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Revision 1.79 by root, Sat Dec 22 16:37:07 2007 UTC vs.
Revision 1.99 by root, Tue Jul 8 09:37:37 2008 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 $w = EV::child 666, sub {
41 my ($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 libev
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62watcher semantics or some discussion on the available backends, or how to 62subtle details on watcher semantics or some discussion on the available
63force a specific backend with C<LIBEV_FLAGS>, or just about in any case 63backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
64because it has much more detailed information. 64about in any case because it has much more detailed information.
65
66This 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
68loops (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
70Perl.
65 71
66=cut 72=cut
67 73
68package EV; 74package EV;
69 75
70use strict; 76use strict;
71 77
72BEGIN { 78BEGIN {
73 our $VERSION = '2.0'; 79 our $VERSION = '3.42';
74 use XSLoader; 80 use XSLoader;
75 XSLoader::load "EV", $VERSION; 81 XSLoader::load "EV", $VERSION;
76} 82}
77 83
78@EV::IO::ISA = 84@EV::IO::ISA =
84@EV::Idle::ISA = 90@EV::Idle::ISA =
85@EV::Prepare::ISA = 91@EV::Prepare::ISA =
86@EV::Check::ISA = 92@EV::Check::ISA =
87@EV::Embed::ISA = 93@EV::Embed::ISA =
88@EV::Fork::ISA = 94@EV::Fork::ISA =
95@EV::Async::ISA =
89 "EV::Watcher"; 96 "EV::Watcher";
90 97
91@EV::Loop::Default::ISA = "EV::Loop"; 98@EV::Loop::Default::ISA = "EV::Loop";
92 99
93=head1 EVENT LOOPS 100=head1 EVENT LOOPS
104default loop as this is fastest (perl-wise), best supported by other 111default loop as this is fastest (perl-wise), best supported by other
105modules (e.g. AnyEvent or Coro) and most portable event loop. 112modules (e.g. AnyEvent or Coro) and most portable event loop.
106 113
107For specific programs you can create additional event loops dynamically. 114For specific programs you can create additional event loops dynamically.
108 115
116If you want to take avdantage of kqueue (which often works properly for
117sockets only) even though the default loop doesn't enable it, you can
118I<embed> a kqueue loop into the default loop: running the default loop
119will then also service the kqueue loop to some extent. See the example in
120the section about embed watchers for an example on how to achieve that.
121
109=over 4 122=over 4
110 123
111=item $loop = new EV::loop [$flags] 124=item $loop = new EV::loop [$flags]
112 125
113Create a new event loop as per the specified flags. Please refer to the 126Create a new event loop as per the specified flags. Please refer to the
123 136
124=item $loop->loop_fork 137=item $loop->loop_fork
125 138
126Must be called after a fork in the child, before entering or continuing 139Must be called after a fork in the child, before entering or continuing
127the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls 140the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
128this fucntion automatically, at some performance loss (refer to the libev 141this function automatically, at some performance loss (refer to the libev
129documentation). 142documentation).
130 143
144=item $loop->loop_verify
145
146Calls C<ev_verify> to make internal consistency checks (for debugging
147libev) and abort the program if any data structures were found to be
148corrupted.
149
131=item $loop = EV::default_loop [$flags] 150=item $loop = EV::default_loop [$flags]
132 151
133Return the default loop (which is a singleton object). 152Return the default loop (which is a singleton object). Since this module
153already creates the default loop with default flags, specifying flags here
154will not have any effect unless you destroy the default loop first, which
155isn't supported. So in short: don't do it, and if you break it, you get to
156keep the pieces.
134 157
135=back 158=back
136 159
137 160
138=head1 BASIC INTERFACE 161=head1 BASIC INTERFACE
154=item $flags = EV::embeddable_backends 177=item $flags = EV::embeddable_backends
155 178
156Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this 179Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
157instance of EV, the set of recommended backends (supposed to be good) for 180instance of EV, the set of recommended backends (supposed to be good) for
158this platform and the set of embeddable backends (see EMBED WATCHERS). 181this platform and the set of embeddable backends (see EMBED WATCHERS).
182
183=item EV::sleep $seconds
184
185Block the process for the given number of (fractional) seconds.
159 186
160=item $time = EV::time 187=item $time = EV::time
161 188
162Returns the current time in (fractional) seconds since the epoch. 189Returns the current time in (fractional) seconds since the epoch.
