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

Comparing EV/EV.pm (file contents):
Revision 1.68 by root, Sun Dec 9 03:54:13 2007 UTC vs.
Revision 1.97 by root, Mon May 26 05:37:18 2008 UTC

35 warn "sigquit received\n"; 35 warn "sigquit received\n";
36 }; 36 };
37 37
38 # CHILD/PID STATUS CHANGES 38 # CHILD/PID STATUS CHANGES
39 39
40 my $w = EV::child 666, sub { 40 my $w = EV::child 666, 0, sub {
41 my ($w, $revents) = @_; 41 my ($w, $revents) = @_;
42 my $status = $w->rstatus; 42 my $status = $w->rstatus;
43 }; 43 };
44 44
45 # STAT CHANGES 45 # STAT CHANGES
56=head1 DESCRIPTION 56=head1 DESCRIPTION
57 57
58This module provides an interface to libev 58This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of libev 60below is comprehensive, one might also consult the documentation of libev
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62watcher semantics or some discussion on the available backends, or how to 62subtle details on watcher semantics or some discussion on the available
63force a specific backend with C<LIBEV_FLAGS>, or just about in any case 63backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
64because it has much more detailed information. 64about in any case because it has much more detailed information.
65
66This 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
68loops (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
70Perl.
65 71
66=cut 72=cut
67 73
68package EV; 74package EV;
69 75
70use strict; 76use strict;
71 77
72BEGIN { 78BEGIN {
73 our $VERSION = '1.72'; 79 our $VERSION = '3.42';
74 use XSLoader; 80 use XSLoader;
75 XSLoader::load "EV", $VERSION; 81 XSLoader::load "EV", $VERSION;
76} 82}
77 83
78@EV::IO::ISA = 84@EV::IO::ISA =
84@EV::Idle::ISA = 90@EV::Idle::ISA =
85@EV::Prepare::ISA = 91@EV::Prepare::ISA =
86@EV::Check::ISA = 92@EV::Check::ISA =
87@EV::Embed::ISA = 93@EV::Embed::ISA =
88@EV::Fork::ISA = 94@EV::Fork::ISA =
95@EV::Async::ISA =
89 "EV::Watcher"; 96 "EV::Watcher";
97
98@EV::Loop::Default::ISA = "EV::Loop";
99
100=head1 EVENT LOOPS
101
102EV supports multiple event loops: There is a single "default event loop"
103that can handle everything including signals and child watchers, and any
104number of "dynamic event loops" that can use different backends (with
105various limitations), but no child and signal watchers.
106
107You do not have to do anything to create the default event loop: When
108the module is loaded a suitable backend is selected on the premise of
109selecting a working backend (which for example rules out kqueue on most
110BSDs). Modules should, unless they have "special needs" always use the
111default loop as this is fastest (perl-wise), best supported by other
112modules (e.g. AnyEvent or Coro) and most portable event loop.
113
114For specific programs you can create additional event loops dynamically.
115
116=over 4
117
118=item $loop = new EV::loop [$flags]
119
120Create a new event loop as per the specified flags. Please refer to the
121C<ev_loop_new ()> function description in the libev documentation
122(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
123for more info.
124
125The loop will automatically be destroyed when it is no longer referenced
126by any watcher and the loop object goes out of scope.
127
128Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
129is protected by this module.
130
131=item $loop->loop_fork
132
133Must be called after a fork in the child, before entering or continuing
134the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
135this function automatically, at some performance loss (refer to the libev
136documentation).
137
138=item $loop->loop_verify
139
140Calls C<ev_verify> to make internal consistency checks (for debugging
141libev) and abort the program if any data structures wree found to be
142corrupted.
143
144=item $loop = EV::default_loop [$flags]
145
146Return the default loop (which is a singleton object). Since this module
147already creates the default loop with default flags, specifying flags here
148will not have any effect unless you destroy the default loop.
