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Revision 1.72 by root, Thu Dec 20 07:12:57 2007 UTC vs.
Revision 1.112 by root, Sun Feb 15 01:44:40 2009 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
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62watcher semantics or some discussion on the available backends, or how to 62F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63force a specific backend with C<LIBEV_FLAGS>, or just about in any case 63discussion on the available backends, or how to force a specific backend
64because it has much more detailed information. 64with C<LIBEV_FLAGS>, or just about in any case because it has much more
65detailed information.
66
67This module is very fast and scalable. It is actually so fast that you
68can use it through the L<AnyEvent> module, stay portable to other event
69loops (if you don't rely on any watcher types not available through it)
70and still be faster than with any other event loop currently supported in
71Perl.
72
73=head2 MODULE EXPORTS
74
75This module does not export any symbols.
65 76
66=cut 77=cut
67 78
68package EV; 79package EV;
69 80
81no warnings;
70use strict; 82use strict;
71 83
72BEGIN { 84BEGIN {
73 our $VERSION = '2.0'; 85 our $VERSION = '3.53';
74 use XSLoader; 86 use XSLoader;
75 XSLoader::load "EV", $VERSION; 87 XSLoader::load "EV", $VERSION;
76} 88}
77 89
78@EV::IO::ISA = 90@EV::IO::ISA =
… …
84@EV::Idle::ISA = 96@EV::Idle::ISA =
85@EV::Prepare::ISA = 97@EV::Prepare::ISA =
86@EV::Check::ISA = 98@EV::Check::ISA =
87@EV::Embed::ISA = 99@EV::Embed::ISA =
88@EV::Fork::ISA = 100@EV::Fork::ISA =
101@EV::Async::ISA =
89 "EV::Watcher"; 102 "EV::Watcher";
90 103
91@EV::Loop::Default::ISA = "EV::Loop"; 104@EV::Loop::Default::ISA = "EV::Loop";
105
106=head1 EVENT LOOPS
107
108EV supports multiple event loops: There is a single "default event loop"
109that can handle everything including signals and child watchers, and any
110number of "dynamic event loops" that can use different backends (with
111various limitations), but no child and signal watchers.
112
113You do not have to do anything to create the default event loop: When
114the module is loaded a suitable backend is selected on the premise of
115selecting a working backend (which for example rules out kqueue on most
116BSDs). Modules should, unless they have "special needs" always use the
117default loop as this is fastest (perl-wise), best supported by other
118modules (e.g. AnyEvent or Coro) and most portable event loop.
119
120For specific programs you can create additional event loops dynamically.
121
122If you want to take advantage of kqueue (which often works properly for
123sockets only) even though the default loop doesn't enable it, you can
124I<embed> a kqueue loop into the default loop: running the default loop
125will then also service the kqueue loop to some extent. See the example in
126the section about embed watchers for an example on how to achieve that.
127
128=over 4
129
130=item $loop = new EV::loop [$flags]
131
132Create a new event loop as per the specified flags. Please refer to
133the C<ev_loop_new ()> function description in the libev documentation
134(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
135or locally-installed as F<EV::libev> manpage) for more info.
136
137The loop will automatically be destroyed when it is no longer referenced
138by any watcher and the loop object goes out of scope.
139
140If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
141is recommended, as only the default event loop is protected by this
142module. If you I<are> embedding this loop in the default loop, this is not
143necessary, as C<EV::embed> automatically does the right thing on fork.
144
145=item $loop->loop_fork
146
147Must be called after a fork in the child, before entering or continuing
148the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
149this function automatically, at some performance loss (refer to the libev
150documentation).
151
152=item $loop->loop_verify
153
154Calls C<ev_verify> to make internal consistency checks (for debugging
155libev) and abort the program if any data structures were found to be
156corrupted.
157
158=item $loop = EV::default_loop [$flags]
159
160Return the default loop (which is a singleton object). Since this module
161already creates the default loop with default flags, specifying flags here
162will not have any effect unless you destroy the default loop first, which
163isn't supported. So in short: don't do it, and if you break it, you get to
164keep the pieces.
