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Revision 1.79 by root, Sat Dec 22 16:37:07 2007 UTC vs.
Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC

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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
76no warnings;
70use strict; 77use strict;
71 78
72BEGIN { 79BEGIN {
73 our $VERSION = '2.0'; 80 our $VERSION = '3.44';
74 use XSLoader; 81 use XSLoader;
75 XSLoader::load "EV", $VERSION; 82 XSLoader::load "EV", $VERSION;
76} 83}
77 84
78@EV::IO::ISA = 85@EV::IO::ISA =
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84@EV::Idle::ISA = 91@EV::Idle::ISA =
85@EV::Prepare::ISA = 92@EV::Prepare::ISA =
86@EV::Check::ISA = 93@EV::Check::ISA =
87@EV::Embed::ISA = 94@EV::Embed::ISA =
88@EV::Fork::ISA = 95@EV::Fork::ISA =
96@EV::Async::ISA =
89 "EV::Watcher"; 97 "EV::Watcher";
90 98
91@EV::Loop::Default::ISA = "EV::Loop"; 99@EV::Loop::Default::ISA = "EV::Loop";
92 100
93=head1 EVENT LOOPS 101=head1 EVENT LOOPS
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104default loop as this is fastest (perl-wise), best supported by other 112default loop as this is fastest (perl-wise), best supported by other
105modules (e.g. AnyEvent or Coro) and most portable event loop. 113modules (e.g. AnyEvent or Coro) and most portable event loop.
106 114
107For specific programs you can create additional event loops dynamically. 115For specific programs you can create additional event loops dynamically.
108 116
117If you want to take avdantage of kqueue (which often works properly for
118sockets only) even though the default loop doesn't enable it, you can
119I<embed> a kqueue loop into the default loop: running the default loop
120will then also service the kqueue loop to some extent. See the example in
121the section about embed watchers for an example on how to achieve that.
122
109=over 4 123=over 4
110 124
111=item $loop = new EV::loop [$flags] 125=item $loop = new EV::loop [$flags]
112 126
113Create a new event loop as per the specified flags. Please refer to the 127Create a new event loop as per the specified flags. Please refer to the
… …
116for more info. 130for more info.
117 131
118The loop will automatically be destroyed when it is no longer referenced 132The loop will automatically be destroyed when it is no longer referenced
119by any watcher and the loop object goes out of scope. 133by any watcher and the loop object goes out of scope.
120 134
121Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 135If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
122is protected by this module. 136is recommended, as only the default event loop is protected by this
137module. If you I<are> embedding this loop in the default loop, this is not
138necessary, as C<EV::embed> automatically does the right thing on fork.
123 139
124=item $loop->loop_fork 140=item $loop->loop_fork
125 141
126Must be called after a fork in the child, before entering or continuing 142Must 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 143the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
128this fucntion automatically, at some performance loss (refer to the libev 144this function automatically, at some performance loss (refer to the libev
129documentation). 145documentation).
130 146
147=item $loop->loop_verify
148
149Calls C<ev_verify> to make internal consistency checks (for debugging
150libev) and abort the program if any data structures were found to be
151corrupted.
152
131=item $loop = EV::default_loop [$flags] 153=item $loop = EV::default_loop [$flags]
132 154
133Return the default loop (which is a singleton object). 155Return the default loop (which is a singleton object). Since this module
156already creates the default loop with default flags, specifying flags here
157will not have any effect unless you destroy the default loop first, which
158isn't supported. So in short: don't do it, and if you break it, you get to
159keep the pieces.
134 160
135=back 161=back
136 162
137 163
138=head1 BASIC INTERFACE 164=head1 BASIC INTERFACE
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154=item $flags = EV::embeddable_backends 180=item $flags = EV::embeddable_backends
155 181
156Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this 182Returns 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 183instance of EV, the set of recommended backends (supposed to be good) for
158this platform and the set of embeddable backends (see EMBED WATCHERS). 184this platform and the set of embeddable backends (see EMBED WATCHERS).
185
186=item EV::sleep $seconds
187
188Block the process for the given number of (fractional) seconds.
159 189
160=item $time = EV::time 190=item $time = EV::time
161 191
162Returns the current time in (fractional) seconds since the epoch. 192Returns the current time in (fractional) seconds since the epoch.
