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Revision 1.29 by root, Sat Jul 12 22:19:22 2008 UTC vs.
Revision 1.40 by root, Thu Jan 19 17:55:23 2012 UTC

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 7
8 # TIMERS 8 # TIMERS
9 9
10 my $w = EV::timer 2, 0, sub { 10 my $w = EV::timer 2, 0, sub {
11 warn "is called after 2s"; 11 warn "is called after 2s";
12 }; 12 };
13 13
14 my $w = EV::timer 2, 2, sub { 14 my $w = EV::timer 2, 2, sub {
15 warn "is called roughly every 2s (repeat = 2)"; 15 warn "is called roughly every 2s (repeat = 2)";
16 }; 16 };
17 17
18 undef $w; # destroy event watcher again 18 undef $w; # destroy event watcher again
19 19
20 my $w = EV::periodic 0, 60, 0, sub { 20 my $w = EV::periodic 0, 60, 0, sub {
21 warn "is called every minute, on the minute, exactly"; 21 warn "is called every minute, on the minute, exactly";
22 }; 22 };
23
23 24 # IO
24 # IO 25
25
26 my $w = EV::io *STDIN, EV::READ, sub { 26 my $w = EV::io *STDIN, EV::READ, sub {
27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask 27 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28 warn "stdin is readable, you entered: ", <STDIN>; 28 warn "stdin is readable, you entered: ", <STDIN>;
29 }; 29 };
30 30
31 # SIGNALS 31 # SIGNALS
32 32
33 my $w = EV::signal 'QUIT', sub { 33 my $w = EV::signal 'QUIT', sub {
34 warn "sigquit received\n"; 34 warn "sigquit received\n";
35 }; 35 };
36 36
37 # CHILD/PID STATUS CHANGES 37 # CHILD/PID STATUS CHANGES
38 38
39 my $w = EV::child 666, 0, sub { 39 my $w = EV::child 666, 0, sub {
40 my ($w, $revents) = @_; 40 my ($w, $revents) = @_;
41 my $status = $w->rstatus; 41 my $status = $w->rstatus;
42 }; 42 };
43 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::run; # 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::run EV::RUN_ONCE; # 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::run EV::RUN_NOWAIT; # try to handle same events, but do not block
54
55BEFORE YOU START USING THIS MODULE
56 If you only need timer, I/O, signal, child and idle watchers and not the
57 advanced functionality of this module, consider using AnyEvent instead,
58 specifically the simplified API described in AE.
59
60 When used with EV as backend, the AE API is as fast as the native EV
61 API, but your programs/modules will still run with many other event
62 loops.
54 63
55DESCRIPTION 64DESCRIPTION
56 This module provides an interface to libev 65 This module provides an interface to libev
57 (<http://software.schmorp.de/pkg/libev.html>). While the documentation 66 (<http://software.schmorp.de/pkg/libev.html>). While the documentation
58 below is comprehensive, one might also consult the documentation of 67 below is comprehensive, one might also consult the documentation of
59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) 68 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 69 perldoc EV::libev) for more subtle details on watcher semantics or some
61 available backends, or how to force a specific backend with 70 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 71 with "LIBEV_FLAGS", or just about in any case because it has much more
63 detailed information. 72 detailed information.
64 73
65 This module is very fast and scalable. It is actually so fast that you 74 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 75 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) 76 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 77 and still be faster than with any other event loop currently supported
69 in Perl. 78 in Perl.
79
80 PORTING FROM EV 3.X to 4.X
81 EV version 4 introduces a number of incompatible changes summarised
82 here. According to the depreciation strategy used by libev, there is a
83 compatibility layer in place so programs should continue to run
84 unchanged (the XS interface lacks this layer, so programs using that one
85 need to be updated).
86
87 This compatibility layer will be switched off in some future release.
88
89 All changes relevant to Perl are renames of symbols, functions and
90 methods:
91
92 EV::loop => EV::run
93 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
94 EV::LOOP_ONESHOT => EV::RUN_ONCE
95
96 EV::unloop => EV::break
97 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
98 EV::UNLOOP_ONE => EV::BREAK_ONE
99 EV::UNLOOP_ALL => EV::BREAK_ALL
100
101 EV::TIMEOUT => EV::TIMER
102
103 EV::loop_count => EV::iteration
104 EV::loop_depth => EV::depth
105 EV::loop_verify => EV::verify
106
107 The loop object methods corresponding to the functions above have been
108 similarly renamed.
