| … | |
… | |
| 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 |
| … | |
… | |
| 91 | *embed* a kqueue loop into the default loop: running the default loop |
91 | *embed* a kqueue loop into the default loop: running the default loop |
| 92 | will then also service the kqueue loop to some extent. See the example |
92 | will then also service the kqueue loop to some extent. See the example |
| 93 | in the section about embed watchers for an example on how to achieve |
93 | in the section about embed watchers for an example on how to achieve |
| 94 | that. |
94 | that. |
| 95 | |
95 | |
| 96 | $loop = new EV::loop [$flags] |
96 | $loop = new EV::Loop [$flags] |
| 97 | Create a new event loop as per the specified flags. Please refer to |
97 | Create a new event loop as per the specified flags. Please refer to |
| 98 | the "ev_loop_new ()" function description in the libev documentation |
98 | the "ev_loop_new ()" function description in the libev documentation |
| 99 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
99 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
| 100 | ONS>, or locally-installed as EV::libev manpage) for more info. |
100 | ONS>, or locally-installed as EV::libev manpage) for more info. |
| 101 | |
101 | |
| … | |
… | |
| 151 | $time = EV::now |
151 | $time = EV::now |
| 152 | $time = $loop->now |
152 | $time = $loop->now |
| 153 | Returns the time the last event loop iteration has been started. |
153 | Returns the time the last event loop iteration has been started. |
| 154 | This is the time that (relative) timers are based on, and referring |
154 | This is the time that (relative) timers are based on, and referring |
| 155 | to it is usually faster then calling EV::time. |
155 | to it is usually faster then calling EV::time. |
|
|
156 | |
|
|
157 | EV::now_update |
|
|
158 | $loop->now_update |
|
|
159 | Establishes the current time by querying the kernel, updating the |
|
|
160 | time returned by "EV::now" in the progress. This is a costly |
|
|
161 | operation and is usually done automatically within "EV::loop". |
|
|
162 | |
|
|
163 | This function is rarely useful, but when some event callback runs |
|
|
164 | for a very long time without entering the event loop, updating |
|
|
165 | libev's idea of the current time is a good idea. |
|
|
166 | |
|
|
167 | EV::suspend |
|
|
168 | $loop->suspend |
|
|
169 | EV::resume |
|
|
170 | $loop->resume |
|
|
171 | These two functions suspend and resume a loop, for use when the loop |
|
|
172 | is not used for a while and timeouts should not be processed. |
|
|
173 | |
|
|
174 | A typical use case would be an interactive program such as a game: |
|
|
175 | When the user presses "^Z" to suspend the game and resumes it an |
|
|
176 | hour later it would be best to handle timeouts as if no time had |
|
|
177 | actually passed while the program was suspended. This can be |
|
|
178 | achieved by calling "suspend" in your "SIGTSTP" handler, sending |
|
|
179 | yourself a "SIGSTOP" and calling "resume" directly afterwards to |
|
|
180 | resume timer processing. |
|
|
181 | |
|
|
182 | Effectively, all "timer" watchers will be delayed by the time spend |
|
|
183 | between "suspend" and "resume", and all "periodic" watchers will be |
|
|
184 | rescheduled (that is, they will lose any events that would have |
|
|
185 | occured while suspended). |
|
|
186 | |
|
|
187 | After calling "suspend" you must not call *any* function on the |
|
|
188 | given loop other than "resume", and you must not call "resume" |
|
|
189 | without a previous call to "suspend". |
|
|
190 | |
|
|
191 | Calling "suspend"/"resume" has the side effect of updating the event |
|
|
192 | loop time (see "now_update"). |
| 156 | |
193 | |
| 157 | $backend = EV::backend |
194 | $backend = EV::backend |
| 158 | $backend = $loop->backend |
195 | $backend = $loop->backend |
| 159 | Returns an integer describing the backend used by libev |
196 | Returns an integer describing the backend used by libev |
| 160 | (EV::BACKEND_SELECT or EV::BACKEND_EPOLL). |
197 | (EV::BACKEND_SELECT or EV::BACKEND_EPOLL). |
| … | |
… | |
| 226 | the libev documentation at |
263 | the libev documentation at |
| 227 | <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 |
| 228 | 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 |
| 229 | detailed discussion. |
266 | detailed discussion. |
| 230 | |
267 | |
|
|
268 | $count = EV::pending_count |
|
|
269 | $count = $loop->pending_count |
|
|
270 | Returns the number of currently pending watchers. |
|
|
271 | |
|
|
272 | EV::invoke_pending |
|
|
273 | $loop->invoke_pending |
|
|
274 | Invoke all currently pending watchers. |
|
|
275 | |
| 231 | WATCHER OBJECTS |
276 | WATCHER OBJECTS |
| 232 | 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 |
| 233 | 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, |
| 234 | you would create an EV::io watcher for that: |
279 | you would create an EV::io watcher for that: |
| 235 | |
280 | |
| … | |
… | |
| 321 | the watcher isn't pending it does nothing and returns 0. |
366 | the watcher isn't pending it does nothing and returns 0. |
| 322 | |
367 | |
| 323 | $previous_state = $w->keepalive ($bool) |
368 | $previous_state = $w->keepalive ($bool) |
