| … | |
… | |
| 2 | EV - perl interface to libev, a high performance full-featured event |
2 | EV - perl interface to libev, a high performance full-featured event |
| 3 | loop |
3 | loop |
| 4 | |
4 | |
| 5 | SYNOPSIS |
5 | SYNOPSIS |
| 6 | use EV; |
6 | use EV; |
| 7 | |
7 | |
| 8 | # TIMERS |
8 | # TIMERS |
| 9 | |
9 | |
| 10 | my $w = EV::timer 2, 0, sub { |
10 | my $w = EV::timer 2, 0, sub { |
| 11 | warn "is called after 2s"; |
11 | warn "is called after 2s"; |
| 12 | }; |
12 | }; |
| 13 | |
13 | |
| 14 | my $w = EV::timer 2, 2, sub { |
14 | my $w = EV::timer 2, 2, sub { |
| 15 | warn "is called roughly every 2s (repeat = 2)"; |
15 | warn "is called roughly every 2s (repeat = 2)"; |
| 16 | }; |
16 | }; |
| 17 | |
17 | |
| 18 | undef $w; # destroy event watcher again |
18 | undef $w; # destroy event watcher again |
| 19 | |
19 | |
| 20 | my $w = EV::periodic 0, 60, 0, sub { |
20 | my $w = EV::periodic 0, 60, 0, sub { |
| 21 | warn "is called every minute, on the minute, exactly"; |
21 | warn "is called every minute, on the minute, exactly"; |
| 22 | }; |
22 | }; |
|
|
23 | |
| 23 | |
24 | # IO |
| 24 | # IO |
25 | |
| 25 | |
|
|
| 26 | my $w = EV::io *STDIN, EV::READ, sub { |
26 | my $w = EV::io *STDIN, EV::READ, sub { |
| 27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
| 28 | warn "stdin is readable, you entered: ", <STDIN>; |
28 | warn "stdin is readable, you entered: ", <STDIN>; |
| 29 | }; |
29 | }; |
| 30 | |
30 | |
| 31 | # SIGNALS |
31 | # SIGNALS |
| 32 | |
32 | |
| 33 | my $w = EV::signal 'QUIT', sub { |
33 | my $w = EV::signal 'QUIT', sub { |
| 34 | warn "sigquit received\n"; |
34 | warn "sigquit received\n"; |
| 35 | }; |
35 | }; |
| 36 | |
36 | |
| 37 | # CHILD/PID STATUS CHANGES |
37 | # CHILD/PID STATUS CHANGES |
| 38 | |
38 | |
| 39 | my $w = EV::child 666, 0, sub { |
39 | my $w = EV::child 666, 0, sub { |
| 40 | my ($w, $revents) = @_; |
40 | my ($w, $revents) = @_; |
| 41 | my $status = $w->rstatus; |
41 | my $status = $w->rstatus; |
| 42 | }; |
42 | }; |
| 43 | |
43 | |
| 44 | # STAT CHANGES |
44 | # STAT CHANGES |
| 45 | my $w = EV::stat "/etc/passwd", 10, sub { |
45 | my $w = EV::stat "/etc/passwd", 10, sub { |
| 46 | my ($w, $revents) = @_; |
46 | my ($w, $revents) = @_; |
| 47 | warn $w->path, " has changed somehow.\n"; |
47 | warn $w->path, " has changed somehow.\n"; |
| 48 | }; |
48 | }; |
| 49 | |
49 | |
| 50 | # MAINLOOP |
50 | # MAINLOOP |
| 51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
| 52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
| 53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
| 54 | |
54 | |
| 55 | DESCRIPTION |
55 | DESCRIPTION |
| … | |
… | |
| 263 | the libev documentation at |
263 | the libev documentation at |
| 264 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
264 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
| 265 | ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more |
265 | ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more |
| 266 | detailed discussion. |
266 | detailed discussion. |
| 267 | |
267 | |
|
|
268 | $count = EV::pending_count |
|
|
269 | $count = $loop->pending_count |
|
|
270 | Returns the number of currently pending watchers. |
|
|
271 | |
|
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272 | EV::invoke_pending |
|
|
273 | $loop->invoke_pending |
|
|
274 | Invoke all currently pending watchers. |
|
|
275 | |
| 268 | WATCHER OBJECTS |
276 | WATCHER OBJECTS |
| 269 | A watcher is an object that gets created to record your interest in some |
277 | A watcher is an object that gets created to record your interest in some |
| 270 | event. For instance, if you want to wait for STDIN to become readable, |
278 | event. For instance, if you want to wait for STDIN to become readable, |
| 271 | you would create an EV::io watcher for that: |
279 | you would create an EV::io watcher for that: |
| 272 | |
280 | |
| … | |
… | |
| 358 | the watcher isn't pending it does nothing and returns 0. |
366 | the watcher isn't pending it does nothing and returns 0. |
| 359 | |
367 | |
| 360 | $previous_state = $w->keepalive ($bool) |
368 | $previous_state = $w->keepalive ($bool) |
| 361 | Normally, "EV::loop" will return when there are no active watchers |
369 | Normally, "EV::loop" will return when there are no active watchers |
| 362 | (which is a "deadlock" because no progress can be made anymore). |
370 | (which is a "deadlock" because no progress can be made anymore). |
| 363 | This is convinient because it allows you to start your watchers (and |
371 | This is convenient because it allows you to start your watchers (and |
| 364 | your jobs), call "EV::loop" once and when it returns you know that |
372 | your jobs), call "EV::loop" once and when it returns you know that |
| 365 | all your jobs are finished (or they forgot to register some watchers |
373 | all your jobs are finished (or they forgot to register some watchers |
| 366 | for their task :). |
374 | for their task :). |
| 367 | |
375 | |
| 368 | Sometimes, however, this gets in your way, for example when the |
376 | Sometimes, however, this gets in your way, for example when the |
| … | |
… | |
| 559 | Return the time that the watcher is expected to trigger next. |
567 | Return the time that the watcher is expected to trigger next. |
| 560 | |
568 | |
| 561 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
569 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
| 562 | $w = EV::signal $signal, $callback |
