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Revision 1.63 by root, Fri Dec 7 18:11:21 2007 UTC vs.
Revision 1.101 by root, Sat Jul 12 22:19:22 2008 UTC

… …
2 2
3EV - perl interface to libev, a high performance full-featured event loop 3EV - perl interface to libev, a high performance full-featured event loop
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use EV; 7 use EV;
8
9 # TIMERS
10
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
8 39
9 # TIMERS 40 my $w = EV::child 666, 0, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
10 44
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
39
40 my $w = EV::child 666, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
44
45 # STAT CHANGES 45 # STAT CHANGES
46 my $w = EV::stat "/etc/passwd", 10, sub { 46 my $w = EV::stat "/etc/passwd", 10, sub {
47 my ($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::loop; # loop until EV::unloop is called or all watchers stop
53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 53 EV::loop EV::LOOP_ONESHOT; # 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::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55 55
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
76no warnings;
70use strict; 77use strict;
71 78
72BEGIN { 79BEGIN {
73 our $VERSION = '1.71'; 80 our $VERSION = '3.431';
74 use XSLoader; 81 use XSLoader;
75 XSLoader::load "EV", $VERSION; 82 XSLoader::load "EV", $VERSION;
76} 83}
77 84
78@EV::IO::ISA = 85@EV::IO::ISA =
… …
84@EV::Idle::ISA = 91@EV::Idle::ISA =
85@EV::Prepare::ISA = 92@EV::Prepare::ISA =
86@EV::Check::ISA = 93@EV::Check::ISA =
87@EV::Embed::ISA = 94@EV::Embed::ISA =
88@EV::Fork::ISA = 95@EV::Fork::ISA =
96@EV::Async::ISA =
89 "EV::Watcher"; 97 "EV::Watcher";
90 98
99@EV::Loop::Default::ISA = "EV::Loop";
100
101=head1 EVENT LOOPS
102
103EV supports multiple event loops: There is a single "default event loop"
104that can handle everything including signals and child watchers, and any
105number of "dynamic event loops" that can use different backends (with
106various limitations), but no child and signal watchers.
107
108You do not have to do anything to create the default event loop: When
109the module is loaded a suitable backend is selected on the premise of
110selecting a working backend (which for example rules out kqueue on most
111BSDs). Modules should, unless they have "special needs" always use the
112default loop as this is fastest (perl-wise), best supported by other
113modules (e.g. AnyEvent or Coro) and most portable event loop.
114
115For specific programs you can create additional event loops dynamically.
116
117If you want to take avdantage of kqueue (which often works properly for
118sockets 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
120will 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.
122
123=over 4
124
125=item $loop = new EV::loop [$flags]
126
127Create a new event loop as per the specified flags. Please refer to the
128C<ev_loop_new ()> function description in the libev documentation
129(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
130for more info.
131
132The loop will automatically be destroyed when it is no longer referenced
133by any watcher and the loop object goes out of scope.
134
135Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
136is protected by this module.
137
138=item $loop->loop_fork
139
140Must be called after a fork in the child, before entering or continuing
141the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
142this function automatically, at some performance loss (refer to the libev
143documentation).
144
145=item $loop->loop_verify
146
147Calls C<ev_verify> to make internal consistency checks (for debugging
148libev) and abort the program if any data structures were found to be
149corrupted.
150
151=item $loop = EV::default_loop [$flags]
152
153Return the default loop (which is a singleton object). Since this module
154already creates the default loop with default flags, specifying flags here
155will not have any effect unless you destroy the default loop first, which
156isn't supported. So in short: don't do it, and if you break it, you get to
157keep the pieces.
158
159=back
160
161
91=head1 BASIC INTERFACE 162=head1 BASIC INTERFACE
92 163
93=over 4 164=over 4
94 165
95=item $EV::DIED 166=item $EV::DIED
96 167
97Must contain a reference to a function that is called when a callback 168Must contain a reference to a function that is called when a callback
98throws an exception (with $@ containing thr error). The default prints an 169throws an exception (with $@ containing the error). The default prints an
99informative message and continues. 170informative message and continues.
100 171
101If this callback throws an exception it will be silently ignored. 172If this callback throws an exception it will be silently ignored.
102 173
174=item $flags = EV::supported_backends
175
176=item $flags = EV::recommended_backends
177
178=item $flags = EV::embeddable_backends
179
180Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
181instance of EV, the set of recommended backends (supposed to be good) for
182this platform and the set of embeddable backends (see EMBED WATCHERS).
