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Revision 1.27 by root, Mon May 26 05:37:18 2008 UTC vs.
Revision 1.32 by root, Tue Apr 28 00:50:57 2009 UTC

1NAME 1NAME
2 EV - perl interface to libev, a high performance full-featured event 2 EV - perl interface to libev, a high performance full-featured event
3 loop 3 loop
4 4
5SYNOPSIS 5SYNOPSIS
6 use EV; 6 use EV;
7
8 # TIMERS
9
10 my $w = EV::timer 2, 0, sub {
11 warn "is called after 2s";
12 };
13
14 my $w = EV::timer 2, 2, sub {
15 warn "is called roughly every 2s (repeat = 2)";
16 };
17
18 undef $w; # destroy event watcher again
19
20 my $w = EV::periodic 0, 60, 0, sub {
21 warn "is called every minute, on the minute, exactly";
22 };
23
24 # IO
25
26 my $w = EV::io *STDIN, EV::READ, sub {
27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28 warn "stdin is readable, you entered: ", <STDIN>;
29 };
30
31 # SIGNALS
32
33 my $w = EV::signal 'QUIT', sub {
34 warn "sigquit received\n";
35 };
36
37 # CHILD/PID STATUS CHANGES
7 38
8 # TIMERS 39 my $w = EV::child 666, 0, sub {
40 my ($w, $revents) = @_;
41 my $status = $w->rstatus;
42 };
9 43
10 my $w = EV::timer 2, 0, sub {
11 warn "is called after 2s";
12 };
13
14 my $w = EV::timer 2, 2, sub {
15 warn "is called roughly every 2s (repeat = 2)";
16 };
17
18 undef $w; # destroy event watcher again
19
20 my $w = EV::periodic 0, 60, 0, sub {
21 warn "is called every minute, on the minute, exactly";
22 };
23
24 # IO
25
26 my $w = EV::io *STDIN, EV::READ, sub {
27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28 warn "stdin is readable, you entered: ", <STDIN>;
29 };
30
31 # SIGNALS
32
33 my $w = EV::signal 'QUIT', sub {
34 warn "sigquit received\n";
35 };
36
37 # CHILD/PID STATUS CHANGES
38
39 my $w = EV::child 666, 0, sub {
40 my ($w, $revents) = @_;
41 my $status = $w->rstatus;
42 };
43
44 # STAT CHANGES 44 # STAT CHANGES
45 my $w = EV::stat "/etc/passwd", 10, sub { 45 my $w = EV::stat "/etc/passwd", 10, sub {
46 my ($w, $revents) = @_; 46 my ($w, $revents) = @_;
47 warn $w->path, " has changed somehow.\n"; 47 warn $w->path, " has changed somehow.\n";
48 }; 48 };
49 49
50 # MAINLOOP 50 # MAINLOOP
51 EV::loop; # loop until EV::unloop is called or all watchers stop 51 EV::loop; # loop until EV::unloop is called or all watchers stop
52 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 52 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
53 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 53 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
54 54
55DESCRIPTION 55DESCRIPTION
56 This module provides an interface to libev 56 This module provides an interface to libev
57 (<http://software.schmorp.de/pkg/libev.html>). While the documentation 57 (<http://software.schmorp.de/pkg/libev.html>). While the documentation
58 below is comprehensive, one might also consult the documentation of 58 below is comprehensive, one might also consult the documentation of
59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) 59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
60 for more subtle details on watcher semantics or some discussion on the 60 perldoc EV::libev) for more subtle details on watcher semantics or some
61 available backends, or how to force a specific backend with 61 discussion on the available backends, or how to force a specific backend
62 "LIBEV_FLAGS", or just about in any case because it has much more 62 with "LIBEV_FLAGS", or just about in any case because it has much more
63 detailed information. 63 detailed information.
64 64
65 This module is very fast and scalable. It is actually so fast that you 65 This module is very fast and scalable. It is actually so fast that you
66 can use it through the AnyEvent module, stay portable to other event 66 can use it through the AnyEvent module, stay portable to other event
67 loops (if you don't rely on any watcher types not available through it) 67 loops (if you don't rely on any watcher types not available through it)
68 and still be faster than with any other event loop currently supported 68 and still be faster than with any other event loop currently supported
69 in Perl. 69 in Perl.