570 | $w = EV::signal $signal, $callback |
| 563 | $w = EV::signal_ns $signal, $callback |
571 | $w = EV::signal_ns $signal, $callback |
|
|
572 | $w = $loop->signal ($signal, $callback) |
|
|
573 | $w = $loop->signal_ns ($signal, $callback) |
| 564 | Call the callback when $signal is received (the signal can be |
574 | Call the callback when $signal is received (the signal can be |
| 565 | specified by number or by name, just as with "kill" or %SIG). |
575 | specified by number or by name, just as with "kill" or %SIG). |
|
|
576 | |
|
|
577 | Only one event loop can grab a given signal - attempting to grab the |
|
|
578 | same signal from two EV loops will crash the program immediately or |
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579 | cause data corruption. |
| 566 | |
580 | |
| 567 | EV will grab the signal for the process (the kernel only allows one |
581 | EV will grab the signal for the process (the kernel only allows one |
| 568 | component to receive a signal at a time) when you start a signal |
582 | component to receive a signal at a time) when you start a signal |
| 569 | watcher, and removes it again when you stop it. Perl does the same |
583 | watcher, and removes it again when you stop it. Perl does the same |
| 570 | when you add/remove callbacks to %SIG, so watch out. |
584 | when you add/remove callbacks to %SIG, so watch out. |
| … | |
… | |
| 820 | |
834 | |
| 821 | In short, this watcher is most useful on BSD systems without working |
835 | In short, this watcher is most useful on BSD systems without working |
| 822 | kqueue to still be able to handle a large number of sockets: |
836 | kqueue to still be able to handle a large number of sockets: |
| 823 | |
837 | |
| 824 | my $socket_loop; |
838 | my $socket_loop; |
| 825 | |
839 | |
| 826 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
840 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
| 827 | if ( |
841 | if ( |
| 828 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
842 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
| 829 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
843 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
| 830 | ) { |
844 | ) { |
| 831 | # use kqueue for sockets |
845 | # use kqueue for sockets |
| 832 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
846 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
| 833 | } |
847 | } |
| 834 | |
848 | |
| 835 | # use the default loop otherwise |
849 | # use the default loop otherwise |
| 836 | $socket_loop ||= EV::default_loop; |
850 | $socket_loop ||= EV::default_loop; |
| 837 | |
851 | |
| 838 | $w = EV::embed $otherloop[, $callback] |
852 | $w = EV::embed $otherloop[, $callback] |
| 839 | $w = EV::embed_ns $otherloop[, $callback] |
853 | $w = EV::embed_ns $otherloop[, $callback] |
| 840 | $w = $loop->embed ($otherloop[, $callback]) |
854 | $w = $loop->embed ($otherloop[, $callback]) |
| … | |
… | |
| 847 | The "embed_ns" variant doesn't start (activate) the newly created |
861 | The "embed_ns" variant doesn't start (activate) the newly created |
| 848 | watcher. |
862 | watcher. |
| 849 | |
863 | |
| 850 | ASYNC WATCHERS - how to wake up another event loop |
864 | ASYNC WATCHERS - how to wake up another event loop |
| 851 | Async watchers are provided by EV, but have little use in perl directly, |
865 | Async watchers are provided by EV, but have little use in perl directly, |
| 852 | as perl neither supports threads nor direct access to signal handlers or |
866 | as perl neither supports threads running in parallel nor direct access |
| 853 | other contexts where they could be of value. |
867 | to signal handlers or other contexts where they could be of value. |
| 854 | |
868 | |
| 855 | It is, however, possible to use them from the XS level. |
869 | It is, however, possible to use them from the XS level. |
| 856 | |
870 | |
| 857 | Please see the libev documentation for further details. |
871 | Please see the libev documentation for further details. |
| 858 | |
872 | |
| … | |
… | |
| 877 | my $async_check = EV::check sub { }; |
891 | my $async_check = EV::check sub { }; |
| 878 | |
892 | |
| 879 | This ensures that perl gets into control for a short time to handle any |
893 | This ensures that perl gets into control for a short time to handle any |
| 880 | pending signals, and also ensures (slightly) slower overall operation. |
894 | pending signals, and also ensures (slightly) slower overall operation. |
| 881 | |
895 | |
| 882 | THREADS |
896 | ITHREADS |
| 883 | Threads are not supported by this module in any way. Perl pseudo-threads |
897 | Ithreads are not supported by this module in any way. Perl |
| 884 | is evil stuff and must die. As soon as Perl gains real threads I will |
898 | pseudo-threads is evil stuff and must die. Real threads as provided by |
| 885 | work on thread support for it. |
899 | Coro are fully supported (and enhanced support is available via |
|
|
900 | Coro::EV). |
| 886 | |
901 | |
| 887 | FORK |
902 | FORK |
| 888 | Most of the "improved" event delivering mechanisms of modern operating |
903 | Most of the "improved" event delivering mechanisms of modern operating |
| 889 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
904 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
| 890 | not supported and usually destructive). Libev makes it possible to work |
905 | not supported and usually destructive). Libev makes it possible to work |