| 324 | Normally, "EV::loop" will return when there are no active watchers |
369 | Normally, "EV::loop" will return when there are no active watchers |
| 325 | (which is a "deadlock" because no progress can be made anymore). |
370 | (which is a "deadlock" because no progress can be made anymore). |
| 326 | 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 |
| 327 | 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 |
| 328 | 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 |
| 329 | for their task :). |
374 | for their task :). |
| 330 | |
375 | |
| 331 | Sometimes, however, this gets in your way, for example when the |
376 | Sometimes, however, this gets in your way, for example when the |
| … | |
… | |
| 522 | Return the time that the watcher is expected to trigger next. |
567 | Return the time that the watcher is expected to trigger next. |
| 523 | |
568 | |
| 524 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
569 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
| 525 | $w = EV::signal $signal, $callback |
570 | $w = EV::signal $signal, $callback |
| 526 | $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) |
| 527 | Call the callback when $signal is received (the signal can be |
574 | Call the callback when $signal is received (the signal can be |
| 528 | 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 |
|
|
579 | cause data corruption. |
| 529 | |
580 | |
| 530 | 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 |
| 531 | 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 |
| 532 | 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 |
| 533 | when you add/remove callbacks to %SIG, so watch out. |
584 | when you add/remove callbacks to %SIG, so watch out. |
| … | |
… | |
| 783 | |
834 | |
| 784 | 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 |
| 785 | 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: |
| 786 | |
837 | |
| 787 | my $socket_loop; |
838 | my $socket_loop; |
| 788 | |
839 | |
| 789 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
840 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
| 790 | if ( |
841 | if ( |
| 791 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
842 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
| 792 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
843 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
| 793 | ) { |
844 | ) { |
| 794 | # use kqueue for sockets |
845 | # use kqueue for sockets |
| 795 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
846 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
| 796 | } |
847 | } |
| 797 | |
848 | |
| 798 | # use the default loop otherwise |
849 | # use the default loop otherwise |
| 799 | $socket_loop ||= EV::default_loop; |
850 | $socket_loop ||= EV::default_loop; |
| 800 | |
851 | |
| 801 | $w = EV::embed $otherloop[, $callback] |
852 | $w = EV::embed $otherloop[, $callback] |
| 802 | $w = EV::embed_ns $otherloop[, $callback] |
853 | $w = EV::embed_ns $otherloop[, $callback] |
| 803 | $w = $loop->embed ($otherloop[, $callback]) |
854 | $w = $loop->embed ($otherloop[, $callback]) |
| … | |
… | |
| 810 | The "embed_ns" variant doesn't start (activate) the newly created |
861 | The "embed_ns" variant doesn't start (activate) the newly created |
| 811 | watcher. |
862 | watcher. |
| 812 | |
863 | |
| 813 | ASYNC WATCHERS - how to wake up another event loop |
864 | ASYNC WATCHERS - how to wake up another event loop |
| 814 | 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, |
| 815 | as perl neither supports threads nor direct access to signal handlers or |
866 | as perl neither supports threads running in parallel nor direct access |
| 816 | other contexts where they could be of value. |
867 | to signal handlers or other contexts where they could be of value. |
| 817 | |
868 | |
| 818 | It is, however, possible to use them from the XS level. |
869 | It is, however, possible to use them from the XS level. |
| 819 | |
870 | |
| 820 | Please see the libev documentation for further details. |
871 | Please see the libev documentation for further details. |
| 821 | |
872 | |
| … | |
… | |
| 840 | my $async_check = EV::check sub { }; |
891 | my $async_check = EV::check sub { }; |
| 841 | |
892 | |
| 842 | 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 |
| 843 | pending signals, and also ensures (slightly) slower overall operation. |
894 | pending signals, and also ensures (slightly) slower overall operation. |
| 844 | |
895 | |
| 845 | THREADS |
896 | ITHREADS |
| 846 | 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 |
| 847 | 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 |
| 848 | work on thread support for it. |
899 | Coro are fully supported (and enhanced support is available via |
|
|
900 | Coro::EV). |
| 849 | |
901 | |
| 850 | FORK |
902 | FORK |
| 851 | Most of the "improved" event delivering mechanisms of modern operating |
903 | Most of the "improved" event delivering mechanisms of modern operating |
| 852 | 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 |
| 853 | not supported and usually destructive). Libev makes it possible to work |
905 | not supported and usually destructive). Libev makes it possible to work |
