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Revision 1.75 by root, Fri Dec 21 10:36:22 2007 UTC vs.
Revision 1.80 by root, Sat Dec 22 16:48:33 2007 UTC

102selecting a working backend (which for example rules out kqueue on most 102selecting a working backend (which for example rules out kqueue on most
103BSDs). Modules should, unless they have "special needs" always use the 103BSDs). Modules should, unless they have "special needs" always use the
104default loop as this is fastest (perl-wise), best supported by other 104default loop as this is fastest (perl-wise), best supported by other
105modules (e.g. AnyEvent or Coro) and most portable event loop. 105modules (e.g. AnyEvent or Coro) and most portable event loop.
106 106
107For specific programs you cna create additional event loops dynamically. 107For specific programs you can create additional event loops dynamically.
108 108
109=over 4 109=over 4
110 110
111=item $loop = new EV::loop [$flags] 111=item $loop = new EV::loop [$flags]
112 112
126Must be called after a fork in the child, before entering or continuing 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 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 128this fucntion automatically, at some performance loss (refer to the libev
129documentation). 129documentation).
130 130
131=item $loop = EV::default_loop [$flags]
132
133Return the default loop (which is a singleton object).
134
131=back 135=back
132 136
133 137
134=head1 BASIC INTERFACE 138=head1 BASIC INTERFACE
135 139
140Must contain a reference to a function that is called when a callback 144Must contain a reference to a function that is called when a callback
141throws an exception (with $@ containing the error). The default prints an 145throws an exception (with $@ containing the error). The default prints an
142informative message and continues. 146informative message and continues.
143 147
144If this callback throws an exception it will be silently ignored. 148If this callback throws an exception it will be silently ignored.
149
150=item $flags = EV::supported_backends
151
152=item $flags = EV::recommended_backends
153
154=item $flags = EV::embeddable_backends
155
156Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
157instance of EV, the set of recommended backends (supposed to be good) for
158this platform and the set of embeddable backends (see EMBED WATCHERS).
159
160=item EV::sleep $seconds
161
162Block the process for the given number of (fractional) seconds.
145 163
146=item $time = EV::time 164=item $time = EV::time
147 165
148Returns the current time in (fractional) seconds since the epoch. 166Returns the current time in (fractional) seconds since the epoch.
149 167
208If timeout is C<undef> or negative, then there will be no 226If timeout is C<undef> or negative, then there will be no
209timeout. Otherwise a EV::timer with this value will be started. 227timeout. Otherwise a EV::timer with this value will be started.
210 228
211When an error occurs or either the timeout or I/O watcher triggers, then 229When an error occurs or either the timeout or I/O watcher triggers, then
212the callback will be called with the received event set (in general 230the callback will be called with the received event set (in general
213you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, 231you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
214C<EV::WRITE> and C<EV::TIMEOUT>). 232C<EV::WRITE> and C<EV::TIMEOUT>).
215 233
216EV::once doesn't return anything: the watchers stay active till either 234EV::once doesn't return anything: the watchers stay active till either
217of them triggers, then they will be stopped and freed, and the callback 235of them triggers, then they will be stopped and freed, and the callback
218invoked. 236invoked.
228=item EV::feed_signal_event ($signal) 246=item EV::feed_signal_event ($signal)
229 247
230Feed a signal event into EV. EV will react to this call as if the signal 248Feed a signal event into EV. EV will react to this call as if the signal
231specified by C<$signal> had occured. 249specified by C<$signal> had occured.
232 250
251=item EV::set_io_collect_interval $time
252
253=item $loop->set_io_collect_interval ($time)
254
255=item EV::set_timeout_collect_interval $time
256
257=item $loop->set_timeout_collect_interval ($time)
258
259These advanced functions set the minimum block interval when polling for I/O events and the minimum
260wait interval for timer events. See the libev documentation at
261L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
262a more detailed discussion.
263
233=back 264=back
234 265
235 266
236=head1 WATCHER OBJECTS 267=head1 WATCHER OBJECTS
237 268
239event. For instance, if you want to wait for STDIN to become readable, you 270event. For instance, if you want to wait for STDIN to become readable, you
240would create an EV::io watcher for that: 271would create an EV::io watcher for that:
241 272
242 my $watcher = EV::io *STDIN, EV::READ, sub { 273 my $watcher = EV::io *STDIN, EV::READ, sub {
243 my ($watcher, $revents) = @_; 274 my ($watcher, $revents) = @_;
244 warn "yeah, STDIN should not be readable without blocking!\n" 275 warn "yeah, STDIN should now be readable without blocking!\n"
245 }; 276 };
246 277
247All watchers can be active (waiting for events) or inactive (paused). Only 278All watchers can be active (waiting for events) or inactive (paused). Only
248active watchers will have their callbacks invoked. All callbacks will be 279active watchers will have their callbacks invoked. All callbacks will be
249called with at least two arguments: the watcher and a bitmask of received 280called with at least two arguments: the watcher and a bitmask of received
333Feed some events on this watcher into EV. EV will react to this call as if 364Feed some events on this watcher into EV. EV will react to this call as if
334the watcher had received the given C<$revents> mask. 365the watcher had received the given C<$revents> mask.