149
150=back
151
90 152
91=head1 BASIC INTERFACE 153=head1 BASIC INTERFACE
92 154
93=over 4 155=over 4
94 156
98throws an exception (with $@ containing the error). The default prints an 160throws an exception (with $@ containing the error). The default prints an
99informative message and continues. 161informative message and continues.
100 162
101If this callback throws an exception it will be silently ignored. 163If this callback throws an exception it will be silently ignored.
102 164
165=item $flags = EV::supported_backends
166
167=item $flags = EV::recommended_backends
168
169=item $flags = EV::embeddable_backends
170
171Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
172instance of EV, the set of recommended backends (supposed to be good) for
173this platform and the set of embeddable backends (see EMBED WATCHERS).
174
175=item EV::sleep $seconds
176
177Block the process for the given number of (fractional) seconds.
178
103=item $time = EV::time 179=item $time = EV::time
104 180
105Returns the current time in (fractional) seconds since the epoch. 181Returns the current time in (fractional) seconds since the epoch.
106 182
107=item $time = EV::now 183=item $time = EV::now
184
185=item $time = $loop->now
108 186
109Returns the time the last event loop iteration has been started. This 187Returns the time the last event loop iteration has been started. This
110is the time that (relative) timers are based on, and refering to it is 188is the time that (relative) timers are based on, and refering to it is
111usually faster then calling EV::time. 189usually faster then calling EV::time.
112 190
113=item $method = EV::method 191=item $backend = EV::backend
192
193=item $backend = $loop->backend
114 194
115Returns an integer describing the backend used by libev (EV::METHOD_SELECT 195Returns an integer describing the backend used by libev (EV::METHOD_SELECT
116or EV::METHOD_EPOLL). 196or EV::METHOD_EPOLL).
117 197
118=item EV::loop [$flags] 198=item EV::loop [$flags]
199
200=item $loop->loop ([$flags])
119 201
120Begin checking for events and calling callbacks. It returns when a 202Begin checking for events and calling callbacks. It returns when a
121callback calls EV::unloop. 203callback calls EV::unloop.
122 204
123The $flags argument can be one of the following: 205The $flags argument can be one of the following:
126 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 208 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
127 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 209 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
128 210
129=item EV::unloop [$how] 211=item EV::unloop [$how]
130 212
213=item $loop->unloop ([$how])
214
131When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 215When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
132innermost call to EV::loop return. 216innermost call to EV::loop return.
133 217
134When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 218When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
135fast as possible. 219fast as possible.
136 220
137=item $count = EV::loop_count 221=item $count = EV::loop_count
138 222
223=item $count = $loop->loop_count
224
139Return the number of times the event loop has polled for new 225Return the number of times the event loop has polled for new
140events. Sometiems useful as a generation counter. 226events. Sometiems useful as a generation counter.
141 227
142=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 228=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
229
230=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
143 231
144This function rolls together an I/O and a timer watcher for a single 232This function rolls together an I/O and a timer watcher for a single
145one-shot event without the need for managing a watcher object. 233one-shot event without the need for managing a watcher object.
146 234
147If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> 235If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
153If timeout is C<undef> or negative, then there will be no 241If timeout is C<undef> or negative, then there will be no
154timeout. Otherwise a EV::timer with this value will be started. 242timeout. Otherwise a EV::timer with this value will be started.
155 243
156When an error occurs or either the timeout or I/O watcher triggers, then 244When an error occurs or either the timeout or I/O watcher triggers, then
157the callback will be called with the received event set (in general 245the callback will be called with the received event set (in general
158you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, 246you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
159C<EV::WRITE> and C<EV::TIMEOUT>). 247C<EV::WRITE> and C<EV::TIMEOUT>).
160 248
161EV::once doesn't return anything: the watchers stay active till either 249EV::once doesn't return anything: the watchers stay active till either
162of them triggers, then they will be stopped and freed, and the callback 250of them triggers, then they will be stopped and freed, and the callback
163invoked. 251invoked.
