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Comparing EV/EV.pm (file contents):
Revision 1.59 by root, Sat Dec 1 22:51:34 2007 UTC vs.
Revision 1.68 by root, Sun Dec 9 03:54:13 2007 UTC

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 libev
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
62watcher semantics or some discussion on the available backends, or how to 62watcher semantics or some discussion on the available backends, or how to
63force a specific backend with C<LIBEV_FLAGS>. 63force a specific backend with C<LIBEV_FLAGS>, or just about in any case
64because it has much more detailed information.
64 65
65=cut 66=cut
66 67
67package EV; 68package EV;
68 69
69use strict; 70use strict;
70 71
71BEGIN { 72BEGIN {
72 our $VERSION = '1.5'; 73 our $VERSION = '1.72';
73 use XSLoader; 74 use XSLoader;
74 XSLoader::load "EV", $VERSION; 75 XSLoader::load "EV", $VERSION;
75} 76}
76 77
77@EV::IO::ISA = 78@EV::IO::ISA =
92=over 4 93=over 4
93 94
94=item $EV::DIED 95=item $EV::DIED
95 96
96Must contain a reference to a function that is called when a callback 97Must contain a reference to a function that is called when a callback
97throws an exception (with $@ containing thr error). The default prints an 98throws an exception (with $@ containing the error). The default prints an
98informative message and continues. 99informative message and continues.
99 100
100If this callback throws an exception it will be silently ignored. 101If this callback throws an exception it will be silently ignored.
101 102
102=item $time = EV::time 103=item $time = EV::time
130When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 131When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131innermost call to EV::loop return. 132innermost call to EV::loop return.
132 133
133When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 134When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134fast as possible. 135fast as possible.
136
137=item $count = EV::loop_count
138
139Return the number of times the event loop has polled for new
140events. Sometiems useful as a generation counter.
135 141
136=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 142=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
137 143
138This function rolls together an I/O and a timer watcher for a single 144This function rolls together an I/O and a timer watcher for a single
139one-shot event without the need for managing a watcher object. 145one-shot event without the need for managing a watcher object.
154 160
155EV::once doesn't return anything: the watchers stay active till either 161EV::once doesn't return anything: the watchers stay active till either
156of them triggers, then they will be stopped and freed, and the callback 162of them triggers, then they will be stopped and freed, and the callback
157invoked. 163invoked.
158 164
165=item EV::feed_fd_event ($fd, $revents)
166
167Feed an event on a file descriptor into EV. EV will react to this call as
168if the readyness notifications specified by C<$revents> (a combination of
169C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
170
171=item EV::feed_signal_event ($signal)
172
173Feed a signal event into EV. EV will react to this call as if the signal
174specified by C<$signal> had occured.
175
159=back 176=back
177
160 178
161=head2 WATCHER OBJECTS 179=head2 WATCHER OBJECTS
162 180
163A watcher is an object that gets created to record your interest in some 181A watcher is an object that gets created to record your interest in some
164event. For instance, if you want to wait for STDIN to become readable, you 182event. For instance, if you want to wait for STDIN to become readable, you
175events. 193events.
176 194
177Each watcher type has its associated bit in revents, so you can use the 195Each watcher type has its associated bit in revents, so you can use the
178same callback for multiple watchers. The event mask is named after the 196same callback for multiple watchers. The event mask is named after the
179type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 197type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
180EV::periodic sets EV::PERIODIC and so on, with the exception of IO events 198EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
181(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 199(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
182uses EV::TIMEOUT). 200uses EV::TIMEOUT).
183 201
184In the rare case where one wants to create a watcher but not start it at 202In the rare case where one wants to create a watcher but not start it at
185the same time, each constructor has a variant with a trailing C<_ns> in 203the same time, each constructor has a variant with a trailing C<_ns> in
207 225
208=item $w->stop 226=item $w->stop
209 227
210Stop a watcher if it is active. Also clear any pending events (events that 228Stop a watcher if it is active. Also clear any pending events (events that
211have been received but that didn't yet result in a callback invocation), 229have been received but that didn't yet result in a callback invocation),
212regardless of wether the watcher was active or not. 230regardless of whether the watcher was active or not.
213 231
214=item $bool = $w->is_active 232=item $bool = $w->is_active
215 233
216Returns true if the watcher is active, false otherwise. 234Returns true if the watcher is active, false otherwise.
217 235
247The default priority of any newly-created watcher is 0. 265The default priority of any newly-created watcher is 0.
248 266
249Note that the priority semantics have not yet been fleshed out and are 267Note that the priority semantics have not yet been fleshed out and are
250subject to almost certain change. 268subject to almost certain change.
251 269
252=item $w->trigger ($revents) 270=item $w->invoke ($revents)
253 271
254Call the callback *now* with the given event mask. 272Call the callback *now* with the given event mask.
273
274=item $w->feed_event ($revents)
275
276Feed some events on this watcher into EV. EV will react to this call as if
277the watcher had received the given C<$revents> mask.
278
279=item $revents = $w->clear_pending
280
281If the watcher is pending, this function returns clears its pending status
282and returns its C<$revents> bitset (as if its callback was invoked). If the
283watcher isn't pending it does nothing and returns C<0>.