163 190
264 291
265A watcher is an object that gets created to record your interest in some 292A watcher is an object that gets created to record your interest in some
266event. For instance, if you want to wait for STDIN to become readable, you 293event. For instance, if you want to wait for STDIN to become readable, you
267would create an EV::io watcher for that: 294would create an EV::io watcher for that:
268 295
269 my $watcher = EV::io *STDIN, EV::READ, sub { 296 my $watcher = EV::io *STDIN, EV::READ, sub {
270 my ($watcher, $revents) = @_; 297 my ($watcher, $revents) = @_;
271 warn "yeah, STDIN should now be readable without blocking!\n" 298 warn "yeah, STDIN should now be readable without blocking!\n"
272 }; 299 };
273 300
274All watchers can be active (waiting for events) or inactive (paused). Only 301All watchers can be active (waiting for events) or inactive (paused). Only
275active watchers will have their callbacks invoked. All callbacks will be 302active watchers will have their callbacks invoked. All callbacks will be
276called with at least two arguments: the watcher and a bitmask of received 303called with at least two arguments: the watcher and a bitmask of received
277events. 304events.
390Example: Register an I/O watcher for some UDP socket but do not keep the 417Example: Register an I/O watcher for some UDP socket but do not keep the
391event loop from running just because of that watcher. 418event loop from running just because of that watcher.
392 419
393 my $udp_socket = ... 420 my $udp_socket = ...
394 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 421 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
395 $1000udp_watcher->keepalive (0); 422 $udp_watcher->keepalive (0);
396 423
397=item $loop = $w->loop 424=item $loop = $w->loop
398 425
399Return the loop that this watcher is attached to. 426Return the loop that this watcher is attached to.
400 427
529This time simply fires at the wallclock time C<$at> and doesn't repeat. It 556This time simply fires at the wallclock time C<$at> and doesn't repeat. It
530will not adjust when a time jump occurs, that is, if it is to be run 557will not adjust when a time jump occurs, that is, if it is to be run
531at January 1st 2011 then it will run when the system time reaches or 558at January 1st 2011 then it will run when the system time reaches or
532surpasses this time. 559surpasses this time.
533 560
534=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 561=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
535 562
536In this mode the watcher will always be scheduled to time out at the 563In this mode the watcher will always be scheduled to time out at the
537next C<$at + N * $interval> time (for some integer N) and then repeat, 564next C<$at + N * $interval> time (for some integer N) and then repeat,
538regardless of any time jumps. 565regardless of any time jumps.
539 566
557time the periodic watcher gets scheduled, the reschedule callback 584time the periodic watcher gets scheduled, the reschedule callback
558($reschedule_cb) will be called with the watcher as first, and the current 585($reschedule_cb) will be called with the watcher as first, and the current
559time as second argument. 586time as second argument.
560 587
561I<This callback MUST NOT stop or destroy this or any other periodic 588I<This callback MUST NOT stop or destroy this or any other periodic
562watcher, ever>. If you need to stop it, return 1e30 and stop it 589watcher, ever, and MUST NOT call any event loop functions or methods>. If
563afterwards. 590you need to stop it, return 1e30 and stop it afterwards. You may create
591and start a C<EV::prepare> watcher for this task.
564 592
565It must return the next time to trigger, based on the passed time value 593It must return the next time to trigger, based on the passed time value
566(that is, the lowest time value larger than to the second argument). It 594(that is, the lowest time value larger than or equal to to the second
567will usually be called just before the callback will be triggered, but 595argument). It will usually be called just before the callback will be
568might be called at other times, too. 596triggered, but might be called at other times, too.
569 597
570This can be used to create very complex timers, such as a timer that 598This can be used to create very complex timers, such as a timer that
571triggers on each midnight, local time (actually 24 hours after the last 599triggers on each midnight, local time (actually 24 hours after the last
572midnight, to keep the example simple. If you know a way to do it correctly 600midnight, to keep the example simple. If you know a way to do it correctly
573in about the same space (without requiring elaborate modules), drop me a 601in about the same space (without requiring elaborate modules), drop me a
640 668
641=head3 CHILD WATCHERS - watch out for process status changes 669=head3 CHILD WATCHERS - watch out for process status changes
642 670
643=over 4 671=over 4
644 672
645=item $w = EV::child $pid, $callback 673=item $w = EV::child $pid, $trace, $callback
646 674
647=item $w = EV::child_ns $pid, $callback 675=item $w = EV::child_ns $pid, $trace, $callback
648 676
649=item $w = $loop->child ($pid, $callback) 677=item $w = $loop->child ($pid, $trace, $callback)
650 678
651=item $w = $loop->child_ns ($pid, $callback) 679=item $w = $loop->child_ns ($pid, $trace, $callback)
652 680
653Call the callback when a status change for pid C<$pid> (or any pid if 681Call the callback when a status change for pid C<$pid> (or any pid
654C<$pid> is 0) has been received. More precisely: when the process receives 682if C<$pid> is 0) has been received (a status change happens when the
683process terminates or is killed, or, when trace is true, additionally when
684it is stopped or continued). More precisely: when the process receives
655a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 685a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
656changed/zombie children and call the callback. 686changed/zombie children and call the callback.