109
110 MODULE EXPORTS
111 This module does not export any symbols.
70 112
71EVENT LOOPS 113EVENT LOOPS
72 EV supports multiple event loops: There is a single "default event loop" 114 EV supports multiple event loops: There is a single "default event loop"
73 that can handle everything including signals and child watchers, and any 115 that can handle everything including signals and child watchers, and any
74 number of "dynamic event loops" that can use different backends (with 116 number of "dynamic event loops" that can use different backends (with
81 default loop as this is fastest (perl-wise), best supported by other 123 default loop as this is fastest (perl-wise), best supported by other
82 modules (e.g. AnyEvent or Coro) and most portable event loop. 124 modules (e.g. AnyEvent or Coro) and most portable event loop.
83 125
84 For specific programs you can create additional event loops dynamically. 126 For specific programs you can create additional event loops dynamically.
85 127
86 If you want to take avdantage of kqueue (which often works properly for 128 If you want to take advantage of kqueue (which often works properly for
87 sockets only) even though the default loop doesn't enable it, you can 129 sockets only) even though the default loop doesn't enable it, you can
88 *embed* a kqueue loop into the default loop: running the default loop 130 *embed* a kqueue loop into the default loop: running the default loop
89 will then also service the kqueue loop to some extent. See the example 131 will then also service the kqueue loop to some extent. See the example
90 in the section about embed watchers for an example on how to achieve 132 in the section about embed watchers for an example on how to achieve
91 that. 133 that.
92 134
93 $loop = new EV::loop [$flags] 135 $loop = new EV::Loop [$flags]
94 Create a new event loop as per the specified flags. Please refer to 136 Create a new event loop as per the specified flags. Please refer to
95 the "ev_loop_new ()" function description in the libev documentation 137 the "ev_loop_new ()" function description in the libev documentation
96 (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI 138 (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI
97 ONS>) for more info. 139 ONS>, or locally-installed as EV::libev manpage) for more info.
98 140
99 The loop will automatically be destroyed when it is no longer 141 The loop will automatically be destroyed when it is no longer
100 referenced by any watcher and the loop object goes out of scope. 142 referenced by any watcher and the loop object goes out of scope.
101 143
102 Using "EV::FLAG_FORKCHECK" is recommended, as only the default event 144 If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
103 loop is protected by this module. 145 is recommended, as only the default event loop is protected by this
146 module. If you *are* embedding this loop in the default loop, this
147 is not necessary, as "EV::embed" automatically does the right thing
148 on fork.
104 149
105 $loop->loop_fork 150 $loop->loop_fork
106 Must be called after a fork in the child, before entering or 151 Must be called after a fork in the child, before entering or
107 continuing the event loop. An alternative is to use 152 continuing the event loop. An alternative is to use
108 "EV::FLAG_FORKCHECK" which calls this function automatically, at 153 "EV::FLAG_FORKCHECK" which calls this function automatically, at
109 some performance loss (refer to the libev documentation). 154 some performance loss (refer to the libev documentation).
110 155
111 $loop->loop_verify 156 $loop->verify
112 Calls "ev_verify" to make internal consistency checks (for debugging 157 Calls "ev_verify" to make internal consistency checks (for debugging
113 libev) and abort the program if any data structures were found to be 158 libev) and abort the program if any data structures were found to be
114 corrupted. 159 corrupted.
115 160
116 $loop = EV::default_loop [$flags] 161 $loop = EV::default_loop [$flags]
143 Returns the current time in (fractional) seconds since the epoch. 188 Returns the current time in (fractional) seconds since the epoch.
144 189
145 $time = EV::now 190 $time = EV::now
146 $time = $loop->now 191 $time = $loop->now
147 Returns the time the last event loop iteration has been started. 192 Returns the time the last event loop iteration has been started.
148 This is the time that (relative) timers are based on, and refering 193 This is the time that (relative) timers are based on, and referring
149 to it is usually faster then calling EV::time. 194 to it is usually faster then calling EV::time.
195
196 EV::now_update
197 $loop->now_update
198 Establishes the current time by querying the kernel, updating the
199 time returned by "EV::now" in the progress. This is a costly
200 operation and is usually done automatically within "EV::loop".
201
202 This function is rarely useful, but when some event callback runs
203 for a very long time without entering the event loop, updating
204 libev's idea of the current time is a good idea.