165
166=back
167
92 168
93=head1 BASIC INTERFACE 169=head1 BASIC INTERFACE
94 170
95=over 4 171=over 4
96 172
… …
100throws an exception (with $@ containing the error). The default prints an 176throws an exception (with $@ containing the error). The default prints an
101informative message and continues. 177informative message and continues.
102 178
103If this callback throws an exception it will be silently ignored. 179If this callback throws an exception it will be silently ignored.
104 180
181=item $flags = EV::supported_backends
182
183=item $flags = EV::recommended_backends
184
185=item $flags = EV::embeddable_backends
186
187Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
188instance of EV, the set of recommended backends (supposed to be good) for
189this platform and the set of embeddable backends (see EMBED WATCHERS).
190
191=item EV::sleep $seconds
192
193Block the process for the given number of (fractional) seconds.
194
105=item $time = EV::time 195=item $time = EV::time
106 196
107Returns the current time in (fractional) seconds since the epoch. 197Returns the current time in (fractional) seconds since the epoch.
108 198
109=item $time = EV::now 199=item $time = EV::now
110 200
201=item $time = $loop->now
202
111Returns the time the last event loop iteration has been started. This 203Returns the time the last event loop iteration has been started. This
112is the time that (relative) timers are based on, and refering to it is 204is the time that (relative) timers are based on, and referring to it is
113usually faster then calling EV::time. 205usually faster then calling EV::time.
114 206
115=item $method = EV::method 207=item $backend = EV::backend
116 208
209=item $backend = $loop->backend
210
117Returns an integer describing the backend used by libev (EV::METHOD_SELECT 211Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
118or EV::METHOD_EPOLL). 212or EV::BACKEND_EPOLL).
119 213
120=item EV::loop [$flags] 214=item EV::loop [$flags]
215
216=item $loop->loop ([$flags])
121 217
122Begin checking for events and calling callbacks. It returns when a 218Begin checking for events and calling callbacks. It returns when a
123callback calls EV::unloop. 219callback calls EV::unloop.
124 220
125The $flags argument can be one of the following: 221The $flags argument can be one of the following:
… …
128 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 224 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
129 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 225 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
130 226
131=item EV::unloop [$how] 227=item EV::unloop [$how]
132 228
229=item $loop->unloop ([$how])
230
133When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 231When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
134innermost call to EV::loop return. 232innermost call to EV::loop return.
135 233
136When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 234When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
137fast as possible. 235fast as possible.
138 236
139=item $count = EV::loop_count 237=item $count = EV::loop_count
140 238
239=item $count = $loop->loop_count
240
141Return the number of times the event loop has polled for new 241Return the number of times the event loop has polled for new
142events. Sometiems useful as a generation counter. 242events. Sometimes useful as a generation counter.
143 243
144=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 244=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
245
246=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
145 247
146This function rolls together an I/O and a timer watcher for a single 248This function rolls together an I/O and a timer watcher for a single
147one-shot event without the need for managing a watcher object. 249one-shot event without the need for managing a watcher object.
148 250
149If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> 251If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
… …
155If timeout is C<undef> or negative, then there will be no 257If timeout is C<undef> or negative, then there will be no
156timeout. Otherwise a EV::timer with this value will be started. 258timeout. Otherwise a EV::timer with this value will be started.
157 259
158When an error occurs or either the timeout or I/O watcher triggers, then 260When an error occurs or either the timeout or I/O watcher triggers, then
159the callback will be called with the received event set (in general 261the callback will be called with the received event set (in general
160you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, 262you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
161C<EV::WRITE> and C<EV::TIMEOUT>). 263C<EV::WRITE> and C<EV::TIMEOUT>).
162 264
163EV::once doesn't return anything: the watchers stay active till either 265EV::once doesn't return anything: the watchers stay active till either
164of them triggers, then they will be stopped and freed, and the callback 266of them triggers, then they will be stopped and freed, and the callback
165invoked. 267invoked.