657 687
658It is valid (and fully supported) to install a child watcher after a child 688It is valid (and fully supported) to install a child watcher after a child
659has exited but before the event loop has started its next iteration (for 689has exited but before the event loop has started its next iteration (for
666You can have as many pid watchers per pid as you want, they will all be 696You can have as many pid watchers per pid as you want, they will all be
667called. 697called.
668 698
669The C<child_ns> variant doesn't start (activate) the newly created watcher. 699The C<child_ns> variant doesn't start (activate) the newly created watcher.
670 700
671=item $w->set ($pid) 701=item $w->set ($pid, $trace)
672 702
673Reconfigures the watcher, see the constructor above for details. Can be called at 703Reconfigures the watcher, see the constructor above for details. Can be called at
674any time. 704any time.
675 705
676=item $current_pid = $w->pid 706=item $current_pid = $w->pid
677
678=item $old_pid = $w->pid ($new_pid)
679 707
680Returns the previously set process id and optionally set a new one. 708Returns the previously set process id and optionally set a new one.
681 709
682=item $exit_status = $w->rstatus 710=item $exit_status = $w->rstatus
683 711
931for more details. 959for more details.
932 960
933In short, this watcher is most useful on BSD systems without working 961In short, this watcher is most useful on BSD systems without working
934kqueue to still be able to handle a large number of sockets: 962kqueue to still be able to handle a large number of sockets:
935 963
936 my $socket_loop; 964 my $socket_loop;
937 965
938 # check wether we use SELECT or POLL _and_ KQUEUE is supported 966 # check wether we use SELECT or POLL _and_ KQUEUE is supported
939 if ( 967 if (
940 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 968 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
941 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 969 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
942 ) { 970 ) {
943 # use kqueue for sockets 971 # use kqueue for sockets
944 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 972 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
945 } 973 }
946 974
947 # use the default loop otherwise 975 # use the default loop otherwise
948 $socket_loop ||= EV::default_loop; 976 $socket_loop ||= EV::default_loop;
949 977
950=over 4 978=over 4
951 979
952=item $w = EV::embed $otherloop, $callback 980=item $w = EV::embed $otherloop, $callback
953 981
961I/O activity. The C<$callback> should alwas be specified as C<undef> in 989I/O activity. The C<$callback> should alwas be specified as C<undef> in
962this version of EV, which means the embedded event loop will be managed 990this version of EV, which means the embedded event loop will be managed
963automatically. 991automatically.
964 992
965The C<embed_ns> variant doesn't start (activate) the newly created watcher. 993The C<embed_ns> variant doesn't start (activate) the newly created watcher.
994
995=back
996
997=head3 ASYNC WATCHERS - how to wake up another event loop
998
999Async watchers are provided by EV, but have little use in perl directly, as perl
1000neither supports threads nor direct access to signal handlers or other
1001contexts where they could be of value.
1002
1003It is, however, possible to use them from the XS level.
1004
1005Please see the libev documentation for further details.
1006
1007=over 4
1008
1009=item $w = EV::async $callback
1010
1011=item $w = EV::async_ns $callback
1012
1013=item $w->send
1014
1015=item $bool = $w->async_pending
966 1016
967=back 1017=back
968 1018
969 1019
970=head1 PERL SIGNALS 1020=head1 PERL SIGNALS
1022 1072
1023=head1 SEE ALSO 1073=head1 SEE ALSO
1024 1074
1025L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1075L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
1026event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1076event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1027coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). 1077coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1078event-loop agnostic and portable event driven programming.
1028 1079
1029=head1 AUTHOR 1080=head1 AUTHOR
1030 1081
1031 Marc Lehmann <schmorp@schmorp.de> 1082 Marc Lehmann <schmorp@schmorp.de>
1032 http://home.schmorp.de/ 1083 http://home.schmorp.de/
1033 1084
1034=cut 1085=cut
1035 1086

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