| … | |
… | |
| 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 | |
|
|
| 24 | # IO |
23 | |
| 25 | |
24 | # IO |
|
|
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, 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 |
| 56 | This module provides an interface to libev |
56 | This module provides an interface to libev |
| 57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
| 58 | below is comprehensive, one might also consult the documentation of |
58 | below is comprehensive, one might also consult the documentation of |
| 59 | libev itself (<http://cvs.schmorp.de/libev/ev.html>) for more subtle |
59 | libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) |
| 60 | details on watcher semantics or some discussion on the available |
60 | for more subtle details on watcher semantics or some discussion on the |
| 61 | backends, or how to force a specific backend with "LIBEV_FLAGS", or just |
61 | available backends, or how to force a specific backend with |
| 62 | about in any case because it has much more detailed information. |
62 | "LIBEV_FLAGS", or just about in any case because it has much more |
|
|
63 | detailed information. |
|
|
64 | |
|
|
65 | This module is very fast and scalable. It is actually so fast that you |
|
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66 | can use it through the AnyEvent module, stay portable to other event |
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67 | loops (if you don't rely on any watcher types not available through it) |
|
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68 | and still be faster than with any other event loop currently supported |
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69 | in Perl. |
| 63 | |
70 | |
| 64 | EVENT LOOPS |
71 | EVENT LOOPS |
| 65 | EV supports multiple event loops: There is a single "default event loop" |
72 | EV supports multiple event loops: There is a single "default event loop" |
| 66 | that can handle everything including signals and child watchers, and any |
73 | that can handle everything including signals and child watchers, and any |
| 67 | number of "dynamic event loops" that can use different backends (with |
74 | number of "dynamic event loops" that can use different backends (with |
| … | |
… | |
| 72 | selecting a working backend (which for example rules out kqueue on most |
79 | selecting a working backend (which for example rules out kqueue on most |
| 73 | BSDs). Modules should, unless they have "special needs" always use the |
80 | BSDs). Modules should, unless they have "special needs" always use the |
| 74 | default loop as this is fastest (perl-wise), best supported by other |
81 | default loop as this is fastest (perl-wise), best supported by other |
| 75 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
82 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
| 76 | |
83 | |
| 77 | For specific programs you cna create additional event loops dynamically. |
84 | For specific programs you can create additional event loops dynamically. |
| 78 | |
85 | |
| 79 | $loop = new EV::loop [$flags] |
86 | $loop = new EV::loop [$flags] |
| 80 | Create a new event loop as per the specified flags. Please refer to |
87 | Create a new event loop as per the specified flags. Please refer to |
| 81 | the "ev_loop_new ()" function description in the libev documentation |
88 | the "ev_loop_new ()" function description in the libev documentation |
| 82 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
89 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
| … | |
… | |
| 92 | Must be called after a fork in the child, before entering or |
99 | Must be called after a fork in the child, before entering or |
| 93 | continuing the event loop. An alternative is to use |
100 | continuing the event loop. An alternative is to use |
| 94 | "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at |
101 | "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at |
| 95 | some performance loss (refer to the libev documentation). |
102 | some performance loss (refer to the libev documentation). |
| 96 | |
103 | |
|
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104 | $loop = EV::default_loop [$flags] |
|
|
105 | Return the default loop (which is a singleton object). |
|
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106 | |
| 97 | BASIC INTERFACE |
107 | BASIC INTERFACE |
| 98 | $EV::DIED |
108 | $EV::DIED |
| 99 | Must contain a reference to a function that is called when a |
109 | Must contain a reference to a function that is called when a |
| 100 | callback throws an exception (with $@ containing the error). The |
110 | callback throws an exception (with $@ containing the error). The |