205
206 EV::suspend
207 $loop->suspend
208 EV::resume
209 $loop->resume
210 These two functions suspend and resume a loop, for use when the loop
211 is not used for a while and timeouts should not be processed.
212
213 A typical use case would be an interactive program such as a game:
214 When the user presses "^Z" to suspend the game and resumes it an
215 hour later it would be best to handle timeouts as if no time had
216 actually passed while the program was suspended. This can be
217 achieved by calling "suspend" in your "SIGTSTP" handler, sending
218 yourself a "SIGSTOP" and calling "resume" directly afterwards to
219 resume timer processing.
220
221 Effectively, all "timer" watchers will be delayed by the time spend
222 between "suspend" and "resume", and all "periodic" watchers will be
223 rescheduled (that is, they will lose any events that would have
224 occured while suspended).
225
226 After calling "suspend" you must not call *any* function on the
227 given loop other than "resume", and you must not call "resume"
228 without a previous call to "suspend".
229
230 Calling "suspend"/"resume" has the side effect of updating the event
231 loop time (see "now_update").
150 232
151 $backend = EV::backend 233 $backend = EV::backend
152 $backend = $loop->backend 234 $backend = $loop->backend
153 Returns an integer describing the backend used by libev 235 Returns an integer describing the backend used by libev
154 (EV::METHOD_SELECT or EV::METHOD_EPOLL). 236 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
155 237
156 EV::loop [$flags] 238 EV::run [$flags]
157 $loop->loop ([$flags]) 239 $loop->run ([$flags])
158 Begin checking for events and calling callbacks. It returns when a 240 Begin checking for events and calling callbacks. It returns when a
159 callback calls EV::unloop. 241 callback calls EV::unloop.
160 242
161 The $flags argument can be one of the following: 243 The $flags argument can be one of the following:
162 244
163 0 as above 245 0 as above
164 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 246 EV::RUN_ONCE block at most once (wait, but do not loop)
165 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 247 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
166 248
167 EV::unloop [$how] 249 EV::break [$how]
168 $loop->unloop ([$how]) 250 $loop->break ([$how])
169 When called with no arguments or an argument of EV::UNLOOP_ONE, 251 When called with no arguments or an argument of EV::BREAK_ONE, makes
170 makes the innermost call to EV::loop return. 252 the innermost call to EV::loop return.
171 253
172 When called with an argument of EV::UNLOOP_ALL, all calls to 254 When called with an argument of EV::BREAK_ALL, all calls to EV::loop
173 EV::loop will return as fast as possible. 255 will return as fast as possible.
174 256
175 $count = EV::loop_count 257 When called with an argument of EV::BREAK_CANCEL, any pending break
176 $count = $loop->loop_count 258 will be cancelled.
259
260 $count = EV::iteration
261 $count = $loop->iteration
177 Return the number of times the event loop has polled for new events. 262 Return the number of times the event loop has polled for new events.
178 Sometiems useful as a generation counter. 263 Sometimes useful as a generation counter.
179 264
180 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 265 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
181 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 266 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
182 This function rolls together an I/O and a timer watcher for a single 267 This function rolls together an I/O and a timer watcher for a single
183 one-shot event without the need for managing a watcher object. 268 one-shot event without the need for managing a watcher object.
192 Otherwise a EV::timer with this value will be started. 277 Otherwise a EV::timer with this value will be started.
193 278
194 When an error occurs or either the timeout or I/O watcher triggers, 279 When an error occurs or either the timeout or I/O watcher triggers,
195 then the callback will be called with the received event set (in 280 then the callback will be called with the received event set (in
196 general you can expect it to be a combination of "EV::ERROR", 281 general you can expect it to be a combination of "EV::ERROR",
197 "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). 282 "EV::READ", "EV::WRITE" and "EV::TIMER").
198 283
199 EV::once doesn't return anything: the watchers stay active till 284 EV::once doesn't return anything: the watchers stay active till
200 either of them triggers, then they will be stopped and freed, and 285 either of them triggers, then they will be stopped and freed, and
201 the callback invoked. 286 the callback invoked.
