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Revision 1.81 by root, Mon Dec 31 00:59:34 2007 UTC vs.
Revision 1.126 by root, Tue Mar 16 17:11:48 2010 UTC

… …
2 2
3EV - perl interface to libev, a high performance full-featured event loop 3EV - perl interface to libev, a high performance full-featured event loop
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use EV; 7 use EV;
8
9 # TIMERS
10
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
8 39
9 # TIMERS 40 my $w = EV::child 666, 0, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
10 44
11 my $w = EV::timer 2, 0, sub {
12 warn "is called after 2s";
13 };
14
15 my $w = EV::timer 2, 2, sub {
16 warn "is called roughly every 2s (repeat = 2)";
17 };
18
19 undef $w; # destroy event watcher again
20
21 my $w = EV::periodic 0, 60, 0, sub {
22 warn "is called every minute, on the minute, exactly";
23 };
24
25 # IO
26
27 my $w = EV::io *STDIN, EV::READ, sub {
28 my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29 warn "stdin is readable, you entered: ", <STDIN>;
30 };
31
32 # SIGNALS
33
34 my $w = EV::signal 'QUIT', sub {
35 warn "sigquit received\n";
36 };
37
38 # CHILD/PID STATUS CHANGES
39
40 my $w = EV::child 666, sub {
41 my ($w, $revents) = @_;
42 my $status = $w->rstatus;
43 };
44
45 # STAT CHANGES 45 # STAT CHANGES
46 my $w = EV::stat "/etc/passwd", 10, sub { 46 my $w = EV::stat "/etc/passwd", 10, sub {
47 my ($w, $revents) = @_; 47 my ($w, $revents) = @_;
48 warn $w->path, " has changed somehow.\n"; 48 warn $w->path, " has changed somehow.\n";
49 }; 49 };
50 50
51 # MAINLOOP 51 # MAINLOOP
52 EV::loop; # loop until EV::unloop is called or all watchers stop 52 EV::loop; # loop until EV::unloop is called or all watchers stop
53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 53 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 54 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55 55
56=head1 DESCRIPTION 56=head1 DESCRIPTION
57 57
58This module provides an interface to libev 58This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of libev 60below is comprehensive, one might also consult the documentation of
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 61libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62watcher semantics or some discussion on the available backends, or how to 62F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63force a specific backend with C<LIBEV_FLAGS>, or just about in any case 63discussion on the available backends, or how to force a specific backend
64because it has much more detailed information. 64with C<LIBEV_FLAGS>, or just about in any case because it has much more
65detailed information.
66
67This module is very fast and scalable. It is actually so fast that you
68can use it through the L<AnyEvent> module, stay portable to other event
69loops (if you don't rely on any watcher types not available through it)
70and still be faster than with any other event loop currently supported in
71Perl.
72
73=head2 MODULE EXPORTS
74
75This module does not export any symbols.
65 76
66=cut 77=cut
67 78
68package EV; 79package EV;
69 80
70use strict; 81use common::sense;
71 82
72BEGIN { 83BEGIN {
73 our $VERSION = '2.01'; 84 our $VERSION = '4.00';
74 use XSLoader; 85 use XSLoader;
75 XSLoader::load "EV", $VERSION; 86 XSLoader::load "EV", $VERSION;
76} 87}
77 88
78@EV::IO::ISA = 89@EV::IO::ISA =
… …
84@EV::Idle::ISA = 95@EV::Idle::ISA =
85@EV::Prepare::ISA = 96@EV::Prepare::ISA =
86@EV::Check::ISA = 97@EV::Check::ISA =
87@EV::Embed::ISA = 98@EV::Embed::ISA =
88@EV::Fork::ISA = 99@EV::Fork::ISA =
100@EV::Async::ISA =
89 "EV::Watcher"; 101 "EV::Watcher";
90 102
91@EV::Loop::Default::ISA = "EV::Loop"; 103@EV::Loop::Default::ISA = "EV::Loop";
92 104
93=head1 EVENT LOOPS 105=head1 EVENT LOOPS
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104default loop as this is fastest (perl-wise), best supported by other 116default loop as this is fastest (perl-wise), best supported by other
105modules (e.g. AnyEvent or Coro) and most portable event loop. 117modules (e.g. AnyEvent or Coro) and most portable event loop.
106 118
107For specific programs you can create additional event loops dynamically. 119For specific programs you can create additional event loops dynamically.
108 120
109=over 4 121If you want to take advantage of kqueue (which often works properly for
122sockets only) even though the default loop doesn't enable it, you can
123I<embed> a kqueue loop into the default loop: running the default loop
124will then also service the kqueue loop to some extent. See the example in
125the section about embed watchers for an example on how to achieve that.
