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Revision 1.25 by root, Sun May 18 10:45:36 2008 UTC vs.
Revision 1.30 by root, Thu Oct 23 04:56:49 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
59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) 59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
60 for more subtle details on watcher semantics or some discussion on the 60 perldoc EV::libev) for more subtle details on watcher semantics or some
61 available backends, or how to force a specific backend with 61 discussion on the available backends, or how to force a specific backend
62 "LIBEV_FLAGS", or just about in any case because it has much more 62 with "LIBEV_FLAGS", or just about in any case because it has much more
63 detailed information. 63 detailed information.
64 64
65 This module is very fast and scalable. It is actually so fast that you 65 This module is very fast and scalable. It is actually so fast that you
66 can use it through the AnyEvent module, stay portable to other event 66 can use it through the AnyEvent module, stay portable to other event
67 loops (if you don't rely on any watcher types not available through it) 67 loops (if you don't rely on any watcher types not available through it)
68 and still be faster than with any other event loop currently supported 68 and still be faster than with any other event loop currently supported
69 in Perl. 69 in Perl.
70
71 MODULE EXPORTS
72 This module does not export any symbols.
70 73
71EVENT LOOPS 74EVENT LOOPS
72 EV supports multiple event loops: There is a single "default event loop" 75 EV supports multiple event loops: There is a single "default event loop"
73 that can handle everything including signals and child watchers, and any 76 that can handle everything including signals and child watchers, and any
74 number of "dynamic event loops" that can use different backends (with 77 number of "dynamic event loops" that can use different backends (with
81 default loop as this is fastest (perl-wise), best supported by other 84 default loop as this is fastest (perl-wise), best supported by other
82 modules (e.g. AnyEvent or Coro) and most portable event loop. 85 modules (e.g. AnyEvent or Coro) and most portable event loop.
83 86
84 For specific programs you can create additional event loops dynamically. 87 For specific programs you can create additional event loops dynamically.
85 88
89 If you want to take avdantage of kqueue (which often works properly for
90 sockets only) even though the default loop doesn't enable it, you can
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
93 in the section about embed watchers for an example on how to achieve
94 that.
95
86 $loop = new EV::loop [$flags] 96 $loop = new EV::loop [$flags]
87 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
88 the "ev_loop_new ()" function description in the libev documentation 98 the "ev_loop_new ()" function description in the libev documentation
89 (<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
90 ONS>) for more info. 100 ONS>, or locally-installed as EV::libev manpage) for more info.
91 101
92 The loop will automatically be destroyed when it is no longer 102 The loop will automatically be destroyed when it is no longer
93 referenced by any watcher and the loop object goes out of scope. 103 referenced by any watcher and the loop object goes out of scope.
94 104
95 Using "EV::FLAG_FORKCHECK" is recommended, as only the default event 105 If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
96 loop is protected by this module. 106 is recommended, as only the default event loop is protected by this
107 module. If you *are* embedding this loop in the default loop, this
108 is not necessary, as "EV::embed" automatically does the right thing
109 on fork.
97 110
98 $loop->loop_fork 111 $loop->loop_fork
99 Must be called after a fork in the child, before entering or 112 Must be called after a fork in the child, before entering or
100 continuing the event loop. An alternative is to use 113 continuing the event loop. An alternative is to use
101 "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at 114 "EV::FLAG_FORKCHECK" which calls this function automatically, at
102 some performance loss (refer to the libev documentation). 115 some performance loss (refer to the libev documentation).
103 116
117 $loop->loop_verify
118 Calls "ev_verify" to make internal consistency checks (for debugging
119 libev) and abort the program if any data structures were found to be
120 corrupted.
121
104 $loop = EV::default_loop [$flags] 122 $loop = EV::default_loop [$flags]
105 Return the default loop (which is a singleton object). 123 Return the default loop (which is a singleton object). Since this
124 module already creates the default loop with default flags,
125 specifying flags here will not have any effect unless you destroy
126 the default loop first, which isn't supported. So in short: don't do
127 it, and if you break it, you get to keep the pieces.
106 128
107BASIC INTERFACE 129BASIC INTERFACE
108 $EV::DIED 130 $EV::DIED
109 Must contain a reference to a function that is called when a 131 Must contain a reference to a function that is called when a
110 callback throws an exception (with $@ containing the error). The 132 callback throws an exception (with $@ containing the error). The
201 $loop->set_timeout_collect_interval ($time) 223 $loop->set_timeout_collect_interval ($time)
202 These advanced functions set the minimum block interval when polling 224 These advanced functions set the minimum block interval when polling
203 for I/O events and the minimum wait interval for timer events. See 225 for I/O events and the minimum wait interval for timer events. See
204 the libev documentation at 226 the libev documentation at
205 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT 227 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
206 ROLLING_THE_EVENT_LOOP> for a more detailed discussion. 228 ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
229 detailed discussion.