202 287
203 EV::feed_fd_event ($fd, $revents) 288 EV::feed_fd_event $fd, $revents
204 $loop->feed_fd_event ($fd, $revents) 289 $loop->feed_fd_event ($fd, $revents)
205 Feed an event on a file descriptor into EV. EV will react to this 290 Feed an event on a file descriptor into EV. EV will react to this
206 call as if the readyness notifications specified by $revents (a 291 call as if the readyness notifications specified by $revents (a
207 combination of "EV::READ" and "EV::WRITE") happened on the file 292 combination of "EV::READ" and "EV::WRITE") happened on the file
208 descriptor $fd. 293 descriptor $fd.
209 294
210 EV::feed_signal_event ($signal) 295 EV::feed_signal_event $signal
211 Feed a signal event into EV. EV will react to this call as if the 296 Feed a signal event into the default loop. EV will react to this
212 signal specified by $signal had occured. 297 call as if the signal specified by $signal had occured.
298
299 EV::feed_signal $signal
300 Feed a signal event into EV - unlike "EV::feed_signal_event", this
301 works regardless of which loop has registered the signal, and is
302 mainly useful fro custom signal implementations.
213 303
214 EV::set_io_collect_interval $time 304 EV::set_io_collect_interval $time
215 $loop->set_io_collect_interval ($time) 305 $loop->set_io_collect_interval ($time)
216 EV::set_timeout_collect_interval $time 306 EV::set_timeout_collect_interval $time
217 $loop->set_timeout_collect_interval ($time) 307 $loop->set_timeout_collect_interval ($time)
218 These advanced functions set the minimum block interval when polling 308 These advanced functions set the minimum block interval when polling
219 for I/O events and the minimum wait interval for timer events. See 309 for I/O events and the minimum wait interval for timer events. See
220 the libev documentation at 310 the libev documentation at
221 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT 311 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
222 ROLLING_THE_EVENT_LOOP> for a more detailed discussion. 312 ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
313 detailed discussion.
314
315 $count = EV::pending_count
316 $count = $loop->pending_count
317 Returns the number of currently pending watchers.
318
319 EV::invoke_pending
320 $loop->invoke_pending
321 Invoke all currently pending watchers.
223 322
224WATCHER OBJECTS 323WATCHER OBJECTS
225 A watcher is an object that gets created to record your interest in some 324 A watcher is an object that gets created to record your interest in some
226 event. For instance, if you want to wait for STDIN to become readable, 325 event. For instance, if you want to wait for STDIN to become readable,
227 you would create an EV::io watcher for that: 326 you would create an EV::io watcher for that:
236 will be called with at least two arguments: the watcher and a bitmask of 335 will be called with at least two arguments: the watcher and a bitmask of
237 received events. 336 received events.
238 337
239 Each watcher type has its associated bit in revents, so you can use the 338 Each watcher type has its associated bit in revents, so you can use the
240 same callback for multiple watchers. The event mask is named after the 339 same callback for multiple watchers. The event mask is named after the
241 type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 340 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
242 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 341 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
243 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 342 events (which can set both EV::READ and EV::WRITE bits).
244 (which uses EV::TIMEOUT).
245 343
246 In the rare case where one wants to create a watcher but not start it at 344 In the rare case where one wants to create a watcher but not start it at
247 the same time, each constructor has a variant with a trailing "_ns" in 345 the same time, each constructor has a variant with a trailing "_ns" in
248 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 346 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
249 347
314 the watcher isn't pending it does nothing and returns 0. 412 the watcher isn't pending it does nothing and returns 0.
315 413
316 $previous_state = $w->keepalive ($bool) 414 $previous_state = $w->keepalive ($bool)
317 Normally, "EV::loop" will return when there are no active watchers 415 Normally, "EV::loop" will return when there are no active watchers
318 (which is a "deadlock" because no progress can be made anymore). 416 (which is a "deadlock" because no progress can be made anymore).
319 This is convinient because it allows you to start your watchers (and 417 This is convenient because it allows you to start your watchers (and
320 your jobs), call "EV::loop" once and when it returns you know that 418 your jobs), call "EV::loop" once and when it returns you know that
321 all your jobs are finished (or they forgot to register some watchers 419 all your jobs are finished (or they forgot to register some watchers
322 for their task :). 420 for their task :).
323 421
324 Sometimes, however, this gets in your way, for example when the 422 Sometimes, however, this gets in your way, for example when the
331 429
332 In this case you can clear the keepalive status, which means that 430 In this case you can clear the keepalive status, which means that
333 even though your watcher is active, it won't keep "EV::loop" from 431 even though your watcher is active, it won't keep "EV::loop" from
334 returning. 432 returning.