164 252
165=item EV::feed_fd_event ($fd, $revents) 253=item EV::feed_fd_event ($fd, $revents)
166 254
255=item $loop->feed_fd_event ($fd, $revents)
256
167Feed an event on a file descriptor into EV. EV will react to this call as 257Feed an event on a file descriptor into EV. EV will react to this call as
168if the readyness notifications specified by C<$revents> (a combination of 258if the readyness notifications specified by C<$revents> (a combination of
169C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 259C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
170 260
171=item EV::feed_signal_event ($signal) 261=item EV::feed_signal_event ($signal)
172 262
173Feed a signal event into EV. EV will react to this call as if the signal 263Feed a signal event into EV. EV will react to this call as if the signal
174specified by C<$signal> had occured. 264specified by C<$signal> had occured.
175 265
176=back 266=item EV::set_io_collect_interval $time
177 267
268=item $loop->set_io_collect_interval ($time)
178 269
270=item EV::set_timeout_collect_interval $time
271
272=item $loop->set_timeout_collect_interval ($time)
273
274These advanced functions set the minimum block interval when polling for I/O events and the minimum
275wait interval for timer events. See the libev documentation at
276L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
277a more detailed discussion.
278
279=back
280
281
179=head2 WATCHER OBJECTS 282=head1 WATCHER OBJECTS
180 283
181A watcher is an object that gets created to record your interest in some 284A watcher is an object that gets created to record your interest in some
182event. For instance, if you want to wait for STDIN to become readable, you 285event. For instance, if you want to wait for STDIN to become readable, you
183would create an EV::io watcher for that: 286would create an EV::io watcher for that:
184 287
185 my $watcher = EV::io *STDIN, EV::READ, sub { 288 my $watcher = EV::io *STDIN, EV::READ, sub {
186 my ($watcher, $revents) = @_; 289 my ($watcher, $revents) = @_;
187 warn "yeah, STDIN should not be readable without blocking!\n" 290 warn "yeah, STDIN should now be readable without blocking!\n"
188 }; 291 };
189 292
190All watchers can be active (waiting for events) or inactive (paused). Only 293All watchers can be active (waiting for events) or inactive (paused). Only
191active watchers will have their callbacks invoked. All callbacks will be 294active watchers will have their callbacks invoked. All callbacks will be
192called with at least two arguments: the watcher and a bitmask of received 295called with at least two arguments: the watcher and a bitmask of received
276Feed some events on this watcher into EV. EV will react to this call as if 379Feed some events on this watcher into EV. EV will react to this call as if
277the watcher had received the given C<$revents> mask. 380the watcher had received the given C<$revents> mask.
278 381
279=item $revents = $w->clear_pending 382=item $revents = $w->clear_pending
280 383
281If the watcher is pending, this function returns clears its pending status 384If the watcher is pending, this function clears its pending status and
282and returns its C<$revents> bitset (as if its callback was invoked). If the 385returns its C<$revents> bitset (as if its callback was invoked). If the
283watcher isn't pending it does nothing and returns C<0>. 386watcher isn't pending it does nothing and returns C<0>.
284 387
285=item $previous_state = $w->keepalive ($bool) 388=item $previous_state = $w->keepalive ($bool)
286 389
287Normally, C<EV::loop> will return when there are no active watchers 390Normally, C<EV::loop> will return when there are no active watchers
288(which is a "deadlock" because no progress can be made anymore). This is 391(which is a "deadlock" because no progress can be made anymore). This is
289convinient because it allows you to start your watchers (and your jobs), 392convinient because it allows you to start your watchers (and your jobs),
290call C<EV::loop> once and when it returns you know that all your jobs are 393call C<EV::loop> once and when it returns you know that all your jobs are
291finished (or they forgot to register some watchers for their task :). 394finished (or they forgot to register some watchers for their task :).
