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Revision 1.72 by root, Thu Dec 20 07:12:57 2007 UTC vs.
Revision 1.73 by root, Fri Dec 21 05:10:01 2007 UTC

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88@EV::Fork::ISA = 88@EV::Fork::ISA =
89 "EV::Watcher"; 89 "EV::Watcher";
90 90
91@EV::Loop::Default::ISA = "EV::Loop"; 91@EV::Loop::Default::ISA = "EV::Loop";
92 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
93=head1 BASIC INTERFACE 134=head1 BASIC INTERFACE
94 135
95=over 4 136=over 4
96 137
97=item $EV::DIED 138=item $EV::DIED
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106 147
107Returns the current time in (fractional) seconds since the epoch. 148Returns the current time in (fractional) seconds since the epoch.
108 149
109=item $time = EV::now 150=item $time = EV::now
110 151
152=item $time = $loop->now
153
111Returns the time the last event loop iteration has been started. This 154Returns 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 155is the time that (relative) timers are based on, and refering to it is
113usually faster then calling EV::time. 156usually faster then calling EV::time.
114 157
115=item $method = EV::method 158=item $backend = EV::backend
159
160=item $backend = $loop->backend
116 161
117Returns an integer describing the backend used by libev (EV::METHOD_SELECT 162Returns an integer describing the backend used by libev (EV::METHOD_SELECT
118or EV::METHOD_EPOLL). 163or EV::METHOD_EPOLL).
119 164
120=item EV::loop [$flags] 165=item EV::loop [$flags]
166
167=item $loop->loop ([$flags])
121 168
122Begin checking for events and calling callbacks. It returns when a 169Begin checking for events and calling callbacks. It returns when a
123callback calls EV::unloop. 170callback calls EV::unloop.
124 171
125The $flags argument can be one of the following: 172The $flags argument can be one of the following:
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128 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 175 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
129 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 176 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
130 177
131=item EV::unloop [$how] 178=item EV::unloop [$how]
132 179
180=item $loop->unloop ([$how])
181
133When 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
134innermost call to EV::loop return. 183innermost call to EV::loop return.
135 184
136When 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
137fast as possible. 186fast as possible.
138 187
139=item $count = EV::loop_count 188=item $count = EV::loop_count
140 189
190=item $count = $loop->loop_count
191
141Return the number of times the event loop has polled for new 192Return the number of times the event loop has polled for new
142events. Sometiems useful as a generation counter. 193events. Sometiems useful as a generation counter.
143 194
144=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))
145 198
146This 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
147one-shot event without the need for managing a watcher object. 200one-shot event without the need for managing a watcher object.
148 201
149If 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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164of 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
165invoked. 218invoked.
166 219
167=item EV::feed_fd_event ($fd, $revents) 220=item EV::feed_fd_event ($fd, $revents)
168 221
222=item $loop->feed_fd_event ($fd, $revents)
223
169Feed an event on a file descriptor into EV. EV will react to this call as 224Feed an event on a file descriptor into EV. EV will react to this call as
170if the readyness notifications specified by C<$revents> (a combination of 225if the readyness notifications specified by C<$revents> (a combination of
171C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 226C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
172 227
173=item EV::feed_signal_event ($signal) 228=item EV::feed_signal_event ($signal)
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176specified by C<$signal> had occured. 231specified by C<$signal> had occured.
177 232
178=back 233=back
179 234
180 235
181=head2 WATCHER OBJECTS 236=head1 WATCHER OBJECTS
182 237
183A 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
184event. 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
185would create an EV::io watcher for that: 240would create an EV::io watcher for that:
186 241
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313 $udp_watcher->keepalive (0); 368 $udp_watcher->keepalive (0);
314 369
315=back 370=back
316 371
317 372
318=head2 WATCHER TYPES 373=head1 WATCHER TYPES
319 374
320Each of the following subsections describes a single watcher type. 375Each of the following subsections describes a single watcher type.
321 376
322=head3 I/O WATCHERS - is this file descriptor readable or writable? 377=head3 I/O WATCHERS - is this file descriptor readable or writable?
323 378
324=over 4 379=over 4
325 380
326=item $w = EV::io $fileno_or_fh, $eventmask, $callback 381=item $w = EV::io $fileno_or_fh, $eventmask, $callback
327 382
328=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, $callback)
329 388
330As long as the returned watcher object is alive, call the C<$callback> 389As long as the returned watcher object is alive, call the C<$callback>
331when at least one of events specified in C<$eventmask> occurs. 390when at least one of events specified in C<$eventmask> occurs.
