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Revision 1.88 by root, Wed Apr 16 17:08:29 2008 UTC vs.
Revision 1.116 by root, Sat Jun 13 15:11:54 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://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62watcher semantics or some discussion on the available backends, or how to 62F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63force a specific backend with C<LIBEV_FLAGS>, or just about in any case 63discussion on the available backends, or how to force a specific backend
64because it has much more detailed information. 64with C<LIBEV_FLAGS>, or just about in any case because it has much more
65detailed information.
66
67This module is very fast and scalable. It is actually so fast that you
68can use it through the L<AnyEvent> module, stay portable to other event
69loops (if you don't rely on any watcher types not available through it)
70and still be faster than with any other event loop currently supported in
71Perl.
72
73=head2 MODULE EXPORTS
74
75This module does not export any symbols.
65 76
66=cut 77=cut
67 78
68package EV; 79package EV;
69 80
81no warnings;
70use strict; 82use strict;
71 83
72BEGIN { 84BEGIN {
73 our $VERSION = '3.3'; 85 our $VERSION = '3.6';
74 use XSLoader; 86 use XSLoader;
75 XSLoader::load "EV", $VERSION; 87 XSLoader::load "EV", $VERSION;
76} 88}
77 89
78@EV::IO::ISA = 90@EV::IO::ISA =
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105default loop as this is fastest (perl-wise), best supported by other 117default loop as this is fastest (perl-wise), best supported by other
106modules (e.g. AnyEvent or Coro) and most portable event loop. 118modules (e.g. AnyEvent or Coro) and most portable event loop.
107 119
108For specific programs you can create additional event loops dynamically. 120For specific programs you can create additional event loops dynamically.
109 121
110=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.
111 127
128=over 4
129
112=item $loop = new EV::loop [$flags] 130=item $loop = new EV::Loop [$flags]
113 131
114Create 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
115C<ev_loop_new ()> function description in the libev documentation 133the C<ev_loop_new ()> function description in the libev documentation
116(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>,
117for more info. 135or locally-installed as F<EV::libev> manpage) for more info.
118 136
119The loop will automatically be destroyed when it is no longer referenced 137The loop will automatically be destroyed when it is no longer referenced
120by any watcher and the loop object goes out of scope. 138by any watcher and the loop object goes out of scope.
121 139
122Using 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>
123is 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.
124 144
125=item $loop->loop_fork 145=item $loop->loop_fork
126 146
127Must 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
128the 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
129this fucntion automatically, at some performance loss (refer to the libev 149this function automatically, at some performance loss (refer to the libev
130documentation). 150documentation).
131 151
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
132=item $loop = EV::default_loop [$flags] 158=item $loop = EV::default_loop [$flags]
133 159
134Return 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.
135 165
136=back 166=back
137 167
138 168
139=head1 BASIC INTERFACE 169=head1 BASIC INTERFACE
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169=item $time = EV::now 199=item $time = EV::now
170 200
171=item $time = $loop->now 201=item $time = $loop->now
172 202
173Returns the time the last event loop iteration has been started. This 203Returns the time the last event loop iteration has been started. This
174is 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
175usually faster then calling EV::time. 205usually faster then calling EV::time.
176 206
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
177=item $backend = EV::backend 249=item $backend = EV::backend
178 250
179=item $backend = $loop->backend 251=item $backend = $loop->backend
180 252
181Returns an integer describing the backend used by libev (EV::METHOD_SELECT 253Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
182or EV::METHOD_EPOLL). 254or EV::BACKEND_EPOLL).
183 255
184=item EV::loop [$flags] 256=item EV::loop [$flags]
185 257
186=item $loop->loop ([$flags]) 258=item $loop->loop ([$flags])
187 259
… …
207=item $count = EV::loop_count 279=item $count = EV::loop_count
208 280
209=item $count = $loop->loop_count 281=item $count = $loop->loop_count
210 282
211Return the number of times the event loop has polled for new 283Return the number of times the event loop has polled for new
212events. Sometiems useful as a generation counter. 284events. Sometimes useful as a generation counter.