335 433
336 The initial value for keepalive is true (enabled), and you cna 434 The initial value for keepalive is true (enabled), and you can
337 change it any time. 435 change it any time.
338 436
339 Example: Register an I/O watcher for some UDP socket but do not keep 437 Example: Register an I/O watcher for some UDP socket but do not keep
340 the event loop from running just because of that watcher. 438 the event loop from running just because of that watcher.
341 439
515 Return the time that the watcher is expected to trigger next. 613 Return the time that the watcher is expected to trigger next.
516 614
517 SIGNAL WATCHERS - signal me when a signal gets signalled! 615 SIGNAL WATCHERS - signal me when a signal gets signalled!
518 $w = EV::signal $signal, $callback 616 $w = EV::signal $signal, $callback
519 $w = EV::signal_ns $signal, $callback 617 $w = EV::signal_ns $signal, $callback
618 $w = $loop->signal ($signal, $callback)
619 $w = $loop->signal_ns ($signal, $callback)
520 Call the callback when $signal is received (the signal can be 620 Call the callback when $signal is received (the signal can be
521 specified by number or by name, just as with "kill" or %SIG). 621 specified by number or by name, just as with "kill" or %SIG).
622
623 Only one event loop can grab a given signal - attempting to grab the
624 same signal from two EV loops will crash the program immediately or
625 cause data corruption.
522 626
523 EV will grab the signal for the process (the kernel only allows one 627 EV will grab the signal for the process (the kernel only allows one
524 component to receive a signal at a time) when you start a signal 628 component to receive a signal at a time) when you start a signal
525 watcher, and removes it again when you stop it. Perl does the same 629 watcher, and removes it again when you stop it. Perl does the same
526 when you add/remove callbacks to %SIG, so watch out. 630 when you add/remove callbacks to %SIG, so watch out.
700 $w = $loop->check_ns ($callback) 804 $w = $loop->check_ns ($callback)
701 Call the callback just after the process wakes up again (after it 805 Call the callback just after the process wakes up again (after it
702 has gathered events), but before any other callbacks have been 806 has gathered events), but before any other callbacks have been
703 invoked. 807 invoked.
704 808
705 This is used to integrate other event-based software into the EV 809 This can be used to integrate other event-based software into the EV
706 mainloop: You register a prepare callback and in there, you create 810 mainloop: You register a prepare callback and in there, you create
707 io and timer watchers as required by the other software. Here is a 811 io and timer watchers as required by the other software. Here is a
708 real-world example of integrating Net::SNMP (with some details left 812 real-world example of integrating Net::SNMP (with some details left
709 out): 813 out):
710 814
741 # make the dispatcher handle any new stuff 845 # make the dispatcher handle any new stuff
742 ... not shown 846 ... not shown
743 }; 847 };
744 848
745 The callbacks of the created watchers will not be called as the 849 The callbacks of the created watchers will not be called as the
746 watchers are destroyed before this cna happen (remember EV::check 850 watchers are destroyed before this can happen (remember EV::check
747 gets called first). 851 gets called first).
748 852
749 The "check_ns" variant doesn't start (activate) the newly created 853 The "check_ns" variant doesn't start (activate) the newly created
750 watcher. 854 watcher.
855
856 EV::CHECK constant issues
857 Like all other watcher types, there is a bitmask constant for use in
858 $revents and other places. The "EV::CHECK" is special as it has the
859 same name as the "CHECK" sub called by Perl. This doesn't cause big
860 issues on newer perls (beginning with 5.8.9), but it means thatthe
861 constant must be *inlined*, i.e. runtime calls will not work. That
862 means that as long as you always "use EV" and then "EV::CHECK" you
863 are on the safe side.
751 864
752 FORK WATCHERS - the audacity to resume the event loop after a fork 865 FORK WATCHERS - the audacity to resume the event loop after a fork
753 Fork watchers are called when a "fork ()" was detected. The invocation 866 Fork watchers are called when a "fork ()" was detected. The invocation
754 is done before the event loop blocks next and before "check" watchers 867 is done before the event loop blocks next and before "check" watchers
755 are being called, and only in the child after the fork. 868 are being called, and only in the child after the fork.
770 embedded loop, other types of watchers might be handled in a delayed or 883 embedded loop, other types of watchers might be handled in a delayed or
771 incorrect fashion and must not be used). 884 incorrect fashion and must not be used).
