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Revision 1.33 by root, Fri Jul 17 14:49:33 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 $w = EV::child 666, sub {
40 my ($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://cvs.schmorp.de/libev/ev.html>) for more subtle 59 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 60 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 61 discussion on the available backends, or how to force a specific backend
62 about in any case because it has much more detailed information. 62 with "LIBEV_FLAGS", or just about in any case because it has much more
63 detailed information.
64
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
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
69 in Perl.
70
71 MODULE EXPORTS
72 This module does not export any symbols.
63 73
64EVENT LOOPS 74EVENT LOOPS
65 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"
66 that can handle everything including signals and child watchers, and any 76 that can handle everything including signals and child watchers, and any
67 number of "dynamic event loops" that can use different backends (with 77 number of "dynamic event loops" that can use different backends (with
… …
72 selecting a working backend (which for example rules out kqueue on most 82 selecting a working backend (which for example rules out kqueue on most
73 BSDs). Modules should, unless they have "special needs" always use the 83 BSDs). Modules should, unless they have "special needs" always use the
74 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
75 modules (e.g. AnyEvent or Coro) and most portable event loop. 85 modules (e.g. AnyEvent or Coro) and most portable event loop.
76 86
77 For specific programs you cna create additional event loops dynamically. 87 For specific programs you can create additional event loops dynamically.
78 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
79 $loop = new EV::loop [$flags] 96 $loop = new EV::Loop [$flags]
80 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
81 the "ev_loop_new ()" function description in the libev documentation 98 the "ev_loop_new ()" function description in the libev documentation
82 (<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
83 ONS>) for more info. 100 ONS>, or locally-installed as EV::libev manpage) for more info.
84 101
85 The loop will automatically be destroyed when it is no longer 102 The loop will automatically be destroyed when it is no longer
86 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.
87 104
88 Using "EV::FLAG_FORKCHECK" is recommended, as only the default event 105 If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
89 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.
90 110
91 $loop->loop_fork 111 $loop->loop_fork
92 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
93 continuing the event loop. An alternative is to use 113 continuing the event loop. An alternative is to use
94 "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at 114 "EV::FLAG_FORKCHECK" which calls this function automatically, at
95 some performance loss (refer to the libev documentation). 115 some performance loss (refer to the libev documentation).
116
117 $loop->loop_verify
118 Calls "ev_verify" to make internal consistency checks (for debugging
119 libev) and abort the program if any data structures were found to be
120 corrupted.
121
122 $loop = EV::default_loop [$flags]
123 Return the default loop (which is a singleton object). Since this
124 module already creates the default loop with default flags,
125 specifying flags here will not have any effect unless you destroy
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.
96 128
97BASIC INTERFACE 129BASIC INTERFACE
98 $EV::DIED 130 $EV::DIED
99 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
100 callback throws an exception (with $@ containing the error). The 132 callback throws an exception (with $@ containing the error). The
101 default prints an informative message and continues. 133 default prints an informative message and continues.
102 134
103 If this callback throws an exception it will be silently ignored. 135 If this callback throws an exception it will be silently ignored.
104 136
137 $flags = EV::supported_backends
138 $flags = EV::recommended_backends
139 $flags = EV::embeddable_backends
140 Returns the set (see "EV::BACKEND_*" flags) of backends supported by
141 this instance of EV, the set of recommended backends (supposed to be
142 good) for this platform and the set of embeddable backends (see
143 EMBED WATCHERS).
144
145 EV::sleep $seconds
146 Block the process for the given number of (fractional) seconds.
147
105 $time = EV::time 148 $time = EV::time
106 Returns the current time in (fractional) seconds since the epoch. 149 Returns the current time in (fractional) seconds since the epoch.
107 150
108 $time = EV::now 151 $time = EV::now
109 $time = $loop->now 152 $time = $loop->now
110 Returns the time the last event loop iteration has been started. 153 Returns the time the last event loop iteration has been started.
111 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
112 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").