166 268
167=item EV::feed_fd_event ($fd, $revents) 269=item EV::feed_fd_event ($fd, $revents)
168 270
271=item $loop->feed_fd_event ($fd, $revents)
272
169Feed an event on a file descriptor into EV. EV will react to this call as 273Feed an event on a file descriptor into EV. EV will react to this call as
170if the readyness notifications specified by C<$revents> (a combination of 274if the readyness notifications specified by C<$revents> (a combination of
171C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 275C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
172 276
173=item EV::feed_signal_event ($signal) 277=item EV::feed_signal_event ($signal)
174 278
175Feed a signal event into EV. EV will react to this call as if the signal 279Feed a signal event into EV. EV will react to this call as if the signal
176specified by C<$signal> had occured. 280specified by C<$signal> had occured.
177 281
178=back 282=item EV::set_io_collect_interval $time
179 283
284=item $loop->set_io_collect_interval ($time)
180 285
286=item EV::set_timeout_collect_interval $time
287
288=item $loop->set_timeout_collect_interval ($time)
289
290These advanced functions set the minimum block interval when polling for I/O events and the minimum
291wait interval for timer events. See the libev documentation at
292L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
293(locally installed as F<EV::libev>) for a more detailed discussion.
294
295=back
296
297
181=head2 WATCHER OBJECTS 298=head1 WATCHER OBJECTS
182 299
183A watcher is an object that gets created to record your interest in some 300A watcher is an object that gets created to record your interest in some
184event. For instance, if you want to wait for STDIN to become readable, you 301event. For instance, if you want to wait for STDIN to become readable, you
185would create an EV::io watcher for that: 302would create an EV::io watcher for that:
186 303
187 my $watcher = EV::io *STDIN, EV::READ, sub { 304 my $watcher = EV::io *STDIN, EV::READ, sub {
188 my ($watcher, $revents) = @_; 305 my ($watcher, $revents) = @_;
189 warn "yeah, STDIN should not be readable without blocking!\n" 306 warn "yeah, STDIN should now be readable without blocking!\n"
190 }; 307 };
191 308
192All watchers can be active (waiting for events) or inactive (paused). Only 309All watchers can be active (waiting for events) or inactive (paused). Only
193active watchers will have their callbacks invoked. All callbacks will be 310active watchers will have their callbacks invoked. All callbacks will be
194called with at least two arguments: the watcher and a bitmask of received 311called with at least two arguments: the watcher and a bitmask of received
195events. 312events.
196 313
197Each watcher type has its associated bit in revents, so you can use the 314Each watcher type has its associated bit in revents, so you can use the
198same callback for multiple watchers. The event mask is named after the 315same callback for multiple watchers. The event mask is named after the
199type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 316type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
200EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 317EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
201(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 318(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
202uses EV::TIMEOUT). 319uses EV::TIMEOUT).
203 320
204In the rare case where one wants to create a watcher but not start it at 321In the rare case where one wants to create a watcher but not start it at
… …
278Feed some events on this watcher into EV. EV will react to this call as if 395Feed some events on this watcher into EV. EV will react to this call as if
279the watcher had received the given C<$revents> mask. 396the watcher had received the given C<$revents> mask.
280 397
281=item $revents = $w->clear_pending 398=item $revents = $w->clear_pending
282 399
283If the watcher is pending, this function returns clears its pending status 400If the watcher is pending, this function clears its pending status and
284and returns its C<$revents> bitset (as if its callback was invoked). If the 401returns its C<$revents> bitset (as if its callback was invoked). If the
285watcher isn't pending it does nothing and returns C<0>. 402watcher isn't pending it does nothing and returns C<0>.
286 403
287=item $previous_state = $w->keepalive ($bool) 404=item $previous_state = $w->keepalive ($bool)
288 405
289Normally, C<EV::loop> will return when there are no active watchers 406Normally, C<EV::loop> will return when there are no active watchers
290(which is a "deadlock" because no progress can be made anymore). This is 407(which is a "deadlock" because no progress can be made anymore). This is
291convinient because it allows you to start your watchers (and your jobs), 408convinient because it allows you to start your watchers (and your jobs),
292call C<EV::loop> once and when it returns you know that all your jobs are 409call C<EV::loop> once and when it returns you know that all your jobs are
293finished (or they forgot to register some watchers for their task :). 410finished (or they forgot to register some watchers for their task :).
