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Revision 1.62 by root, Fri Dec 7 18:09:38 2007 UTC vs.
Revision 1.73 by root, Fri Dec 21 05:10:01 2007 UTC

… …
68package EV; 68package EV;
69 69
70use strict; 70use strict;
71 71
72BEGIN { 72BEGIN {
73 our $VERSION = '1.7'; 73 our $VERSION = '2.0';
74 use XSLoader; 74 use XSLoader;
75 XSLoader::load "EV", $VERSION; 75 XSLoader::load "EV", $VERSION;
76} 76}
77 77
78@EV::IO::ISA = 78@EV::IO::ISA =
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86@EV::Check::ISA = 86@EV::Check::ISA =
87@EV::Embed::ISA = 87@EV::Embed::ISA =
88@EV::Fork::ISA = 88@EV::Fork::ISA =
89 "EV::Watcher"; 89 "EV::Watcher";
90 90
91@EV::Loop::Default::ISA = "EV::Loop";
92
93=head1 EVENT LOOPS
94
95EV supports multiple event loops: There is a single "default event loop"
96that can handle everything including signals and child watchers, and any
97number of "dynamic event loops" that can use different backends (with
98various limitations), but no child and signal watchers.
99
100You do not have to do anything to create the default event loop: When
101the module is loaded a suitable backend is selected on the premise of
102selecting a working backend (which for example rules out kqueue on most
103BSDs). Modules should, unless they have "special needs" always use the
104default loop as this is fastest (perl-wise), best supported by other
105modules (e.g. AnyEvent or Coro) and most portable event loop.
106
107For specific programs you cna create additional event loops dynamically.
108
109=over 4
110
111=item $loop = new EV::loop [$flags]
112
113Create a new event loop as per the specified flags. Please refer to the
114C<ev_loop_new ()> function description in the libev documentation
115(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
116for more info.
117
118The loop will automatically be destroyed when it is no longer referenced
119by any watcher and the loop object goes out of scope.
120
121Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
122is protected by this module.
123
124=item $loop->loop_fork
125
126Must be called after a fork in the child, before entering or continuing
127the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
128this fucntion automatically, at some performance loss (refer to the libev
129documentation).
130
131=back
132
133
91=head1 BASIC INTERFACE 134=head1 BASIC INTERFACE
92 135
93=over 4 136=over 4
94 137
95=item $EV::DIED 138=item $EV::DIED
96 139
97Must contain a reference to a function that is called when a callback 140Must contain a reference to a function that is called when a callback
98throws an exception (with $@ containing thr error). The default prints an 141throws an exception (with $@ containing the error). The default prints an
99informative message and continues. 142informative message and continues.
100 143
101If this callback throws an exception it will be silently ignored. 144If this callback throws an exception it will be silently ignored.
102 145
103=item $time = EV::time 146=item $time = EV::time
104 147
105Returns the current time in (fractional) seconds since the epoch. 148Returns the current time in (fractional) seconds since the epoch.
106 149
107=item $time = EV::now 150=item $time = EV::now
151
152=item $time = $loop->now
108 153
109Returns the time the last event loop iteration has been started. This 154Returns 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 155is the time that (relative) timers are based on, and refering to it is
111usually faster then calling EV::time. 156usually faster then calling EV::time.
112 157
113=item $method = EV::method 158=item $backend = EV::backend
159
160=item $backend = $loop->backend
114 161
115Returns an integer describing the backend used by libev (EV::METHOD_SELECT 162Returns an integer describing the backend used by libev (EV::METHOD_SELECT
116or EV::METHOD_EPOLL). 163or EV::METHOD_EPOLL).
117 164
118=item EV::loop [$flags] 165=item EV::loop [$flags]
166
167=item $loop->loop ([$flags])
119 168
120Begin checking for events and calling callbacks. It returns when a 169Begin checking for events and calling callbacks. It returns when a
121callback calls EV::unloop. 170callback calls EV::unloop.
122 171
123The $flags argument can be one of the following: 172The $flags argument can be one of the following:
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126 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 175 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
127 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 176 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
128 177
129=item EV::unloop [$how] 178=item EV::unloop [$how]
130 179
180=item $loop->unloop ([$how])
181
131When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 182When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
132innermost call to EV::loop return. 183innermost call to EV::loop return.
133 184
134When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 185When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
135fast as possible. 186fast as possible.
136 187
137=item $count = EV::loop_count 188=item $count = EV::loop_count
138 189
190=item $count = $loop->loop_count
191
139Return the number of times the event loop has polled for new 192Return the number of times the event loop has polled for new
140events. Sometiems useful as a generation counter. 193events. Sometiems useful as a generation counter.
141 194
142=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 195=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
196
197=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
143 198
144This function rolls together an I/O and a timer watcher for a single 199This function rolls together an I/O and a timer watcher for a single
145one-shot event without the need for managing a watcher object. 200one-shot event without the need for managing a watcher object.