335 366
336=item $revents = $w->clear_pending 367=item $revents = $w->clear_pending
337 368
338If the watcher is pending, this function returns clears its pending status 369If the watcher is pending, this function clears its pending status and
339and returns its C<$revents> bitset (as if its callback was invoked). If the 370returns its C<$revents> bitset (as if its callback was invoked). If the
340watcher isn't pending it does nothing and returns C<0>. 371watcher isn't pending it does nothing and returns C<0>.
341 372
342=item $previous_state = $w->keepalive ($bool) 373=item $previous_state = $w->keepalive ($bool)
343 374
344Normally, C<EV::loop> will return when there are no active watchers 375Normally, C<EV::loop> will return when there are no active watchers
345(which is a "deadlock" because no progress can be made anymore). This is 376(which is a "deadlock" because no progress can be made anymore). This is
346convinient because it allows you to start your watchers (and your jobs), 377convinient because it allows you to start your watchers (and your jobs),
347call C<EV::loop> once and when it returns you know that all your jobs are 378call C<EV::loop> once and when it returns you know that all your jobs are
348finished (or they forgot to register some watchers for their task :). 379finished (or they forgot to register some watchers for their task :).
349 380
350Sometimes, however, this gets in your way, for example when you the module 381Sometimes, however, this gets in your way, for example when the module
351that calls C<EV::loop> (usually the main program) is not the same module 382that calls C<EV::loop> (usually the main program) is not the same module
352as a long-living watcher (for example a DNS client module written by 383as a long-living watcher (for example a DNS client module written by
353somebody else even). Then you might want any outstanding requests to be 384somebody else even). Then you might want any outstanding requests to be
354handled, but you would not want to keep C<EV::loop> from returning just 385handled, but you would not want to keep C<EV::loop> from returning just
355because you happen to have this long-running UDP port watcher. 386because you happen to have this long-running UDP port watcher.
384 415
385=item $w = EV::io $fileno_or_fh, $eventmask, $callback 416=item $w = EV::io $fileno_or_fh, $eventmask, $callback
386 417
387=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 418=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
388 419
389=item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback) 420=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
390 421
391=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) 422=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
392 423
393As long as the returned watcher object is alive, call the C<$callback> 424As long as the returned watcher object is alive, call the C<$callback>
394when at least one of events specified in C<$eventmask> occurs. 425when at least one of events specified in C<$eventmask> occurs.
791 822
792=item $w = EV::prepare_ns $callback 823=item $w = EV::prepare_ns $callback
793 824
794=item $w = $loop->prepare ($callback) 825=item $w = $loop->prepare ($callback)
795 826
796=item $w = $loop->prepare_ns 8$callback) 827=item $w = $loop->prepare_ns ($callback)
797 828
798Call the callback just before the process would block. You can still 829Call the callback just before the process would block. You can still
799create/modify any watchers at this point. 830create/modify any watchers at this point.
800 831
801See the EV::check watcher, below, for explanations and an example. 832See the EV::check watcher, below, for explanations and an example.
886 917
887Call the callback before the event loop is resumed in the child process 918Call the callback before the event loop is resumed in the child process
888after a fork. 919after a fork.
889 920
890The C<fork_ns> variant doesn't start (activate) the newly created watcher. 921The C<fork_ns> variant doesn't start (activate) the newly created watcher.
922
923=back
924
925
926=head3 EMBED WATCHERS - when one backend isn't enough...
927
928This is a rather advanced watcher type that lets you embed one event loop
929into another (currently only IO events are supported in the embedded
930loop, other types of watchers might be handled in a delayed or incorrect
931fashion and must not be used).
932
933See the libev documentation at
934L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
935for more details.
936
937In short, this watcher is most useful on BSD systems without working
938kqueue to still be able to handle a large number of sockets:
939
940 my $socket_loop;
941
942 # check wether we use SELECT or POLL _and_ KQUEUE is supported
943 if (
944 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
945 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
946 ) {
947 # use kqueue for sockets
948 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
949 }
950
951 # use the default loop otherwise
952 $socket_loop ||= EV::default_loop;
953
954=over 4
955
956=item $w = EV::embed $otherloop, $callback
957
958=item $w = EV::embed_ns $otherloop, $callback
959
960=item $w = $loop->embed ($otherloop, $callback)
961
962=item $w = $loop->embed_ns ($otherloop, $callback)
963
964Call the callback when the embedded event loop (C<$otherloop>) has any
965I/O activity. The C<$callback> should alwas be specified as C<undef> in
966this version of EV, which means the embedded event loop will be managed
967automatically.
968
969The C<embed_ns> variant doesn't start (activate) the newly created watcher.
891 970
892=back 971=back
893 972
894 973
895=head1 PERL SIGNALS 974=head1 PERL SIGNALS

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