294 411
295Sometimes, however, this gets in your way, for example when you the module 412Sometimes, however, this gets in your way, for example when the module
296that calls C<EV::loop> (usually the main program) is not the same module 413that calls C<EV::loop> (usually the main program) is not the same module
297as a long-living watcher (for example a DNS client module written by 414as a long-living watcher (for example a DNS client module written by
298somebody else even). Then you might want any outstanding requests to be 415somebody else even). Then you might want any outstanding requests to be
299handled, but you would not want to keep C<EV::loop> from returning just 416handled, but you would not want to keep C<EV::loop> from returning just
300because you happen to have this long-running UDP port watcher. 417because you happen to have this long-running UDP port watcher.
301 418
302In this case you can clear the keepalive status, which means that even 419In this case you can clear the keepalive status, which means that even
303though your watcher is active, it won't keep C<EV::loop> from returning. 420though your watcher is active, it won't keep C<EV::loop> from returning.
304 421
305The initial value for keepalive is true (enabled), and you cna change it 422The initial value for keepalive is true (enabled), and you can change it
306any time. 423any time.
307 424
308Example: Register an I/O watcher for some UDP socket but do not keep the 425Example: Register an I/O watcher for some UDP socket but do not keep the
309event loop from running just because of that watcher. 426event loop from running just because of that watcher.
310 427
311 my $udp_socket = ... 428 my $udp_socket = ...
312 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 429 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
313 $udp_watcher->keepalive (0); 430 $udp_watcher->keepalive (0);
314 431
315=back 432=item $loop = $w->loop
316 433
434Return the loop that this watcher is attached to.
317 435
436=back
437
438
318=head2 WATCHER TYPES 439=head1 WATCHER TYPES
319 440
320Each of the following subsections describes a single watcher type. 441Each of the following subsections describes a single watcher type.
321 442
322=head3 I/O WATCHERS - is this file descriptor readable or writable? 443=head3 I/O WATCHERS - is this file descriptor readable or writable?
323 444
324=over 4 445=over 4
325 446
326=item $w = EV::io $fileno_or_fh, $eventmask, $callback 447=item $w = EV::io $fileno_or_fh, $eventmask, $callback
327 448
328=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 449=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
450
451=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
452
453=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
329 454
330As long as the returned watcher object is alive, call the C<$callback> 455As long as the returned watcher object is alive, call the C<$callback>
331when at least one of events specified in C<$eventmask> occurs. 456when at least one of events specified in C<$eventmask> occurs.
332 457
333The $eventmask can be one or more of these constants ORed together: 458The $eventmask can be one or more of these constants ORed together:
… …
362=over 4 487=over 4
363 488
364=item $w = EV::timer $after, $repeat, $callback 489=item $w = EV::timer $after, $repeat, $callback
365 490
366=item $w = EV::timer_ns $after, $repeat, $callback 491=item $w = EV::timer_ns $after, $repeat, $callback
492
493=item $w = $loop->timer ($after, $repeat, $callback)
494
495=item $w = $loop->timer_ns ($after, $repeat, $callback)
367 496
368Calls the callback after C<$after> seconds (which may be fractional). If 497Calls the callback after C<$after> seconds (which may be fractional). If
369C<$repeat> is non-zero, the timer will be restarted (with the $repeat 498C<$repeat> is non-zero, the timer will be restarted (with the $repeat
370value as $after) after the callback returns. 499value as $after) after the callback returns.
371 500
… …
412=over 4 541=over 4
413 542
414=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 543=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
415 544
416=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 545=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
546
547=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
548
549=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
417 550
418Similar to EV::timer, but is not based on relative timeouts but on 551Similar to EV::timer, but is not based on relative timeouts but on
419absolute times. Apart from creating "simple" timers that trigger "at" the 552absolute times. Apart from creating "simple" timers that trigger "at" the
420specified time, it can also be used for non-drifting absolute timers and 553specified time, it can also be used for non-drifting absolute timers and
421more complex, cron-like, setups that are not adversely affected by time 554more complex, cron-like, setups that are not adversely affected by time
… …
431This time simply fires at the wallclock time C<$at> and doesn't repeat. It 564This time simply fires at the wallclock time C<$at> and doesn't repeat. It
432will not adjust when a time jump occurs, that is, if it is to be run 565will not adjust when a time jump occurs, that is, if it is to be run
433at January 1st 2011 then it will run when the system time reaches or 566at January 1st 2011 then it will run when the system time reaches or
434surpasses this time. 567surpasses this time.