332 391
333The $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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362=over 4 421=over 4
363 422
364=item $w = EV::timer $after, $repeat, $callback 423=item $w = EV::timer $after, $repeat, $callback
365 424
366=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, $callback)
367 430
368Calls the callback after C<$after> seconds (which may be fractional). If 431Calls the callback after C<$after> seconds (which may be fractional). If
369C<$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
370value as $after) after the callback returns. 433value as $after) after the callback returns.
371 434
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412=over 4 475=over 4
413 476
414=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 477=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
415 478
416=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)
417 484
418Similar 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
419absolute times. Apart from creating "simple" timers that trigger "at" the 486absolute times. Apart from creating "simple" timers that trigger "at" the
420specified 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
421more 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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546 613
547=item $w = EV::child $pid, $callback 614=item $w = EV::child $pid, $callback
548 615
549=item $w = EV::child_ns $pid, $callback 616=item $w = EV::child_ns $pid, $callback
550 617
618=item $w = $loop->child ($pid, $callback)
619
620=item $w = $loop->child_ns ($pid, $callback)
621
551Call the callback when a status change for pid C<$pid> (or any pid if 622Call the callback when a status change for pid C<$pid> (or any pid if
552C<$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
553a 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
554changed/zombie children and call the callback. 625changed/zombie children and call the callback.
555 626
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596 667
597=item $w = EV::stat $path, $interval, $callback 668=item $w = EV::stat $path, $interval, $callback
598 669
599=item $w = EV::stat_ns $path, $interval, $callback 670=item $w = EV::stat_ns $path, $interval, $callback
600 671
672=item $w = $loop->stat ($path, $interval, $callback)
673
674=item $w = $loop->stat_ns ($path, $interval, $callback)
675
601Call the callback when a file status change has been detected on 676Call the callback when a file status change has been detected on
602C<$path>. The C<$path> does not need to exist, changing from "path exists" 677C<$path>. The C<$path> does not need to exist, changing from "path exists"
603to "path does not exist" is a status change like any other. 678to "path does not exist" is a status change like any other.
604 679
605The C<$interval> is a recommended polling interval for systems where 680The C<$interval> is a recommended polling interval for systems where
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674=over 4 749=over 4
675 750
676=item $w = EV::idle $callback 751=item $w = EV::idle $callback
677 752
678=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)
679 758
680Call 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
681higher priority (excluding check, prepare and other idle watchers of the 760higher priority (excluding check, prepare and other idle watchers of the
682same or lower priority, of course). They are called idle watchers because 761same or lower priority, of course). They are called idle watchers because
683when 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
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706 785
707=item $w = EV::prepare $callback 786=item $w = EV::prepare $callback
708 787
709=item $w = EV::prepare_ns $callback 788=item $w = EV::prepare_ns $callback
710 789
790=item $w = $loop->prepare ($callback)
791
792=item $w = $loop->prepare_ns 8$callback)
793
711Call the callback just before the process would block. You can still 794Call the callback just before the process would block. You can still
712create/modify any watchers at this point. 795create/modify any watchers at this point.
713 796
714See the EV::check watcher, below, for explanations and an example. 797See the EV::check watcher, below, for explanations and an example.
715 798
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723=over 4 806=over 4
724 807
725=item $w = EV::check $callback 808=item $w = EV::check $callback
726 809
727=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)
728 815
729Call 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
730gathered events), but before any other callbacks have been invoked. 817gathered events), but before any other callbacks have been invoked.
731 818
732This 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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786=over 4 873=over 4
787 874
788=item $w = EV::fork $callback 875=item $w = EV::fork $callback
789 876
790=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)
791 882
792Call 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
793after a fork. 884after a fork.
794 885
795The 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.
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850 941
8511; 9421;
852 943
853=head1 SEE ALSO 944=head1 SEE ALSO
854 945
855L<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
856event 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).
857 949
858=head1 AUTHOR 950=head1 AUTHOR
859 951
860 Marc Lehmann <schmorp@schmorp.de> 952 Marc Lehmann <schmorp@schmorp.de>
861 http://home.schmorp.de/ 953 http://home.schmorp.de/

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