292 395
293Sometimes, however, this gets in your way, for example when you the module 396Sometimes, however, this gets in your way, for example when the module
294that calls C<EV::loop> (usually the main program) is not the same module 397that calls C<EV::loop> (usually the main program) is not the same module
295as a long-living watcher (for example a DNS client module written by 398as a long-living watcher (for example a DNS client module written by
296somebody else even). Then you might want any outstanding requests to be 399somebody else even). Then you might want any outstanding requests to be
297handled, but you would not want to keep C<EV::loop> from returning just 400handled, but you would not want to keep C<EV::loop> from returning just
298because you happen to have this long-running UDP port watcher. 401because you happen to have this long-running UDP port watcher.
306Example: Register an I/O watcher for some UDP socket but do not keep the 409Example: Register an I/O watcher for some UDP socket but do not keep the
307event loop from running just because of that watcher. 410event loop from running just because of that watcher.
308 411
309 my $udp_socket = ... 412 my $udp_socket = ...
310 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 413 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
311 $udp_watcher->keepalive (0); 414 $1000udp_watcher->keepalive (0);
312 415
313=back 416=item $loop = $w->loop
314 417
418Return the loop that this watcher is attached to.
315 419
420=back
421
422
316=head2 WATCHER TYPES 423=head1 WATCHER TYPES
317 424
318Each of the following subsections describes a single watcher type. 425Each of the following subsections describes a single watcher type.
319 426
320=head3 I/O WATCHERS - is this file descriptor readable or writable? 427=head3 I/O WATCHERS - is this file descriptor readable or writable?
321 428
322=over 4 429=over 4
323 430
324=item $w = EV::io $fileno_or_fh, $eventmask, $callback 431=item $w = EV::io $fileno_or_fh, $eventmask, $callback
325 432
326=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 433=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
434
435=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
436
437=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
327 438
328As long as the returned watcher object is alive, call the C<$callback> 439As long as the returned watcher object is alive, call the C<$callback>
329when at least one of events specified in C<$eventmask> occurs. 440when at least one of events specified in C<$eventmask> occurs.
330 441
331The $eventmask can be one or more of these constants ORed together: 442The $eventmask can be one or more of these constants ORed together:
360=over 4 471=over 4
361 472
362=item $w = EV::timer $after, $repeat, $callback 473=item $w = EV::timer $after, $repeat, $callback
363 474
364=item $w = EV::timer_ns $after, $repeat, $callback 475=item $w = EV::timer_ns $after, $repeat, $callback
476
477=item $w = $loop->timer ($after, $repeat, $callback)
478
479=item $w = $loop->timer_ns ($after, $repeat, $callback)
365 480
366Calls the callback after C<$after> seconds (which may be fractional). If 481Calls the callback after C<$after> seconds (which may be fractional). If
367C<$repeat> is non-zero, the timer will be restarted (with the $repeat 482C<$repeat> is non-zero, the timer will be restarted (with the $repeat
368value as $after) after the callback returns. 483value as $after) after the callback returns.
369 484
410=over 4 525=over 4
411 526
412=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 527=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
413 528
414=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 529=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
530
531=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
532
533=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
415 534
416Similar to EV::timer, but is not based on relative timeouts but on 535Similar to EV::timer, but is not based on relative timeouts but on
417absolute times. Apart from creating "simple" timers that trigger "at" the 536absolute times. Apart from creating "simple" timers that trigger "at" the
418specified time, it can also be used for non-drifting absolute timers and 537specified time, it can also be used for non-drifting absolute timers and
419more complex, cron-like, setups that are not adversely affected by time 538more complex, cron-like, setups that are not adversely affected by time
429This time simply fires at the wallclock time C<$at> and doesn't repeat. It 548This time simply fires at the wallclock time C<$at> and doesn't repeat. It
430will not adjust when a time jump occurs, that is, if it is to be run 549will not adjust when a time jump occurs, that is, if it is to be run
431at January 1st 2011 then it will run when the system time reaches or 550at January 1st 2011 then it will run when the system time reaches or
432surpasses this time. 551surpasses this time.