| 101 | default prints an informative message and continues. |
111 | default prints an informative message and continues. |
| 102 | |
112 | |
| 103 | If this callback throws an exception it will be silently ignored. |
113 | If this callback throws an exception it will be silently ignored. |
|
|
114 | |
|
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115 | $flags = EV::supported_backends |
|
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116 | $flags = EV::recommended_backends |
|
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117 | $flags = EV::embeddable_backends |
|
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118 | Returns the set (see "EV::BACKEND_*" flags) of backends supported by |
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119 | this instance of EV, the set of recommended backends (supposed to be |
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120 | good) for this platform and the set of embeddable backends (see |
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121 | EMBED WATCHERS). |
|
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122 | |
|
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123 | EV::sleep $seconds |
|
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124 | Block the process for the given number of (fractional) seconds. |
| 104 | |
125 | |
| 105 | $time = EV::time |
126 | $time = EV::time |
| 106 | Returns the current time in (fractional) seconds since the epoch. |
127 | Returns the current time in (fractional) seconds since the epoch. |
| 107 | |
128 | |
| 108 | $time = EV::now |
129 | $time = EV::now |
| … | |
… | |
| 171 | descriptor $fd. |
192 | descriptor $fd. |
| 172 | |
193 | |
| 173 | EV::feed_signal_event ($signal) |
194 | EV::feed_signal_event ($signal) |
| 174 | Feed a signal event into EV. EV will react to this call as if the |
195 | Feed a signal event into EV. EV will react to this call as if the |
| 175 | signal specified by $signal had occured. |
196 | signal specified by $signal had occured. |
|
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197 | |
|
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198 | EV::set_io_collect_interval $time |
|
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199 | $loop->set_io_collect_interval ($time) |
|
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200 | EV::set_timeout_collect_interval $time |
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201 | $loop->set_timeout_collect_interval ($time) |
|
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202 | These advanced functions set the minimum block interval when polling |
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203 | for I/O events and the minimum wait interval for timer events. See |
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204 | the libev documentation at |
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205 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
|
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206 | ROLLING_THE_EVENT_LOOP> for a more detailed discussion. |
| 176 | |
207 | |
| 177 | WATCHER OBJECTS |
208 | WATCHER OBJECTS |
| 178 | A watcher is an object that gets created to record your interest in some |
209 | A watcher is an object that gets created to record your interest in some |
| 179 | event. For instance, if you want to wait for STDIN to become readable, |
210 | event. For instance, if you want to wait for STDIN to become readable, |
| 180 | you would create an EV::io watcher for that: |
211 | you would create an EV::io watcher for that: |
| … | |
… | |
| 390 | changed by explicit date -s or other means such as ntpd). It is also |
421 | changed by explicit date -s or other means such as ntpd). It is also |
| 391 | the most complex watcher type in EV. |
422 | the most complex watcher type in EV. |
| 392 | |
423 | |
| 393 | It has three distinct "modes": |
424 | It has three distinct "modes": |
| 394 | |
425 | |
| 395 | * absolute timer ($interval = $reschedule_cb = 0) |
426 | * absolute timer ($interval = $reschedule_cb = 0) |
|
|
427 | |
| 396 | This time simply fires at the wallclock time $at and doesn't |
428 | This time simply fires at the wallclock time $at and doesn't |
| 397 | repeat. It will not adjust when a time jump occurs, that is, if |
429 | repeat. It will not adjust when a time jump occurs, that is, if |
| 398 | it is to be run at January 1st 2011 then it will run when the |
430 | it is to be run at January 1st 2011 then it will run when the |
| 399 | system time reaches or surpasses this time. |
431 | system time reaches or surpasses this time. |
| 400 | |
432 | |
| 401 | * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
