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Revision 1.67 by root, Sun Dec 9 02:14:23 2007 UTC vs.
Revision 1.78 by root, Sat Dec 22 11:50:04 2007 UTC

68package EV; 68package EV;
69 69
70use strict; 70use strict;
71 71
72BEGIN { 72BEGIN {
73 our $VERSION = '1.72'; 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 =
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
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
108 151
152=item $time = $loop->now
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 $flags argument can be one of the following:
126 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 175 EV::LOOP_ONESHOT block at most once (wait, but do not loop)
127 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 176 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
128 177
129=item EV::unloop [$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>
153If timeout is C<undef> or negative, then there will be no 208If timeout is C<undef> or negative, then there will be no
154timeout. Otherwise a EV::timer with this value will be started. 209timeout. Otherwise a EV::timer with this value will be started.
155 210
156When an error occurs or either the timeout or I/O watcher triggers, then 211When 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 212the 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>, 213you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
159C<EV::WRITE> and C<EV::TIMEOUT>). 214C<EV::WRITE> and C<EV::TIMEOUT>).
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=item EV::feed_fd_event ($fd, $revents) 220=item EV::feed_fd_event ($fd, $revents)
166 221
222=item $loop->feed_fd_event ($fd, $revents)
223
167Feed an event on a file descriptor into EV. EV will react to this call as 224Feed an event on a file descriptor into EV. EV will react to this call as
168if the readyness notifications specified by C<$revents> (a combination of 225if the readyness notifications specified by C<$revents> (a combination of
169C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 226C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
170 227
171=item EV::feed_signal_event ($signal) 228=item EV::feed_signal_event ($signal)
174specified by C<$signal> had occured. 231specified by C<$signal> had occured.
175 232
176=back 233=back
177 234
178 235
179=head2 WATCHER OBJECTS 236=head1 WATCHER OBJECTS
180 237
181A 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
182event. 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
183would create an EV::io watcher for that: 240would create an EV::io watcher for that:
184 241
185 my $watcher = EV::io *STDIN, EV::READ, sub { 242 my $watcher = EV::io *STDIN, EV::READ, sub {
186 my ($watcher, $revents) = @_; 243 my ($watcher, $revents) = @_;
187 warn "yeah, STDIN should not be readable without blocking!\n" 244 warn "yeah, STDIN should now be readable without blocking!\n"
188 }; 245 };
189 246
190All watchers can be active (waiting for events) or inactive (paused). Only 247All watchers can be active (waiting for events) or inactive (paused). Only
191active watchers will have their callbacks invoked. All callbacks will be 248active watchers will have their callbacks invoked. All callbacks will be
192called with at least two arguments: the watcher and a bitmask of received 249called with at least two arguments: the watcher and a bitmask of received
276Feed some events on this watcher into EV. EV will react to this call as if 333Feed some events on this watcher into EV. EV will react to this call as if
277the watcher had received the given C<$revents> mask. 334the watcher had received the given C<$revents> mask.
278 335
279=item $revents = $w->clear_pending 336=item $revents = $w->clear_pending
280 337
281If the watcher is pending, this function returns clears its pending status 338If the watcher is pending, this function clears its pending status and
282and returns its C<$revents> bitset (as if its callback was invoked). If the 339returns its C<$revents> bitset (as if its callback was invoked). If the
283watcher isn't pending it does nothing and returns C<0>. 340watcher isn't pending it does nothing and returns C<0>.
284 341
285=item $previous_state = $w->keepalive ($bool) 342=item $previous_state = $w->keepalive ($bool)
286 343
287Normally, C<EV::loop> will return when there are no active watchers 344Normally, C<EV::loop> will return when there are no active watchers
288(which is a "deadlock" because no progress can be made anymore). This is 345(which is a "deadlock" because no progress can be made anymore). This is
289convinient because it allows you to start your watchers (and your jobs), 346convinient because it allows you to start your watchers (and your jobs),
290call C<EV::loop> once and when it returns you know that all your jobs are 347call C<EV::loop> once and when it returns you know that all your jobs are
291finished (or they forgot to register some watchers for their task :). 348finished (or they forgot to register some watchers for their task :).
292 349
293Sometimes, however, this gets in your way, for example when you the module 350Sometimes, however, this gets in your way, for example when the module
294that calls C<EV::loop> (usually the main program) is not the same module 351that calls C<EV::loop> (usually the main program) is not the same module
295as a long-living watcher (for example a DNS client module written by 352as a long-living watcher (for example a DNS client module written by
296somebody else even). Then you might want any outstanding requests to be 353somebody else even). Then you might want any outstanding requests to be
297handled, but you would not want to keep C<EV::loop> from returning just 354handled, but you would not want to keep C<EV::loop> from returning just
298because you happen to have this long-running UDP port watcher. 355because you happen to have this long-running UDP port watcher.