433 552
434=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 553=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
435 554
436In this mode the watcher will always be scheduled to time out at the 555In this mode the watcher will always be scheduled to time out at the
437next C<$at + N * $interval> time (for some integer N) and then repeat, 556next C<$at + N * $interval> time (for some integer N) and then repeat,
438regardless of any time jumps. 557regardless of any time jumps.
439 558
457time the periodic watcher gets scheduled, the reschedule callback 576time the periodic watcher gets scheduled, the reschedule callback
458($reschedule_cb) will be called with the watcher as first, and the current 577($reschedule_cb) will be called with the watcher as first, and the current
459time as second argument. 578time as second argument.
460 579
461I<This callback MUST NOT stop or destroy this or any other periodic 580I<This callback MUST NOT stop or destroy this or any other periodic
462watcher, ever>. If you need to stop it, return 1e30 and stop it 581watcher, ever, and MUST NOT call any event loop functions or methods>. If
463afterwards. 582you need to stop it, return 1e30 and stop it afterwards. You may create
583and start a C<EV::prepare> watcher for this task.
464 584
465It must return the next time to trigger, based on the passed time value 585It must return the next time to trigger, based on the passed time value
466(that is, the lowest time value larger than to the second argument). It 586(that is, the lowest time value larger than or equal to to the second
467will usually be called just before the callback will be triggered, but 587argument). It will usually be called just before the callback will be
468might be called at other times, too. 588triggered, but might be called at other times, too.
469 589
470This can be used to create very complex timers, such as a timer that 590This can be used to create very complex timers, such as a timer that
471triggers on each midnight, local time (actually 24 hours after the last 591triggers on each midnight, local time (actually 24 hours after the last
472midnight, to keep the example simple. If you know a way to do it correctly 592midnight, to keep the example simple. If you know a way to do it correctly
473in about the same space (without requiring elaborate modules), drop me a 593in about the same space (without requiring elaborate modules), drop me a
494 614
495=item $w->again 615=item $w->again
496 616
497Simply stops and starts the watcher again. 617Simply stops and starts the watcher again.
498 618
619=item $time = $w->at
620
621Return the time that the watcher is expected to trigger next.
622
499=back 623=back
500 624
501 625
502=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 626=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
503 627
536 660
537=head3 CHILD WATCHERS - watch out for process status changes 661=head3 CHILD WATCHERS - watch out for process status changes
538 662
539=over 4 663=over 4
540 664
541=item $w = EV::child $pid, $callback 665=item $w = EV::child $pid, $trace, $callback
542 666
543=item $w = EV::child_ns $pid, $callback 667=item $w = EV::child_ns $pid, $trace, $callback
544 668
669=item $w = $loop->child ($pid, $trace, $callback)
670
671=item $w = $loop->child_ns ($pid, $trace, $callback)
672
545Call the callback when a status change for pid C<$pid> (or any pid if 673Call the callback when a status change for pid C<$pid> (or any pid
546C<$pid> is 0) has been received. More precisely: when the process receives 674if C<$pid> is 0) has been received (a status change happens when the
675process terminates or is killed, or, when trace is true, additionally when
676it is stopped or continued). More precisely: when the process receives
547a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 677a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
548changed/zombie children and call the callback. 678changed/zombie children and call the callback.
549 679
550It is valid (and fully supported) to install a child watcher after a child 680It is valid (and fully supported) to install a child watcher after a child
551has exited but before the event loop has started its next iteration (for 681has exited but before the event loop has started its next iteration (for
558You can have as many pid watchers per pid as you want, they will all be 688You can have as many pid watchers per pid as you want, they will all be
559called. 689called.