163 193
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264 294
265A watcher is an object that gets created to record your interest in some 295A 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 296event. For instance, if you want to wait for STDIN to become readable, you
267would create an EV::io watcher for that: 297would create an EV::io watcher for that:
268 298
269 my $watcher = EV::io *STDIN, EV::READ, sub { 299 my $watcher = EV::io *STDIN, EV::READ, sub {
270 my ($watcher, $revents) = @_; 300 my ($watcher, $revents) = @_;
271 warn "yeah, STDIN should now be readable without blocking!\n" 301 warn "yeah, STDIN should now be readable without blocking!\n"
272 }; 302 };
273 303
274All watchers can be active (waiting for events) or inactive (paused). Only 304All watchers can be active (waiting for events) or inactive (paused). Only
275active watchers will have their callbacks invoked. All callbacks will be 305active watchers will have their callbacks invoked. All callbacks will be
276called with at least two arguments: the watcher and a bitmask of received 306called with at least two arguments: the watcher and a bitmask of received
277events. 307events.
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390Example: Register an I/O watcher for some UDP socket but do not keep the 420Example: Register an I/O watcher for some UDP socket but do not keep the
391event loop from running just because of that watcher. 421event loop from running just because of that watcher.
392 422
393 my $udp_socket = ... 423 my $udp_socket = ...
394 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 424 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
395 $1000udp_watcher->keepalive (0); 425 $udp_watcher->keepalive (0);
396 426
397=item $loop = $w->loop 427=item $loop = $w->loop
398 428
399Return the loop that this watcher is attached to. 429Return the loop that this watcher is attached to.
400 430
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529This time simply fires at the wallclock time C<$at> and doesn't repeat. It 559This time simply fires at the wallclock time C<$at> and doesn't repeat. It
530will not adjust when a time jump occurs, that is, if it is to be run 560will not adjust when a time jump occurs, that is, if it is to be run
531at January 1st 2011 then it will run when the system time reaches or 561at January 1st 2011 then it will run when the system time reaches or
532surpasses this time. 562surpasses this time.
533 563
534=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 564=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
535 565
536In this mode the watcher will always be scheduled to time out at the 566In this mode the watcher will always be scheduled to time out at the
537next C<$at + N * $interval> time (for some integer N) and then repeat, 567next C<$at + N * $interval> time (for some integer N) and then repeat,
538regardless of any time jumps. 568regardless of any time jumps.
539 569
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557time the periodic watcher gets scheduled, the reschedule callback 587time the periodic watcher gets scheduled, the reschedule callback
558($reschedule_cb) will be called with the watcher as first, and the current 588($reschedule_cb) will be called with the watcher as first, and the current
559time as second argument. 589time as second argument.
560 590
561I<This callback MUST NOT stop or destroy this or any other periodic 591I<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 592watcher, ever, and MUST NOT call any event loop functions or methods>. If
563afterwards. 593you need to stop it, return 1e30 and stop it afterwards. You may create
594and start a C<EV::prepare> watcher for this task.
564 595
565It must return the next time to trigger, based on the passed time value 596It 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 597(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 598argument). It will usually be called just before the callback will be
568might be called at other times, too. 599triggered, but might be called at other times, too.
569 600
570This can be used to create very complex timers, such as a timer that 601This 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 602triggers 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 603midnight, 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 604in about the same space (without requiring elaborate modules), drop me a
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640 671
641=head3 CHILD WATCHERS - watch out for process status changes 672=head3 CHILD WATCHERS - watch out for process status changes
642 673
643=over 4 674=over 4
644 675
645=item $w = EV::child $pid, $callback 676=item $w = EV::child $pid, $trace, $callback
646 677
647=item $w = EV::child_ns $pid, $callback 678=item $w = EV::child_ns $pid, $trace, $callback
648 679
649=item $w = $loop->child ($pid, $callback) 680=item $w = $loop->child ($pid, $trace, $callback)
650 681
651=item $w = $loop->child_ns ($pid, $callback) 682=item $w = $loop->child_ns ($pid, $trace, $callback)
652 683
653Call the callback when a status change for pid C<$pid> (or any pid if 684Call 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 685if C<$pid> is 0) has been received (a status change happens when the
686process terminates or is killed, or, when trace is true, additionally when
687it is stopped or continued). More precisely: when the process receives
655a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 688a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
656changed/zombie children and call the callback. 689changed/zombie children and call the callback.