183
184=item EV::sleep $seconds
185
186Block the process for the given number of (fractional) seconds.
187
103=item $time = EV::time 188=item $time = EV::time
104 189
105Returns the current time in (fractional) seconds since the epoch. 190Returns the current time in (fractional) seconds since the epoch.
106 191
107=item $time = EV::now 192=item $time = EV::now
193
194=item $time = $loop->now
108 195
109Returns the time the last event loop iteration has been started. This 196Returns 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 197is the time that (relative) timers are based on, and refering to it is
111usually faster then calling EV::time. 198usually faster then calling EV::time.
112 199
113=item $method = EV::method 200=item $backend = EV::backend
201
202=item $backend = $loop->backend
114 203
115Returns an integer describing the backend used by libev (EV::METHOD_SELECT 204Returns an integer describing the backend used by libev (EV::METHOD_SELECT
116or EV::METHOD_EPOLL). 205or EV::METHOD_EPOLL).
117 206
118=item EV::loop [$flags] 207=item EV::loop [$flags]
208
209=item $loop->loop ([$flags])
119 210
120Begin checking for events and calling callbacks. It returns when a 211Begin checking for events and calling callbacks. It returns when a
121callback calls EV::unloop. 212callback calls EV::unloop.
122 213
123The $flags argument can be one of the following: 214The $flags argument can be one of the following:
… …
126 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 217 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
127 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 218 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
128 219
129=item EV::unloop [$how] 220=item EV::unloop [$how]
130 221
222=item $loop->unloop ([$how])
223
131When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 224When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
132innermost call to EV::loop return. 225innermost call to EV::loop return.
133 226
134When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 227When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
135fast as possible. 228fast as possible.
136 229
137=item $count = EV::loop_count 230=item $count = EV::loop_count
138 231
232=item $count = $loop->loop_count
233
139Return the number of times the event loop has polled for new 234Return the number of times the event loop has polled for new
140events. Sometiems useful as a generation counter. 235events. Sometiems useful as a generation counter.
141 236
142=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 237=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
238
239=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
143 240
144This function rolls together an I/O and a timer watcher for a single 241This function rolls together an I/O and a timer watcher for a single
145one-shot event without the need for managing a watcher object. 242one-shot event without the need for managing a watcher object.
146 243
147If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> 244If 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 250If timeout is C<undef> or negative, then there will be no
154timeout. Otherwise a EV::timer with this value will be started. 251timeout. Otherwise a EV::timer with this value will be started.
155 252
156When an error occurs or either the timeout or I/O watcher triggers, then 253When 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 254the 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>, 255you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
159C<EV::WRITE> and C<EV::TIMEOUT>). 256C<EV::WRITE> and C<EV::TIMEOUT>).
160 257
161EV::once doesn't return anything: the watchers stay active till either 258EV::once doesn't return anything: the watchers stay active till either
162of them triggers, then they will be stopped and freed, and the callback 259of them triggers, then they will be stopped and freed, and the callback
163invoked. 260invoked.
164 261
165=back 262=item EV::feed_fd_event ($fd, $revents)
166 263
264=item $loop->feed_fd_event ($fd, $revents)
265
266Feed an event on a file descriptor into EV. EV will react to this call as
267if the readyness notifications specified by C<$revents> (a combination of
268C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
269
270=item EV::feed_signal_event ($signal)
271
272Feed a signal event into EV. EV will react to this call as if the signal
273specified by C<$signal> had occured.
274
275=item EV::set_io_collect_interval $time
276
277=item $loop->set_io_collect_interval ($time)
278
279=item EV::set_timeout_collect_interval $time
280
281=item $loop->set_timeout_collect_interval ($time)
282
283These advanced functions set the minimum block interval when polling for I/O events and the minimum
284wait interval for timer events. See the libev documentation at
285L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
286a more detailed discussion.
287
288=back
289
290
167=head2 WATCHER OBJECTS 291=head1 WATCHER OBJECTS
168 292
169A watcher is an object that gets created to record your interest in some 293A watcher is an object that gets created to record your interest in some
170event. For instance, if you want to wait for STDIN to become readable, you 294event. For instance, if you want to wait for STDIN to become readable, you
171would create an EV::io watcher for that: 295would create an EV::io watcher for that:
172 296
173 my $watcher = EV::io *STDIN, EV::READ, sub { 297 my $watcher = EV::io *STDIN, EV::READ, sub {
174 my ($watcher, $revents) = @_; 298 my ($watcher, $revents) = @_;
175 warn "yeah, STDIN should not be readable without blocking!\n" 299 warn "yeah, STDIN should now be readable without blocking!\n"
176 }; 300 };
177 301
178All watchers can be active (waiting for events) or inactive (paused). Only 302All watchers can be active (waiting for events) or inactive (paused). Only
179active watchers will have their callbacks invoked. All callbacks will be 303active watchers will have their callbacks invoked. All callbacks will be
180called with at least two arguments: the watcher and a bitmask of received 304called with at least two arguments: the watcher and a bitmask of received
181events. 305events.