435 568
436=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 569=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
437 570
438In this mode the watcher will always be scheduled to time out at the 571In this mode the watcher will always be scheduled to time out at the
439next C<$at + N * $interval> time (for some integer N) and then repeat, 572next C<$at + N * $interval> time (for some integer N) and then repeat,
440regardless of any time jumps. 573regardless of any time jumps.
441 574
… …
459time the periodic watcher gets scheduled, the reschedule callback 592time the periodic watcher gets scheduled, the reschedule callback
460($reschedule_cb) will be called with the watcher as first, and the current 593($reschedule_cb) will be called with the watcher as first, and the current
461time as second argument. 594time as second argument.
462 595
463I<This callback MUST NOT stop or destroy this or any other periodic 596I<This callback MUST NOT stop or destroy this or any other periodic
464watcher, ever>. If you need to stop it, return 1e30 and stop it 597watcher, ever, and MUST NOT call any event loop functions or methods>. If
465afterwards. 598you need to stop it, return 1e30 and stop it afterwards. You may create
599and start a C<EV::prepare> watcher for this task.
466 600
467It must return the next time to trigger, based on the passed time value 601It must return the next time to trigger, based on the passed time value
468(that is, the lowest time value larger than to the second argument). It 602(that is, the lowest time value larger than or equal to to the second
469will usually be called just before the callback will be triggered, but 603argument). It will usually be called just before the callback will be
470might be called at other times, too. 604triggered, but might be called at other times, too.
471 605
472This can be used to create very complex timers, such as a timer that 606This can be used to create very complex timers, such as a timer that
473triggers on each midnight, local time (actually 24 hours after the last 607triggers on each midnight, local time (actually 24 hours after the last
474midnight, to keep the example simple. If you know a way to do it correctly 608midnight, to keep the example simple. If you know a way to do it correctly
475in about the same space (without requiring elaborate modules), drop me a 609in about the same space (without requiring elaborate modules), drop me a
… …
542 676
543=head3 CHILD WATCHERS - watch out for process status changes 677=head3 CHILD WATCHERS - watch out for process status changes
544 678
545=over 4 679=over 4
546 680
547=item $w = EV::child $pid, $callback 681=item $w = EV::child $pid, $trace, $callback
548 682
549=item $w = EV::child_ns $pid, $callback 683=item $w = EV::child_ns $pid, $trace, $callback
550 684
685=item $w = $loop->child ($pid, $trace, $callback)
686
687=item $w = $loop->child_ns ($pid, $trace, $callback)
688
551Call the callback when a status change for pid C<$pid> (or any pid if 689Call the callback when a status change for pid C<$pid> (or any pid
552C<$pid> is 0) has been received. More precisely: when the process receives 690if C<$pid> is 0) has been received (a status change happens when the
691process terminates or is killed, or, when trace is true, additionally when
692it is stopped or continued). More precisely: when the process receives
553a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 693a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
554changed/zombie children and call the callback. 694changed/zombie children and call the callback.
555 695
556It is valid (and fully supported) to install a child watcher after a child 696It is valid (and fully supported) to install a child watcher after a child
557has exited but before the event loop has started its next iteration (for 697has exited but before the event loop has started its next iteration (for
… …
564You can have as many pid watchers per pid as you want, they will all be 704You can have as many pid watchers per pid as you want, they will all be
565called. 705called.
566 706
567The C<child_ns> variant doesn't start (activate) the newly created watcher. 707The C<child_ns> variant doesn't start (activate) the newly created watcher.
568 708
569=item $w->set ($pid) 709=item $w->set ($pid, $trace)
570 710
571Reconfigures the watcher, see the constructor above for details. Can be called at 711Reconfigures the watcher, see the constructor above for details. Can be called at
572any time. 712any time.
