1 | NAME |
1 | NAME |
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; |
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7 | |
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8 | # TIMERS |
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9 | |
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10 | my $w = EV::timer 2, 0, sub { |
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11 | warn "is called after 2s"; |
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12 | }; |
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13 | |
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14 | my $w = EV::timer 2, 2, sub { |
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15 | warn "is called roughly every 2s (repeat = 2)"; |
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16 | }; |
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17 | |
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18 | undef $w; # destroy event watcher again |
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19 | |
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20 | my $w = EV::periodic 0, 60, 0, sub { |
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21 | warn "is called every minute, on the minute, exactly"; |
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22 | }; |
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23 | |
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24 | # IO |
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25 | |
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26 | my $w = EV::io *STDIN, EV::READ, sub { |
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27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
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28 | warn "stdin is readable, you entered: ", <STDIN>; |
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29 | }; |
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30 | |
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31 | # SIGNALS |
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32 | |
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33 | my $w = EV::signal 'QUIT', sub { |
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34 | warn "sigquit received\n"; |
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35 | }; |
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36 | |
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37 | # CHILD/PID STATUS CHANGES |
7 | |
38 | |
8 | # TIMERS |
39 | my $w = EV::child 666, 0, sub { |
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40 | my ($w, $revents) = @_; |
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41 | my $status = $w->rstatus; |
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42 | }; |
9 | |
43 | |
10 | my $w = EV::timer 2, 0, sub { |
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11 | warn "is called after 2s"; |
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12 | }; |
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13 | |
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14 | my $w = EV::timer 2, 2, sub { |
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15 | warn "is called roughly every 2s (repeat = 2)"; |
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16 | }; |
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17 | |
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18 | undef $w; # destroy event watcher again |
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19 | |
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20 | my $w = EV::periodic 0, 60, 0, sub { |
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21 | warn "is called every minute, on the minute, exactly"; |
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22 | }; |
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23 | |
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24 | # IO |
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25 | |
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26 | my $w = EV::io *STDIN, EV::READ, sub { |
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27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
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28 | warn "stdin is readable, you entered: ", <STDIN>; |
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29 | }; |
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30 | |
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31 | # SIGNALS |
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32 | |
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33 | my $w = EV::signal 'QUIT', sub { |
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34 | warn "sigquit received\n"; |
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35 | }; |
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36 | |
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37 | # CHILD/PID STATUS CHANGES |
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38 | |
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39 | my $w = EV::child 666, 0, sub { |
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40 | my ($w, $revents) = @_; |
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41 | my $status = $w->rstatus; |
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42 | }; |
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43 | |
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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 |
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81 | 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 |
82 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
82 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
83 | |
83 | |