560 690
561The C<child_ns> variant doesn't start (activate) the newly created watcher. 691The C<child_ns> variant doesn't start (activate) the newly created watcher.
562 692
563=item $w->set ($pid) 693=item $w->set ($pid, $trace)
564 694
565Reconfigures the watcher, see the constructor above for details. Can be called at 695Reconfigures the watcher, see the constructor above for details. Can be called at
566any time. 696any time.
567 697
568=item $current_pid = $w->pid 698=item $current_pid = $w->pid
569 699
570=item $old_pid = $w->pid ($new_pid)
571
572Returns the previously set process id and optionally set a new one. 700Returns the previously set process id and optionally set a new one.
573 701
574=item $exit_status = $w->rstatus 702=item $exit_status = $w->rstatus
575 703
576Return the exit/wait status (as returned by waitpid, see the waitpid entry 704Return the exit/wait status (as returned by waitpid, see the waitpid entry
589=over 4 717=over 4
590 718
591=item $w = EV::stat $path, $interval, $callback 719=item $w = EV::stat $path, $interval, $callback
592 720
593=item $w = EV::stat_ns $path, $interval, $callback 721=item $w = EV::stat_ns $path, $interval, $callback
722
723=item $w = $loop->stat ($path, $interval, $callback)
724
725=item $w = $loop->stat_ns ($path, $interval, $callback)
594 726
595Call the callback when a file status change has been detected on 727Call the callback when a file status change has been detected on
596C<$path>. The C<$path> does not need to exist, changing from "path exists" 728C<$path>. The C<$path> does not need to exist, changing from "path exists"
597to "path does not exist" is a status change like any other. 729to "path does not exist" is a status change like any other.
598 730
668=over 4 800=over 4
669 801
670=item $w = EV::idle $callback 802=item $w = EV::idle $callback
671 803
672=item $w = EV::idle_ns $callback 804=item $w = EV::idle_ns $callback
805
806=item $w = $loop->idle ($callback)
807
808=item $w = $loop->idle_ns ($callback)
673 809
674Call the callback when there are no other pending watchers of the same or 810Call the callback when there are no other pending watchers of the same or
675higher priority (excluding check, prepare and other idle watchers of the 811higher priority (excluding check, prepare and other idle watchers of the
676same or lower priority, of course). They are called idle watchers because 812same or lower priority, of course). They are called idle watchers because
677when the watcher is the highest priority pending event in the process, the 813when the watcher is the highest priority pending event in the process, the
700 836
701=item $w = EV::prepare $callback 837=item $w = EV::prepare $callback
702 838
703=item $w = EV::prepare_ns $callback 839=item $w = EV::prepare_ns $callback
704 840
841=item $w = $loop->prepare ($callback)
842
843=item $w = $loop->prepare_ns ($callback)
844
705Call the callback just before the process would block. You can still 845Call the callback just before the process would block. You can still
706create/modify any watchers at this point. 846create/modify any watchers at this point.
707 847
708See the EV::check watcher, below, for explanations and an example. 848See the EV::check watcher, below, for explanations and an example.
709 849
717=over 4 857=over 4
718 858
719=item $w = EV::check $callback 859=item $w = EV::check $callback
720 860
721=item $w = EV::check_ns $callback 861=item $w = EV::check_ns $callback
862
863=item $w = $loop->check ($callback)
864
865=item $w = $loop->check_ns ($callback)
722 866
723Call the callback just after the process wakes up again (after it has 867Call the callback just after the process wakes up again (after it has
724gathered events), but before any other callbacks have been invoked. 868gathered events), but before any other callbacks have been invoked.
