ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/EV/EV.pm
(Generate patch)

Comparing EV/EV.pm (file contents):
Revision 1.88 by root, Wed Apr 16 17:08:29 2008 UTC vs.
Revision 1.117 by root, Tue Jul 14 00:09:59 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
70use strict; 81use common::sense;
71 82
72BEGIN { 83BEGIN {
73 our $VERSION = '3.3'; 84 our $VERSION = '3.6';
74 use XSLoader; 85 use XSLoader;
75 XSLoader::load "EV", $VERSION; 86 XSLoader::load "EV", $VERSION;
76} 87}
77 88
78@EV::IO::ISA = 89@EV::IO::ISA =
… …
105default loop as this is fastest (perl-wise), best supported by other 116default loop as this is fastest (perl-wise), best supported by other
106modules (e.g. AnyEvent or Coro) and most portable event loop. 117modules (e.g. AnyEvent or Coro) and most portable event loop.
107 118
108For specific programs you can create additional event loops dynamically. 119For specific programs you can create additional event loops dynamically.
109 120
110=over 4 121If you want to take advantage of kqueue (which often works properly for
122sockets only) even though the default loop doesn't enable it, you can
123I<embed> a kqueue loop into the default loop: running the default loop
124will then also service the kqueue loop to some extent. See the example in
125the section about embed watchers for an example on how to achieve that.
111 126
127=over 4
128
112=item $loop = new EV::loop [$flags] 129=item $loop = new EV::Loop [$flags]
113 130
114Create a new event loop as per the specified flags. Please refer to the 131Create a new event loop as per the specified flags. Please refer to
115C<ev_loop_new ()> function description in the libev documentation 132the 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>) 133(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
117for more info. 134or locally-installed as F<EV::libev> manpage) for more info.
118 135
119The loop will automatically be destroyed when it is no longer referenced 136The loop will automatically be destroyed when it is no longer referenced
120by any watcher and the loop object goes out of scope. 137by any watcher and the loop object goes out of scope.
121 138
122Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 139If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
123is protected by this module. 140is recommended, as only the default event loop is protected by this
141module. If you I<are> embedding this loop in the default loop, this is not
142necessary, as C<EV::embed> automatically does the right thing on fork.
124 143
125=item $loop->loop_fork 144=item $loop->loop_fork
126 145
127Must be called after a fork in the child, before entering or continuing 146Must 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 147the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
129this fucntion automatically, at some performance loss (refer to the libev 148this function automatically, at some performance loss (refer to the libev
130documentation). 149documentation).
131 150
151=item $loop->loop_verify
152
153Calls C<ev_verify> to make internal consistency checks (for debugging
154libev) and abort the program if any data structures were found to be
155corrupted.
156
132=item $loop = EV::default_loop [$flags] 157=item $loop = EV::default_loop [$flags]
133 158
134Return the default loop (which is a singleton object). 159Return the default loop (which is a singleton object). Since this module
160already creates the default loop with default flags, specifying flags here
161will not have any effect unless you destroy the default loop first, which
162isn't supported. So in short: don't do it, and if you break it, you get to
163keep the pieces.
135 164
136=back 165=back
137 166
138 167
139=head1 BASIC INTERFACE 168=head1 BASIC INTERFACE
… …
169=item $time = EV::now 198=item $time = EV::now
170 199
171=item $time = $loop->now 200=item $time = $loop->now
172 201
173Returns the time the last event loop iteration has been started. This 202Returns 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 203is the time that (relative) timers are based on, and referring to it is
175usually faster then calling EV::time. 204usually faster then calling EV::time.
176 205
206=item EV::now_update
207
208=item $loop->now_update
209
210Establishes the current time by querying the kernel, updating the time
211returned by C<EV::now> in the progress. This is a costly operation and
212is usually done automatically within C<EV::loop>.
213
214This function is rarely useful, but when some event callback runs for a
215very long time without entering the event loop, updating libev's idea of
216the current time is a good idea.
217
218=item EV::suspend
219
220=item $loop->suspend
221
222=item EV::resume
223
224=item $loop->resume
225
226These two functions suspend and resume a loop, for use when the loop is
227not used for a while and timeouts should not be processed.
228
229A typical use case would be an interactive program such as a game: When
230the user presses C<^Z> to suspend the game and resumes it an hour later it
231would be best to handle timeouts as if no time had actually passed while
232the program was suspended. This can be achieved by calling C<suspend>
233in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
234C<resume> directly afterwards to resume timer processing.
235
236Effectively, all C<timer> watchers will be delayed by the time spend
237between C<suspend> and C<resume>, and all C<periodic> watchers
238will be rescheduled (that is, they will lose any events that would have
239occured while suspended).
240
241After calling C<suspend> you B<must not> call I<any> function on the given
242loop other than C<resume>, and you B<must not> call C<resume>
243without a previous call to C<suspend>.
244
245Calling C<suspend>/C<resume> has the side effect of updating the event
246loop time (see C<now_update>).