657 690
658It is valid (and fully supported) to install a child watcher after a child 691It 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 692has exited but before the event loop has started its next iteration (for
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666You can have as many pid watchers per pid as you want, they will all be 699You can have as many pid watchers per pid as you want, they will all be
667called. 700called.
668 701
669The C<child_ns> variant doesn't start (activate) the newly created watcher. 702The C<child_ns> variant doesn't start (activate) the newly created watcher.
670 703
671=item $w->set ($pid) 704=item $w->set ($pid, $trace)
672 705
673Reconfigures the watcher, see the constructor above for details. Can be called at 706Reconfigures the watcher, see the constructor above for details. Can be called at
674any time. 707any time.
675 708
676=item $current_pid = $w->pid 709=item $current_pid = $w->pid
677
678=item $old_pid = $w->pid ($new_pid)
679 710
680Returns the previously set process id and optionally set a new one. 711Returns the previously set process id and optionally set a new one.
681 712
682=item $exit_status = $w->rstatus 713=item $exit_status = $w->rstatus
683 714
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931for more details. 962for more details.
932 963
933In short, this watcher is most useful on BSD systems without working 964In short, this watcher is most useful on BSD systems without working
934kqueue to still be able to handle a large number of sockets: 965kqueue to still be able to handle a large number of sockets:
935 966
936 my $socket_loop; 967 my $socket_loop;
937 968
938 # check wether we use SELECT or POLL _and_ KQUEUE is supported 969 # check wether we use SELECT or POLL _and_ KQUEUE is supported
939 if ( 970 if (
940 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 971 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
941 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 972 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
942 ) { 973 ) {
943 # use kqueue for sockets 974 # use kqueue for sockets
944 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 975 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
945 } 976 }
946 977
947 # use the default loop otherwise 978 # use the default loop otherwise
948 $socket_loop ||= EV::default_loop; 979 $socket_loop ||= EV::default_loop;
949 980
950=over 4 981=over 4
951 982
952=item $w = EV::embed $otherloop, $callback 983=item $w = EV::embed $otherloop[, $callback]
953 984
954=item $w = EV::embed_ns $otherloop, $callback 985=item $w = EV::embed_ns $otherloop[, $callback]
955 986
956=item $w = $loop->embed ($otherloop, $callback) 987=item $w = $loop->embed ($otherloop[, $callback])
957 988
958=item $w = $loop->embed_ns ($otherloop, $callback) 989=item $w = $loop->embed_ns ($otherloop[, $callback])
959 990
960Call the callback when the embedded event loop (C<$otherloop>) has any 991Call the callback when the embedded event loop (C<$otherloop>) has any
961I/O activity. The C<$callback> should alwas be specified as C<undef> in 992I/O activity. The C<$callback> is optional: if it is missing, then the
962this version of EV, which means the embedded event loop will be managed 993embedded event loop will be managed automatically (which is recommended),
963automatically. 994otherwise you have to invoke C<sweep> yourself.
964 995
965The C<embed_ns> variant doesn't start (activate) the newly created watcher. 996The C<embed_ns> variant doesn't start (activate) the newly created watcher.
997
998=back
999
1000=head3 ASYNC WATCHERS - how to wake up another event loop
1001
1002Async watchers are provided by EV, but have little use in perl directly, as perl
1003neither supports threads nor direct access to signal handlers or other
1004contexts where they could be of value.
1005
1006It is, however, possible to use them from the XS level.
1007
1008Please see the libev documentation for further details.
1009
1010=over 4
1011
1012=item $w = EV::async $callback
1013
1014=item $w = EV::async_ns $callback
1015
1016=item $w->send
1017
1018=item $bool = $w->async_pending
966 1019
967=back 1020=back
968 1021
969 1022
970=head1 PERL SIGNALS 1023=head1 PERL SIGNALS
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1022 1075
1023=head1 SEE ALSO 1076=head1 SEE ALSO
1024 1077
1025L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1078L<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 1079event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1027coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). 1080coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1081event-loop agnostic and portable event driven programming.
1028 1082
1029=head1 AUTHOR 1083=head1 AUTHOR
1030 1084
1031 Marc Lehmann <schmorp@schmorp.de> 1085 Marc Lehmann <schmorp@schmorp.de>
1032 http://home.schmorp.de/ 1086 http://home.schmorp.de/
1033 1087
1034=cut 1088=cut
1035 1089

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