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Comparing EV/EV.pm (file contents):
Revision 1.114 by root, Wed Apr 15 19:35:53 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
76 85
77=cut 86=cut
78 87
79package EV; 88package EV;
80 89
81no warnings; 90use common::sense;
82use strict;
83 91
84BEGIN { 92BEGIN {
85 our $VERSION = '3.53'; 93 our $VERSION = '4.00';
86 use XSLoader; 94 use XSLoader;
87 XSLoader::load "EV", $VERSION; 95 XSLoader::load "EV", $VERSION;
88} 96}
89 97
90@EV::IO::ISA = 98@EV::IO::ISA =
300timeout. Otherwise a EV::timer with this value will be started. 308timeout. Otherwise a EV::timer with this value will be started.
301 309
302When 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
303the callback will be called with the received event set (in general 311the callback will be called with the received event set (in general
304you 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>,
305C<EV::WRITE> and C<EV::TIMEOUT>). 313C<EV::WRITE> and C<EV::TIMER>).
306 314
307EV::once doesn't return anything: the watchers stay active till either 315EV::once doesn't return anything: the watchers stay active till either
308of 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
309invoked. 317invoked.
310 318
332These advanced functions set the minimum block interval when polling for I/O events and the minimum 340These advanced functions set the minimum block interval when polling for I/O events and the minimum
333wait interval for timer events. See the libev documentation at 341wait interval for timer events. See the libev documentation at
334L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> 342L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
335(locally installed as F<EV::libev>) for a more detailed discussion. 343(locally installed as F<EV::libev>) for a more detailed discussion.
336 344
345=item $count = EV::pending_count
346
347=item $count = $loop->pending_count
348
349Returns the number of currently pending watchers.
350
351=item EV::invoke_pending
352
353=item $loop->invoke_pending
354
355Invoke all currently pending watchers.
356
337=back 357=back
338 358
339 359
340=head1 WATCHER OBJECTS 360=head1 WATCHER OBJECTS
341 361
355 375
356Each 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
357same callback for multiple watchers. The event mask is named after the 377same callback for multiple watchers. The event mask is named after the
358type, 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,
359EV::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
360(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).
361uses EV::TIMEOUT).
362 381
363In 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
364the 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
365its 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.
366 385
445 464
446=item $previous_state = $w->keepalive ($bool) 465=item $previous_state = $w->keepalive ($bool)
447 466
448Normally, C<EV::loop> will return when there are no active watchers 467Normally, C<EV::loop> will return when there are no active watchers
449(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
450convinient because it allows you to start your watchers (and your jobs), 469convenient because it allows you to start your watchers (and your jobs),
451call 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
452finished (or they forgot to register some watchers for their task :). 471finished (or they forgot to register some watchers for their task :).
453 472
454Sometimes, however, this gets in your way, for example when the module 473Sometimes, however, this gets in your way, for example when the module
455that 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
687 706
688=item $w = EV::signal $signal, $callback 707=item $w = EV::signal $signal, $callback
689 708
690=item $w = EV::signal_ns $signal, $callback 709=item $w = EV::signal_ns $signal, $callback
691 710
711=item $w = $loop->signal ($signal, $callback)
712
713=item $w = $loop->signal_ns ($signal, $callback)
714
692Call 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
693number 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.
694 721
695EV 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
696component 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,
697and 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
698add/remove callbacks to C<%SIG>, so watch out. 725add/remove callbacks to C<%SIG>, so watch out.
923=item $w = $loop->check_ns ($callback) 950=item $w = $loop->check_ns ($callback)
924 951
925Call 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
926gathered events), but before any other callbacks have been invoked. 953gathered events), but before any other callbacks have been invoked.
927 954
928This is used to integrate other event-based software into the EV 955This can be used to integrate other event-based software into the EV
929mainloop: 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
930timer 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
931example of integrating Net::SNMP (with some details left out): 958example of integrating Net::SNMP (with some details left out):
932 959
933 our @snmp_watcher; 960 our @snmp_watcher;
967The 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
968are destroyed before this can happen (remember EV::check gets called 995are destroyed before this can happen (remember EV::check gets called
969first). 996first).
970 997
971The 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.
972 1009
973=back 1010=back
974 1011
975 1012
976=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
1044 1081
1045=back 1082=back
1046 1083
1047=head3 ASYNC WATCHERS - how to wake up another event loop 1084=head3 ASYNC WATCHERS - how to wake up another event loop
1048 1085
1049Async watchers are provided by EV, but have little use in perl directly, as perl 1086Async watchers are provided by EV, but have little use in perl directly,
1050neither supports threads nor direct access to signal handlers or other 1087as perl neither supports threads running in parallel nor direct access to
1051contexts where they could be of value. 1088signal handlers or other contexts where they could be of value.
1052 1089
1053It is, however, possible to use them from the XS level. 1090It is, however, possible to use them from the XS level.
1054 1091
1055Please see the libev documentation for further details. 1092Please see the libev documentation for further details.
1056 1093
1084 my $async_check = EV::check sub { }; 1121 my $async_check = EV::check sub { };
1085 1122
1086This ensures that perl gets into control for a short time to handle any 1123This ensures that perl gets into control for a short time to handle any
1087pending signals, and also ensures (slightly) slower overall operation. 1124pending signals, and also ensures (slightly) slower overall operation.
1088 1125
1089=head1 THREADS 1126=head1 ITHREADS
1090 1127
1091Threads are not supported by this module in any way. Perl pseudo-threads 1128Ithreads are not supported by this module in any way. Perl pseudo-threads
1092is evil stuff and must die. As soon as Perl gains real threads I will work 1129is evil stuff and must die. Real threads as provided by Coro are fully
1093on thread support for it. 1130supported (and enhanced support is available via L<Coro::EV>).
1094 1131
1095=head1 FORK 1132=head1 FORK
1096 1133
1097Most of the "improved" event delivering mechanisms of modern operating 1134Most of the "improved" event delivering mechanisms of modern operating
1098systems have quite a few problems with fork(2) (to put it bluntly: it is 1135systems have quite a few problems with fork(2) (to put it bluntly: it is

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