306Example: Register an I/O watcher for some UDP socket but do not keep the 363Example: Register an I/O watcher for some UDP socket but do not keep the
307event loop from running just because of that watcher. 364event loop from running just because of that watcher.
308 365
309 my $udp_socket = ... 366 my $udp_socket = ...
310 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 367 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
311 $udp_watcher->keepalive (0); 368 $1000udp_watcher->keepalive (0);
312 369
313=back 370=item $loop = $w->loop
314 371
372Return the loop that this watcher is attached to.
315 373
374=back
375
376
316=head2 WATCHER TYPES 377=head1 WATCHER TYPES
317 378
318Each of the following subsections describes a single watcher type. 379Each of the following subsections describes a single watcher type.
319 380
320=head3 I/O WATCHERS - is this file descriptor readable or writable? 381=head3 I/O WATCHERS - is this file descriptor readable or writable?
321 382
322=over 4 383=over 4
323 384
324=item $w = EV::io $fileno_or_fh, $eventmask, $callback 385=item $w = EV::io $fileno_or_fh, $eventmask, $callback
325 386
326=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 387=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
388
389=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
390
391=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
327 392
328As long as the returned watcher object is alive, call the C<$callback> 393As long as the returned watcher object is alive, call the C<$callback>
329when at least one of events specified in C<$eventmask> occurs. 394when at least one of events specified in C<$eventmask> occurs.
330 395
331The $eventmask can be one or more of these constants ORed together: 396The $eventmask can be one or more of these constants ORed together:
360=over 4 425=over 4
361 426
362=item $w = EV::timer $after, $repeat, $callback 427=item $w = EV::timer $after, $repeat, $callback
363 428
364=item $w = EV::timer_ns $after, $repeat, $callback 429=item $w = EV::timer_ns $after, $repeat, $callback
430
431=item $w = $loop->timer ($after, $repeat, $callback)
432
433=item $w = $loop->timer_ns ($after, $repeat, $callback)
365 434
366Calls the callback after C<$after> seconds (which may be fractional). If 435Calls the callback after C<$after> seconds (which may be fractional). If
367C<$repeat> is non-zero, the timer will be restarted (with the $repeat 436C<$repeat> is non-zero, the timer will be restarted (with the $repeat
368value as $after) after the callback returns. 437value as $after) after the callback returns.
369 438
410=over 4 479=over 4
411 480
412=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 481=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
413 482
414=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 483=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
484
485=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
486
487=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
415 488
416Similar to EV::timer, but is not based on relative timeouts but on 489Similar to EV::timer, but is not based on relative timeouts but on
417absolute times. Apart from creating "simple" timers that trigger "at" the 490absolute times. Apart from creating "simple" timers that trigger "at" the
418specified time, it can also be used for non-drifting absolute timers and 491specified time, it can also be used for non-drifting absolute timers and
419more complex, cron-like, setups that are not adversely affected by time 492more complex, cron-like, setups that are not adversely affected by time
494 567
495=item $w->again 568=item $w->again
496 569
497Simply stops and starts the watcher again. 570Simply stops and starts the watcher again.
498 571
572=item $time = $w->at
573
574Return the time that the watcher is expected to trigger next.
575
499=back 576=back
500 577
501 578
502=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! 579=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
503 580
540 617
541=item $w = EV::child $pid, $callback 618=item $w = EV::child $pid, $callback
542 619
543=item $w = EV::child_ns $pid, $callback 620=item $w = EV::child_ns $pid, $callback
544 621
622=item $w = $loop->child ($pid, $callback)
623
624=item $w = $loop->child_ns ($pid, $callback)
625
545Call the callback when a status change for pid C<$pid> (or any pid if 626Call the callback when a status change for pid C<$pid> (or any pid if
546C<$pid> is 0) has been received. More precisely: when the process receives 627C<$pid> is 0) has been received. More precisely: when the process receives
547a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 628a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
548changed/zombie children and call the callback. 629changed/zombie children and call the callback.
549 630
590 671
591=item $w = EV::stat $path, $interval, $callback 672=item $w = EV::stat $path, $interval, $callback
592 673
593=item $w = EV::stat_ns $path, $interval, $callback 674=item $w = EV::stat_ns $path, $interval, $callback
594 675
676=item $w = $loop->stat ($path, $interval, $callback)
677
678=item $w = $loop->stat_ns ($path, $interval, $callback)
679
595Call the callback when a file status change has been detected on 680Call the callback when a file status change has been detected on
596C<$path>. The C<$path> does not need to exist, changing from "path exists" 681C<$path>. The C<$path> does not need to exist, changing from "path exists"
597to "path does not exist" is a status change like any other. 682to "path does not exist" is a status change like any other.