113 193
114 $backend = EV::backend 194 $backend = EV::backend
115 $backend = $loop->backend 195 $backend = $loop->backend
116 Returns an integer describing the backend used by libev 196 Returns an integer describing the backend used by libev
117 (EV::METHOD_SELECT or EV::METHOD_EPOLL). 197 (EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
118 198
119 EV::loop [$flags] 199 EV::loop [$flags]
120 $loop->loop ([$flags]) 200 $loop->loop ([$flags])
121 Begin checking for events and calling callbacks. It returns when a 201 Begin checking for events and calling callbacks. It returns when a
122 callback calls EV::unloop. 202 callback calls EV::unloop.
… …
136 EV::loop will return as fast as possible. 216 EV::loop will return as fast as possible.
137 217
138 $count = EV::loop_count 218 $count = EV::loop_count
139 $count = $loop->loop_count 219 $count = $loop->loop_count
140 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.
141 Sometiems useful as a generation counter. 221 Sometimes useful as a generation counter.
142 222
143 EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 223 EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
144 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 224 $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
145 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
146 one-shot event without the need for managing a watcher object. 226 one-shot event without the need for managing a watcher object.
… …
172 252
173 EV::feed_signal_event ($signal) 253 EV::feed_signal_event ($signal)
174 Feed a signal event into EV. EV will react to this call as if the 254 Feed a signal event into EV. EV will react to this call as if the
175 signal specified by $signal had occured. 255 signal specified by $signal had occured.
176 256
257 EV::set_io_collect_interval $time
258 $loop->set_io_collect_interval ($time)
259 EV::set_timeout_collect_interval $time
260 $loop->set_timeout_collect_interval ($time)
261 These advanced functions set the minimum block interval when polling
262 for I/O events and the minimum wait interval for timer events. See
263 the libev documentation at
264 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
265 ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
266 detailed discussion.
267
268 $count = EV::pending_count
269 $count = $loop->pending_count
270 Returns the number of currently pending watchers.
271
272 EV::invoke_pending
273 $loop->invoke_pending
274 Invoke all currently pending watchers.
275
177WATCHER OBJECTS 276WATCHER OBJECTS
178 A watcher is an object that gets created to record your interest in some 277 A watcher is an object that gets created to record your interest in some
179 event. For instance, if you want to wait for STDIN to become readable, 278 event. For instance, if you want to wait for STDIN to become readable,
180 you would create an EV::io watcher for that: 279 you would create an EV::io watcher for that:
181 280
182 my $watcher = EV::io *STDIN, EV::READ, sub { 281 my $watcher = EV::io *STDIN, EV::READ, sub {
183 my ($watcher, $revents) = @_; 282 my ($watcher, $revents) = @_;
184 warn "yeah, STDIN should now be readable without blocking!\n" 283 warn "yeah, STDIN should now be readable without blocking!\n"
185 }; 284 };
186 285
187 All watchers can be active (waiting for events) or inactive (paused). 286 All watchers can be active (waiting for events) or inactive (paused).
188 Only active watchers will have their callbacks invoked. All callbacks 287 Only active watchers will have their callbacks invoked. All callbacks
189 will be called with at least two arguments: the watcher and a bitmask of 288 will be called with at least two arguments: the watcher and a bitmask of
190 received events. 289 received events.
191 290
192 Each watcher type has its associated bit in revents, so you can use the 291 Each watcher type has its associated bit in revents, so you can use the
193 same callback for multiple watchers. The event mask is named after the 292 same callback for multiple watchers. The event mask is named after the
194 type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 293 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
195 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 294 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
196 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 295 events (which can set both EV::READ and EV::WRITE bits), and EV::timer
197 (which uses EV::TIMEOUT). 296 (which uses EV::TIMEOUT).
198 297
199 In the rare case where one wants to create a watcher but not start it at 298 In the rare case where one wants to create a watcher but not start it at
… …
284 383
285 In this case you can clear the keepalive status, which means that 384 In this case you can clear the keepalive status, which means that
286 even though your watcher is active, it won't keep "EV::loop" from 385 even though your watcher is active, it won't keep "EV::loop" from
287 returning. 386 returning.
