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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 | |
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56 | =head1 BEFORE YOU START USING THIS MODULE |
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57 | |
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58 | If you only need timer, I/O, signal, child and idle watchers and not the |
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59 | advanced functionality of this module, consider using L<AnyEvent> instead, |
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60 | specifically the simplified API described in L<AE>. |
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61 | |
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62 | When used with EV as backend, the L<AE> API is as fast as the native L<EV> |
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63 | API, but your programs/modules will still run with many other event loops. |
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64 | |
56 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
57 | |
66 | |
58 | This module provides an interface to libev |
67 | This 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 |
60 | below is comprehensive, one might also consult the documentation of |
69 | below is comprehensive, one might also consult the documentation of |
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76 | |
85 | |
77 | =cut |
86 | =cut |
78 | |
87 | |
79 | package EV; |
88 | package EV; |
80 | |
89 | |
81 | no warnings; |
90 | use common::sense; |
82 | use strict; |
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83 | |
91 | |
84 | BEGIN { |
92 | BEGIN { |
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 = |
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300 | timeout. Otherwise a EV::timer with this value will be started. |
308 | timeout. Otherwise a EV::timer with this value will be started. |
301 | |
309 | |
302 | When an error occurs or either the timeout or I/O watcher triggers, then |
310 | When an error occurs or either the timeout or I/O watcher triggers, then |
303 | the callback will be called with the received event set (in general |
311 | the callback will be called with the received event set (in general |
304 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
312 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
305 | C<EV::WRITE> and C<EV::TIMEOUT>). |
313 | C<EV::WRITE> and C<EV::TIMER>). |
306 | |
314 | |
307 | EV::once doesn't return anything: the watchers stay active till either |
315 | EV::once doesn't return anything: the watchers stay active till either |
308 | of them triggers, then they will be stopped and freed, and the callback |
316 | of them triggers, then they will be stopped and freed, and the callback |
309 | invoked. |
317 | invoked. |
310 | |
318 | |
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332 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
340 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
333 | wait interval for timer events. See the libev documentation at |
341 | wait interval for timer events. See the libev documentation at |
334 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
342 | L<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 | |
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345 | =item $count = EV::pending_count |
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346 | |
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347 | =item $count = $loop->pending_count |
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348 | |
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349 | Returns the number of currently pending watchers. |
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350 | |
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351 | =item EV::invoke_pending |
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352 | |
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353 | =item $loop->invoke_pending |
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354 | |
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355 | Invoke all currently pending watchers. |
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356 | |
337 | =back |
357 | =back |
338 | |
358 | |
339 | |
359 | |
340 | =head1 WATCHER OBJECTS |
360 | =head1 WATCHER OBJECTS |
341 | |
361 | |
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355 | |
375 | |
356 | Each watcher type has its associated bit in revents, so you can use the |
376 | Each watcher type has its associated bit in revents, so you can use the |
357 | same callback for multiple watchers. The event mask is named after the |
377 | same callback for multiple watchers. The event mask is named after the |
358 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
378 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
359 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
379 | EV::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). |
361 | uses EV::TIMEOUT). |
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362 | |
381 | |
363 | In the rare case where one wants to create a watcher but not start it at |
382 | In the rare case where one wants to create a watcher but not start it at |
364 | the same time, each constructor has a variant with a trailing C<_ns> in |
383 | the same time, each constructor has a variant with a trailing C<_ns> in |
365 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
384 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
366 | |
385 | |
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445 | |
464 | |
446 | =item $previous_state = $w->keepalive ($bool) |
465 | =item $previous_state = $w->keepalive ($bool) |
447 | |
466 | |
448 | Normally, C<EV::loop> will return when there are no active watchers |
467 | Normally, 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 |
450 | convinient because it allows you to start your watchers (and your jobs), |
469 | convenient because it allows you to start your watchers (and your jobs), |
451 | call C<EV::loop> once and when it returns you know that all your jobs are |
470 | call C<EV::loop> once and when it returns you know that all your jobs are |
452 | finished (or they forgot to register some watchers for their task :). |
471 | finished (or they forgot to register some watchers for their task :). |
453 | |
472 | |
454 | Sometimes, however, this gets in your way, for example when the module |
473 | Sometimes, however, this gets in your way, for example when the module |
455 | that calls C<EV::loop> (usually the main program) is not the same module |
474 | that calls C<EV::loop> (usually the main program) is not the same module |
