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Revision 1.25 by root, Sun May 18 10:45:36 2008 UTC vs.
Revision 1.28 by root, Tue Jul 8 18:56:48 2008 UTC

1NAME 1NAME
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
5SYNOPSIS 5SYNOPSIS
6 use EV; 6 use EV;
7
8 # TIMERS
9
10 my $w = EV::timer 2, 0, sub {
11 warn "is called after 2s";
12 };
13
14 my $w = EV::timer 2, 2, sub {
15 warn "is called roughly every 2s (repeat = 2)";
16 };
17
18 undef $w; # destroy event watcher again
19
20 my $w = EV::periodic 0, 60, 0, sub {
21 warn "is called every minute, on the minute, exactly";
22 };
23
24 # IO
25
26 my $w = EV::io *STDIN, EV::READ, sub {
27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28 warn "stdin is readable, you entered: ", <STDIN>;
29 };
30
31 # SIGNALS
32
33 my $w = EV::signal 'QUIT', sub {
34 warn "sigquit received\n";
35 };
36
37 # CHILD/PID STATUS CHANGES
7 38
8 # TIMERS 39 my $w = EV::child 666, 0, sub {
40 my ($w, $revents) = @_;
41 my $status = $w->rstatus;
42 };
9 43
10 my $w = EV::timer 2, 0, sub {
11 warn "is called after 2s";
12 };
13
14 my $w = EV::timer 2, 2, sub {
15 warn "is called roughly every 2s (repeat = 2)";
16 };
17
18 undef $w; # destroy event watcher again
19
20 my $w = EV::periodic 0, 60, 0, sub {
21 warn "is called every minute, on the minute, exactly";
22 };
23
24 # IO
25
26 my $w = EV::io *STDIN, EV::READ, sub {
27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28 warn "stdin is readable, you entered: ", <STDIN>;
29 };
30
31 # SIGNALS
32
33 my $w = EV::signal 'QUIT', sub {
34 warn "sigquit received\n";
35 };
36
37 # CHILD/PID STATUS CHANGES
38
39 my $w = EV::child 666, 0, sub {
40 my ($w, $revents) = @_;
41 my $status = $w->rstatus;
42 };
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
55DESCRIPTION 55DESCRIPTION
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
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
86 If you want to take avdantage of kqueue (which often works properly for
87 sockets only) even though the default loop doesn't enable it, you can
88 *embed* a kqueue loop into the default loop: running the default loop
89 will then also service the kqueue loop to some extent. See the example
90 in the section about embed watchers for an example on how to achieve
91 that.
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.
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
111 $loop->loop_verify
112 Calls "ev_verify" to make internal consistency checks (for debugging
113 libev) and abort the program if any data structures were found to be
114 corrupted.
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
118 module already creates the default loop with default flags,
119 specifying flags here will not have any effect unless you destroy
120 the default loop first, which isn't supported. So in short: don't do
121 it, and if you break it, you get to keep the pieces.
106 122
107BASIC INTERFACE 123BASIC 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
208WATCHER OBJECTS 224WATCHER 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.
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 = $w->loop
331 Return the loop that this watcher is attached to. 347 Return the loop that this watcher is attached to.
332 348
333WATCHER TYPES 349WATCHER TYPES
456 each time the periodic watcher gets scheduled, the reschedule 472 each time the periodic watcher gets scheduled, the reschedule
457 callback ($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
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"
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
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)
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
848AUTHOR 866AUTHOR
849 Marc Lehmann <schmorp@schmorp.de> 867 Marc Lehmann <schmorp@schmorp.de>
850 http://home.schmorp.de/ 868 http://home.schmorp.de/
851 869

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