573 713
574=item $current_pid = $w->pid 714=item $current_pid = $w->pid
575 715
576=item $old_pid = $w->pid ($new_pid)
577
578Returns the previously set process id and optionally set a new one. 716Returns the previously set process id and optionally set a new one.
579 717
580=item $exit_status = $w->rstatus 718=item $exit_status = $w->rstatus
581 719
582Return the exit/wait status (as returned by waitpid, see the waitpid entry 720Return the exit/wait status (as returned by waitpid, see the waitpid entry
… …
595=over 4 733=over 4
596 734
597=item $w = EV::stat $path, $interval, $callback 735=item $w = EV::stat $path, $interval, $callback
598 736
599=item $w = EV::stat_ns $path, $interval, $callback 737=item $w = EV::stat_ns $path, $interval, $callback
738
739=item $w = $loop->stat ($path, $interval, $callback)
740
741=item $w = $loop->stat_ns ($path, $interval, $callback)
600 742
601Call the callback when a file status change has been detected on 743Call the callback when a file status change has been detected on
602C<$path>. The C<$path> does not need to exist, changing from "path exists" 744C<$path>. The C<$path> does not need to exist, changing from "path exists"
603to "path does not exist" is a status change like any other. 745to "path does not exist" is a status change like any other.
604 746
… …
674=over 4 816=over 4
675 817
676=item $w = EV::idle $callback 818=item $w = EV::idle $callback
677 819
678=item $w = EV::idle_ns $callback 820=item $w = EV::idle_ns $callback
821
822=item $w = $loop->idle ($callback)
823
824=item $w = $loop->idle_ns ($callback)
679 825
680Call the callback when there are no other pending watchers of the same or 826Call the callback when there are no other pending watchers of the same or
681higher priority (excluding check, prepare and other idle watchers of the 827higher priority (excluding check, prepare and other idle watchers of the
682same or lower priority, of course). They are called idle watchers because 828same or lower priority, of course). They are called idle watchers because
683when the watcher is the highest priority pending event in the process, the 829when the watcher is the highest priority pending event in the process, the
… …
706 852
707=item $w = EV::prepare $callback 853=item $w = EV::prepare $callback
708 854
709=item $w = EV::prepare_ns $callback 855=item $w = EV::prepare_ns $callback
710 856
857=item $w = $loop->prepare ($callback)
858
859=item $w = $loop->prepare_ns ($callback)
860
711Call the callback just before the process would block. You can still 861Call the callback just before the process would block. You can still
712create/modify any watchers at this point. 862create/modify any watchers at this point.
713 863
714See the EV::check watcher, below, for explanations and an example. 864See the EV::check watcher, below, for explanations and an example.
715 865
… …
723=over 4 873=over 4
724 874
725=item $w = EV::check $callback 875=item $w = EV::check $callback
726 876
727=item $w = EV::check_ns $callback 877=item $w = EV::check_ns $callback
878
879=item $w = $loop->check ($callback)
880
881=item $w = $loop->check_ns ($callback)
728 882
729Call the callback just after the process wakes up again (after it has 883Call the callback just after the process wakes up again (after it has
730gathered events), but before any other callbacks have been invoked. 884gathered events), but before any other callbacks have been invoked.
731 885
732This is used to integrate other event-based software into the EV 886This is used to integrate other event-based software into the EV
… …
767 # make the dispatcher handle any new stuff 921 # make the dispatcher handle any new stuff
768 ... not shown 922 ... not shown
769 }; 923 };
770 924
771The callbacks of the created watchers will not be called as the watchers 925The callbacks of the created watchers will not be called as the watchers
772are destroyed before this cna happen (remember EV::check gets called 926are destroyed before this can happen (remember EV::check gets called
773first). 927first).
774 928
775The C<check_ns> variant doesn't start (activate) the newly created watcher. 929The C<check_ns> variant doesn't start (activate) the newly created watcher.