146 201
147If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> 202If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
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160 215
161EV::once doesn't return anything: the watchers stay active till either 216EV::once doesn't return anything: the watchers stay active till either
162of them triggers, then they will be stopped and freed, and the callback 217of them triggers, then they will be stopped and freed, and the callback
163invoked. 218invoked.
164 219
165=back 220=item EV::feed_fd_event ($fd, $revents)
166 221
222=item $loop->feed_fd_event ($fd, $revents)
223
224Feed an event on a file descriptor into EV. EV will react to this call as
225if the readyness notifications specified by C<$revents> (a combination of
226C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
227
228=item EV::feed_signal_event ($signal)
229
230Feed a signal event into EV. EV will react to this call as if the signal
231specified by C<$signal> had occured.
232
233=back
234
235
167=head2 WATCHER OBJECTS 236=head1 WATCHER OBJECTS
168 237
169A watcher is an object that gets created to record your interest in some 238A 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 239event. For instance, if you want to wait for STDIN to become readable, you
171would create an EV::io watcher for that: 240would create an EV::io watcher for that:
172 241
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253The default priority of any newly-created watcher is 0. 322The default priority of any newly-created watcher is 0.
254 323
255Note that the priority semantics have not yet been fleshed out and are 324Note that the priority semantics have not yet been fleshed out and are
256subject to almost certain change. 325subject to almost certain change.
257 326
258=item $w->trigger ($revents) 327=item $w->invoke ($revents)
259 328
260Call the callback *now* with the given event mask. 329Call the callback *now* with the given event mask.
330
331=item $w->feed_event ($revents)
332
333Feed some events on this watcher into EV. EV will react to this call as if
334the watcher had received the given C<$revents> mask.
335
336=item $revents = $w->clear_pending
337
338If the watcher is pending, this function returns clears its pending status
339and returns its C<$revents> bitset (as if its callback was invoked). If the
340watcher isn't pending it does nothing and returns C<0>.
261 341
262=item $previous_state = $w->keepalive ($bool) 342=item $previous_state = $w->keepalive ($bool)
263 343
264Normally, C<EV::loop> will return when there are no active watchers 344Normally, 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 345(which is a "deadlock" because no progress can be made anymore). This is
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288 $udp_watcher->keepalive (0); 368 $udp_watcher->keepalive (0);
289 369
290=back 370=back
291 371
292 372
293=head2 WATCHER TYPES 373=head1 WATCHER TYPES
294 374
295Each of the following subsections describes a single watcher type. 375Each of the following subsections describes a single watcher type.
296 376
297=head3 I/O WATCHERS - is this file descriptor readable or writable? 377=head3 I/O WATCHERS - is this file descriptor readable or writable?
298 378
299=over 4 379=over 4
300 380
301=item $w = EV::io $fileno_or_fh, $eventmask, $callback 381=item $w = EV::io $fileno_or_fh, $eventmask, $callback
302 382
303=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 383=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
384
385=item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback)
386
387=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
304 388
305As long as the returned watcher object is alive, call the C<$callback> 389As long as the returned watcher object is alive, call the C<$callback>
306when at least one of events specified in C<$eventmask> occurs. 390when at least one of events specified in C<$eventmask> occurs.
307 391
308The $eventmask can be one or more of these constants ORed together: 392The $eventmask can be one or more of these constants ORed together:
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337=over 4 421=over 4
338 422
339=item $w = EV::timer $after, $repeat, $callback 423=item $w = EV::timer $after, $repeat, $callback
340 424
341=item $w = EV::timer_ns $after, $repeat, $callback 425=item $w = EV::timer_ns $after, $repeat, $callback
426
427=item $w = $loop->timer ($after, $repeat, $callback)
428
429=item $w = $loop->timer_ns ($after, $repeat, $callback)
342 430
343Calls the callback after C<$after> seconds (which may be fractional). If 431Calls the callback after C<$after> seconds (which may be fractional). If
344C<$repeat> is non-zero, the timer will be restarted (with the $repeat 432C<$repeat> is non-zero, the timer will be restarted (with the $repeat
345value as $after) after the callback returns. 433value as $after) after the callback returns.
346 434
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387=over 4 475=over 4
388 476
389=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 477=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
390 478
391=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 479=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
480
481=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
482
483=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
392 484
393Similar to EV::timer, but is not based on relative timeouts but on 485Similar to EV::timer, but is not based on relative timeouts but on
394absolute times. Apart from creating "simple" timers that trigger "at" the 486absolute times. Apart from creating "simple" timers that trigger "at" the
395specified time, it can also be used for non-drifting absolute timers and 487specified time, it can also be used for non-drifting absolute timers and
396more complex, cron-like, setups that are not adversely affected by time 488more complex, cron-like, setups that are not adversely affected by time
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471 563
472=item $w->again 564=item $w->again
473 565
474Simply stops and starts the watcher again. 566Simply stops and starts the watcher again.
475 567
568=item $time = $w->at
569
570Return the time that the watcher is expected to trigger next.