… …
253The default priority of any newly-created watcher is 0. 377The default priority of any newly-created watcher is 0.
254 378
255Note that the priority semantics have not yet been fleshed out and are 379Note that the priority semantics have not yet been fleshed out and are
256subject to almost certain change. 380subject to almost certain change.
257 381
258=item $w->trigger ($revents) 382=item $w->invoke ($revents)
259 383
260Call the callback *now* with the given event mask. 384Call the callback *now* with the given event mask.
385
386=item $w->feed_event ($revents)
387
388Feed some events on this watcher into EV. EV will react to this call as if
389the watcher had received the given C<$revents> mask.
390
391=item $revents = $w->clear_pending
392
393If the watcher is pending, this function clears its pending status and
394returns its C<$revents> bitset (as if its callback was invoked). If the
395watcher isn't pending it does nothing and returns C<0>.
261 396
262=item $previous_state = $w->keepalive ($bool) 397=item $previous_state = $w->keepalive ($bool)
263 398
264Normally, C<EV::loop> will return when there are no active watchers 399Normally, C<EV::loop> will return when there are no active watchers
265(which is a "deadlock" because no progress can be made anymore). This is 400(which is a "deadlock" because no progress can be made anymore). This is
266convinient because it allows you to start your watchers (and your jobs), 401convinient because it allows you to start your watchers (and your jobs),
267call C<EV::loop> once and when it returns you know that all your jobs are 402call C<EV::loop> once and when it returns you know that all your jobs are
268finished (or they forgot to register some watchers for their task :). 403finished (or they forgot to register some watchers for their task :).
269 404
270Sometimes, however, this gets in your way, for example when you the module 405Sometimes, however, this gets in your way, for example when the module
271that calls C<EV::loop> (usually the main program) is not the same module 406that calls C<EV::loop> (usually the main program) is not the same module
272as a long-living watcher (for example a DNS client module written by 407as a long-living watcher (for example a DNS client module written by
273somebody else even). Then you might want any outstanding requests to be 408somebody else even). Then you might want any outstanding requests to be
274handled, but you would not want to keep C<EV::loop> from returning just 409handled, but you would not want to keep C<EV::loop> from returning just
275because you happen to have this long-running UDP port watcher. 410because you happen to have this long-running UDP port watcher.
… …
285 420
286 my $udp_socket = ... 421 my $udp_socket = ...
287 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 422 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
288 $udp_watcher->keepalive (0); 423 $udp_watcher->keepalive (0);
289 424
290=back 425=item $loop = $w->loop
291 426
427Return the loop that this watcher is attached to.
292 428
429=back
430
431
293=head2 WATCHER TYPES 432=head1 WATCHER TYPES
294 433
295Each of the following subsections describes a single watcher type. 434Each of the following subsections describes a single watcher type.
296 435
297=head3 I/O WATCHERS - is this file descriptor readable or writable? 436=head3 I/O WATCHERS - is this file descriptor readable or writable?
298 437
299=over 4 438=over 4
300 439
301=item $w = EV::io $fileno_or_fh, $eventmask, $callback 440=item $w = EV::io $fileno_or_fh, $eventmask, $callback
302 441
303=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 442=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
443
444=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
445
446=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
304 447
305As long as the returned watcher object is alive, call the C<$callback> 448As long as the returned watcher object is alive, call the C<$callback>
306when at least one of events specified in C<$eventmask> occurs. 449when at least one of events specified in C<$eventmask> occurs.