207 230
208WATCHER OBJECTS 231WATCHER OBJECTS
209 A watcher is an object that gets created to record your interest in some 232 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, 233 event. For instance, if you want to wait for STDIN to become readable,
211 you would create an EV::io watcher for that: 234 you would create an EV::io watcher for that:
212 235
213 my $watcher = EV::io *STDIN, EV::READ, sub { 236 my $watcher = EV::io *STDIN, EV::READ, sub {
214 my ($watcher, $revents) = @_; 237 my ($watcher, $revents) = @_;
215 warn "yeah, STDIN should now be readable without blocking!\n" 238 warn "yeah, STDIN should now be readable without blocking!\n"
216 }; 239 };
217 240
218 All watchers can be active (waiting for events) or inactive (paused). 241 All watchers can be active (waiting for events) or inactive (paused).
219 Only active watchers will have their callbacks invoked. All callbacks 242 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 243 will be called with at least two arguments: the watcher and a bitmask of
221 received events. 244 received events.
323 Example: Register an I/O watcher for some UDP socket but do not keep 346 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. 347 the event loop from running just because of that watcher.
325 348
326 my $udp_socket = ... 349 my $udp_socket = ...
327 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 350 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
328 $1000udp_watcher->keepalive (0); 351 $udp_watcher->keepalive (0);
329 352
330 $loop = $w->loop 353 $loop = $w->loop
331 Return the loop that this watcher is attached to. 354 Return the loop that this watcher is attached to.
332 355
333WATCHER TYPES 356WATCHER TYPES
456 each time the periodic watcher gets scheduled, the reschedule 479 each time the periodic watcher gets scheduled, the reschedule
457 callback ($reschedule_cb) will be called with the watcher as 480 callback ($reschedule_cb) will be called with the watcher as
458 first, and the current time as second argument. 481 first, and the current time as second argument.
459 482
460 *This callback MUST NOT stop or destroy this or any other 483 *This callback MUST NOT stop or destroy this or any other
484 periodic watcher, ever, and MUST NOT call any event loop
461 periodic watcher, ever*. If you need to stop it, return 1e30 and 485 functions or methods*. If you need to stop it, return 1e30 and
462 stop it afterwards. 486 stop it afterwards. You may create and start a "EV::prepare"
487 watcher for this task.
463 488
464 It must return the next time to trigger, based on the passed 489 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 490 time value (that is, the lowest time value larger than or equal
466 second argument). It will usually be called just before the 491 to to the second argument). It will usually be called just
467 callback will be triggered, but might be called at other times, 492 before the callback will be triggered, but might be called at
468 too. 493 other times, too.
469 494
470 This can be used to create very complex timers, such as a timer 495 This can be used to create very complex timers, such as a timer
471 that triggers on each midnight, local time (actually 24 hours 496 that triggers on each midnight, local time (actually 24 hours
472 after the last midnight, to keep the example simple. If you know 497 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 498 a way to do it correctly in about the same space (without
752 embedded loop, other types of watchers might be handled in a delayed or 777 embedded loop, other types of watchers might be handled in a delayed or
753 incorrect fashion and must not be used). 778 incorrect fashion and must not be used).
754 779
755 See the libev documentation at 780 See the libev documentation at
756 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code 781 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
757 _when_one_backend_> for more details. 782 _when_one_backend_> (locally installed as EV::libev) for more details.
758 783
759 In short, this watcher is most useful on BSD systems without working 784 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: 785 kqueue to still be able to handle a large number of sockets:
761 786
762 my $socket_loop; 787 my $socket_loop;
763 788
764 # check wether we use SELECT or POLL _and_ KQUEUE is supported 789 # check wether we use SELECT or POLL _and_ KQUEUE is supported
765 if ( 790 if (
766 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 791 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
767 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 792 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
768 ) { 793 ) {
769 # use kqueue for sockets 794 # use kqueue for sockets
770 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 795 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
771 } 796 }
772 797
773 # use the default loop otherwise 798 # use the default loop otherwise
774 $socket_loop ||= EV::default_loop; 799 $socket_loop ||= EV::default_loop;
775 800
776 $w = EV::embed $otherloop, $callback 801 $w = EV::embed $otherloop[, $callback]
777 $w = EV::embed_ns $otherloop, $callback 802 $w = EV::embed_ns $otherloop[, $callback]
778 $w = $loop->embed ($otherloop, $callback) 803 $w = $loop->embed ($otherloop[, $callback])
779 $w = $loop->embed_ns ($otherloop, $callback) 804 $w = $loop->embed_ns ($otherloop[, $callback])
780 Call the callback when the embedded event loop ($otherloop) has any 805 Call the callback when the embedded event loop ($otherloop) has any
781 I/O activity. The $callback should alwas be specified as "undef" in 806 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 807 embedded event loop will be managed automatically (which is
783 managed automatically. 808 recommended), otherwise you have to invoke "sweep" yourself.
784 809
785 The "embed_ns" variant doesn't start (activate) the newly created 810 The "embed_ns" variant doesn't start (activate) the newly created
786 watcher. 811 watcher.
787 812
788 ASYNC WATCHERS - how to wake up another event loop 813 ASYNC WATCHERS - how to wake up another event loop
844 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 869 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
845 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 870 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
846 agnostic and portable event driven programming. 871 agnostic and portable event driven programming.
847 872
848AUTHOR 873AUTHOR
849 Marc Lehmann <schmorp@schmorp.de> 874 Marc Lehmann <schmorp@schmorp.de>
850 http://home.schmorp.de/ 875 http://home.schmorp.de/
851 876

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