70
71 MODULE EXPORTS
72 This module does not export any symbols.
70 73
71EVENT LOOPS 74EVENT LOOPS
72 EV supports multiple event loops: There is a single "default event loop" 75 EV supports multiple event loops: There is a single "default event loop"
73 that can handle everything including signals and child watchers, and any 76 that can handle everything including signals and child watchers, and any
74 number of "dynamic event loops" that can use different backends (with 77 number of "dynamic event loops" that can use different backends (with
… …
81 default loop as this is fastest (perl-wise), best supported by other 84 default loop as this is fastest (perl-wise), best supported by other
82 modules (e.g. AnyEvent or Coro) and most portable event loop. 85 modules (e.g. AnyEvent or Coro) and most portable event loop.
83 86
84 For specific programs you can create additional event loops dynamically. 87 For specific programs you can create additional event loops dynamically.
85 88
89 If you want to take advantage of kqueue (which often works properly for
90 sockets only) even though the default loop doesn't enable it, you can
91 *embed* a kqueue loop into the default loop: running the default loop
92 will then also service the kqueue loop to some extent. See the example
93 in the section about embed watchers for an example on how to achieve
94 that.
95
86 $loop = new EV::loop [$flags] 96 $loop = new EV::Loop [$flags]
87 Create a new event loop as per the specified flags. Please refer to 97 Create a new event loop as per the specified flags. Please refer to
88 the "ev_loop_new ()" function description in the libev documentation 98 the "ev_loop_new ()" function description in the libev documentation
89 (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI 99 (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI
90 ONS>) for more info. 100 ONS>, or locally-installed as EV::libev manpage) for more info.
91 101
92 The loop will automatically be destroyed when it is no longer 102 The loop will automatically be destroyed when it is no longer
93 referenced by any watcher and the loop object goes out of scope. 103 referenced by any watcher and the loop object goes out of scope.
94 104
95 Using "EV::FLAG_FORKCHECK" is recommended, as only the default event 105 If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
96 loop is protected by this module. 106 is recommended, as only the default event loop is protected by this
107 module. If you *are* embedding this loop in the default loop, this
108 is not necessary, as "EV::embed" automatically does the right thing
109 on fork.
97 110
98 $loop->loop_fork 111 $loop->loop_fork
99 Must be called after a fork in the child, before entering or 112 Must be called after a fork in the child, before entering or
100 continuing the event loop. An alternative is to use 113 continuing the event loop. An alternative is to use
101 "EV::FLAG_FORKCHECK" which calls this function automatically, at 114 "EV::FLAG_FORKCHECK" which calls this function automatically, at
102 some performance loss (refer to the libev documentation). 115 some performance loss (refer to the libev documentation).
103 116
104 $loop->loop_verify 117 $loop->loop_verify
105 Calls "ev_verify" to make internal consistency checks (for debugging 118 Calls "ev_verify" to make internal consistency checks (for debugging
106 libev) and abort the program if any data structures wree found to be 119 libev) and abort the program if any data structures were found to be
107 corrupted. 120 corrupted.
108 121
109 $loop = EV::default_loop [$flags] 122 $loop = EV::default_loop [$flags]
110 Return the default loop (which is a singleton object). Since this 123 Return the default loop (which is a singleton object). Since this
111 module already creates the default loop with default flags, 124 module already creates the default loop with default flags,
112 specifying flags here will not have any effect unless you destroy 125 specifying flags here will not have any effect unless you destroy
113 the default loop. 126 the default loop first, which isn't supported. So in short: don't do
127 it, and if you break it, you get to keep the pieces.
114 128
115BASIC INTERFACE 129BASIC INTERFACE
116 $EV::DIED 130 $EV::DIED
117 Must contain a reference to a function that is called when a 131 Must contain a reference to a function that is called when a
118 callback throws an exception (with $@ containing the error). The 132 callback throws an exception (with $@ containing the error). The
… …
135 Returns the current time in (fractional) seconds since the epoch. 149 Returns the current time in (fractional) seconds since the epoch.
136 150
137 $time = EV::now 151 $time = EV::now
138 $time = $loop->now 152 $time = $loop->now
139 Returns the time the last event loop iteration has been started. 153 Returns the time the last event loop iteration has been started.
140 This is the time that (relative) timers are based on, and refering 154 This is the time that (relative) timers are based on, and referring
141 to it is usually faster then calling EV::time. 155 to it is usually faster then calling EV::time.
156
157 EV::now_update
158 $loop->now_update
159 Establishes the current time by querying the kernel, updating the
160 time returned by "EV::now" in the progress. This is a costly
161 operation and is usually done automatically within "EV::loop".
162
163 This function is rarely useful, but when some event callback runs
164 for a very long time without entering the event loop, updating
165 libev's idea of the current time is a good idea.
166
167 EV::suspend
168 $loop->suspend
169 EV::resume
170 $loop->resume
171 These two functions suspend and resume a loop, for use when the loop
172 is not used for a while and timeouts should not be processed.