288 387
289 The initial value for keepalive is true (enabled), and you cna 388 The initial value for keepalive is true (enabled), and you can
290 change it any time. 389 change it any time.
291 390
292 Example: Register an I/O watcher for some UDP socket but do not keep 391 Example: Register an I/O watcher for some UDP socket but do not keep
293 the event loop from running just because of that watcher. 392 the event loop from running just because of that watcher.
294 393
295 my $udp_socket = ... 394 my $udp_socket = ...
296 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 395 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
297 $1000udp_watcher->keepalive (0); 396 $udp_watcher->keepalive (0);
298 397
299 $loop = $w->loop 398 $loop = $w->loop
300 Return the loop that this watcher is attached to. 399 Return the loop that this watcher is attached to.
301 400
302WATCHER TYPES 401WATCHER TYPES
… …
390 changed by explicit date -s or other means such as ntpd). It is also 489 changed by explicit date -s or other means such as ntpd). It is also
391 the most complex watcher type in EV. 490 the most complex watcher type in EV.
392 491
393 It has three distinct "modes": 492 It has three distinct "modes":
394 493
395 * absolute timer ($interval = $reschedule_cb = 0) 494 * absolute timer ($interval = $reschedule_cb = 0)
495
396 This time simply fires at the wallclock time $at and doesn't 496 This time simply fires at the wallclock time $at and doesn't
397 repeat. It will not adjust when a time jump occurs, that is, if 497 repeat. It will not adjust when a time jump occurs, that is, if
398 it is to be run at January 1st 2011 then it will run when the 498 it is to be run at January 1st 2011 then it will run when the
399 system time reaches or surpasses this time. 499 system time reaches or surpasses this time.
400 500
401 * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 501 * repeating interval timer ($interval > 0, $reschedule_cb = 0)
502
402 In this mode the watcher will always be scheduled to time out at 503 In this mode the watcher will always be scheduled to time out at
403 the next "$at + N * $interval" time (for some integer N) and 504 the next "$at + N * $interval" time (for some integer N) and
404 then repeat, regardless of any time jumps. 505 then repeat, regardless of any time jumps.
405 506
406 This can be used to create timers that do not drift with respect 507 This can be used to create timers that do not drift with respect
… …
415 Another way to think about it (for the mathematically inclined) 516 Another way to think about it (for the mathematically inclined)
416 is that EV::periodic will try to run the callback in this mode 517 is that EV::periodic will try to run the callback in this mode
417 at the next possible time where "$time = $at (mod $interval)", 518 at the next possible time where "$time = $at (mod $interval)",
418 regardless of any time jumps. 519 regardless of any time jumps.
419 520
420 * manual reschedule mode ($reschedule_cb = coderef) 521 * manual reschedule mode ($reschedule_cb = coderef)
522
421 In this mode $interval and $at are both being ignored. Instead, 523 In this mode $interval and $at are both being ignored. Instead,
422 each time the periodic watcher gets scheduled, the reschedule 524 each time the periodic watcher gets scheduled, the reschedule
423 callback ($reschedule_cb) will be called with the watcher as 525 callback ($reschedule_cb) will be called with the watcher as
424 first, and the current time as second argument. 526 first, and the current time as second argument.
425 527
426 *This callback MUST NOT stop or destroy this or any other 528 *This callback MUST NOT stop or destroy this or any other
529 periodic watcher, ever, and MUST NOT call any event loop
427 periodic watcher, ever*. If you need to stop it, return 1e30 and 530 functions or methods*. If you need to stop it, return 1e30 and
428 stop it afterwards. 531 stop it afterwards. You may create and start a "EV::prepare"
532 watcher for this task.
429 533
430 It must return the next time to trigger, based on the passed 534 It must return the next time to trigger, based on the passed
431 time value (that is, the lowest time value larger than to the 535 time value (that is, the lowest time value larger than or equal
432 second argument). It will usually be called just before the 536 to to the second argument). It will usually be called just
433 callback will be triggered, but might be called at other times, 537 before the callback will be triggered, but might be called at
434 too. 538 other times, too.
