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Revision 1.91 by root, Tue May 6 12:43:58 2008 UTC vs.
Revision 1.114 by root, Wed Apr 15 19:35:53 2009 UTC

… …
2 2
3EV - perl interface to libev, a high performance full-featured event loop 3EV - perl interface to libev, a high performance full-featured event loop
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use EV; 7 use EV;
8
9 # TIMERS
10
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
8 39
9 # TIMERS 40 my $w = EV::child 666, 0, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
10 44
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
39
40 my $w = EV::child 666, 0, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
44
45 # STAT CHANGES 45 # STAT CHANGES
46 my $w = EV::stat "/etc/passwd", 10, sub { 46 my $w = EV::stat "/etc/passwd", 10, sub {
47 my ($w, $revents) = @_; 47 my ($w, $revents) = @_;
48 warn $w->path, " has changed somehow.\n"; 48 warn $w->path, " has changed somehow.\n";
49 }; 49 };
50 50
51 # MAINLOOP 51 # MAINLOOP
52 EV::loop; # loop until EV::unloop is called or all watchers stop 52 EV::loop; # loop until EV::unloop is called or all watchers stop
53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55 55
56=head1 DESCRIPTION 56=head1 DESCRIPTION
57 57
58This module provides an interface to libev 58This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of libev 60below is comprehensive, one might also consult the documentation of
61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more 61libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62subtle details on watcher semantics or some discussion on the available 62F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just 63discussion on the available backends, or how to force a specific backend
64about in any case because it has much more detailed information. 64with C<LIBEV_FLAGS>, or just about in any case because it has much more
65detailed information.
65 66
66This module is very fast and scalable. It is actually so fast that you 67This module is very fast and scalable. It is actually so fast that you
67can use it through the L<AnyEvent> module, stay portable to other event 68can use it through the L<AnyEvent> module, stay portable to other event
68loops (if you don't rely on any watcher types not available through it) 69loops (if you don't rely on any watcher types not available through it)
69and still be faster than with any other event loop currently supported in 70and still be faster than with any other event loop currently supported in
70Perl. 71Perl.
71 72
73=head2 MODULE EXPORTS
74
75This module does not export any symbols.
76
72=cut 77=cut
73 78
74package EV; 79package EV;
75 80
81no warnings;
76use strict; 82use strict;
77 83
78BEGIN { 84BEGIN {
79 our $VERSION = '3.31'; 85 our $VERSION = '3.53';
80 use XSLoader; 86 use XSLoader;
81 XSLoader::load "EV", $VERSION; 87 XSLoader::load "EV", $VERSION;
82} 88}
83 89
84@EV::IO::ISA = 90@EV::IO::ISA =
… …
111default loop as this is fastest (perl-wise), best supported by other 117default loop as this is fastest (perl-wise), best supported by other
112modules (e.g. AnyEvent or Coro) and most portable event loop. 118modules (e.g. AnyEvent or Coro) and most portable event loop.
113 119
114For specific programs you can create additional event loops dynamically. 120For specific programs you can create additional event loops dynamically.
115 121
116=over 4 122If you want to take advantage of kqueue (which often works properly for
123sockets only) even though the default loop doesn't enable it, you can
124I<embed> a kqueue loop into the default loop: running the default loop
125will then also service the kqueue loop to some extent. See the example in
126the section about embed watchers for an example on how to achieve that.
117 127
128=over 4
129
118=item $loop = new EV::loop [$flags] 130=item $loop = new EV::Loop [$flags]
119 131
120Create a new event loop as per the specified flags. Please refer to the 132Create a new event loop as per the specified flags. Please refer to
121C<ev_loop_new ()> function description in the libev documentation 133the C<ev_loop_new ()> function description in the libev documentation
122(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) 134(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
123for more info. 135or locally-installed as F<EV::libev> manpage) for more info.
124 136
125The loop will automatically be destroyed when it is no longer referenced 137The loop will automatically be destroyed when it is no longer referenced
126by any watcher and the loop object goes out of scope. 138by any watcher and the loop object goes out of scope.