247
177=item $backend = EV::backend 248=item $backend = EV::backend
178 249
179=item $backend = $loop->backend 250=item $backend = $loop->backend
180 251
181Returns an integer describing the backend used by libev (EV::METHOD_SELECT 252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
182or EV::METHOD_EPOLL). 253or EV::BACKEND_EPOLL).
183 254
184=item EV::loop [$flags] 255=item EV::loop [$flags]
185 256
186=item $loop->loop ([$flags]) 257=item $loop->loop ([$flags])
187 258
… …
207=item $count = EV::loop_count 278=item $count = EV::loop_count
208 279
209=item $count = $loop->loop_count 280=item $count = $loop->loop_count
210 281
211Return the number of times the event loop has polled for new 282Return the number of times the event loop has polled for new
212events. Sometiems useful as a generation counter. 283events. Sometimes useful as a generation counter.
213 284
214=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
215 286
216=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 287=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
217 288
… …
257 328
258=item $loop->set_timeout_collect_interval ($time) 329=item $loop->set_timeout_collect_interval ($time)
259 330
260These advanced functions set the minimum block interval when polling for I/O events and the minimum 331These 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 332wait 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 333L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
263a more detailed discussion. 334(locally installed as F<EV::libev>) for a more detailed discussion.
264 335
265=back 336=back
266 337
267 338
268=head1 WATCHER OBJECTS 339=head1 WATCHER OBJECTS
269 340
270A watcher is an object that gets created to record your interest in some 341A 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 342event. For instance, if you want to wait for STDIN to become readable, you
272would create an EV::io watcher for that: 343would create an EV::io watcher for that:
273 344
274 my $watcher = EV::io *STDIN, EV::READ, sub { 345 my $watcher = EV::io *STDIN, EV::READ, sub {
275 my ($watcher, $revents) = @_; 346 my ($watcher, $revents) = @_;
276 warn "yeah, STDIN should now be readable without blocking!\n" 347 warn "yeah, STDIN should now be readable without blocking!\n"
277 }; 348 };
278 349
279All watchers can be active (waiting for events) or inactive (paused). Only 350All watchers can be active (waiting for events) or inactive (paused). Only
280active watchers will have their callbacks invoked. All callbacks will be 351active watchers will have their callbacks invoked. All callbacks will be
281called with at least two arguments: the watcher and a bitmask of received 352called with at least two arguments: the watcher and a bitmask of received
282events. 353events.
283 354
284Each watcher type has its associated bit in revents, so you can use the 355Each 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 356same callback for multiple watchers. The event mask is named after the
286type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 357type, 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 358EV::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 359(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
289uses EV::TIMEOUT). 360uses EV::TIMEOUT).
290 361
291In the rare case where one wants to create a watcher but not start it at 362In the rare case where one wants to create a watcher but not start it at
… …
387because you happen to have this long-running UDP port watcher. 458because you happen to have this long-running UDP port watcher.
388 459
389In this case you can clear the keepalive status, which means that even 460In 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. 461though your watcher is active, it won't keep C<EV::loop> from returning.
391 462
392The initial value for keepalive is true (enabled), and you cna change it 463The initial value for keepalive is true (enabled), and you can change it
393any time. 464any time.
394 465
395Example: Register an I/O watcher for some UDP socket but do not keep the 466Example: Register an I/O watcher for some UDP socket but do not keep the
396event loop from running just because of that watcher. 467event loop from running just because of that watcher.
397 468
398 my $udp_socket = ... 469 my $udp_socket = ...
399 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 470 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
400 $1000udp_watcher->keepalive (0); 471 $udp_watcher->keepalive (0);
401 472
402=item $loop = $w->loop 473=item $loop = $w->loop
403 474
404Return the loop that this watcher is attached to. 475Return the loop that this watcher is attached to.
405 476
… …
562time the periodic watcher gets scheduled, the reschedule callback 633time the periodic watcher gets scheduled, the reschedule callback
563($reschedule_cb) will be called with the watcher as first, and the current 634($reschedule_cb) will be called with the watcher as first, and the current
564time as second argument. 635time as second argument.
565 636
566I<This callback MUST NOT stop or destroy this or any other periodic 637I<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 638watcher, ever, and MUST NOT call any event loop functions or methods>. If
568afterwards. 639you need to stop it, return 1e30 and stop it afterwards. You may create
640and start a C<EV::prepare> watcher for this task.
569 641
570It must return the next time to trigger, based on the passed time value 642It 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 643(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 644argument). It will usually be called just before the callback will be
573might be called at other times, too. 645triggered, but might be called at other times, too.
574 646
575This can be used to create very complex timers, such as a timer that 647This 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 648triggers 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 649midnight, 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 650in about the same space (without requiring elaborate modules), drop me a
… …
890 # make the dispatcher handle any new stuff 962 # make the dispatcher handle any new stuff
891 ... not shown 963 ... not shown
892 }; 964 };
893 965
894The callbacks of the created watchers will not be called as the watchers 966The callbacks of the created watchers will not be called as the watchers
895are destroyed before this cna happen (remember EV::check gets called 967are destroyed before this can happen (remember EV::check gets called
896first). 968first).