433 | * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
|
|
434 | |
| 402 | In this mode the watcher will always be scheduled to time out at |
435 | In this mode the watcher will always be scheduled to time out at |
| 403 | the next "$at + N * $interval" time (for some integer N) and |
436 | the next "$at + N * $interval" time (for some integer N) and |
| 404 | then repeat, regardless of any time jumps. |
437 | then repeat, regardless of any time jumps. |
| 405 | |
438 | |
| 406 | This can be used to create timers that do not drift with respect |
439 | This can be used to create timers that do not drift with respect |
| … | |
… | |
| 415 | Another way to think about it (for the mathematically inclined) |
448 | Another way to think about it (for the mathematically inclined) |
| 416 | is that EV::periodic will try to run the callback in this mode |
449 | is that EV::periodic will try to run the callback in this mode |
| 417 | at the next possible time where "$time = $at (mod $interval)", |
450 | at the next possible time where "$time = $at (mod $interval)", |
| 418 | regardless of any time jumps. |
451 | regardless of any time jumps. |
| 419 | |
452 | |
| 420 | * manual reschedule mode ($reschedule_cb = coderef) |
453 | * manual reschedule mode ($reschedule_cb = coderef) |
|
|
454 | |
| 421 | In this mode $interval and $at are both being ignored. Instead, |
455 | In this mode $interval and $at are both being ignored. Instead, |
| 422 | each time the periodic watcher gets scheduled, the reschedule |
456 | each time the periodic watcher gets scheduled, the reschedule |
| 423 | callback ($reschedule_cb) will be called with the watcher as |
457 | callback ($reschedule_cb) will be called with the watcher as |
| 424 | first, and the current time as second argument. |
458 | first, and the current time as second argument. |
| 425 | |
459 | |
| … | |
… | |
| 486 | $old_signum = $w->signal ($new_signal) |
520 | $old_signum = $w->signal ($new_signal) |
| 487 | Returns the previously set signal (always as a number not name) and |
521 | Returns the previously set signal (always as a number not name) and |
| 488 | optionally set a new one. |
522 | optionally set a new one. |
| 489 | |
523 | |
| 490 | CHILD WATCHERS - watch out for process status changes |
524 | CHILD WATCHERS - watch out for process status changes |
| 491 | $w = EV::child $pid, $callback |
525 | $w = EV::child $pid, $trace, $callback |
| 492 | $w = EV::child_ns $pid, $callback |
526 | $w = EV::child_ns $pid, $trace, $callback |
| 493 | $w = $loop->child ($pid, $callback) |
527 | $w = $loop->child ($pid, $trace, $callback) |
| 494 | $w = $loop->child_ns ($pid, $callback) |
528 | $w = $loop->child_ns ($pid, $trace, $callback) |
| 495 | Call the callback when a status change for pid $pid (or any pid if |
529 | Call the callback when a status change for pid $pid (or any pid if |
| 496 | $pid is 0) has been received. More precisely: when the process |
530 | $pid is 0) has been received (a status change happens when the |
|
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531 | process terminates or is killed, or, when trace is true, |
|
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532 | additionally when it is stopped or continued). More precisely: when |
| 497 | receives a "SIGCHLD", EV will fetch the outstanding exit/wait status |
533 | the process receives a "SIGCHLD", EV will fetch the outstanding |
| 498 | for all changed/zombie children and call the callback. |
534 | exit/wait status for all changed/zombie children and call the |
|
|
535 | callback. |
| 499 | |
536 | |
| 500 | It is valid (and fully supported) to install a child watcher after a |
537 | It is valid (and fully supported) to install a child watcher after a |
| 501 | child has exited but before the event loop has started its next |
538 | child has exited but before the event loop has started its next |
| 502 | iteration (for example, first you "fork", then the new child process |
539 | iteration (for example, first you "fork", then the new child process |
| 503 | might exit, and only then do you install a child watcher in the |
540 | might exit, and only then do you install a child watcher in the |
| … | |
… | |
| 510 | be called. |
547 | be called. |
| 511 | |
548 | |
| 512 | The "child_ns" variant doesn't start (activate) the newly created |
549 | The "child_ns" variant doesn't start (activate) the newly created |
| 513 | watcher. |
550 | watcher. |
| 514 | |
551 | |
| 515 | $w->set ($pid) |
552 | $w->set ($pid, $trace) |
| 516 | Reconfigures the watcher, see the constructor above for details. Can |
553 | Reconfigures the watcher, see the constructor above for details. Can |
| 517 | be called at any time. |
