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Revision 1.120 by root, Sun Jul 19 01:36:34 2009 UTC vs.
Revision 1.133 by root, Tue Jan 11 02:31:24 2011 UTC

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51 # MAINLOOP 51 # MAINLOOP
52 EV::loop; # loop until EV::unloop is called or all watchers stop 52 EV::loop; # loop until EV::unloop is called or all watchers stop
53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55 55
56=head1 BEFORE YOU START USING THIS MODULE
57
58If you only need timer, I/O, signal, child and idle watchers and not the
59advanced functionality of this module, consider using L<AnyEvent> instead,
60specifically the simplified API described in L<AE>.
61
62When used with EV as backend, the L<AE> API is as fast as the native L<EV>
63API, but your programs/modules will still run with many other event loops.
64
56=head1 DESCRIPTION 65=head1 DESCRIPTION
57 66
58This module provides an interface to libev 67This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 68(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of 69below is comprehensive, one might also consult the documentation of
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68can use it through the L<AnyEvent> module, stay portable to other event 77can use it through the L<AnyEvent> module, stay portable to other event
69loops (if you don't rely on any watcher types not available through it) 78loops (if you don't rely on any watcher types not available through it)
70and still be faster than with any other event loop currently supported in 79and still be faster than with any other event loop currently supported in
71Perl. 80Perl.
72 81
82=head2 PORTING FROM EV 3.X to 4.X
83
84EV version 4 introduces a number of incompatible changes summarised
85here. According to the depreciation strategy used by libev, there is a
86compatibility layer in place so programs should continue to run unchanged
87(the XS interface lacks this layer, so programs using that one need to be
88updated).
89
90This compatibility layer will be switched off in some future release.
91
92All changes relevant to Perl are renames of symbols, functions and
93methods:
94
95 EV::loop => EV::run
96 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
97 EV::LOOP_ONESHOT => EV::RUN_ONCE
98
99 EV::unloop => EV::break
100 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
101 EV::UNLOOP_ONE => EV::BREAK_ONE
102 EV::UNLOOP_ALL => EV::BREAK_ALL
103
104 EV::TIMEOUT => EV::TIMER
105
106 EV::loop_count => EV::iteration
107 EV::loop_depth => EV::depth
108 EV::loop_verify => EV::verify
109
110The loop object methods corresponding to the functions above have been
111similarly renamed.
112
73=head2 MODULE EXPORTS 113=head2 MODULE EXPORTS
74 114
75This module does not export any symbols. 115This module does not export any symbols.
76 116
77=cut 117=cut
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79package EV; 119package EV;
80 120
81use common::sense; 121use common::sense;
82 122
83BEGIN { 123BEGIN {
84 our $VERSION = '3.8'; 124 our $VERSION = '4.02';
85 use XSLoader; 125 use XSLoader;
86 XSLoader::load "EV", $VERSION; 126 XSLoader::load "EV", $VERSION;
87} 127}
88 128
89@EV::IO::ISA = 129@EV::IO::ISA =
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259Begin checking for events and calling callbacks. It returns when a 299Begin checking for events and calling callbacks. It returns when a
260callback calls EV::unloop. 300callback calls EV::unloop.
261 301
262The $flags argument can be one of the following: 302The $flags argument can be one of the following:
263 303
264 0 as above 304 0 as above
265 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 305 EV::LOOP_ONCE block at most once (wait, but do not loop)
266 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 306 EV::LOOP_NOWAIT do not block at all (fetch/handle events but do not wait)
267 307
268=item EV::unloop [$how] 308=item EV::break [$how]
269 309
270=item $loop->unloop ([$how]) 310=item $loop->break ([$how])
271 311
272When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 312When called with no arguments or an argument of EV::BREAK_ONE, makes the
273innermost call to EV::loop return. 313innermost call to EV::loop return.
274 314
275When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 315When called with an argument of EV::BREAK_ALL, all calls to EV::loop will
276fast as possible. 316return as fast as possible.
317
318When called with an argument of EV::BREAK_CANCEL, any pending break will
319be cancelled.
277 320
278=item $count = EV::loop_count 321=item $count = EV::loop_count
279 322
280=item $count = $loop->loop_count 323=item $count = $loop->loop_count
281 324
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299timeout. Otherwise a EV::timer with this value will be started. 342timeout. Otherwise a EV::timer with this value will be started.
300 343
301When an error occurs or either the timeout or I/O watcher triggers, then 344When an error occurs or either the timeout or I/O watcher triggers, then
302the callback will be called with the received event set (in general 345the callback will be called with the received event set (in general
303you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, 346you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
304C<EV::WRITE> and C<EV::TIMEOUT>). 347C<EV::WRITE> and C<EV::TIMER>).
305 348
306EV::once doesn't return anything: the watchers stay active till either 349EV::once doesn't return anything: the watchers stay active till either
307of them triggers, then they will be stopped and freed, and the callback 350of them triggers, then they will be stopped and freed, and the callback
308invoked. 351invoked.
309 352
310=item EV::feed_fd_event ($fd, $revents) 353=item EV::feed_fd_event $fd, $revents
311 354
312=item $loop->feed_fd_event ($fd, $revents) 355=item $loop->feed_fd_event ($fd, $revents)
313 356
314Feed an event on a file descriptor into EV. EV will react to this call as 357Feed an event on a file descriptor into EV. EV will react to this call as
315if the readyness notifications specified by C<$revents> (a combination of 358if the readyness notifications specified by C<$revents> (a combination of
316C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 359C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
317 360
318=item EV::feed_signal_event ($signal) 361=item EV::feed_signal_event $signal
319 362
320Feed a signal event into EV. EV will react to this call as if the signal 363Feed a signal event into the default loop. EV will react to this call as
321specified by C<$signal> had occured. 364if the signal specified by C<$signal> had occured.
