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Revision 1.119 by root, Tue Jul 14 20:34:58 2009 UTC vs.
Revision 1.128 by root, Thu Oct 21 02:46:59 2010 UTC

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
79package EV; 88package EV;
80 89
81use common::sense; 90use common::sense;
82 91
83BEGIN { 92BEGIN {
84 our $VERSION = '3.7'; 93 our $VERSION = '4.00';
85 use XSLoader; 94 use XSLoader;
86 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
87} 96}
88 97
89@EV::IO::ISA = 98@EV::IO::ISA =
299timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
300 309
301When an error occurs or either the timeout or I/O watcher triggers, then 310When 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 311the 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>, 312you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
304C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
305 314
306EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
307of them triggers, then they will be stopped and freed, and the callback 316of them triggers, then they will be stopped and freed, and the callback
308invoked. 317invoked.
309 318
366 375
367Each watcher type has its associated bit in revents, so you can use the 376Each 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 377same callback for multiple watchers. The event mask is named after the
369type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 378type, 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 379EV::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 380(which can set both EV::READ and EV::WRITE bits).
372uses EV::TIMEOUT).
373 381
374In the rare case where one wants to create a watcher but not start it at 382In 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 383the 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. 384its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
377 385
456 464
457=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
458 466
459Normally, C<EV::loop> will return when there are no active watchers 467Normally, 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 468(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), 469convenient 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 470call 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 :). 471finished (or they forgot to register some watchers for their task :).
464 472
465Sometimes, however, this gets in your way, for example when the module 473Sometimes, 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 474that calls C<EV::loop> (usually the main program) is not the same module
698 706
699=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
700 708
701=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
702 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
703Call the callback when $signal is received (the signal can be specified by 715Call the callback when $signal is received (the signal can be specified by
704number or by name, just as with C<kill> or C<%SIG>). 716number or by name, just as with C<kill> or C<%SIG>).
717
718Only one event loop can grab a given signal - attempting to grab the same
719signal from two EV loops will crash the program immediately or cause data
720corruption.
705 721
706EV will grab the signal for the process (the kernel only allows one 722EV 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, 723component 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 724and removes it again when you stop it. Perl does the same when you
709add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
934=item $w = $loop->check_ns ($callback) 950=item $w = $loop->check_ns ($callback)
935 951
936Call the callback just after the process wakes up again (after it has 952Call the callback just after the process wakes up again (after it has
937gathered events), but before any other callbacks have been invoked. 953gathered events), but before any other callbacks have been invoked.
938 954
939This is used to integrate other event-based software into the EV 955This 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 956mainloop: 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 957timer watchers as required by the other software. Here is a real-world
942example of integrating Net::SNMP (with some details left out): 958example of integrating Net::SNMP (with some details left out):
943 959
944 our @snmp_watcher; 960 our @snmp_watcher;
978The callbacks of the created watchers will not be called as the watchers 994The callbacks of the created watchers will not be called as the watchers
979are destroyed before this can happen (remember EV::check gets called 995are destroyed before this can happen (remember EV::check gets called
980first). 996first).
981 997
982The C<check_ns> variant doesn't start (activate) the newly created watcher. 998The C<check_ns> variant doesn't start (activate) the newly created watcher.
999
1000=item EV::CHECK constant issues
1001
1002Like all other watcher types, there is a bitmask constant for use in
1003C<$revents> and other places. The C<EV::CHECK> is special as it has
1004the same name as the C<CHECK> sub called by Perl. This doesn't cause
1005big issues on newer perls (beginning with 5.8.9), but it means thatthe
1006constant must be I<inlined>, i.e. runtime calls will not work. That means
1007that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1008safe side.
983 1009
984=back 1010=back
985 1011
986 1012
987=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1013=head3 FORK WATCHERS - the audacity to resume the event loop after a fork

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