173
174 A typical use case would be an interactive program such as a game:
175 When the user presses "^Z" to suspend the game and resumes it an
176 hour later it would be best to handle timeouts as if no time had
177 actually passed while the program was suspended. This can be
178 achieved by calling "suspend" in your "SIGTSTP" handler, sending
179 yourself a "SIGSTOP" and calling "resume" directly afterwards to
180 resume timer processing.
181
182 Effectively, all "timer" watchers will be delayed by the time spend
183 between "suspend" and "resume", and all "periodic" watchers will be
184 rescheduled (that is, they will lose any events that would have
185 occured while suspended).
186
187 After calling "suspend" you must not call *any* function on the
188 given loop other than "resume", and you must not call "resume"
189 without a previous call to "suspend".
190
191 Calling "suspend"/"resume" has the side effect of updating the event
192 loop time (see "now_update").
142 193
143 $backend = EV::backend 194 $backend = EV::backend
144 $backend = $loop->backend 195 $backend = $loop->backend
145 Returns an integer describing the backend used by libev 196 Returns an integer describing the backend used by libev
146 (EV::METHOD_SELECT or EV::METHOD_EPOLL). 197 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
147 198
148 EV::loop [$flags] 199 EV::loop [$flags]
149 $loop->loop ([$flags]) 200 $loop->loop ([$flags])
150 Begin checking for events and calling callbacks. It returns when a 201 Begin checking for events and calling callbacks. It returns when a
151 callback calls EV::unloop. 202 callback calls EV::unloop.
… …
165 EV::loop will return as fast as possible. 216 EV::loop will return as fast as possible.
166 217
167 $count = EV::loop_count 218 $count = EV::loop_count
168 $count = $loop->loop_count 219 $count = $loop->loop_count
169 Return the number of times the event loop has polled for new events. 220 Return the number of times the event loop has polled for new events.
170 Sometiems useful as a generation counter. 221 Sometimes useful as a generation counter.
171 222
172 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 223 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
173 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 224 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
174 This function rolls together an I/O and a timer watcher for a single 225 This function rolls together an I/O and a timer watcher for a single
175 one-shot event without the need for managing a watcher object. 226 one-shot event without the need for managing a watcher object.
… …
209 $loop->set_timeout_collect_interval ($time) 260 $loop->set_timeout_collect_interval ($time)
210 These advanced functions set the minimum block interval when polling 261 These advanced functions set the minimum block interval when polling
211 for I/O events and the minimum wait interval for timer events. See 262 for I/O events and the minimum wait interval for timer events. See
212 the libev documentation at 263 the libev documentation at
213 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT 264 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
214 ROLLING_THE_EVENT_LOOP> for a more detailed discussion. 265 ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
266 detailed discussion.
215 267
216WATCHER OBJECTS 268WATCHER OBJECTS
217 A watcher is an object that gets created to record your interest in some 269 A watcher is an object that gets created to record your interest in some
218 event. For instance, if you want to wait for STDIN to become readable, 270 event. For instance, if you want to wait for STDIN to become readable,
219 you would create an EV::io watcher for that: 271 you would create an EV::io watcher for that:
220 272
221 my $watcher = EV::io *STDIN, EV::READ, sub { 273 my $watcher = EV::io *STDIN, EV::READ, sub {
222 my ($watcher, $revents) = @_; 274 my ($watcher, $revents) = @_;
223 warn "yeah, STDIN should now be readable without blocking!\n" 275 warn "yeah, STDIN should now be readable without blocking!\n"
224 }; 276 };
225 277
226 All watchers can be active (waiting for events) or inactive (paused). 278 All watchers can be active (waiting for events) or inactive (paused).
227 Only active watchers will have their callbacks invoked. All callbacks 279 Only active watchers will have their callbacks invoked. All callbacks
228 will be called with at least two arguments: the watcher and a bitmask of 280 will be called with at least two arguments: the watcher and a bitmask of
229 received events. 281 received events.
230 282
231 Each watcher type has its associated bit in revents, so you can use the 283 Each watcher type has its associated bit in revents, so you can use the
232 same callback for multiple watchers. The event mask is named after the 284 same callback for multiple watchers. The event mask is named after the
233 type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 285 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
234 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 286 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
235 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 287 events (which can set both EV::READ and EV::WRITE bits), and EV::timer
236 (which uses EV::TIMEOUT). 288 (which uses EV::TIMEOUT).