365
366=item EV::feed_signal $signal
367
368Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
369regardless of which loop has registered the signal, and is mainly useful
370fro custom signal implementations.
322 371
323=item EV::set_io_collect_interval $time 372=item EV::set_io_collect_interval $time
324 373
325=item $loop->set_io_collect_interval ($time) 374=item $loop->set_io_collect_interval ($time)
326 375
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366 415
367Each watcher type has its associated bit in revents, so you can use the 416Each watcher type has its associated bit in revents, so you can use the
368same callback for multiple watchers. The event mask is named after the 417same callback for multiple watchers. The event mask is named after the
369type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 418type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
370EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 419EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
371(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 420(which can set both EV::READ and EV::WRITE bits).
372uses EV::TIMEOUT).
373 421
374In the rare case where one wants to create a watcher but not start it at 422In the rare case where one wants to create a watcher but not start it at
375the same time, each constructor has a variant with a trailing C<_ns> in 423the same time, each constructor has a variant with a trailing C<_ns> in
376its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 424its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
377 425
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456 504
457=item $previous_state = $w->keepalive ($bool) 505=item $previous_state = $w->keepalive ($bool)
458 506
459Normally, C<EV::loop> will return when there are no active watchers 507Normally, C<EV::loop> will return when there are no active watchers
460(which is a "deadlock" because no progress can be made anymore). This is 508(which is a "deadlock" because no progress can be made anymore). This is
461convinient because it allows you to start your watchers (and your jobs), 509convenient because it allows you to start your watchers (and your jobs),
462call C<EV::loop> once and when it returns you know that all your jobs are 510call C<EV::loop> once and when it returns you know that all your jobs are
463finished (or they forgot to register some watchers for their task :). 511finished (or they forgot to register some watchers for their task :).
464 512
465Sometimes, however, this gets in your way, for example when the module 513Sometimes, however, this gets in your way, for example when the module
466that calls C<EV::loop> (usually the main program) is not the same module 514that calls C<EV::loop> (usually the main program) is not the same module
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698 746
699=item $w = EV::signal $signal, $callback 747=item $w = EV::signal $signal, $callback
700 748
701=item $w = EV::signal_ns $signal, $callback 749=item $w = EV::signal_ns $signal, $callback
702 750
751=item $w = $loop->signal ($signal, $callback)
752
753=item $w = $loop->signal_ns ($signal, $callback)
754
703Call the callback when $signal is received (the signal can be specified by 755Call the callback when $signal is received (the signal can be specified by
704number or by name, just as with C<kill> or C<%SIG>). 756number or by name, just as with C<kill> or C<%SIG>).
757
758Only one event loop can grab a given signal - attempting to grab the same
759signal from two EV loops will crash the program immediately or cause data
760corruption.
705 761
706EV will grab the signal for the process (the kernel only allows one 762EV will grab the signal for the process (the kernel only allows one
707component to receive a signal at a time) when you start a signal watcher, 763component to receive a signal at a time) when you start a signal watcher,
708and removes it again when you stop it. Perl does the same when you 764and removes it again when you stop it. Perl does the same when you
709add/remove callbacks to C<%SIG>, so watch out. 765add/remove callbacks to C<%SIG>, so watch out.
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934=item $w = $loop->check_ns ($callback) 990=item $w = $loop->check_ns ($callback)
935 991
936Call the callback just after the process wakes up again (after it has 992Call the callback just after the process wakes up again (after it has
937gathered events), but before any other callbacks have been invoked. 993gathered events), but before any other callbacks have been invoked.
938 994
939This is used to integrate other event-based software into the EV 995This can be used to integrate other event-based software into the EV
940mainloop: You register a prepare callback and in there, you create io and 996mainloop: You register a prepare callback and in there, you create io and
941timer watchers as required by the other software. Here is a real-world 997timer watchers as required by the other software. Here is a real-world
942example of integrating Net::SNMP (with some details left out): 998example of integrating Net::SNMP (with some details left out):
943 999
944 our @snmp_watcher; 1000 our @snmp_watcher;
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978The callbacks of the created watchers will not be called as the watchers 1034The callbacks of the created watchers will not be called as the watchers
979are destroyed before this can happen (remember EV::check gets called 1035are destroyed before this can happen (remember EV::check gets called
980first). 1036first).
981 1037
982The C<check_ns> variant doesn't start (activate) the newly created watcher. 1038The C<check_ns> variant doesn't start (activate) the newly created watcher.
1039
1040=item EV::CHECK constant issues
1041
1042Like all other watcher types, there is a bitmask constant for use in
1043C<$revents> and other places. The C<EV::CHECK> is special as it has
1044the same name as the C<CHECK> sub called by Perl. This doesn't cause
1045big issues on newer perls (beginning with 5.8.9), but it means thatthe
1046constant must be I<inlined>, i.e. runtime calls will not work. That means
1047that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1048safe side.
983 1049
984=back 1050=back
985 1051
986 1052
987=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1053=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
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1131 1197
11321; 11981;
1133 1199
1134=head1 SEE ALSO 1200=head1 SEE ALSO
1135 1201
1202L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
1136L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1203(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
1137event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1204loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1138coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1205integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1139event-loop agnostic and portable event driven programming. 1206event-loop agnostic and portable event driven programming.
1140 1207
1141=head1 AUTHOR 1208=head1 AUTHOR
1142 1209
1143 Marc Lehmann <schmorp@schmorp.de> 1210 Marc Lehmann <schmorp@schmorp.de>

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