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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 | |
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711 | =item $w = $loop->signal ($signal, $callback) |
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712 | |
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713 | =item $w = $loop->signal_ns ($signal, $callback) |
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714 | |
692 | Call the callback when $signal is received (the signal can be specified by |
715 | Call the callback when $signal is received (the signal can be specified by |
693 | number or by name, just as with C<kill> or C<%SIG>). |
716 | number or by name, just as with C<kill> or C<%SIG>). |
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717 | |
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718 | Only one event loop can grab a given signal - attempting to grab the same |
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719 | signal from two EV loops will crash the program immediately or cause data |
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720 | corruption. |
694 | |
721 | |
695 | EV will grab the signal for the process (the kernel only allows one |
722 | EV will grab the signal for the process (the kernel only allows one |
696 | component to receive a signal at a time) when you start a signal watcher, |
723 | component to receive a signal at a time) when you start a signal watcher, |
697 | and removes it again when you stop it. Perl does the same when you |
724 | and removes it again when you stop it. Perl does the same when you |
698 | add/remove callbacks to C<%SIG>, so watch out. |
725 | add/remove callbacks to C<%SIG>, so watch out. |
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923 | =item $w = $loop->check_ns ($callback) |
950 | =item $w = $loop->check_ns ($callback) |
924 | |
951 | |
925 | Call the callback just after the process wakes up again (after it has |
952 | Call the callback just after the process wakes up again (after it has |
926 | gathered events), but before any other callbacks have been invoked. |
953 | gathered events), but before any other callbacks have been invoked. |
927 | |
954 | |
928 | This is used to integrate other event-based software into the EV |
955 | This can be used to integrate other event-based software into the EV |
929 | mainloop: You register a prepare callback and in there, you create io and |
956 | mainloop: You register a prepare callback and in there, you create io and |
930 | timer watchers as required by the other software. Here is a real-world |
957 | timer watchers as required by the other software. Here is a real-world |
931 | example of integrating Net::SNMP (with some details left out): |
958 | example of integrating Net::SNMP (with some details left out): |
932 | |
959 | |
933 | our @snmp_watcher; |
960 | our @snmp_watcher; |
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967 | The callbacks of the created watchers will not be called as the watchers |
994 | The callbacks of the created watchers will not be called as the watchers |
968 | are destroyed before this can happen (remember EV::check gets called |
995 | are destroyed before this can happen (remember EV::check gets called |
969 | first). |
996 | first). |
970 | |
997 | |
971 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
998 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
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999 | |
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1000 | =item EV::CHECK constant issues |
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1001 | |
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1002 | Like all other watcher types, there is a bitmask constant for use in |
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1003 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
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1004 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
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1005 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
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1006 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
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1007 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
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1008 | safe 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 |
… | |
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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 | |
1049 | Async watchers are provided by EV, but have little use in perl directly, as perl |
1086 | Async watchers are provided by EV, but have little use in perl directly, |
1050 | neither supports threads nor direct access to signal handlers or other |
1087 | as perl neither supports threads running in parallel nor direct access to |
1051 | contexts where they could be of value. |
1088 | signal handlers or other contexts where they could be of value. |
1052 | |
1089 | |
1053 | It is, however, possible to use them from the XS level. |
1090 | It is, however, possible to use them from the XS level. |
1054 | |
1091 | |
1055 | Please see the libev documentation for further details. |
1092 | Please see the libev documentation for further details. |
1056 | |
1093 | |
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1084 | my $async_check = EV::check sub { }; |
1121 | my $async_check = EV::check sub { }; |
1085 | |
1122 | |
1086 | This ensures that perl gets into control for a short time to handle any |
1123 | This ensures that perl gets into control for a short time to handle any |
1087 | pending signals, and also ensures (slightly) slower overall operation. |
1124 | pending signals, and also ensures (slightly) slower overall operation. |
1088 | |
1125 | |
1089 | =head1 THREADS |
1126 | =head1 ITHREADS |
1090 | |
1127 | |
1091 | Threads are not supported by this module in any way. Perl pseudo-threads |
1128 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
1092 | is evil stuff and must die. As soon as Perl gains real threads I will work |
1129 | is evil stuff and must die. Real threads as provided by Coro are fully |
1093 | on thread support for it. |
1130 | supported (and enhanced support is available via L<Coro::EV>). |
1094 | |
1131 | |
1095 | =head1 FORK |
1132 | =head1 FORK |
1096 | |
1133 | |
1097 | Most of the "improved" event delivering mechanisms of modern operating |
1134 | Most of the "improved" event delivering mechanisms of modern operating |
1098 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
1135 | systems have quite a few problems with fork(2) (to put it bluntly: it is |