897 969
898The C<check_ns> variant doesn't start (activate) the newly created watcher. 970The C<check_ns> variant doesn't start (activate) the newly created watcher.
899 971
900=back 972=back
… …
931loop, other types of watchers might be handled in a delayed or incorrect 1003loop, other types of watchers might be handled in a delayed or incorrect
932fashion and must not be used). 1004fashion and must not be used).
933 1005
934See the libev documentation at 1006See the libev documentation at
935L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1007L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
936for more details. 1008(locally installed as F<EV::libev>) for more details.
937 1009
938In short, this watcher is most useful on BSD systems without working 1010In short, this watcher is most useful on BSD systems without working
939kqueue to still be able to handle a large number of sockets: 1011kqueue to still be able to handle a large number of sockets:
940 1012
941 my $socket_loop; 1013 my $socket_loop;
942 1014
943 # check wether we use SELECT or POLL _and_ KQUEUE is supported 1015 # check wether we use SELECT or POLL _and_ KQUEUE is supported
944 if ( 1016 if (
945 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 1017 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
946 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 1018 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
947 ) { 1019 ) {
948 # use kqueue for sockets 1020 # use kqueue for sockets
949 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 1021 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
950 } 1022 }
951 1023
952 # use the default loop otherwise 1024 # use the default loop otherwise
953 $socket_loop ||= EV::default_loop; 1025 $socket_loop ||= EV::default_loop;
954 1026
955=over 4 1027=over 4
956 1028
957=item $w = EV::embed $otherloop, $callback 1029=item $w = EV::embed $otherloop[, $callback]
958 1030
959=item $w = EV::embed_ns $otherloop, $callback 1031=item $w = EV::embed_ns $otherloop[, $callback]
960 1032
961=item $w = $loop->embed ($otherloop, $callback) 1033=item $w = $loop->embed ($otherloop[, $callback])
962 1034
963=item $w = $loop->embed_ns ($otherloop, $callback) 1035=item $w = $loop->embed_ns ($otherloop[, $callback])
964 1036
965Call the callback when the embedded event loop (C<$otherloop>) has any 1037Call 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 1038I/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 1039embedded event loop will be managed automatically (which is recommended),
968automatically. 1040otherwise you have to invoke C<sweep> yourself.
969 1041
970The C<embed_ns> variant doesn't start (activate) the newly created watcher. 1042The C<embed_ns> variant doesn't start (activate) the newly created watcher.
971 1043
972=back 1044=back
973 1045
974=head3 ASYNC WATCHERS - how to wake up another event loop 1046=head3 ASYNC WATCHERS - how to wake up another event loop
975 1047
976Async watchers are provided by EV, but have little use in perl directly, as perl 1048Async watchers are provided by EV, but have little use in perl directly,
977neither supports threads nor direct access to signal handlers or other 1049as perl neither supports threads running in parallel nor direct access to
978contexts where they could be of value. 1050signal handlers or other contexts where they could be of value.
979 1051
980It is, however, possible to use them from the XS level. 1052It is, however, possible to use them from the XS level.
981 1053
982Please see the libev documentation for further details. 1054Please see the libev documentation for further details.
983 1055
… …
1011 my $async_check = EV::check sub { }; 1083 my $async_check = EV::check sub { };
1012 1084
1013This ensures that perl gets into control for a short time to handle any 1085This ensures that perl gets into control for a short time to handle any
1014pending signals, and also ensures (slightly) slower overall operation. 1086pending signals, and also ensures (slightly) slower overall operation.
1015 1087
1016=head1 THREADS 1088=head1 ITHREADS
1017 1089
1018Threads are not supported by this module in any way. Perl pseudo-threads 1090Ithreads 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 1091is evil stuff and must die. Real threads as provided by Coro are fully
1020on thread support for it. 1092supported (and enhanced support is available via L<Coro::EV>).
1021 1093
1022=head1 FORK 1094=head1 FORK
1023 1095
1024Most of the "improved" event delivering mechanisms of modern operating 1096Most of the "improved" event delivering mechanisms of modern operating
1025systems have quite a few problems with fork(2) (to put it bluntly: it is 1097systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
1049 1121
1050=head1 SEE ALSO 1122=head1 SEE ALSO
1051 1123
1052L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1124L<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 1125event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1054coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). 1126coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1127event-loop agnostic and portable event driven programming.
1055 1128
1056=head1 AUTHOR 1129=head1 AUTHOR
1057 1130
1058 Marc Lehmann <schmorp@schmorp.de> 1131 Marc Lehmann <schmorp@schmorp.de>
1059 http://home.schmorp.de/ 1132 http://home.schmorp.de/
1060 1133
1061=cut 1134=cut
1062 1135

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines