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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 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::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
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://cvs.schmorp.de/libev/ev.html>) for more subtle 68 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
60 details on watcher semantics or some discussion on the available 69 perldoc EV::libev) for more subtle details on watcher semantics or some
61 backends, or how to force a specific backend with "LIBEV_FLAGS", or just 70 discussion on the available backends, or how to force a specific backend
62 about in any case because it has much more detailed information. 71 with "LIBEV_FLAGS", or just about in any case because it has much more
72 detailed information.
73
74 This module is very fast and scalable. It is actually so fast that you
75 can use it through the AnyEvent module, stay portable to other event
76 loops (if you don't rely on any watcher types not available through it)
77 and still be faster than with any other event loop currently supported
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.
63 112
64EVENT LOOPS 113EVENT LOOPS
65 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"
66 that can handle everything including signals and child watchers, and any 115 that can handle everything including signals and child watchers, and any
67 number of "dynamic event loops" that can use different backends (with 116 number of "dynamic event loops" that can use different backends (with
… …
74 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
75 modules (e.g. AnyEvent or Coro) and most portable event loop. 124 modules (e.g. AnyEvent or Coro) and most portable event loop.
76 125
77 For specific programs you can create additional event loops dynamically. 126 For specific programs you can create additional event loops dynamically.
78 127
128 If you want to take advantage of kqueue (which often works properly for
129 sockets only) even though the default loop doesn't enable it, you can
130 *embed* a kqueue loop into the default loop: running the default loop
131 will then also service the kqueue loop to some extent. See the example
132 in the section about embed watchers for an example on how to achieve
133 that.
134
79 $loop = new EV::loop [$flags] 135 $loop = new EV::Loop [$flags]
80 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
81 the "ev_loop_new ()" function description in the libev documentation 137 the "ev_loop_new ()" function description in the libev documentation
82 (<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
83 ONS>) for more info. 139 ONS>, or locally-installed as EV::libev manpage) for more info.
84 140
85 The loop will automatically be destroyed when it is no longer 141 The loop will automatically be destroyed when it is no longer
86 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.
87 143
88 Using "EV::FLAG_FORKCHECK" is recommended, as only the default event 144 If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
89 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.
90 149
91 $loop->loop_fork 150 $loop->loop_fork
92 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
93 continuing the event loop. An alternative is to use 152 continuing the event loop. An alternative is to use
94 "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at 153 "EV::FLAG_FORKCHECK" which calls this function automatically, at
95 some performance loss (refer to the libev documentation). 154 some performance loss (refer to the libev documentation).
96 155
156 $loop->loop_verify
157 Calls "ev_verify" to make internal consistency checks (for debugging
158 libev) and abort the program if any data structures were found to be
159 corrupted.
160
97 $loop = EV::default_loop [$flags] 161 $loop = EV::default_loop [$flags]
98 Return the default loop (which is a singleton object). 162 Return the default loop (which is a singleton object). Since this
163 module already creates the default loop with default flags,
164 specifying flags here will not have any effect unless you destroy
165 the default loop first, which isn't supported. So in short: don't do
166 it, and if you break it, you get to keep the pieces.
99 167
100BASIC INTERFACE 168BASIC INTERFACE
101 $EV::DIED 169 $EV::DIED
102 Must contain a reference to a function that is called when a 170 Must contain a reference to a function that is called when a
103 callback throws an exception (with $@ containing the error). The 171 callback throws an exception (with $@ containing the error). The
… …
120 Returns the current time in (fractional) seconds since the epoch. 188 Returns the current time in (fractional) seconds since the epoch.
121 189
122 $time = EV::now 190 $time = EV::now
123 $time = $loop->now 191 $time = $loop->now
124 Returns the time the last event loop iteration has been started. 192 Returns the time the last event loop iteration has been started.
125 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
126 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").
127 232
128 $backend = EV::backend 233 $backend = EV::backend
129 $backend = $loop->backend 234 $backend = $loop->backend
130 Returns an integer describing the backend used by libev 235 Returns an integer describing the backend used by libev
131 (EV::METHOD_SELECT or EV::METHOD_EPOLL). 236 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
132 237
133 EV::loop [$flags] 238 EV::loop [$flags]
134 $loop->loop ([$flags]) 239 $loop->loop ([$flags])
135 Begin checking for events and calling callbacks. It returns when a 240 Begin checking for events and calling callbacks. It returns when a
136 callback calls EV::unloop. 241 callback calls EV::unloop.
… …
150 EV::loop will return as fast as possible. 255 EV::loop will return as fast as possible.
151 256
152 $count = EV::loop_count 257 $count = EV::loop_count
153 $count = $loop->loop_count 258 $count = $loop->loop_count
154 Return the number of times the event loop has polled for new events. 259 Return the number of times the event loop has polled for new events.
155 Sometiems useful as a generation counter. 260 Sometimes useful as a generation counter.
156 261
157 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 262 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
158 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 263 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
159 This function rolls together an I/O and a timer watcher for a single 264 This function rolls together an I/O and a timer watcher for a single
160 one-shot event without the need for managing a watcher object. 265 one-shot event without the need for managing a watcher object.
… …
169 Otherwise a EV::timer with this value will be started. 274 Otherwise a EV::timer with this value will be started.
170 275
171 When an error occurs or either the timeout or I/O watcher triggers, 276 When an error occurs or either the timeout or I/O watcher triggers,
172 then the callback will be called with the received event set (in 277 then the callback will be called with the received event set (in
173 general you can expect it to be a combination of "EV::ERROR", 278 general you can expect it to be a combination of "EV::ERROR",
174 "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). 279 "EV::READ", "EV::WRITE" and "EV::TIMER").
175 280
176 EV::once doesn't return anything: the watchers stay active till 281 EV::once doesn't return anything: the watchers stay active till
177 either of them triggers, then they will be stopped and freed, and 282 either of them triggers, then they will be stopped and freed, and
178 the callback invoked. 283 the callback invoked.
179 284
… …
194 $loop->set_timeout_collect_interval ($time) 299 $loop->set_timeout_collect_interval ($time)
195 These advanced functions set the minimum block interval when polling 300 These advanced functions set the minimum block interval when polling
196 for I/O events and the minimum wait interval for timer events. See 301 for I/O events and the minimum wait interval for timer events. See
197 the libev documentation at 302 the libev documentation at
198 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT 303 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
199 ROLLING_THE_EVENT_LOOP> for a more detailed discussion. 304 ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
305 detailed discussion.
306
307 $count = EV::pending_count
308 $count = $loop->pending_count
309 Returns the number of currently pending watchers.
310
311 EV::invoke_pending
312 $loop->invoke_pending
313 Invoke all currently pending watchers.
200 314
201WATCHER OBJECTS 315WATCHER OBJECTS
202 A watcher is an object that gets created to record your interest in some 316 A watcher is an object that gets created to record your interest in some
203 event. For instance, if you want to wait for STDIN to become readable, 317 event. For instance, if you want to wait for STDIN to become readable,
204 you would create an EV::io watcher for that: 318 you would create an EV::io watcher for that:
205 319
206 my $watcher = EV::io *STDIN, EV::READ, sub { 320 my $watcher = EV::io *STDIN, EV::READ, sub {
207 my ($watcher, $revents) = @_; 321 my ($watcher, $revents) = @_;
208 warn "yeah, STDIN should now be readable without blocking!\n" 322 warn "yeah, STDIN should now be readable without blocking!\n"
209 }; 323 };
210 324
211 All watchers can be active (waiting for events) or inactive (paused). 325 All watchers can be active (waiting for events) or inactive (paused).
212 Only active watchers will have their callbacks invoked. All callbacks 326 Only active watchers will have their callbacks invoked. All callbacks
213 will be called with at least two arguments: the watcher and a bitmask of 327 will be called with at least two arguments: the watcher and a bitmask of
214 received events. 328 received events.
215 329
216 Each watcher type has its associated bit in revents, so you can use the 330 Each watcher type has its associated bit in revents, so you can use the
217 same callback for multiple watchers. The event mask is named after the 331 same callback for multiple watchers. The event mask is named after the
218 type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 332 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
219 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 333 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
220 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 334 events (which can set both EV::READ and EV::WRITE bits).
221 (which uses EV::TIMEOUT).
222 335
223 In the rare case where one wants to create a watcher but not start it at 336 In the rare case where one wants to create a watcher but not start it at
224 the same time, each constructor has a variant with a trailing "_ns" in 337 the same time, each constructor has a variant with a trailing "_ns" in
225 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 338 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
226 339
… …
291 the watcher isn't pending it does nothing and returns 0. 404 the watcher isn't pending it does nothing and returns 0.
292 405
293 $previous_state = $w->keepalive ($bool) 406 $previous_state = $w->keepalive ($bool)
294 Normally, "EV::loop" will return when there are no active watchers 407 Normally, "EV::loop" will return when there are no active watchers
295 (which is a "deadlock" because no progress can be made anymore). 408 (which is a "deadlock" because no progress can be made anymore).
296 This is convinient because it allows you to start your watchers (and 409 This is convenient because it allows you to start your watchers (and
297 your jobs), call "EV::loop" once and when it returns you know that 410 your jobs), call "EV::loop" once and when it returns you know that
298 all your jobs are finished (or they forgot to register some watchers 411 all your jobs are finished (or they forgot to register some watchers
299 for their task :). 412 for their task :).
300 413
301 Sometimes, however, this gets in your way, for example when the 414 Sometimes, however, this gets in your way, for example when the
… …
308 421
309 In this case you can clear the keepalive status, which means that 422 In this case you can clear the keepalive status, which means that
310 even though your watcher is active, it won't keep "EV::loop" from 423 even though your watcher is active, it won't keep "EV::loop" from
311 returning. 424 returning.
312 425
313 The initial value for keepalive is true (enabled), and you cna 426 The initial value for keepalive is true (enabled), and you can
314 change it any time. 427 change it any time.
315 428
316 Example: Register an I/O watcher for some UDP socket but do not keep 429 Example: Register an I/O watcher for some UDP socket but do not keep
317 the event loop from running just because of that watcher. 430 the event loop from running just because of that watcher.
318 431
319 my $udp_socket = ... 432 my $udp_socket = ...
320 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 433 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
321 $1000udp_watcher->keepalive (0); 434 $udp_watcher->keepalive (0);
322 435
323 $loop = $w->loop 436 $loop = $w->loop
324 Return the loop that this watcher is attached to. 437 Return the loop that this watcher is attached to.
325 438
326WATCHER TYPES 439WATCHER TYPES
… …
449 each time the periodic watcher gets scheduled, the reschedule 562 each time the periodic watcher gets scheduled, the reschedule
450 callback ($reschedule_cb) will be called with the watcher as 563 callback ($reschedule_cb) will be called with the watcher as
451 first, and the current time as second argument. 564 first, and the current time as second argument.
452 565
453 *This callback MUST NOT stop or destroy this or any other 566 *This callback MUST NOT stop or destroy this or any other
567 periodic watcher, ever, and MUST NOT call any event loop
454 periodic watcher, ever*. If you need to stop it, return 1e30 and 568 functions or methods*. If you need to stop it, return 1e30 and
455 stop it afterwards. 569 stop it afterwards. You may create and start a "EV::prepare"
570 watcher for this task.
456 571
457 It must return the next time to trigger, based on the passed 572 It must return the next time to trigger, based on the passed
458 time value (that is, the lowest time value larger than to the 573 time value (that is, the lowest time value larger than or equal
459 second argument). It will usually be called just before the 574 to to the second argument). It will usually be called just
460 callback will be triggered, but might be called at other times, 575 before the callback will be triggered, but might be called at
461 too. 576 other times, too.
462 577
463 This can be used to create very complex timers, such as a timer 578 This can be used to create very complex timers, such as a timer
464 that triggers on each midnight, local time (actually 24 hours 579 that triggers on each midnight, local time (actually 24 hours
465 after the last midnight, to keep the example simple. If you know 580 after the last midnight, to keep the example simple. If you know
466 a way to do it correctly in about the same space (without 581 a way to do it correctly in about the same space (without
… …
490 Return the time that the watcher is expected to trigger next. 605 Return the time that the watcher is expected to trigger next.
491 606
492 SIGNAL WATCHERS - signal me when a signal gets signalled! 607 SIGNAL WATCHERS - signal me when a signal gets signalled!
493 $w = EV::signal $signal, $callback 608 $w = EV::signal $signal, $callback
494 $w = EV::signal_ns $signal, $callback 609 $w = EV::signal_ns $signal, $callback
610 $w = $loop->signal ($signal, $callback)
611 $w = $loop->signal_ns ($signal, $callback)
495 Call the callback when $signal is received (the signal can be 612 Call the callback when $signal is received (the signal can be
496 specified by number or by name, just as with "kill" or %SIG). 613 specified by number or by name, just as with "kill" or %SIG).
614
615 Only one event loop can grab a given signal - attempting to grab the
616 same signal from two EV loops will crash the program immediately or
617 cause data corruption.
497 618
498 EV will grab the signal for the process (the kernel only allows one 619 EV will grab the signal for the process (the kernel only allows one
499 component to receive a signal at a time) when you start a signal 620 component to receive a signal at a time) when you start a signal
500 watcher, and removes it again when you stop it. Perl does the same 621 watcher, and removes it again when you stop it. Perl does the same
501 when you add/remove callbacks to %SIG, so watch out. 622 when you add/remove callbacks to %SIG, so watch out.
… …
675 $w = $loop->check_ns ($callback) 796 $w = $loop->check_ns ($callback)
676 Call the callback just after the process wakes up again (after it 797 Call the callback just after the process wakes up again (after it
677 has gathered events), but before any other callbacks have been 798 has gathered events), but before any other callbacks have been
678 invoked. 799 invoked.
679 800
680 This is used to integrate other event-based software into the EV 801 This can be used to integrate other event-based software into the EV
681 mainloop: You register a prepare callback and in there, you create 802 mainloop: You register a prepare callback and in there, you create
682 io and timer watchers as required by the other software. Here is a 803 io and timer watchers as required by the other software. Here is a
683 real-world example of integrating Net::SNMP (with some details left 804 real-world example of integrating Net::SNMP (with some details left
684 out): 805 out):
685 806
… …
716 # make the dispatcher handle any new stuff 837 # make the dispatcher handle any new stuff
717 ... not shown 838 ... not shown
718 }; 839 };
719 840
720 The callbacks of the created watchers will not be called as the 841 The callbacks of the created watchers will not be called as the
721 watchers are destroyed before this cna happen (remember EV::check 842 watchers are destroyed before this can happen (remember EV::check
722 gets called first). 843 gets called first).
723 844
724 The "check_ns" variant doesn't start (activate) the newly created 845 The "check_ns" variant doesn't start (activate) the newly created
725 watcher. 846 watcher.
847
848 EV::CHECK constant issues
849 Like all other watcher types, there is a bitmask constant for use in
850 $revents and other places. The "EV::CHECK" is special as it has the
851 same name as the "CHECK" sub called by Perl. This doesn't cause big
852 issues on newer perls (beginning with 5.8.9), but it means thatthe
853 constant must be *inlined*, i.e. runtime calls will not work. That
854 means that as long as you always "use EV" and then "EV::CHECK" you
855 are on the safe side.
726 856
727 FORK WATCHERS - the audacity to resume the event loop after a fork 857 FORK WATCHERS - the audacity to resume the event loop after a fork
728 Fork watchers are called when a "fork ()" was detected. The invocation 858 Fork watchers are called when a "fork ()" was detected. The invocation
729 is done before the event loop blocks next and before "check" watchers 859 is done before the event loop blocks next and before "check" watchers
730 are being called, and only in the child after the fork. 860 are being called, and only in the child after the fork.
… …
745 embedded loop, other types of watchers might be handled in a delayed or 875 embedded loop, other types of watchers might be handled in a delayed or
746 incorrect fashion and must not be used). 876 incorrect fashion and must not be used).
747 877
748 See the libev documentation at 878 See the libev documentation at
749 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code 879 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
750 _when_one_backend_> for more details. 880 _when_one_backend_> (locally installed as EV::libev) for more details.
751 881
752 In short, this watcher is most useful on BSD systems without working 882 In short, this watcher is most useful on BSD systems without working
753 kqueue to still be able to handle a large number of sockets: 883 kqueue to still be able to handle a large number of sockets:
754 884
755 my $socket_loop; 885 my $socket_loop;
756 886
757 # check wether we use SELECT or POLL _and_ KQUEUE is supported 887 # check wether we use SELECT or POLL _and_ KQUEUE is supported
758 if ( 888 if (
759 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 889 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
760 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 890 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
761 ) { 891 ) {
762 # use kqueue for sockets 892 # use kqueue for sockets
763 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 893 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
764 } 894 }
765 895
766 # use the default loop otherwise 896 # use the default loop otherwise
767 $socket_loop ||= EV::default_loop; 897 $socket_loop ||= EV::default_loop;
768 898
769 $w = EV::embed $otherloop, $callback 899 $w = EV::embed $otherloop[, $callback]
770 $w = EV::embed_ns $otherloop, $callback 900 $w = EV::embed_ns $otherloop[, $callback]
771 $w = $loop->embed ($otherloop, $callback) 901 $w = $loop->embed ($otherloop[, $callback])
772 $w = $loop->embed_ns ($otherloop, $callback) 902 $w = $loop->embed_ns ($otherloop[, $callback])
773 Call the callback when the embedded event loop ($otherloop) has any 903 Call the callback when the embedded event loop ($otherloop) has any
774 I/O activity. The $callback should alwas be specified as "undef" in 904 I/O activity. The $callback is optional: if it is missing, then the
775 this version of EV, which means the embedded event loop will be 905 embedded event loop will be managed automatically (which is
776 managed automatically. 906 recommended), otherwise you have to invoke "sweep" yourself.
777 907
778 The "embed_ns" variant doesn't start (activate) the newly created 908 The "embed_ns" variant doesn't start (activate) the newly created
779 watcher. 909 watcher.
780 910
781 ASYNC WATCHERS - how to wake up another event loop 911 ASYNC WATCHERS - how to wake up another event loop
782 Async watchers are provided by EV, but have little use in perl directly, 912 Async watchers are provided by EV, but have little use in perl directly,
783 as perl neither supports threads nor direct access to signal handlers or 913 as perl neither supports threads running in parallel nor direct access
784 other contexts where they could be of value. 914 to signal handlers or other contexts where they could be of value.
785 915
786 It is, however, possible to use them from the XS level. 916 It is, however, possible to use them from the XS level.
787 917
788 Please see the libev documentation for further details. 918 Please see the libev documentation for further details.
919
920 $w = EV::async $callback
921 $w = EV::async_ns $callback
922 $w->send
923 $bool = $w->async_pending
789 924
790PERL SIGNALS 925PERL SIGNALS
791 While Perl signal handling (%SIG) is not affected by EV, the behaviour 926 While Perl signal handling (%SIG) is not affected by EV, the behaviour
792 with EV is as the same as any other C library: Perl-signals will only be 927 with EV is as the same as any other C library: Perl-signals will only be
793 handled when Perl runs, which means your signal handler might be invoked 928 handled when Perl runs, which means your signal handler might be invoked
… …
803 my $async_check = EV::check sub { }; 938 my $async_check = EV::check sub { };
804 939
805 This ensures that perl gets into control for a short time to handle any 940 This ensures that perl gets into control for a short time to handle any
806 pending signals, and also ensures (slightly) slower overall operation. 941 pending signals, and also ensures (slightly) slower overall operation.
807 942
808THREADS 943ITHREADS
809 Threads are not supported by this module in any way. Perl pseudo-threads 944 Ithreads are not supported by this module in any way. Perl
810 is evil stuff and must die. As soon as Perl gains real threads I will 945 pseudo-threads is evil stuff and must die. Real threads as provided by
811 work on thread support for it. 946 Coro are fully supported (and enhanced support is available via
947 Coro::EV).
812 948
813FORK 949FORK
814 Most of the "improved" event delivering mechanisms of modern operating 950 Most of the "improved" event delivering mechanisms of modern operating
815 systems have quite a few problems with fork(2) (to put it bluntly: it is 951 systems have quite a few problems with fork(2) (to put it bluntly: it is
816 not supported and usually destructive). Libev makes it possible to work 952 not supported and usually destructive). Libev makes it possible to work
… …
826 962
827 On win32, there is no notion of fork so all this doesn't apply, of 963 On win32, there is no notion of fork so all this doesn't apply, of
828 course. 964 course.
829 965
830SEE ALSO 966SEE ALSO
831 EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event 967 EV::MakeMaker - MakeMaker interface to XS API, EV::ADNS (asynchronous
832 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 968 DNS), Glib::EV (makes Glib/Gtk2 use EV as event loop), EV::Glib (embed
833 with EV), Net::SNMP::EV (asynchronous SNMP). 969 Glib into EV), Coro::EV (efficient thread integration), Net::SNMP::EV
970 (asynchronous SNMP), AnyEvent for event-loop agnostic and portable event
971 driven programming.
834 972
835AUTHOR 973AUTHOR
836 Marc Lehmann <schmorp@schmorp.de> 974 Marc Lehmann <schmorp@schmorp.de>
837 http://home.schmorp.de/ 975 http://home.schmorp.de/
838 976

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