725 869
726This is used to integrate other event-based software into the EV 870This is used to integrate other event-based software into the EV
781 925
782=item $w = EV::fork $callback 926=item $w = EV::fork $callback
783 927
784=item $w = EV::fork_ns $callback 928=item $w = EV::fork_ns $callback
785 929
930=item $w = $loop->fork ($callback)
931
932=item $w = $loop->fork_ns ($callback)
933
786Call the callback before the event loop is resumed in the child process 934Call the callback before the event loop is resumed in the child process
787after a fork. 935after a fork.
788 936
789The C<fork_ns> variant doesn't start (activate) the newly created watcher. 937The C<fork_ns> variant doesn't start (activate) the newly created watcher.
938
939=back
940
941
942=head3 EMBED WATCHERS - when one backend isn't enough...
943
944This is a rather advanced watcher type that lets you embed one event loop
945into another (currently only IO events are supported in the embedded
946loop, other types of watchers might be handled in a delayed or incorrect
947fashion and must not be used).
948
949See the libev documentation at
950L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
951for more details.
952
953In short, this watcher is most useful on BSD systems without working
954kqueue to still be able to handle a large number of sockets:
955
956 my $socket_loop;
957
958 # check wether we use SELECT or POLL _and_ KQUEUE is supported
959 if (
960 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
961 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
962 ) {
963 # use kqueue for sockets
964 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
965 }
966
967 # use the default loop otherwise
968 $socket_loop ||= EV::default_loop;
969
970=over 4
971
972=item $w = EV::embed $otherloop, $callback
973
974=item $w = EV::embed_ns $otherloop, $callback
975
976=item $w = $loop->embed ($otherloop, $callback)
977
978=item $w = $loop->embed_ns ($otherloop, $callback)
979
980Call the callback when the embedded event loop (C<$otherloop>) has any
981I/O activity. The C<$callback> should alwas be specified as C<undef> in
982this version of EV, which means the embedded event loop will be managed
983automatically.
984
985The C<embed_ns> variant doesn't start (activate) the newly created watcher.
986
987=back
988
989=head3 ASYNC WATCHERS - how to wake up another event loop
990
991Async watchers are provided by EV, but have little use in perl directly, as perl
992neither supports threads nor direct access to signal handlers or other
993contexts where they could be of value.
994
995It is, however, possible to use them from the XS level.
996
997Please see the libev documentation for further details.
998
999=over 4
1000
1001=item $w = EV::async $callback
1002
1003=item $w = EV::async_ns $callback
1004
1005=item $w->send
1006
1007=item $bool = $w->async_pending
790 1008
791=back 1009=back
792 1010
793 1011
794=head1 PERL SIGNALS 1012=head1 PERL SIGNALS
805to be called on every event loop iteration by installing a C<EV::check> 1023to be called on every event loop iteration by installing a C<EV::check>
806watcher: 1024watcher:
807 1025
808 my $async_check = EV::check sub { }; 1026 my $async_check = EV::check sub { };
809 1027
810This ensures that perl shortly gets into control for a short time, and 1028This ensures that perl gets into control for a short time to handle any
811also ensures slower overall operation. 1029pending signals, and also ensures (slightly) slower overall operation.
812 1030
813=head1 THREADS 1031=head1 THREADS
814 1032
815Threads are not supported by this module in any way. Perl pseudo-threads 1033Threads are not supported by this module in any way. Perl pseudo-threads
816is evil stuff and must die. As soon as Perl gains real threads I will work 1034is evil stuff and must die. As soon as Perl gains real threads I will work
844 1062
8451; 10631;
846 1064
847=head1 SEE ALSO 1065=head1 SEE ALSO
848 1066
849L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 1067L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
850event loop), L<Coro::EV> (efficient coroutines with EV). 1068event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1069coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1070event-loop agnostic and portable event driven programming.
851 1071
852=head1 AUTHOR 1072=head1 AUTHOR
853 1073
854 Marc Lehmann <schmorp@schmorp.de> 1074 Marc Lehmann <schmorp@schmorp.de>
855 http://home.schmorp.de/ 1075 http://home.schmorp.de/

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines