
521 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
522 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"
523 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.
524 535
525 PERIODIC WATCHERS - to cron or not to cron? 536 PERIODIC WATCHERS - to cron or not to cron?
526 $w = EV::periodic $at, $interval, $reschedule_cb, $callback 537 $w = EV::periodic $at, $interval, $reschedule_cb, $callback
527 $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 538 $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
528 $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) 539 $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
545 system time reaches or surpasses this time. 556 system time reaches or surpasses this time.
546 557
547 * repeating interval timer ($interval > 0, $reschedule_cb = 0) 558 * repeating interval timer ($interval > 0, $reschedule_cb = 0)
548 559
549 In this mode the watcher will always be scheduled to time out at 560 In this mode the watcher will always be scheduled to time out at
550 the next "$at + N * $interval" time (for some integer N) and 561 the next "$at + N * $interval" time (for the lowest integer N)
551 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.
552 564
553 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
554 to system time: 566 to system time:
555 567
556 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; 568 my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
557 569
558 That doesn't mean there will always be 3600 seconds in between 570 That doesn't mean there will always be 3600 seconds in between
559 triggers, but only that the the clalback will be called when the 571 triggers, but only that the the callback will be called when the
560 system time shows a full hour (UTC). 572 system time shows a full hour (UTC).
561 573
562 Another way to think about it (for the mathematically inclined) 574 Another way to think about it (for the mathematically inclined)
563 is that EV::periodic will try to run the callback in this mode 575 is that EV::periodic will try to run the callback in this mode
564 at the next possible time where "$time = $at (mod $interval)", 576 at the next possible time where "$time = $at (mod $interval)",
572 first, and the current time as second argument. 584 first, and the current time as second argument.
573 585
574 *This callback MUST NOT stop or destroy this or any other 586 *This callback MUST NOT stop or destroy this or any other
575 periodic watcher, ever, and MUST NOT call any event loop 587 periodic watcher, ever, and MUST NOT call any event loop
576 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
577 stop it afterwards. You may create and start a "EV::prepare" 589 stop it afterwards. You may create and start an "EV::prepare"
578 watcher for this task. 590 watcher for this task.
579 591
580 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
581 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
582 to to the second argument). It will usually be called just 594 to to the second argument). It will usually be called just
583 before the callback will be triggered, but might be called at 595 before the callback will be triggered, but might be called at
584 other times, too. 596 other times, too.
585 597
586 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
587 that triggers on each midnight, local time (actually 24 hours 599 that triggers on each midnight, local time (actually one day
588 after the last midnight, to keep the example simple. If you know 600 after the last midnight, to keep the example simple):
589 a way to do it correctly in about the same space (without
590 requiring elaborate modules), drop me a note :):
591 601
592 my $daily = EV::periodic 0, 0, sub { 602 my $daily = EV::periodic 0, 0, sub {
593 my ($w, $now) = @_; 603 my ($w, $now) = @_;
594 604
595 use Time::Local (); 605 use Time::Local ();
596 my (undef, undef, undef, $d, $m, $y) = localtime $now; 606 my (undef, undef, undef, $d, $m, $y) = localtime $now;
597 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y 607 Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
598 }, sub { 608 }, sub {
599 print "it's midnight or likely shortly after, now\n"; 609 print "it's midnight or likely shortly after, now\n";
600 }; 610 };
601 611
602 The "periodic_ns" variant doesn't start (activate) the newly created 612 The "periodic_ns" variant doesn't start (activate) the newly created
925 935
926 Please see the libev documentation for further details. 936 Please see the libev documentation for further details.
927 937
928 $w = EV::async $callback 938 $w = EV::async $callback
929 $w = EV::async_ns $callback 939 $w = EV::async_ns $callback
940 $w = $loop->async ($callback)
941 $w = $loop->async_ns ($callback)
930 $w->send 942 $w->send
931 $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.
932 948
933PERL SIGNALS 949PERL SIGNALS
934 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
935 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
936 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

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