127 139
128Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 140If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
129is protected by this module. 141is recommended, as only the default event loop is protected by this
142module. If you I<are> embedding this loop in the default loop, this is not
143necessary, as C<EV::embed> automatically does the right thing on fork.
130 144
131=item $loop->loop_fork 145=item $loop->loop_fork
132 146
133Must be called after a fork in the child, before entering or continuing 147Must be called after a fork in the child, before entering or continuing
134the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls 148the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
135this fucntion automatically, at some performance loss (refer to the libev 149this function automatically, at some performance loss (refer to the libev
136documentation). 150documentation).
137 151
152=item $loop->loop_verify
153
154Calls C<ev_verify> to make internal consistency checks (for debugging
155libev) and abort the program if any data structures were found to be
156corrupted.
157
138=item $loop = EV::default_loop [$flags] 158=item $loop = EV::default_loop [$flags]
139 159
140Return the default loop (which is a singleton object). 160Return the default loop (which is a singleton object). Since this module
161already creates the default loop with default flags, specifying flags here
162will not have any effect unless you destroy the default loop first, which
163isn't supported. So in short: don't do it, and if you break it, you get to
164keep the pieces.
141 165
142=back 166=back
143 167
144 168
145=head1 BASIC INTERFACE 169=head1 BASIC INTERFACE
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175=item $time = EV::now 199=item $time = EV::now
176 200
177=item $time = $loop->now 201=item $time = $loop->now
178 202
179Returns the time the last event loop iteration has been started. This 203Returns the time the last event loop iteration has been started. This
180is the time that (relative) timers are based on, and refering to it is 204is the time that (relative) timers are based on, and referring to it is
181usually faster then calling EV::time. 205usually faster then calling EV::time.
182 206
207=item EV::now_update
208
209=item $loop->now_update
210
211Establishes the current time by querying the kernel, updating the time
212returned by C<EV::now> in the progress. This is a costly operation and
213is usually done automatically within C<EV::loop>.
214
215This function is rarely useful, but when some event callback runs for a
216very long time without entering the event loop, updating libev's idea of
217the current time is a good idea.
218
219=item EV::suspend
220
221=item $loop->suspend
222
223=item EV::resume
224
225=item $loop->resume
226
227These two functions suspend and resume a loop, for use when the loop is
228not used for a while and timeouts should not be processed.
229
230A typical use case would be an interactive program such as a game: When
231the user presses C<^Z> to suspend the game and resumes it an hour later it
232would be best to handle timeouts as if no time had actually passed while
233the program was suspended. This can be achieved by calling C<suspend>
234in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
235C<resume> directly afterwards to resume timer processing.
236
237Effectively, all C<timer> watchers will be delayed by the time spend
238between C<suspend> and C<resume>, and all C<periodic> watchers
239will be rescheduled (that is, they will lose any events that would have
240occured while suspended).
241
242After calling C<suspend> you B<must not> call I<any> function on the given
243loop other than C<resume>, and you B<must not> call C<resume>
244without a previous call to C<suspend>.
245
246Calling C<suspend>/C<resume> has the side effect of updating the event
247loop time (see C<now_update>).
248
183=item $backend = EV::backend 249=item $backend = EV::backend
184 250
185=item $backend = $loop->backend 251=item $backend = $loop->backend
186 252
187Returns an integer describing the backend used by libev (EV::METHOD_SELECT 253Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
188or EV::METHOD_EPOLL). 254or EV::BACKEND_EPOLL).
189 255
190=item EV::loop [$flags] 256=item EV::loop [$flags]
191 257
192=item $loop->loop ([$flags]) 258=item $loop->loop ([$flags])
193 259
… …
213=item $count = EV::loop_count 279=item $count = EV::loop_count
214 280
215=item $count = $loop->loop_count 281=item $count = $loop->loop_count
216 282
217Return the number of times the event loop has polled for new 283Return the number of times the event loop has polled for new
218events. Sometiems useful as a generation counter. 284events. Sometimes useful as a generation counter.