307 450
308The $eventmask can be one or more of these constants ORed together: 451The $eventmask can be one or more of these constants ORed together:
… …
337=over 4 480=over 4
338 481
339=item $w = EV::timer $after, $repeat, $callback 482=item $w = EV::timer $after, $repeat, $callback
340 483
341=item $w = EV::timer_ns $after, $repeat, $callback 484=item $w = EV::timer_ns $after, $repeat, $callback
485
486=item $w = $loop->timer ($after, $repeat, $callback)
487
488=item $w = $loop->timer_ns ($after, $repeat, $callback)
342 489
343Calls the callback after C<$after> seconds (which may be fractional). If 490Calls the callback after C<$after> seconds (which may be fractional). If
344C<$repeat> is non-zero, the timer will be restarted (with the $repeat 491C<$repeat> is non-zero, the timer will be restarted (with the $repeat
345value as $after) after the callback returns. 492value as $after) after the callback returns.
346 493
… …
387=over 4 534=over 4
388 535
389=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 536=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
390 537
391=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 538=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
539
540=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
541
542=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
392 543
393Similar to EV::timer, but is not based on relative timeouts but on 544Similar to EV::timer, but is not based on relative timeouts but on
394absolute times. Apart from creating "simple" timers that trigger "at" the 545absolute times. Apart from creating "simple" timers that trigger "at" the
395specified time, it can also be used for non-drifting absolute timers and 546specified time, it can also be used for non-drifting absolute timers and
396more complex, cron-like, setups that are not adversely affected by time 547more complex, cron-like, setups that are not adversely affected by time
… …
406This time simply fires at the wallclock time C<$at> and doesn't repeat. It 557This time simply fires at the wallclock time C<$at> and doesn't repeat. It
407will not adjust when a time jump occurs, that is, if it is to be run 558will not adjust when a time jump occurs, that is, if it is to be run
408at January 1st 2011 then it will run when the system time reaches or 559at January 1st 2011 then it will run when the system time reaches or
409surpasses this time. 560surpasses this time.
410 561
411=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 562=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
412 563
413In this mode the watcher will always be scheduled to time out at the 564In this mode the watcher will always be scheduled to time out at the
414next C<$at + N * $interval> time (for some integer N) and then repeat, 565next C<$at + N * $interval> time (for some integer N) and then repeat,
415regardless of any time jumps. 566regardless of any time jumps.
416 567
… …
434time the periodic watcher gets scheduled, the reschedule callback 585time the periodic watcher gets scheduled, the reschedule callback
435($reschedule_cb) will be called with the watcher as first, and the current 586($reschedule_cb) will be called with the watcher as first, and the current
436time as second argument. 587time as second argument.
437 588
438I<This callback MUST NOT stop or destroy this or any other periodic 589I<This callback MUST NOT stop or destroy this or any other periodic
439watcher, ever>. If you need to stop it, return 1e30 and stop it 590watcher, ever, and MUST NOT call any event loop functions or methods>. If
440afterwards. 591you need to stop it, return 1e30 and stop it afterwards. You may create
592and start a C<EV::prepare> watcher for this task.
441 593
442It must return the next time to trigger, based on the passed time value 594It must return the next time to trigger, based on the passed time value
443(that is, the lowest time value larger than to the second argument). It 595(that is, the lowest time value larger than or equal to to the second
444will usually be called just before the callback will be triggered, but 596argument). It will usually be called just before the callback will be
445might be called at other times, too. 597triggered, but might be called at other times, too.
446 598
447This can be used to create very complex timers, such as a timer that 599This can be used to create very complex timers, such as a timer that
448triggers on each midnight, local time (actually 24 hours after the last 600triggers on each midnight, local time (actually 24 hours after the last
449midnight, to keep the example simple. If you know a way to do it correctly 601midnight, to keep the example simple. If you know a way to do it correctly
450in about the same space (without requiring elaborate modules), drop me a 602in about the same space (without requiring elaborate modules), drop me a
… …
471 623
472=item $w->again 624=item $w->again
473 625
474Simply stops and starts the watcher again. 626Simply stops and starts the watcher again.
475 627
628=item $time = $w->at
629
630Return the time that the watcher is expected to trigger next.
631
476=back 632=back
477 633
478 634
479=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 635=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
480 636
… …
513 669
514=head3 CHILD WATCHERS - watch out for process status changes 670=head3 CHILD WATCHERS - watch out for process status changes
515 671
516=over 4 672=over 4
517 673
518=item $w = EV::child $pid, $callback 674=item $w = EV::child $pid, $trace, $callback
519 675
520=item $w = EV::child_ns $pid, $callback 676=item $w = EV::child_ns $pid, $trace, $callback
521 677
678=item $w = $loop->child ($pid, $trace, $callback)
679
680=item $w = $loop->child_ns ($pid, $trace, $callback)
681
522Call the callback when a status change for pid C<$pid> (or any pid if 682Call the callback when a status change for pid C<$pid> (or any pid
523C<$pid> is 0) has been received. More precisely: when the process receives 683if C<$pid> is 0) has been received (a status change happens when the
684process terminates or is killed, or, when trace is true, additionally when
685it is stopped or continued). More precisely: when the process receives
524a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 686a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
525changed/zombie children and call the callback. 687changed/zombie children and call the callback.