255 284
256=item $previous_state = $w->keepalive ($bool) 285=item $previous_state = $w->keepalive ($bool)
257 286
258Normally, C<EV::loop> will return when there are no active watchers 287Normally, C<EV::loop> will return when there are no active watchers
259(which is a "deadlock" because no progress can be made anymore). This is 288(which is a "deadlock" because no progress can be made anymore). This is
272though your watcher is active, it won't keep C<EV::loop> from returning. 301though your watcher is active, it won't keep C<EV::loop> from returning.
273 302
274The initial value for keepalive is true (enabled), and you cna change it 303The initial value for keepalive is true (enabled), and you cna change it
275any time. 304any time.
276 305
277Example: Register an IO watcher for some UDP socket but do not keep the 306Example: Register an I/O watcher for some UDP socket but do not keep the
278event loop from running just because of that watcher. 307event loop from running just because of that watcher.
279 308
280 my $udp_socket = ... 309 my $udp_socket = ...
281 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 310 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282 $udp_watcher->keepalive (0); 311 $udp_watcher->keepalive (0);
286 315
287=head2 WATCHER TYPES 316=head2 WATCHER TYPES
288 317
289Each of the following subsections describes a single watcher type. 318Each of the following subsections describes a single watcher type.
290 319
291=head3 IO WATCHERS - is this file descriptor readable or writable? 320=head3 I/O WATCHERS - is this file descriptor readable or writable?
292 321
293=over 4 322=over 4
294 323
295=item $w = EV::io $fileno_or_fh, $eventmask, $callback 324=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296 325
640 669
641=item $w = EV::idle $callback 670=item $w = EV::idle $callback
642 671
643=item $w = EV::idle_ns $callback 672=item $w = EV::idle_ns $callback
644 673
645Call the callback when there are no pending io, timer/periodic, signal or 674Call the callback when there are no other pending watchers of the same or
646child events, i.e. when the process is idle. 675higher priority (excluding check, prepare and other idle watchers of the
676same or lower priority, of course). They are called idle watchers because
677when the watcher is the highest priority pending event in the process, the
678process is considered to be idle at that priority.
679
680If you want a watcher that is only ever called when I<no> other events are
681outstanding you have to set the priority to C<EV::MINPRI>.
647 682
648The process will not block as long as any idle watchers are active, and 683The process will not block as long as any idle watchers are active, and
649they will be called repeatedly until stopped. 684they will be called repeatedly until stopped.
685
686For example, if you have idle watchers at priority C<0> and C<1>, and
687an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
688and the I/O watcher will always run when ready. Only when the idle watcher
689at priority C<1> is stopped and the I/O watcher at priority C<0> is not
690pending with the C<0>-priority idle watcher be invoked.
650 691
651The C<idle_ns> variant doesn't start (activate) the newly created watcher. 692The C<idle_ns> variant doesn't start (activate) the newly created watcher.
652 693
653=back 694=back
654 695
695 or return; 736 or return;
696 737
697 # make the dispatcher handle any outstanding stuff 738 # make the dispatcher handle any outstanding stuff
698 ... not shown 739 ... not shown
699 740
700 # create an IO watcher for each and every socket 741 # create an I/O watcher for each and every socket
701 @snmp_watcher = ( 742 @snmp_watcher = (
702 (map { EV::io $_, EV::READ, sub { } } 743 (map { EV::io $_, EV::READ, sub { } }
703 keys %{ $dispatcher->{_descriptors} }), 744 keys %{ $dispatcher->{_descriptors} }),
704 745
705 EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] 746 EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
747 788
748The C<fork_ns> variant doesn't start (activate) the newly created watcher. 789The C<fork_ns> variant doesn't start (activate) the newly created watcher.
749 790
750=back 791=back
751 792
793
794=head1 PERL SIGNALS
795
796While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
797with EV is as the same as any other C library: Perl-signals will only be
798handled when Perl runs, which means your signal handler might be invoked
799only the next time an event callback is invoked.
800
801The solution is to use EV signal watchers (see C<EV::signal>), which will
802ensure proper operations with regards to other event watchers.
803
804If you cannot do this for whatever reason, you can also force a watcher
805to be called on every event loop iteration by installing a C<EV::check>
806watcher:
807
808 my $async_check = EV::check sub { };
809
810This ensures that perl shortly gets into control for a short time, and
811also ensures slower overall operation.
752 812
753=head1 THREADS 813=head1 THREADS
754 814
755Threads are not supported by this module in any way. Perl pseudo-threads 815Threads are not supported by this module in any way. Perl pseudo-threads
756is evil stuff and must die. As soon as Perl gains real threads I will work 816is evil stuff and must die. As soon as Perl gains real threads I will work
778our $DIED = sub { 838our $DIED = sub {
779 warn "EV: error in callback (ignoring): $@"; 839 warn "EV: error in callback (ignoring): $@";
780}; 840};
781 841
782default_loop 842default_loop
783 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; 843 or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
784 844
7851; 8451;
786 846
787=head1 SEE ALSO 847=head1 SEE ALSO
788 848

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