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Revision 1.26 by root, Wed May 21 23:40:08 2008 UTC vs.
Revision 1.31 by root, Wed Nov 19 10:33:32 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 advantage 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
… …
127 Returns the current time in (fractional) seconds since the epoch. 149 Returns the current time in (fractional) seconds since the epoch.
128 150
129 $time = EV::now 151 $time = EV::now
130 $time = $loop->now 152 $time = $loop->now
131 Returns the time the last event loop iteration has been started. 153 Returns the time the last event loop iteration has been started.
132 This is the time that (relative) timers are based on, and refering 154 This is the time that (relative) timers are based on, and referring
133 to it is usually faster then calling EV::time. 155 to it is usually faster then calling EV::time.
134 156
135 $backend = EV::backend 157 $backend = EV::backend
136 $backend = $loop->backend 158 $backend = $loop->backend
137 Returns an integer describing the backend used by libev 159 Returns an integer describing the backend used by libev
138 (EV::METHOD_SELECT or EV::METHOD_EPOLL). 160 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
139 161
140 EV::loop [$flags] 162 EV::loop [$flags]
141 $loop->loop ([$flags]) 163 $loop->loop ([$flags])
142 Begin checking for events and calling callbacks. It returns when a 164 Begin checking for events and calling callbacks. It returns when a
143 callback calls EV::unloop. 165 callback calls EV::unloop.
… …
157 EV::loop will return as fast as possible. 179 EV::loop will return as fast as possible.
158 180
159 $count = EV::loop_count 181 $count = EV::loop_count
160 $count = $loop->loop_count 182 $count = $loop->loop_count
161 Return the number of times the event loop has polled for new events. 183 Return the number of times the event loop has polled for new events.
162 Sometiems useful as a generation counter. 184 Sometimes useful as a generation counter.
163 185
164 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 186 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
165 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 187 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
166 This function rolls together an I/O and a timer watcher for a single 188 This function rolls together an I/O and a timer watcher for a single
167 one-shot event without the need for managing a watcher object. 189 one-shot event without the need for managing a watcher object.
… …
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.
222 245
223 Each watcher type has its associated bit in revents, so you can use the 246 Each watcher type has its associated bit in revents, so you can use the
224 same callback for multiple watchers. The event mask is named after the 247 same callback for multiple watchers. The event mask is named after the
225 type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 248 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
226 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 249 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
227 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 250 events (which can set both EV::READ and EV::WRITE bits), and EV::timer
228 (which uses EV::TIMEOUT). 251 (which uses EV::TIMEOUT).
229 252
230 In the rare case where one wants to create a watcher but not start it at 253 In the rare case where one wants to create a watcher but not start it at
… …
315 338
316 In this case you can clear the keepalive status, which means that 339 In this case you can clear the keepalive status, which means that
317 even though your watcher is active, it won't keep "EV::loop" from 340 even though your watcher is active, it won't keep "EV::loop" from
318 returning. 341 returning.
319 342
320 The initial value for keepalive is true (enabled), and you cna 343 The initial value for keepalive is true (enabled), and you can
321 change it any time. 344 change it any time.
322 345
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
… …
725 # make the dispatcher handle any new stuff 748 # make the dispatcher handle any new stuff
726 ... not shown 749 ... not shown
727 }; 750 };
728 751
729 The callbacks of the created watchers will not be called as the 752 The callbacks of the created watchers will not be called as the
730 watchers are destroyed before this cna happen (remember EV::check 753 watchers are destroyed before this can happen (remember EV::check
731 gets called first). 754 gets called first).
732 755
733 The "check_ns" variant doesn't start (activate) the newly created 756 The "check_ns" variant doesn't start (activate) the newly created
734 watcher. 757 watcher.
735 758
… …
754 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
755 incorrect fashion and must not be used). 778 incorrect fashion and must not be used).
756 779
757 See the libev documentation at 780 See the libev documentation at
758 <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
759 _when_one_backend_> for more details. 782 _when_one_backend_> (locally installed as EV::libev) for more details.
760 783
761 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
762 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:
763 786
764 my $socket_loop; 787 my $socket_loop;
765 788
766 # check wether we use SELECT or POLL _and_ KQUEUE is supported 789 # check wether we use SELECT or POLL _and_ KQUEUE is supported
767 if ( 790 if (
768 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 791 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
769 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 792 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
770 ) { 793 ) {
771 # use kqueue for sockets 794 # use kqueue for sockets
772 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 795 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
773 } 796 }
774 797
775 # use the default loop otherwise 798 # use the default loop otherwise
776 $socket_loop ||= EV::default_loop; 799 $socket_loop ||= EV::default_loop;
777 800
778 $w = EV::embed $otherloop, $callback 801 $w = EV::embed $otherloop[, $callback]
779 $w = EV::embed_ns $otherloop, $callback 802 $w = EV::embed_ns $otherloop[, $callback]
780 $w = $loop->embed ($otherloop, $callback) 803 $w = $loop->embed ($otherloop[, $callback])
781 $w = $loop->embed_ns ($otherloop, $callback) 804 $w = $loop->embed_ns ($otherloop[, $callback])
782 Call the callback when the embedded event loop ($otherloop) has any 805 Call the callback when the embedded event loop ($otherloop) has any
783 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
784 this version of EV, which means the embedded event loop will be 807 embedded event loop will be managed automatically (which is
785 managed automatically. 808 recommended), otherwise you have to invoke "sweep" yourself.
786 809
787 The "embed_ns" variant doesn't start (activate) the newly created 810 The "embed_ns" variant doesn't start (activate) the newly created
788 watcher. 811 watcher.
789 812
790 ASYNC WATCHERS - how to wake up another event loop 813 ASYNC WATCHERS - how to wake up another event loop
… …
846 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 869 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
847 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 870 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
848 agnostic and portable event driven programming. 871 agnostic and portable event driven programming.
849 872
850AUTHOR 873AUTHOR
851 Marc Lehmann <schmorp@schmorp.de> 874 Marc Lehmann <schmorp@schmorp.de>
852 http://home.schmorp.de/ 875 http://home.schmorp.de/
853 876

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