237 289
238 In the rare case where one wants to create a watcher but not start it at 290 In the rare case where one wants to create a watcher but not start it at
… …
323 375
324 In this case you can clear the keepalive status, which means that 376 In this case you can clear the keepalive status, which means that
325 even though your watcher is active, it won't keep "EV::loop" from 377 even though your watcher is active, it won't keep "EV::loop" from
326 returning. 378 returning.
327 379
328 The initial value for keepalive is true (enabled), and you cna 380 The initial value for keepalive is true (enabled), and you can
329 change it any time. 381 change it any time.
330 382
331 Example: Register an I/O watcher for some UDP socket but do not keep 383 Example: Register an I/O watcher for some UDP socket but do not keep
332 the event loop from running just because of that watcher. 384 the event loop from running just because of that watcher.
333 385
334 my $udp_socket = ... 386 my $udp_socket = ...
335 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 387 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
336 $1000udp_watcher->keepalive (0); 388 $udp_watcher->keepalive (0);
337 389
338 $loop = $w->loop 390 $loop = $w->loop
339 Return the loop that this watcher is attached to. 391 Return the loop that this watcher is attached to.
340 392
341WATCHER TYPES 393WATCHER TYPES
… …
733 # make the dispatcher handle any new stuff 785 # make the dispatcher handle any new stuff
734 ... not shown 786 ... not shown
735 }; 787 };
736 788
737 The callbacks of the created watchers will not be called as the 789 The callbacks of the created watchers will not be called as the
738 watchers are destroyed before this cna happen (remember EV::check 790 watchers are destroyed before this can happen (remember EV::check
739 gets called first). 791 gets called first).
740 792
741 The "check_ns" variant doesn't start (activate) the newly created 793 The "check_ns" variant doesn't start (activate) the newly created
742 watcher. 794 watcher.
743 795
… …
762 embedded loop, other types of watchers might be handled in a delayed or 814 embedded loop, other types of watchers might be handled in a delayed or
763 incorrect fashion and must not be used). 815 incorrect fashion and must not be used).
764 816
765 See the libev documentation at 817 See the libev documentation at
766 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code 818 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
767 _when_one_backend_> for more details. 819 _when_one_backend_> (locally installed as EV::libev) for more details.
768 820
769 In short, this watcher is most useful on BSD systems without working 821 In short, this watcher is most useful on BSD systems without working
770 kqueue to still be able to handle a large number of sockets: 822 kqueue to still be able to handle a large number of sockets:
771 823
772 my $socket_loop; 824 my $socket_loop;
773 825
774 # check wether we use SELECT or POLL _and_ KQUEUE is supported 826 # check wether we use SELECT or POLL _and_ KQUEUE is supported
775 if ( 827 if (
776 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 828 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
777 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 829 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
778 ) { 830 ) {
779 # use kqueue for sockets 831 # use kqueue for sockets
780 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 832 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
781 } 833 }
782 834
783 # use the default loop otherwise 835 # use the default loop otherwise
784 $socket_loop ||= EV::default_loop; 836 $socket_loop ||= EV::default_loop;
785 837
786 $w = EV::embed $otherloop, $callback 838 $w = EV::embed $otherloop[, $callback]
787 $w = EV::embed_ns $otherloop, $callback 839 $w = EV::embed_ns $otherloop[, $callback]
788 $w = $loop->embed ($otherloop, $callback) 840 $w = $loop->embed ($otherloop[, $callback])
789 $w = $loop->embed_ns ($otherloop, $callback) 841 $w = $loop->embed_ns ($otherloop[, $callback])
790 Call the callback when the embedded event loop ($otherloop) has any 842 Call the callback when the embedded event loop ($otherloop) has any
791 I/O activity. The $callback should alwas be specified as "undef" in 843 I/O activity. The $callback is optional: if it is missing, then the
792 this version of EV, which means the embedded event loop will be 844 embedded event loop will be managed automatically (which is
793 managed automatically. 845 recommended), otherwise you have to invoke "sweep" yourself.
794 846
795 The "embed_ns" variant doesn't start (activate) the newly created 847 The "embed_ns" variant doesn't start (activate) the newly created
796 watcher. 848 watcher.
797 849
798 ASYNC WATCHERS - how to wake up another event loop 850 ASYNC WATCHERS - how to wake up another event loop
… …
854 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 906 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
855 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 907 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
856 agnostic and portable event driven programming. 908 agnostic and portable event driven programming.
857 909
858AUTHOR 910AUTHOR
859 Marc Lehmann <schmorp@schmorp.de> 911 Marc Lehmann <schmorp@schmorp.de>
860 http://home.schmorp.de/ 912 http://home.schmorp.de/
861 913

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