84 | For specific programs you can create additional event loops dynamically. |
84 | For specific programs you can create additional event loops dynamically. |
85 | |
85 | |
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86 | If you want to take avdantage of kqueue (which often works properly for |
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87 | sockets only) even though the default loop doesn't enable it, you can |
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88 | *embed* a kqueue loop into the default loop: running the default loop |
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89 | will then also service the kqueue loop to some extent. See the example |
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90 | in the section about embed watchers for an example on how to achieve |
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91 | that. |
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92 | |
86 | $loop = new EV::loop [$flags] |
93 | $loop = new EV::loop [$flags] |
87 | Create a new event loop as per the specified flags. Please refer to |
94 | Create a new event loop as per the specified flags. Please refer to |
88 | the "ev_loop_new ()" function description in the libev documentation |
95 | the "ev_loop_new ()" function description in the libev documentation |
89 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
96 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
90 | ONS>) for more info. |
97 | ONS>) for more info. |
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96 | loop is protected by this module. |
103 | loop is protected by this module. |
97 | |
104 | |
98 | $loop->loop_fork |
105 | $loop->loop_fork |
99 | Must be called after a fork in the child, before entering or |
106 | Must be called after a fork in the child, before entering or |
100 | continuing the event loop. An alternative is to use |
107 | continuing the event loop. An alternative is to use |
101 | "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at |
108 | "EV::FLAG_FORKCHECK" which calls this function automatically, at |
102 | some performance loss (refer to the libev documentation). |
109 | some performance loss (refer to the libev documentation). |
103 | |
110 | |
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111 | $loop->loop_verify |
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112 | Calls "ev_verify" to make internal consistency checks (for debugging |
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113 | libev) and abort the program if any data structures were found to be |
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114 | corrupted. |
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115 | |
104 | $loop = EV::default_loop [$flags] |
116 | $loop = EV::default_loop [$flags] |
105 | Return the default loop (which is a singleton object). |
117 | Return the default loop (which is a singleton object). Since this |
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118 | module already creates the default loop with default flags, |
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119 | specifying flags here will not have any effect unless you destroy |
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120 | the default loop first, which isn't supported. So in short: don't do |
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121 | it, and if you break it, you get to keep the pieces. |
106 | |
122 | |
107 | BASIC INTERFACE |
123 | BASIC INTERFACE |
108 | $EV::DIED |
124 | $EV::DIED |
109 | Must contain a reference to a function that is called when a |
125 | Must contain a reference to a function that is called when a |
110 | callback throws an exception (with $@ containing the error). The |
126 | callback throws an exception (with $@ containing the error). The |
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208 | WATCHER OBJECTS |
224 | WATCHER OBJECTS |
209 | A watcher is an object that gets created to record your interest in some |
225 | A watcher is an object that gets created to record your interest in some |
210 | event. For instance, if you want to wait for STDIN to become readable, |
226 | event. For instance, if you want to wait for STDIN to become readable, |
211 | you would create an EV::io watcher for that: |
227 | you would create an EV::io watcher for that: |
212 | |
228 | |
213 | my $watcher = EV::io *STDIN, EV::READ, sub { |
229 | my $watcher = EV::io *STDIN, EV::READ, sub { |
214 | my ($watcher, $revents) = @_; |
230 | my ($watcher, $revents) = @_; |
215 | warn "yeah, STDIN should now be readable without blocking!\n" |
231 | warn "yeah, STDIN should now be readable without blocking!\n" |
216 | }; |
232 | }; |
217 | |
233 | |
218 | All watchers can be active (waiting for events) or inactive (paused). |
234 | All watchers can be active (waiting for events) or inactive (paused). |
219 | Only active watchers will have their callbacks invoked. All callbacks |
235 | Only active watchers will have their callbacks invoked. All callbacks |
220 | will be called with at least two arguments: the watcher and a bitmask of |
236 | will be called with at least two arguments: the watcher and a bitmask of |
221 | received events. |
237 | received events. |
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323 | Example: Register an I/O watcher for some UDP socket but do not keep |
339 | Example: Register an I/O watcher for some UDP socket but do not keep |
324 | the event loop from running just because of that watcher. |
340 | the event loop from running just because of that watcher. |
325 | |
341 | |
326 | my $udp_socket = ... |
342 | my $udp_socket = ... |
327 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