219 285
220=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 286=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
221 287
222=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 288=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
223 289
… …
263 329
264=item $loop->set_timeout_collect_interval ($time) 330=item $loop->set_timeout_collect_interval ($time)
265 331
266These advanced functions set the minimum block interval when polling for I/O events and the minimum 332These advanced functions set the minimum block interval when polling for I/O events and the minimum
267wait interval for timer events. See the libev documentation at 333wait interval for timer events. See the libev documentation at
268L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for 334L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
269a more detailed discussion. 335(locally installed as F<EV::libev>) for a more detailed discussion.
270 336
271=back 337=back
272 338
273 339
274=head1 WATCHER OBJECTS 340=head1 WATCHER OBJECTS
275 341
276A watcher is an object that gets created to record your interest in some 342A watcher is an object that gets created to record your interest in some
277event. For instance, if you want to wait for STDIN to become readable, you 343event. For instance, if you want to wait for STDIN to become readable, you
278would create an EV::io watcher for that: 344would create an EV::io watcher for that:
279 345
280 my $watcher = EV::io *STDIN, EV::READ, sub { 346 my $watcher = EV::io *STDIN, EV::READ, sub {
281 my ($watcher, $revents) = @_; 347 my ($watcher, $revents) = @_;
282 warn "yeah, STDIN should now be readable without blocking!\n" 348 warn "yeah, STDIN should now be readable without blocking!\n"
283 }; 349 };
284 350
285All watchers can be active (waiting for events) or inactive (paused). Only 351All watchers can be active (waiting for events) or inactive (paused). Only
286active watchers will have their callbacks invoked. All callbacks will be 352active watchers will have their callbacks invoked. All callbacks will be
287called with at least two arguments: the watcher and a bitmask of received 353called with at least two arguments: the watcher and a bitmask of received
288events. 354events.
289 355
290Each watcher type has its associated bit in revents, so you can use the 356Each watcher type has its associated bit in revents, so you can use the
291same callback for multiple watchers. The event mask is named after the 357same callback for multiple watchers. The event mask is named after the
292type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 358type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
293EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 359EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
294(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 360(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
295uses EV::TIMEOUT). 361uses EV::TIMEOUT).
296 362
297In the rare case where one wants to create a watcher but not start it at 363In the rare case where one wants to create a watcher but not start it at
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393because you happen to have this long-running UDP port watcher. 459because you happen to have this long-running UDP port watcher.
394 460
395In this case you can clear the keepalive status, which means that even 461In this case you can clear the keepalive status, which means that even
396though your watcher is active, it won't keep C<EV::loop> from returning. 462though your watcher is active, it won't keep C<EV::loop> from returning.
397 463
398The initial value for keepalive is true (enabled), and you cna change it 464The initial value for keepalive is true (enabled), and you can change it
399any time. 465any time.
400 466
401Example: Register an I/O watcher for some UDP socket but do not keep the 467Example: Register an I/O watcher for some UDP socket but do not keep the
402event loop from running just because of that watcher. 468event loop from running just because of that watcher.
403 469
404 my $udp_socket = ... 470 my $udp_socket = ...
405 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 471 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
406 $1000udp_watcher->keepalive (0); 472 $udp_watcher->keepalive (0);
407 473
408=item $loop = $w->loop 474=item $loop = $w->loop
409 475
410Return the loop that this watcher is attached to. 476Return the loop that this watcher is attached to.
411 477
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568time the periodic watcher gets scheduled, the reschedule callback 634time the periodic watcher gets scheduled, the reschedule callback
569($reschedule_cb) will be called with the watcher as first, and the current 635($reschedule_cb) will be called with the watcher as first, and the current
570time as second argument. 636time as second argument.
571 637
572I<This callback MUST NOT stop or destroy this or any other periodic 638I<This callback MUST NOT stop or destroy this or any other periodic
573watcher, ever>. If you need to stop it, return 1e30 and stop it 639watcher, ever, and MUST NOT call any event loop functions or methods>. If
574afterwards. 640you need to stop it, return 1e30 and stop it afterwards. You may create
641and start a C<EV::prepare> watcher for this task.
575 642
576It must return the next time to trigger, based on the passed time value 643It must return the next time to trigger, based on the passed time value
577(that is, the lowest time value larger than to the second argument). It 644(that is, the lowest time value larger than or equal to to the second
578will usually be called just before the callback will be triggered, but 645argument). It will usually be called just before the callback will be
579might be called at other times, too. 646triggered, but might be called at other times, too.
