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Revision 1.27 by root, Mon May 26 05:37:18 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 function 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
104 $loop->loop_verify 117 $loop->loop_verify
105 Calls "ev_verify" to make internal consistency checks (for debugging 118 Calls "ev_verify" to make internal consistency checks (for debugging
106 libev) and abort the program if any data structures wree found to be 119 libev) and abort the program if any data structures were found to be
107 corrupted. 120 corrupted.
108 121
109 $loop = EV::default_loop [$flags] 122 $loop = EV::default_loop [$flags]
110 Return the default loop (which is a singleton object). Since this 123 Return the default loop (which is a singleton object). Since this
111 module already creates the default loop with default flags, 124 module already creates the default loop with default flags,
112 specifying flags here will not have any effect unless you destroy 125 specifying flags here will not have any effect unless you destroy
113 the default loop. 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.
114 128
115BASIC INTERFACE 129BASIC INTERFACE
116 $EV::DIED 130 $EV::DIED
117 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
118 callback throws an exception (with $@ containing the error). The 132 callback throws an exception (with $@ containing the error). The
209 $loop->set_timeout_collect_interval ($time) 223 $loop->set_timeout_collect_interval ($time)
210 These advanced functions set the minimum block interval when polling 224 These advanced functions set the minimum block interval when polling
211 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
212 the libev documentation at 226 the libev documentation at
213 <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
214 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.
215 230
216WATCHER OBJECTS 231WATCHER OBJECTS
217 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
218 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,
219 you would create an EV::io watcher for that: 234 you would create an EV::io watcher for that:
220 235
221 my $watcher = EV::io *STDIN, EV::READ, sub { 236 my $watcher = EV::io *STDIN, EV::READ, sub {
222 my ($watcher, $revents) = @_; 237 my ($watcher, $revents) = @_;
223 warn "yeah, STDIN should now be readable without blocking!\n" 238 warn "yeah, STDIN should now be readable without blocking!\n"
224 }; 239 };
225 240
226 All watchers can be active (waiting for events) or inactive (paused). 241 All watchers can be active (waiting for events) or inactive (paused).
227 Only active watchers will have their callbacks invoked. All callbacks 242 Only active watchers will have their callbacks invoked. All callbacks
228 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
229 received events. 244 received events.
331 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
332 the event loop from running just because of that watcher. 347 the event loop from running just because of that watcher.
333 348
334 my $udp_socket = ... 349 my $udp_socket = ...
335 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 350 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
336 $1000udp_watcher->keepalive (0); 351 $udp_watcher->keepalive (0);
337 352
338 $loop = $w->loop 353 $loop = $w->loop
339 Return the loop that this watcher is attached to. 354 Return the loop that this watcher is attached to.
340 355
341WATCHER TYPES 356WATCHER TYPES
762 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
763 incorrect fashion and must not be used). 778 incorrect fashion and must not be used).
764 779
765 See the libev documentation at 780 See the libev documentation at
766 <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
767 _when_one_backend_> for more details. 782 _when_one_backend_> (locally installed as EV::libev) for more details.
768 783
769 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
770 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:
771 786
772 my $socket_loop; 787 my $socket_loop;
773 788
774 # check wether we use SELECT or POLL _and_ KQUEUE is supported 789 # check wether we use SELECT or POLL _and_ KQUEUE is supported
775 if ( 790 if (
776 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 791 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
777 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 792 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
778 ) { 793 ) {
779 # use kqueue for sockets 794 # use kqueue for sockets
780 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 795 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
781 } 796 }
782 797
783 # use the default loop otherwise 798 # use the default loop otherwise
784 $socket_loop ||= EV::default_loop; 799 $socket_loop ||= EV::default_loop;
785 800
786 $w = EV::embed $otherloop, $callback 801 $w = EV::embed $otherloop[, $callback]
787 $w = EV::embed_ns $otherloop, $callback 802 $w = EV::embed_ns $otherloop[, $callback]
788 $w = $loop->embed ($otherloop, $callback) 803 $w = $loop->embed ($otherloop[, $callback])
789 $w = $loop->embed_ns ($otherloop, $callback) 804 $w = $loop->embed_ns ($otherloop[, $callback])
790 Call the callback when the embedded event loop ($otherloop) has any 805 Call the callback when the embedded event loop ($otherloop) has any
791 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
792 this version of EV, which means the embedded event loop will be 807 embedded event loop will be managed automatically (which is
793 managed automatically. 808 recommended), otherwise you have to invoke "sweep" yourself.
794 809
795 The "embed_ns" variant doesn't start (activate) the newly created 810 The "embed_ns" variant doesn't start (activate) the newly created
796 watcher. 811 watcher.
797 812
798 ASYNC WATCHERS - how to wake up another event loop 813 ASYNC WATCHERS - how to wake up another event loop
854 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 869 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
855 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 870 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
856 agnostic and portable event driven programming. 871 agnostic and portable event driven programming.
857 872
858AUTHOR 873AUTHOR
859 Marc Lehmann <schmorp@schmorp.de> 874 Marc Lehmann <schmorp@schmorp.de>
860 http://home.schmorp.de/ 875 http://home.schmorp.de/
861 876

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