343 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
328 | $1000udp_watcher->keepalive (0); |
344 | $udp_watcher->keepalive (0); |
329 | |
345 | |
330 | $loop = $w->loop |
346 | $loop = $w->loop |
331 | Return the loop that this watcher is attached to. |
347 | Return the loop that this watcher is attached to. |
332 | |
348 | |
333 | WATCHER TYPES |
349 | WATCHER TYPES |
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456 | each time the periodic watcher gets scheduled, the reschedule |
472 | each time the periodic watcher gets scheduled, the reschedule |
457 | callback ($reschedule_cb) will be called with the watcher as |
473 | callback ($reschedule_cb) will be called with the watcher as |
458 | first, and the current time as second argument. |
474 | first, and the current time as second argument. |
459 | |
475 | |
460 | *This callback MUST NOT stop or destroy this or any other |
476 | *This callback MUST NOT stop or destroy this or any other |
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477 | periodic watcher, ever, and MUST NOT call any event loop |
461 | periodic watcher, ever*. If you need to stop it, return 1e30 and |
478 | functions or methods*. If you need to stop it, return 1e30 and |
462 | stop it afterwards. |
479 | stop it afterwards. You may create and start a "EV::prepare" |
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480 | watcher for this task. |
463 | |
481 | |
464 | It must return the next time to trigger, based on the passed |
482 | It must return the next time to trigger, based on the passed |
465 | time value (that is, the lowest time value larger than to the |
483 | time value (that is, the lowest time value larger than or equal |
466 | second argument). It will usually be called just before the |
484 | to to the second argument). It will usually be called just |
467 | callback will be triggered, but might be called at other times, |
485 | before the callback will be triggered, but might be called at |
468 | too. |
486 | other times, too. |
469 | |
487 | |
470 | This can be used to create very complex timers, such as a timer |
488 | This can be used to create very complex timers, such as a timer |
471 | that triggers on each midnight, local time (actually 24 hours |
489 | that triggers on each midnight, local time (actually 24 hours |
472 | after the last midnight, to keep the example simple. If you know |
490 | after the last midnight, to keep the example simple. If you know |
473 | a way to do it correctly in about the same space (without |
491 | a way to do it correctly in about the same space (without |
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757 | _when_one_backend_> for more details. |
775 | _when_one_backend_> for more details. |
758 | |
776 | |
759 | In short, this watcher is most useful on BSD systems without working |
777 | 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: |
778 | kqueue to still be able to handle a large number of sockets: |
761 | |
779 | |
762 | my $socket_loop; |
780 | my $socket_loop; |
763 | |
781 | |
764 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
782 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
765 | if ( |
783 | if ( |
766 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
784 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
767 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
785 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
768 | ) { |
786 | ) { |
769 | # use kqueue for sockets |
787 | # use kqueue for sockets |
770 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
788 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
771 | } |
789 | } |
772 | |
790 | |
773 | # use the default loop otherwise |
791 | # use the default loop otherwise |
774 | $socket_loop ||= EV::default_loop; |
792 | $socket_loop ||= EV::default_loop; |
775 | |
793 | |
776 | $w = EV::embed $otherloop, $callback |
794 | $w = EV::embed $otherloop[, $callback] |
777 | $w = EV::embed_ns $otherloop, $callback |
795 | $w = EV::embed_ns $otherloop[, $callback] |
778 | $w = $loop->embed ($otherloop, $callback) |
796 | $w = $loop->embed ($otherloop[, $callback]) |
779 | $w = $loop->embed_ns ($otherloop, $callback) |
797 | $w = $loop->embed_ns ($otherloop[, $callback]) |
780 | Call the callback when the embedded event loop ($otherloop) has any |
798 | Call the callback when the embedded event loop ($otherloop) has any |
781 | I/O activity. The $callback should alwas be specified as "undef" in |
799 | I/O activity. The $callback is optional: if it is missing, then the |
782 | this version of EV, which means the embedded event loop will be |
800 | embedded event loop will be managed automatically (which is |
783 | managed automatically. |
801 | recommended), otherwise you have to invoke "sweep" yourself. |
784 | |
802 | |
785 | The "embed_ns" variant doesn't start (activate) the newly created |
803 | The "embed_ns" variant doesn't start (activate) the newly created |
786 | watcher. |
804 | watcher. |
787 | |
805 | |
788 | ASYNC WATCHERS - how to wake up another event loop |
806 | ASYNC WATCHERS - how to wake up another event loop |
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844 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
862 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
845 | with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop |
863 | with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop |
846 | agnostic and portable event driven programming. |
864 | agnostic and portable event driven programming. |
847 | |
865 | |
848 | AUTHOR |
866 | AUTHOR |
849 | Marc Lehmann <schmorp@schmorp.de> |
867 | Marc Lehmann <schmorp@schmorp.de> |
850 | http://home.schmorp.de/ |
868 | http://home.schmorp.de/ |
851 | |
869 | |