435 539
436 This can be used to create very complex timers, such as a timer 540 This can be used to create very complex timers, such as a timer
437 that triggers on each midnight, local time (actually 24 hours 541 that triggers on each midnight, local time (actually 24 hours
438 after the last midnight, to keep the example simple. If you know 542 after the last midnight, to keep the example simple. If you know
439 a way to do it correctly in about the same space (without 543 a way to do it correctly in about the same space (without
… …
486 $old_signum = $w->signal ($new_signal) 590 $old_signum = $w->signal ($new_signal)
487 Returns the previously set signal (always as a number not name) and 591 Returns the previously set signal (always as a number not name) and
488 optionally set a new one. 592 optionally set a new one.
489 593
490 CHILD WATCHERS - watch out for process status changes 594 CHILD WATCHERS - watch out for process status changes
491 $w = EV::child $pid, $callback 595 $w = EV::child $pid, $trace, $callback
492 $w = EV::child_ns $pid, $callback 596 $w = EV::child_ns $pid, $trace, $callback
493 $w = $loop->child ($pid, $callback) 597 $w = $loop->child ($pid, $trace, $callback)
494 $w = $loop->child_ns ($pid, $callback) 598 $w = $loop->child_ns ($pid, $trace, $callback)
495 Call the callback when a status change for pid $pid (or any pid if 599 Call the callback when a status change for pid $pid (or any pid if
496 $pid is 0) has been received. More precisely: when the process 600 $pid is 0) has been received (a status change happens when the
601 process terminates or is killed, or, when trace is true,
602 additionally when it is stopped or continued). More precisely: when
497 receives a "SIGCHLD", EV will fetch the outstanding exit/wait status 603 the process receives a "SIGCHLD", EV will fetch the outstanding
498 for all changed/zombie children and call the callback. 604 exit/wait status for all changed/zombie children and call the
605 callback.
499 606
500 It is valid (and fully supported) to install a child watcher after a 607 It is valid (and fully supported) to install a child watcher after a
501 child has exited but before the event loop has started its next 608 child has exited but before the event loop has started its next
502 iteration (for example, first you "fork", then the new child process 609 iteration (for example, first you "fork", then the new child process
503 might exit, and only then do you install a child watcher in the 610 might exit, and only then do you install a child watcher in the
… …
510 be called. 617 be called.
511 618
512 The "child_ns" variant doesn't start (activate) the newly created 619 The "child_ns" variant doesn't start (activate) the newly created
513 watcher. 620 watcher.
514 621
515 $w->set ($pid) 622 $w->set ($pid, $trace)
516 Reconfigures the watcher, see the constructor above for details. Can 623 Reconfigures the watcher, see the constructor above for details. Can
517 be called at any time. 624 be called at any time.
518 625
519 $current_pid = $w->pid 626 $current_pid = $w->pid
520 $old_pid = $w->pid ($new_pid)
521 Returns the previously set process id and optionally set a new one. 627 Returns the previously set process id and optionally set a new one.
522 628
523 $exit_status = $w->rstatus 629 $exit_status = $w->rstatus
524 Return the exit/wait status (as returned by waitpid, see the waitpid 630 Return the exit/wait status (as returned by waitpid, see the waitpid
525 entry in perlfunc). 631 entry in perlfunc).
… …
687 # make the dispatcher handle any new stuff 793 # make the dispatcher handle any new stuff
688 ... not shown 794 ... not shown
689 }; 795 };
690 796
691 The callbacks of the created watchers will not be called as the 797 The callbacks of the created watchers will not be called as the
692 watchers are destroyed before this cna happen (remember EV::check 798 watchers are destroyed before this can happen (remember EV::check
693 gets called first). 799 gets called first).
694 800
695 The "check_ns" variant doesn't start (activate) the newly created 801 The "check_ns" variant doesn't start (activate) the newly created
696 watcher. 802 watcher.
697 803
… …
708 process after a fork. 814 process after a fork.
709 815
710 The "fork_ns" variant doesn't start (activate) the newly created 816 The "fork_ns" variant doesn't start (activate) the newly created
711 watcher. 817 watcher.