213 285
214=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 286=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
215 287
216=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 288=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
217 289
… …
257 329
258=item $loop->set_timeout_collect_interval ($time) 330=item $loop->set_timeout_collect_interval ($time)
259 331
260These 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
261wait interval for timer events. See the libev documentation at 333wait interval for timer events. See the libev documentation at
262L<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>
263a more detailed discussion. 335(locally installed as F<EV::libev>) for a more detailed discussion.
264 336
265=back 337=back
266 338
267 339
268=head1 WATCHER OBJECTS 340=head1 WATCHER OBJECTS
269 341
270A 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
271event. 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
272would create an EV::io watcher for that: 344would create an EV::io watcher for that:
273 345
274 my $watcher = EV::io *STDIN, EV::READ, sub { 346 my $watcher = EV::io *STDIN, EV::READ, sub {
275 my ($watcher, $revents) = @_; 347 my ($watcher, $revents) = @_;
276 warn "yeah, STDIN should now be readable without blocking!\n" 348 warn "yeah, STDIN should now be readable without blocking!\n"
277 }; 349 };
278 350
279All watchers can be active (waiting for events) or inactive (paused). Only 351All watchers can be active (waiting for events) or inactive (paused). Only
280active watchers will have their callbacks invoked. All callbacks will be 352active watchers will have their callbacks invoked. All callbacks will be
281called 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
282events. 354events.
283 355
284Each 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
285same callback for multiple watchers. The event mask is named after the 357same callback for multiple watchers. The event mask is named after the
286type, 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,
287EV::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
288(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
289uses EV::TIMEOUT). 361uses EV::TIMEOUT).
290 362
291In 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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387because you happen to have this long-running UDP port watcher. 459because you happen to have this long-running UDP port watcher.
388 460
389In 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
390though 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.
391 463
392The 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
393any time. 465any time.
394 466
395Example: 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
396event loop from running just because of that watcher. 468event loop from running just because of that watcher.
397 469
398 my $udp_socket = ... 470 my $udp_socket = ...
399 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 471 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
400 $1000udp_watcher->keepalive (0); 472 $udp_watcher->keepalive (0);
401 473
402=item $loop = $w->loop 474=item $loop = $w->loop
403 475
404Return the loop that this watcher is attached to. 476Return the loop that this watcher is attached to.
405 477
… …
562time the periodic watcher gets scheduled, the reschedule callback 634time the periodic watcher gets scheduled, the reschedule callback
563($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
564time as second argument. 636time as second argument.
565 637
566I<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
567watcher, 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
568afterwards. 640you need to stop it, return 1e30 and stop it afterwards. You may create
641and start a C<EV::prepare> watcher for this task.
569 642
570It 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
571(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
572will usually be called just before the callback will be triggered, but 645argument). It will usually be called just before the callback will be
573might be called at other times, too. 646triggered, but might be called at other times, too.
574 647
575This 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
576triggers on each midnight, local time (actually 24 hours after the last 649triggers on each midnight, local time (actually 24 hours after the last
577midnight, 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
578in about the same space (without requiring elaborate modules), drop me a 651in about the same space (without requiring elaborate modules), drop me a
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890 # make the dispatcher handle any new stuff 963 # make the dispatcher handle any new stuff
891 ... not shown 964 ... not shown
892 }; 965 };
893 966
894The 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
895are destroyed before this cna happen (remember EV::check gets called 968are destroyed before this can happen (remember EV::check gets called
896first). 969first).
897 970
898The 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.
899 972
900=back 973=back
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931loop, 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
932fashion and must not be used). 1005fashion and must not be used).
933 1006
934See the libev documentation at 1007See the libev documentation at
935L<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_>
936for more details. 1009(locally installed as F<EV::libev>) for more details.