598 683
599The C<$interval> is a recommended polling interval for systems where 684The C<$interval> is a recommended polling interval for systems where
668=over 4 753=over 4
669 754
670=item $w = EV::idle $callback 755=item $w = EV::idle $callback
671 756
672=item $w = EV::idle_ns $callback 757=item $w = EV::idle_ns $callback
758
759=item $w = $loop->idle ($callback)
760
761=item $w = $loop->idle_ns ($callback)
673 762
674Call the callback when there are no other pending watchers of the same or 763Call the callback when there are no other pending watchers of the same or
675higher priority (excluding check, prepare and other idle watchers of the 764higher priority (excluding check, prepare and other idle watchers of the
676same or lower priority, of course). They are called idle watchers because 765same or lower priority, of course). They are called idle watchers because
677when the watcher is the highest priority pending event in the process, the 766when the watcher is the highest priority pending event in the process, the
700 789
701=item $w = EV::prepare $callback 790=item $w = EV::prepare $callback
702 791
703=item $w = EV::prepare_ns $callback 792=item $w = EV::prepare_ns $callback
704 793
794=item $w = $loop->prepare ($callback)
795
796=item $w = $loop->prepare_ns ($callback)
797
705Call the callback just before the process would block. You can still 798Call the callback just before the process would block. You can still
706create/modify any watchers at this point. 799create/modify any watchers at this point.
707 800
708See the EV::check watcher, below, for explanations and an example. 801See the EV::check watcher, below, for explanations and an example.
709 802
717=over 4 810=over 4
718 811
719=item $w = EV::check $callback 812=item $w = EV::check $callback
720 813
721=item $w = EV::check_ns $callback 814=item $w = EV::check_ns $callback
815
816=item $w = $loop->check ($callback)
817
818=item $w = $loop->check_ns ($callback)
722 819
723Call the callback just after the process wakes up again (after it has 820Call the callback just after the process wakes up again (after it has
724gathered events), but before any other callbacks have been invoked. 821gathered events), but before any other callbacks have been invoked.
725 822
726This is used to integrate other event-based software into the EV 823This is used to integrate other event-based software into the EV
781 878
782=item $w = EV::fork $callback 879=item $w = EV::fork $callback
783 880
784=item $w = EV::fork_ns $callback 881=item $w = EV::fork_ns $callback
785 882
883=item $w = $loop->fork ($callback)
884
885=item $w = $loop->fork_ns ($callback)
886
786Call the callback before the event loop is resumed in the child process 887Call the callback before the event loop is resumed in the child process
787after a fork. 888after a fork.
788 889
789The C<fork_ns> variant doesn't start (activate) the newly created watcher. 890The C<fork_ns> variant doesn't start (activate) the newly created watcher.
790 891
805to be called on every event loop iteration by installing a C<EV::check> 906to be called on every event loop iteration by installing a C<EV::check>
806watcher: 907watcher:
807 908
808 my $async_check = EV::check sub { }; 909 my $async_check = EV::check sub { };
809 910
810This ensures that perl shortly gets into control for a short time, and 911This ensures that perl gets into control for a short time to handle any
811also ensures slower overall operation. 912pending signals, and also ensures (slightly) slower overall operation.
812 913
813=head1 THREADS 914=head1 THREADS
814 915
815Threads are not supported by this module in any way. Perl pseudo-threads 916Threads are not supported by this module in any way. Perl pseudo-threads
816is evil stuff and must die. As soon as Perl gains real threads I will work 917is evil stuff and must die. As soon as Perl gains real threads I will work
838our $DIED = sub { 939our $DIED = sub {
839 warn "EV: error in callback (ignoring): $@"; 940 warn "EV: error in callback (ignoring): $@";
840}; 941};
841 942
842default_loop 943default_loop
843 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; 944 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
844 945
8451; 9461;
846 947
847=head1 SEE ALSO 948=head1 SEE ALSO
848 949
849L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 950L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
850event loop), L<Coro::EV> (efficient coroutines with EV). 951event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
952coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
851 953
852=head1 AUTHOR 954=head1 AUTHOR
853 955
854 Marc Lehmann <schmorp@schmorp.de> 956 Marc Lehmann <schmorp@schmorp.de>
855 http://home.schmorp.de/ 957 http://home.schmorp.de/

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