712 818
819 EMBED WATCHERS - when one backend isn't enough...
820 This is a rather advanced watcher type that lets you embed one event
821 loop into another (currently only IO events are supported in the
822 embedded loop, other types of watchers might be handled in a delayed or
823 incorrect fashion and must not be used).
824
825 See the libev documentation at
826 <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
827 _when_one_backend_> (locally installed as EV::libev) for more details.
828
829 In short, this watcher is most useful on BSD systems without working
830 kqueue to still be able to handle a large number of sockets:
831
832 my $socket_loop;
833
834 # check wether we use SELECT or POLL _and_ KQUEUE is supported
835 if (
836 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
837 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
838 ) {
839 # use kqueue for sockets
840 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
841 }
842
843 # use the default loop otherwise
844 $socket_loop ||= EV::default_loop;
845
846 $w = EV::embed $otherloop[, $callback]
847 $w = EV::embed_ns $otherloop[, $callback]
848 $w = $loop->embed ($otherloop[, $callback])
849 $w = $loop->embed_ns ($otherloop[, $callback])
850 Call the callback when the embedded event loop ($otherloop) has any
851 I/O activity. The $callback is optional: if it is missing, then the
852 embedded event loop will be managed automatically (which is
853 recommended), otherwise you have to invoke "sweep" yourself.
854
855 The "embed_ns" variant doesn't start (activate) the newly created
856 watcher.
857
858 ASYNC WATCHERS - how to wake up another event loop
859 Async watchers are provided by EV, but have little use in perl directly,
860 as perl neither supports threads running in parallel nor direct access
861 to signal handlers or other contexts where they could be of value.
862
863 It is, however, possible to use them from the XS level.
864
865 Please see the libev documentation for further details.
866
867 $w = EV::async $callback
868 $w = EV::async_ns $callback
869 $w->send
870 $bool = $w->async_pending
871
713PERL SIGNALS 872PERL SIGNALS
714 While Perl signal handling (%SIG) is not affected by EV, the behaviour 873 While Perl signal handling (%SIG) is not affected by EV, the behaviour
715 with EV is as the same as any other C library: Perl-signals will only be 874 with EV is as the same as any other C library: Perl-signals will only be
716 handled when Perl runs, which means your signal handler might be invoked 875 handled when Perl runs, which means your signal handler might be invoked
717 only the next time an event callback is invoked. 876 only the next time an event callback is invoked.
… …
726 my $async_check = EV::check sub { }; 885 my $async_check = EV::check sub { };
727 886
728 This ensures that perl gets into control for a short time to handle any 887 This ensures that perl gets into control for a short time to handle any
729 pending signals, and also ensures (slightly) slower overall operation. 888 pending signals, and also ensures (slightly) slower overall operation.
730 889
731THREADS 890ITHREADS
732 Threads are not supported by this module in any way. Perl pseudo-threads 891 Ithreads are not supported by this module in any way. Perl
733 is evil stuff and must die. As soon as Perl gains real threads I will 892 pseudo-threads is evil stuff and must die. Real threads as provided by
734 work on thread support for it. 893 Coro are fully supported (and enhanced support is available via
894 Coro::EV).
735 895
736FORK 896FORK
737 Most of the "improved" event delivering mechanisms of modern operating 897 Most of the "improved" event delivering mechanisms of modern operating
738 systems have quite a few problems with fork(2) (to put it bluntly: it is 898 systems have quite a few problems with fork(2) (to put it bluntly: it is
739 not supported and usually destructive). Libev makes it possible to work 899 not supported and usually destructive). Libev makes it possible to work
… …
751 course. 911 course.
752 912
753SEE ALSO 913SEE ALSO
754 EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event 914 EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event
755 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines 915 loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines
756 with EV), Net::SNMP::EV (asynchronous SNMP). 916 with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop
917 agnostic and portable event driven programming.
757 918
758AUTHOR 919AUTHOR
759 Marc Lehmann <schmorp@schmorp.de> 920 Marc Lehmann <schmorp@schmorp.de>
760 http://home.schmorp.de/ 921 http://home.schmorp.de/
761 922

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