571
476=back 572=back
477 573
478 574
479=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 575=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
480 576
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517 613
518=item $w = EV::child $pid, $callback 614=item $w = EV::child $pid, $callback
519 615
520=item $w = EV::child_ns $pid, $callback 616=item $w = EV::child_ns $pid, $callback
521 617
618=item $w = $loop->child ($pid, $callback)
619
620=item $w = $loop->child_ns ($pid, $callback)
621
522Call the callback when a status change for pid C<$pid> (or any pid if 622Call the callback when a status change for pid C<$pid> (or any pid if
523C<$pid> is 0) has been received. More precisely: when the process receives 623C<$pid> is 0) has been received. More precisely: when the process receives
524a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 624a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
525changed/zombie children and call the callback. 625changed/zombie children and call the callback.
526 626
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567 667
568=item $w = EV::stat $path, $interval, $callback 668=item $w = EV::stat $path, $interval, $callback
569 669
570=item $w = EV::stat_ns $path, $interval, $callback 670=item $w = EV::stat_ns $path, $interval, $callback
571 671
672=item $w = $loop->stat ($path, $interval, $callback)
673
674=item $w = $loop->stat_ns ($path, $interval, $callback)
675
572Call the callback when a file status change has been detected on 676Call the callback when a file status change has been detected on
573C<$path>. The C<$path> does not need to exist, changing from "path exists" 677C<$path>. The C<$path> does not need to exist, changing from "path exists"
574to "path does not exist" is a status change like any other. 678to "path does not exist" is a status change like any other.
575 679
576The C<$interval> is a recommended polling interval for systems where 680The C<$interval> is a recommended polling interval for systems where
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645=over 4 749=over 4
646 750
647=item $w = EV::idle $callback 751=item $w = EV::idle $callback
648 752
649=item $w = EV::idle_ns $callback 753=item $w = EV::idle_ns $callback
754
755=item $w = $loop->idle ($callback)
756
757=item $w = $loop->idle_ns ($callback)
650 758
651Call the callback when there are no other pending watchers of the same or 759Call the callback when there are no other pending watchers of the same or
652higher priority (excluding check, prepare and other idle watchers of the 760higher priority (excluding check, prepare and other idle watchers of the
653same or lower priority, of course). They are called idle watchers because 761same or lower priority, of course). They are called idle watchers because
654when the watcher is the highest priority pending event in the process, the 762when the watcher is the highest priority pending event in the process, the
… …
677 785
678=item $w = EV::prepare $callback 786=item $w = EV::prepare $callback
679 787
680=item $w = EV::prepare_ns $callback 788=item $w = EV::prepare_ns $callback
681 789
790=item $w = $loop->prepare ($callback)
791
792=item $w = $loop->prepare_ns 8$callback)
793
682Call the callback just before the process would block. You can still 794Call the callback just before the process would block. You can still
683create/modify any watchers at this point. 795create/modify any watchers at this point.
684 796
685See the EV::check watcher, below, for explanations and an example. 797See the EV::check watcher, below, for explanations and an example.
686 798
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694=over 4 806=over 4
695 807
696=item $w = EV::check $callback 808=item $w = EV::check $callback
697 809
698=item $w = EV::check_ns $callback 810=item $w = EV::check_ns $callback
811
812=item $w = $loop->check ($callback)
813
814=item $w = $loop->check_ns ($callback)
699 815
700Call the callback just after the process wakes up again (after it has 816Call the callback just after the process wakes up again (after it has
701gathered events), but before any other callbacks have been invoked. 817gathered events), but before any other callbacks have been invoked.
702 818
703This is used to integrate other event-based software into the EV 819This is used to integrate other event-based software into the EV
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757=over 4 873=over 4
758 874
759=item $w = EV::fork $callback 875=item $w = EV::fork $callback
760 876
761=item $w = EV::fork_ns $callback 877=item $w = EV::fork_ns $callback
878
879=item $w = $loop->fork ($callback)
880
881=item $w = $loop->fork_ns ($callback)
762 882
763Call the callback before the event loop is resumed in the child process 883Call the callback before the event loop is resumed in the child process
764after a fork. 884after a fork.
765 885
766The C<fork_ns> variant doesn't start (activate) the newly created watcher. 886The C<fork_ns> variant doesn't start (activate) the newly created watcher.
… …
815our $DIED = sub { 935our $DIED = sub {
816 warn "EV: error in callback (ignoring): $@"; 936 warn "EV: error in callback (ignoring): $@";
817}; 937};
818 938
819default_loop 939default_loop
820 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; 940 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
821 941
8221; 9421;
823 943
824=head1 SEE ALSO 944=head1 SEE ALSO
825 945
826L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 946L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
827event loop), L<Coro::EV> (efficient coroutines with EV). 947event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
948coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
828 949
829=head1 AUTHOR 950=head1 AUTHOR
830 951
831 Marc Lehmann <schmorp@schmorp.de> 952 Marc Lehmann <schmorp@schmorp.de>
832 http://home.schmorp.de/ 953 http://home.schmorp.de/

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