554 | be called at any time. |
| 518 | |
555 | |
| 519 | $current_pid = $w->pid |
556 | $current_pid = $w->pid |
| 520 | $old_pid = $w->pid ($new_pid) |
|
|
| 521 | Returns the previously set process id and optionally set a new one. |
557 | Returns the previously set process id and optionally set a new one. |
| 522 | |
558 | |
| 523 | $exit_status = $w->rstatus |
559 | $exit_status = $w->rstatus |
| 524 | Return the exit/wait status (as returned by waitpid, see the waitpid |
560 | Return the exit/wait status (as returned by waitpid, see the waitpid |
| 525 | entry in perlfunc). |
561 | entry in perlfunc). |
| … | |
… | |
| 708 | process after a fork. |
744 | process after a fork. |
| 709 | |
745 | |
| 710 | The "fork_ns" variant doesn't start (activate) the newly created |
746 | The "fork_ns" variant doesn't start (activate) the newly created |
| 711 | watcher. |
747 | watcher. |
| 712 | |
748 | |
|
|
749 | EMBED WATCHERS - when one backend isn't enough... |
|
|
750 | This is a rather advanced watcher type that lets you embed one event |
|
|
751 | loop into another (currently only IO events are supported in the |
|
|
752 | embedded loop, other types of watchers might be handled in a delayed or |
|
|
753 | incorrect fashion and must not be used). |
|
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754 | |
|
|
755 | See the libev documentation at |
|
|
756 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code |
|
|
757 | _when_one_backend_> for more details. |
|
|
758 | |
|
|
759 | In short, this watcher is most useful on BSD systems without working |
|
|
760 | kqueue to still be able to handle a large number of sockets: |
|
|
761 | |
|
|
762 | my $socket_loop; |
|
|
763 | |
|
|
764 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
765 | if ( |
|
|
766 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
767 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
768 | ) { |
|
|
769 | # use kqueue for sockets |
|
|
770 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
771 | } |
|
|
772 | |
|
|
773 | # use the default loop otherwise |
|
|
774 | $socket_loop ||= EV::default_loop; |
|
|
775 | |
|
|
776 | $w = EV::embed $otherloop, $callback |
|
|
777 | $w = EV::embed_ns $otherloop, $callback |
|
|
778 | $w = $loop->embed ($otherloop, $callback) |
|
|
779 | $w = $loop->embed_ns ($otherloop, $callback) |
|
|
780 | Call the callback when the embedded event loop ($otherloop) has any |
|
|
781 | I/O activity. The $callback should alwas be specified as "undef" in |
|
|
782 | this version of EV, which means the embedded event loop will be |
|
|
783 | managed automatically. |
|
|
784 | |
|
|
785 | The "embed_ns" variant doesn't start (activate) the newly created |
|
|
786 | watcher. |
|
|
787 | |
|
|
788 | ASYNC WATCHERS - how to wake up another event loop |
|
|
789 | Async watchers are provided by EV, but have little use in perl directly, |
|
|
790 | as perl neither supports threads nor direct access to signal handlers or |
|
|
791 | other contexts where they could be of value. |
|
|
792 | |
|
|
793 | It is, however, possible to use them from the XS level. |
|
|
794 | |
|
|
795 | Please see the libev documentation for further details. |
|
|
796 | |
|
|
797 | $w = EV::async $callback |
|
|
798 | $w = EV::async_ns $callback |
|
|
799 | $w->send |
|
|
800 | $bool = $w->async_pending |
|
|
801 | |
| 713 | PERL SIGNALS |
802 | PERL SIGNALS |
| 714 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
803 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
| 715 | with EV is as the same as any other C library: Perl-signals will only be |
804 | with EV is as the same as any other C library: Perl-signals will only be |
| 716 | handled when Perl runs, which means your signal handler might be invoked |
805 | handled when Perl runs, which means your signal handler might be invoked |
| 717 | only the next time an event callback is invoked. |
806 | only the next time an event callback is invoked. |
| … | |
… | |
| 751 | course. |
840 | course. |
| 752 | |
841 | |
| 753 | SEE ALSO |
842 | SEE ALSO |
| 754 | EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event |
843 | EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event |
| 755 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
844 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
| 756 | with EV), Net::SNMP::EV (asynchronous SNMP). |
845 | with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop |
|
|
846 | agnostic and portable event driven programming. |
| 757 | |
847 | |
| 758 | AUTHOR |
848 | AUTHOR |
| 759 | Marc Lehmann <schmorp@schmorp.de> |
849 | Marc Lehmann <schmorp@schmorp.de> |
| 760 | http://home.schmorp.de/ |
850 | http://home.schmorp.de/ |
| 761 | |
851 | |