580 647
581This can be used to create very complex timers, such as a timer that 648This can be used to create very complex timers, such as a timer that
582triggers on each midnight, local time (actually 24 hours after the last 649triggers on each midnight, local time (actually 24 hours after the last
583midnight, to keep the example simple. If you know a way to do it correctly 650midnight, to keep the example simple. If you know a way to do it correctly
584in about the same space (without requiring elaborate modules), drop me a 651in about the same space (without requiring elaborate modules), drop me a
… …
896 # make the dispatcher handle any new stuff 963 # make the dispatcher handle any new stuff
897 ... not shown 964 ... not shown
898 }; 965 };
899 966
900The callbacks of the created watchers will not be called as the watchers 967The callbacks of the created watchers will not be called as the watchers
901are destroyed before this cna happen (remember EV::check gets called 968are destroyed before this can happen (remember EV::check gets called
902first). 969first).
903 970
904The C<check_ns> variant doesn't start (activate) the newly created watcher. 971The C<check_ns> variant doesn't start (activate) the newly created watcher.
905 972
906=back 973=back
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937loop, other types of watchers might be handled in a delayed or incorrect 1004loop, other types of watchers might be handled in a delayed or incorrect
938fashion and must not be used). 1005fashion and must not be used).
939 1006
940See the libev documentation at 1007See the libev documentation at
941L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1008L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
942for more details. 1009(locally installed as F<EV::libev>) for more details.
943 1010
944In short, this watcher is most useful on BSD systems without working 1011In short, this watcher is most useful on BSD systems without working
945kqueue to still be able to handle a large number of sockets: 1012kqueue to still be able to handle a large number of sockets:
946 1013
947 my $socket_loop; 1014 my $socket_loop;
948 1015
949 # check wether we use SELECT or POLL _and_ KQUEUE is supported 1016 # check wether we use SELECT or POLL _and_ KQUEUE is supported
950 if ( 1017 if (
951 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 1018 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
952 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 1019 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
953 ) { 1020 ) {
954 # use kqueue for sockets 1021 # use kqueue for sockets
955 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 1022 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
956 } 1023 }
957 1024
958 # use the default loop otherwise 1025 # use the default loop otherwise
959 $socket_loop ||= EV::default_loop; 1026 $socket_loop ||= EV::default_loop;
960 1027
961=over 4 1028=over 4
962 1029
963=item $w = EV::embed $otherloop, $callback 1030=item $w = EV::embed $otherloop[, $callback]
964 1031
965=item $w = EV::embed_ns $otherloop, $callback 1032=item $w = EV::embed_ns $otherloop[, $callback]
966 1033
967=item $w = $loop->embed ($otherloop, $callback) 1034=item $w = $loop->embed ($otherloop[, $callback])
968 1035
969=item $w = $loop->embed_ns ($otherloop, $callback) 1036=item $w = $loop->embed_ns ($otherloop[, $callback])
970 1037
971Call the callback when the embedded event loop (C<$otherloop>) has any 1038Call the callback when the embedded event loop (C<$otherloop>) has any
972I/O activity. The C<$callback> should alwas be specified as C<undef> in 1039I/O activity. The C<$callback> is optional: if it is missing, then the
973this version of EV, which means the embedded event loop will be managed 1040embedded event loop will be managed automatically (which is recommended),
974automatically. 1041otherwise you have to invoke C<sweep> yourself.
975 1042
976The C<embed_ns> variant doesn't start (activate) the newly created watcher. 1043The C<embed_ns> variant doesn't start (activate) the newly created watcher.
977 1044
978=back 1045=back
979 1046
… …
1060coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for 1127coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1061event-loop agnostic and portable event driven programming. 1128event-loop agnostic and portable event driven programming.
1062 1129
1063=head1 AUTHOR 1130=head1 AUTHOR
1064 1131
1065 Marc Lehmann <schmorp@schmorp.de> 1132 Marc Lehmann <schmorp@schmorp.de>
1066 http://home.schmorp.de/ 1133 http://home.schmorp.de/
1067 1134
1068=cut 1135=cut
1069 1136

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