776 930
777=back 931=back
… …
787 941
788=item $w = EV::fork $callback 942=item $w = EV::fork $callback
789 943
790=item $w = EV::fork_ns $callback 944=item $w = EV::fork_ns $callback
791 945
946=item $w = $loop->fork ($callback)
947
948=item $w = $loop->fork_ns ($callback)
949
792Call the callback before the event loop is resumed in the child process 950Call the callback before the event loop is resumed in the child process
793after a fork. 951after a fork.
794 952
795The C<fork_ns> variant doesn't start (activate) the newly created watcher. 953The C<fork_ns> variant doesn't start (activate) the newly created watcher.
954
955=back
956
957
958=head3 EMBED WATCHERS - when one backend isn't enough...
959
960This is a rather advanced watcher type that lets you embed one event loop
961into another (currently only IO events are supported in the embedded
962loop, other types of watchers might be handled in a delayed or incorrect
963fashion and must not be used).
964
965See the libev documentation at
966L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
967(locally installed as F<EV::libev>) for more details.
968
969In short, this watcher is most useful on BSD systems without working
970kqueue to still be able to handle a large number of sockets:
971
972 my $socket_loop;
973
974 # check wether we use SELECT or POLL _and_ KQUEUE is supported
975 if (
976 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
977 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
978 ) {
979 # use kqueue for sockets
980 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
981 }
982
983 # use the default loop otherwise
984 $socket_loop ||= EV::default_loop;
985
986=over 4
987
988=item $w = EV::embed $otherloop[, $callback]
989
990=item $w = EV::embed_ns $otherloop[, $callback]
991
992=item $w = $loop->embed ($otherloop[, $callback])
993
994=item $w = $loop->embed_ns ($otherloop[, $callback])
995
996Call the callback when the embedded event loop (C<$otherloop>) has any
997I/O activity. The C<$callback> is optional: if it is missing, then the
998embedded event loop will be managed automatically (which is recommended),
999otherwise you have to invoke C<sweep> yourself.
1000
1001The C<embed_ns> variant doesn't start (activate) the newly created watcher.
1002
1003=back
1004
1005=head3 ASYNC WATCHERS - how to wake up another event loop
1006
1007Async watchers are provided by EV, but have little use in perl directly, as perl
1008neither supports threads nor direct access to signal handlers or other
1009contexts where they could be of value.
1010
1011It is, however, possible to use them from the XS level.
1012
1013Please see the libev documentation for further details.
1014
1015=over 4
1016
1017=item $w = EV::async $callback
1018
1019=item $w = EV::async_ns $callback
1020
1021=item $w->send
1022
1023=item $bool = $w->async_pending
796 1024
797=back 1025=back
798 1026
799 1027
800=head1 PERL SIGNALS 1028=head1 PERL SIGNALS
… …
811to be called on every event loop iteration by installing a C<EV::check> 1039to be called on every event loop iteration by installing a C<EV::check>
812watcher: 1040watcher:
813 1041
814 my $async_check = EV::check sub { }; 1042 my $async_check = EV::check sub { };
815 1043
816This ensures that perl shortly gets into control for a short time, and 1044This ensures that perl gets into control for a short time to handle any
817also ensures slower overall operation. 1045pending signals, and also ensures (slightly) slower overall operation.
818 1046
819=head1 THREADS 1047=head1 THREADS
820 1048
821Threads are not supported by this module in any way. Perl pseudo-threads 1049Threads are not supported by this module in any way. Perl pseudo-threads
822is evil stuff and must die. As soon as Perl gains real threads I will work 1050is evil stuff and must die. As soon as Perl gains real threads I will work
… …
850 1078
8511; 10791;
852 1080
853=head1 SEE ALSO 1081=head1 SEE ALSO
854 1082
855L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 1083L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
856event loop), L<Coro::EV> (efficient coroutines with EV). 1084event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1085coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1086event-loop agnostic and portable event driven programming.
857 1087
858=head1 AUTHOR 1088=head1 AUTHOR
859 1089
860 Marc Lehmann <schmorp@schmorp.de> 1090 Marc Lehmann <schmorp@schmorp.de>
861 http://home.schmorp.de/ 1091 http://home.schmorp.de/
862 1092
863=cut 1093=cut
864 1094

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