772 885
773 See the libev documentation at 886 See the libev documentation at
774 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code 887 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
775 _when_one_backend_> for more details. 888 _when_one_backend_> (locally installed as EV::libev) for more details.
776 889
777 In short, this watcher is most useful on BSD systems without working 890 In short, this watcher is most useful on BSD systems without working
778 kqueue to still be able to handle a large number of sockets: 891 kqueue to still be able to handle a large number of sockets:
779 892
780 my $socket_loop; 893 my $socket_loop;
781 894
782 # check wether we use SELECT or POLL _and_ KQUEUE is supported 895 # check wether we use SELECT or POLL _and_ KQUEUE is supported
783 if ( 896 if (
784 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 897 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
785 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 898 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
786 ) { 899 ) {
787 # use kqueue for sockets 900 # use kqueue for sockets
788 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 901 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
789 } 902 }
790 903
791 # use the default loop otherwise 904 # use the default loop otherwise
792 $socket_loop ||= EV::default_loop; 905 $socket_loop ||= EV::default_loop;
793 906
794 $w = EV::embed $otherloop[, $callback] 907 $w = EV::embed $otherloop[, $callback]
795 $w = EV::embed_ns $otherloop[, $callback] 908 $w = EV::embed_ns $otherloop[, $callback]
796 $w = $loop->embed ($otherloop[, $callback]) 909 $w = $loop->embed ($otherloop[, $callback])
803 The "embed_ns" variant doesn't start (activate) the newly created 916 The "embed_ns" variant doesn't start (activate) the newly created
804 watcher. 917 watcher.
805 918
806 ASYNC WATCHERS - how to wake up another event loop 919 ASYNC WATCHERS - how to wake up another event loop
807 Async watchers are provided by EV, but have little use in perl directly, 920 Async watchers are provided by EV, but have little use in perl directly,
808 as perl neither supports threads nor direct access to signal handlers or 921 as perl neither supports threads running in parallel nor direct access
809 other contexts where they could be of value. 922 to signal handlers or other contexts where they could be of value.
810 923
811 It is, however, possible to use them from the XS level. 924 It is, however, possible to use them from the XS level.
812 925
813 Please see the libev documentation for further details. 926 Please see the libev documentation for further details.
814 927
833 my $async_check = EV::check sub { }; 946 my $async_check = EV::check sub { };
834 947
835 This ensures that perl gets into control for a short time to handle any 948 This ensures that perl gets into control for a short time to handle any
836 pending signals, and also ensures (slightly) slower overall operation. 949 pending signals, and also ensures (slightly) slower overall operation.
837 950
838THREADS 951ITHREADS
839 Threads are not supported by this module in any way. Perl pseudo-threads 952 Ithreads are not supported by this module in any way. Perl
840 is evil stuff and must die. As soon as Perl gains real threads I will 953 pseudo-threads is evil stuff and must die. Real threads as provided by
841 work on thread support for it. 954 Coro are fully supported (and enhanced support is available via
955 Coro::EV).
842 956
843FORK 957FORK
844 Most of the "improved" event delivering mechanisms of modern operating 958 Most of the "improved" event delivering mechanisms of modern operating
845 systems have quite a few problems with fork(2) (to put it bluntly: it is 959 systems have quite a few problems with fork(2) (to put it bluntly: it is
846 not supported and usually destructive). Libev makes it possible to work 960 not supported and usually destructive). Libev makes it possible to work
856 970
857 On win32, there is no notion of fork so all this doesn't apply, of 971 On win32, there is no notion of fork so all this doesn't apply, of
858 course. 972 course.
859 973
860SEE ALSO 974SEE ALSO
861 EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event 975 EV::MakeMaker - MakeMaker interface to XS API, EV::ADNS (asynchronous
862 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 976 DNS), Glib::EV (makes Glib/Gtk2 use EV as event loop), EV::Glib (embed
863 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop 977 Glib into EV), Coro::EV (efficient thread integration), Net::SNMP::EV
864 agnostic and portable event driven programming. 978 (asynchronous SNMP), AnyEvent for event-loop agnostic and portable event
979 driven programming.
865 980
866AUTHOR 981AUTHOR
867 Marc Lehmann <schmorp@schmorp.de> 982 Marc Lehmann <schmorp@schmorp.de>
868 http://home.schmorp.de/ 983 http://home.schmorp.de/
869 984

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