937 1010
938In short, this watcher is most useful on BSD systems without working 1011In short, this watcher is most useful on BSD systems without working
939kqueue to still be able to handle a large number of sockets: 1012kqueue to still be able to handle a large number of sockets:
940 1013
941 my $socket_loop; 1014 my $socket_loop;
942 1015
943 # check wether we use SELECT or POLL _and_ KQUEUE is supported 1016 # check wether we use SELECT or POLL _and_ KQUEUE is supported
944 if ( 1017 if (
945 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 1018 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
946 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 1019 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
947 ) { 1020 ) {
948 # use kqueue for sockets 1021 # use kqueue for sockets
949 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 1022 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
950 } 1023 }
951 1024
952 # use the default loop otherwise 1025 # use the default loop otherwise
953 $socket_loop ||= EV::default_loop; 1026 $socket_loop ||= EV::default_loop;
954 1027
955=over 4 1028=over 4
956 1029
957=item $w = EV::embed $otherloop, $callback 1030=item $w = EV::embed $otherloop[, $callback]
958 1031
959=item $w = EV::embed_ns $otherloop, $callback 1032=item $w = EV::embed_ns $otherloop[, $callback]
960 1033
961=item $w = $loop->embed ($otherloop, $callback) 1034=item $w = $loop->embed ($otherloop[, $callback])
962 1035
963=item $w = $loop->embed_ns ($otherloop, $callback) 1036=item $w = $loop->embed_ns ($otherloop[, $callback])
964 1037
965Call the callback when the embedded event loop (C<$otherloop>) has any 1038Call the callback when the embedded event loop (C<$otherloop>) has any
966I/O activity. The C<$callback> should alwas be specified as C<undef> in 1039I/O activity. The C<$callback> is optional: if it is missing, then the
967this version of EV, which means the embedded event loop will be managed 1040embedded event loop will be managed automatically (which is recommended),
968automatically. 1041otherwise you have to invoke C<sweep> yourself.
969 1042
970The 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.
971 1044
972=back 1045=back
973 1046
974=head3 ASYNC WATCHERS - how to wake up another event loop 1047=head3 ASYNC WATCHERS - how to wake up another event loop
975 1048
976Async watchers are provided by EV, but have little use in perl directly, as perl 1049Async watchers are provided by EV, but have little use in perl directly,
977neither supports threads nor direct access to signal handlers or other 1050as perl neither supports threads running in parallel nor direct access to
978contexts where they could be of value. 1051signal handlers or other contexts where they could be of value.
979 1052
980It is, however, possible to use them from the XS level. 1053It is, however, possible to use them from the XS level.
981 1054
982Please see the libev documentation for further details. 1055Please see the libev documentation for further details.
983 1056
… …
1011 my $async_check = EV::check sub { }; 1084 my $async_check = EV::check sub { };
1012 1085
1013This ensures that perl gets into control for a short time to handle any 1086This ensures that perl gets into control for a short time to handle any
1014pending signals, and also ensures (slightly) slower overall operation. 1087pending signals, and also ensures (slightly) slower overall operation.
1015 1088
1016=head1 THREADS 1089=head1 ITHREADS
1017 1090
1018Threads are not supported by this module in any way. Perl pseudo-threads 1091Ithreads are not supported by this module in any way. Perl pseudo-threads
1019is evil stuff and must die. As soon as Perl gains real threads I will work 1092is evil stuff and must die. Real threads as provided by Coro are fully
1020on thread support for it. 1093supported (and enhanced support is available via L<Coro::EV>).
1021 1094
1022=head1 FORK 1095=head1 FORK
1023 1096
1024Most of the "improved" event delivering mechanisms of modern operating 1097Most of the "improved" event delivering mechanisms of modern operating
1025systems have quite a few problems with fork(2) (to put it bluntly: it is 1098systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
1049 1122
1050=head1 SEE ALSO 1123=head1 SEE ALSO
1051 1124
1052L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1125L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
1053event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1126event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1054coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). 1127coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1128event-loop agnostic and portable event driven programming.
1055 1129
1056=head1 AUTHOR 1130=head1 AUTHOR
1057 1131
1058 Marc Lehmann <schmorp@schmorp.de> 1132 Marc Lehmann <schmorp@schmorp.de>
1059 http://home.schmorp.de/ 1133 http://home.schmorp.de/
1060 1134
1061=cut 1135=cut
1062 1136

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