526 688
527It is valid (and fully supported) to install a child watcher after a child 689It is valid (and fully supported) to install a child watcher after a child
528has exited but before the event loop has started its next iteration (for 690has exited but before the event loop has started its next iteration (for
… …
535You can have as many pid watchers per pid as you want, they will all be 697You can have as many pid watchers per pid as you want, they will all be
536called. 698called.
537 699
538The C<child_ns> variant doesn't start (activate) the newly created watcher. 700The C<child_ns> variant doesn't start (activate) the newly created watcher.
539 701
540=item $w->set ($pid) 702=item $w->set ($pid, $trace)
541 703
542Reconfigures the watcher, see the constructor above for details. Can be called at 704Reconfigures the watcher, see the constructor above for details. Can be called at
543any time. 705any time.
544 706
545=item $current_pid = $w->pid 707=item $current_pid = $w->pid
546 708
547=item $old_pid = $w->pid ($new_pid)
548
549Returns the previously set process id and optionally set a new one. 709Returns the previously set process id and optionally set a new one.
550 710
551=item $exit_status = $w->rstatus 711=item $exit_status = $w->rstatus
552 712
553Return the exit/wait status (as returned by waitpid, see the waitpid entry 713Return the exit/wait status (as returned by waitpid, see the waitpid entry
… …
566=over 4 726=over 4
567 727
568=item $w = EV::stat $path, $interval, $callback 728=item $w = EV::stat $path, $interval, $callback
569 729
570=item $w = EV::stat_ns $path, $interval, $callback 730=item $w = EV::stat_ns $path, $interval, $callback
731
732=item $w = $loop->stat ($path, $interval, $callback)
733
734=item $w = $loop->stat_ns ($path, $interval, $callback)
571 735
572Call the callback when a file status change has been detected on 736Call the callback when a file status change has been detected on
573C<$path>. The C<$path> does not need to exist, changing from "path exists" 737C<$path>. The C<$path> does not need to exist, changing from "path exists"
574to "path does not exist" is a status change like any other. 738to "path does not exist" is a status change like any other.
575 739
… …
645=over 4 809=over 4
646 810
647=item $w = EV::idle $callback 811=item $w = EV::idle $callback
648 812
649=item $w = EV::idle_ns $callback 813=item $w = EV::idle_ns $callback
814
815=item $w = $loop->idle ($callback)
816
817=item $w = $loop->idle_ns ($callback)
650 818
651Call the callback when there are no other pending watchers of the same or 819Call the callback when there are no other pending watchers of the same or
652higher priority (excluding check, prepare and other idle watchers of the 820higher priority (excluding check, prepare and other idle watchers of the
653same or lower priority, of course). They are called idle watchers because 821same or lower priority, of course). They are called idle watchers because
654when the watcher is the highest priority pending event in the process, the 822when the watcher is the highest priority pending event in the process, the
… …
677 845
678=item $w = EV::prepare $callback 846=item $w = EV::prepare $callback
679 847
680=item $w = EV::prepare_ns $callback 848=item $w = EV::prepare_ns $callback
681 849
850=item $w = $loop->prepare ($callback)
851
852=item $w = $loop->prepare_ns ($callback)
853
682Call the callback just before the process would block. You can still 854Call the callback just before the process would block. You can still
683create/modify any watchers at this point. 855create/modify any watchers at this point.
684 856
685See the EV::check watcher, below, for explanations and an example. 857See the EV::check watcher, below, for explanations and an example.
686 858
… …
694=over 4 866=over 4
695 867
696=item $w = EV::check $callback 868=item $w = EV::check $callback
697 869
698=item $w = EV::check_ns $callback 870=item $w = EV::check_ns $callback
871
872=item $w = $loop->check ($callback)
873
874=item $w = $loop->check_ns ($callback)
699 875
700Call the callback just after the process wakes up again (after it has 876Call the callback just after the process wakes up again (after it has
701gathered events), but before any other callbacks have been invoked. 877gathered events), but before any other callbacks have been invoked.
702 878
703This is used to integrate other event-based software into the EV 879This is used to integrate other event-based software into the EV
… …
758 934
759=item $w = EV::fork $callback 935=item $w = EV::fork $callback
760 936
761=item $w = EV::fork_ns $callback 937=item $w = EV::fork_ns $callback
762 938
939=item $w = $loop->fork ($callback)
940
941=item $w = $loop->fork_ns ($callback)
942
763Call the callback before the event loop is resumed in the child process 943Call the callback before the event loop is resumed in the child process
764after a fork. 944after a fork.
765 945
766The C<fork_ns> variant doesn't start (activate) the newly created watcher. 946The C<fork_ns> variant doesn't start (activate) the newly created watcher.
947
948=back
949
950
951=head3 EMBED WATCHERS - when one backend isn't enough...
952
953This is a rather advanced watcher type that lets you embed one event loop
954into another (currently only IO events are supported in the embedded
955loop, other types of watchers might be handled in a delayed or incorrect
956fashion and must not be used).
957
958See the libev documentation at
959L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
960for more details.
961
962In short, this watcher is most useful on BSD systems without working
963kqueue to still be able to handle a large number of sockets:
964
965 my $socket_loop;
966
967 # check wether we use SELECT or POLL _and_ KQUEUE is supported
968 if (
969 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
970 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
971 ) {
972 # use kqueue for sockets
973 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
974 }
975
976 # use the default loop otherwise
977 $socket_loop ||= EV::default_loop;
978
979=over 4
980
981=item $w = EV::embed $otherloop[, $callback]
982
983=item $w = EV::embed_ns $otherloop[, $callback]
984
985=item $w = $loop->embed ($otherloop[, $callback])
986
987=item $w = $loop->embed_ns ($otherloop[, $callback])
988
989Call the callback when the embedded event loop (C<$otherloop>) has any
990I/O activity. The C<$callback> is optional: if it is missing, then the
991embedded event loop will be managed automatically (which is recommended),
992otherwise you have to invoke C<sweep> yourself.
993
994The C<embed_ns> variant doesn't start (activate) the newly created watcher.
995
996=back
997
998=head3 ASYNC WATCHERS - how to wake up another event loop
999
1000Async watchers are provided by EV, but have little use in perl directly, as perl
1001neither supports threads nor direct access to signal handlers or other
1002contexts where they could be of value.
1003
1004It is, however, possible to use them from the XS level.
1005
1006Please see the libev documentation for further details.
1007
1008=over 4
1009
1010=item $w = EV::async $callback
1011
1012=item $w = EV::async_ns $callback
1013
1014=item $w->send
1015
1016=item $bool = $w->async_pending
767 1017
768=back 1018=back
769 1019
770 1020
771=head1 PERL SIGNALS 1021=head1 PERL SIGNALS
… …
782to be called on every event loop iteration by installing a C<EV::check> 1032to be called on every event loop iteration by installing a C<EV::check>
783watcher: 1033watcher:
784 1034
785 my $async_check = EV::check sub { }; 1035 my $async_check = EV::check sub { };
786 1036
787This ensures that perl shortly gets into control for a short time, and 1037This ensures that perl gets into control for a short time to handle any
788also ensures slower overall operation. 1038pending signals, and also ensures (slightly) slower overall operation.
789 1039
790=head1 THREADS 1040=head1 THREADS
791 1041
792Threads are not supported by this module in any way. Perl pseudo-threads 1042Threads are not supported by this module in any way. Perl pseudo-threads
793is evil stuff and must die. As soon as Perl gains real threads I will work 1043is evil stuff and must die. As soon as Perl gains real threads I will work
… …
815our $DIED = sub { 1065our $DIED = sub {
816 warn "EV: error in callback (ignoring): $@"; 1066 warn "EV: error in callback (ignoring): $@";
817}; 1067};
818 1068
819default_loop 1069default_loop
820 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; 1070 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
821 1071
8221; 10721;
823 1073
824=head1 SEE ALSO 1074=head1 SEE ALSO
825 1075
826L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 1076L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
827event loop), L<Coro::EV> (efficient coroutines with EV). 1077event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1078coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1079event-loop agnostic and portable event driven programming.
828 1080
829=head1 AUTHOR 1081=head1 AUTHOR
830 1082
831 Marc Lehmann <schmorp@schmorp.de> 1083 Marc Lehmann <schmorp@schmorp.de>
832 http://home.schmorp.de/ 1084 http://home.schmorp.de/
833 1085
834=cut 1086=cut
835 1087

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