110 126
127=over 4
128
111=item $loop = new EV::loop [$flags] 129=item $loop = new EV::Loop [$flags]
112 130
113Create a new event loop as per the specified flags. Please refer to the 131Create a new event loop as per the specified flags. Please refer to
114C<ev_loop_new ()> function description in the libev documentation 132the C<ev_loop_new ()> function description in the libev documentation
115(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) 133(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
116for more info. 134or locally-installed as F<EV::libev> manpage) for more info.
117 135
118The loop will automatically be destroyed when it is no longer referenced 136The loop will automatically be destroyed when it is no longer referenced
119by any watcher and the loop object goes out of scope. 137by any watcher and the loop object goes out of scope.
120 138
121Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop 139If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
122is protected by this module. 140is recommended, as only the default event loop is protected by this
141module. If you I<are> embedding this loop in the default loop, this is not
142necessary, as C<EV::embed> automatically does the right thing on fork.
123 143
124=item $loop->loop_fork 144=item $loop->loop_fork
125 145
126Must be called after a fork in the child, before entering or continuing 146Must be called after a fork in the child, before entering or continuing
127the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls 147the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
128this fucntion automatically, at some performance loss (refer to the libev 148this function automatically, at some performance loss (refer to the libev
129documentation). 149documentation).
130 150
151=item $loop->loop_verify
152
153Calls C<ev_verify> to make internal consistency checks (for debugging
154libev) and abort the program if any data structures were found to be
155corrupted.
156
131=item $loop = EV::default_loop [$flags] 157=item $loop = EV::default_loop [$flags]
132 158
133Return the default loop (which is a singleton object). 159Return the default loop (which is a singleton object). Since this module
160already creates the default loop with default flags, specifying flags here
161will not have any effect unless you destroy the default loop first, which
162isn't supported. So in short: don't do it, and if you break it, you get to
163keep the pieces.
134 164
135=back 165=back
136 166
137 167
138=head1 BASIC INTERFACE 168=head1 BASIC INTERFACE
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168=item $time = EV::now 198=item $time = EV::now
169 199
170=item $time = $loop->now 200=item $time = $loop->now
171 201
172Returns the time the last event loop iteration has been started. This 202Returns the time the last event loop iteration has been started. This
173is the time that (relative) timers are based on, and refering to it is 203is the time that (relative) timers are based on, and referring to it is
174usually faster then calling EV::time. 204usually faster then calling EV::time.
175 205
206=item EV::now_update
207
208=item $loop->now_update
209
210Establishes the current time by querying the kernel, updating the time
211returned by C<EV::now> in the progress. This is a costly operation and
212is usually done automatically within C<EV::loop>.
213
214This function is rarely useful, but when some event callback runs for a
215very long time without entering the event loop, updating libev's idea of
216the current time is a good idea.
217
218=item EV::suspend
219
220=item $loop->suspend
221
222=item EV::resume
223
224=item $loop->resume
225
226These two functions suspend and resume a loop, for use when the loop is
227not used for a while and timeouts should not be processed.
228
229A typical use case would be an interactive program such as a game: When
230the user presses C<^Z> to suspend the game and resumes it an hour later it
231would be best to handle timeouts as if no time had actually passed while
232the program was suspended. This can be achieved by calling C<suspend>
233in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
234C<resume> directly afterwards to resume timer processing.
235
236Effectively, all C<timer> watchers will be delayed by the time spend
237between C<suspend> and C<resume>, and all C<periodic> watchers
238will be rescheduled (that is, they will lose any events that would have
239occured while suspended).
240
241After calling C<suspend> you B<must not> call I<any> function on the given
242loop other than C<resume>, and you B<must not> call C<resume>
243without a previous call to C<suspend>.
244
245Calling C<suspend>/C<resume> has the side effect of updating the event
246loop time (see C<now_update>).
247
176=item $backend = EV::backend 248=item $backend = EV::backend
177 249
178=item $backend = $loop->backend 250=item $backend = $loop->backend
179 251
180Returns an integer describing the backend used by libev (EV::METHOD_SELECT 252Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
181or EV::METHOD_EPOLL). 253or EV::BACKEND_EPOLL).
182 254
183=item EV::loop [$flags] 255=item EV::loop [$flags]
184 256
185=item $loop->loop ([$flags]) 257=item $loop->loop ([$flags])
186 258
… …
206=item $count = EV::loop_count 278=item $count = EV::loop_count
207 279
208=item $count = $loop->loop_count 280=item $count = $loop->loop_count
209 281
210Return the number of times the event loop has polled for new 282Return the number of times the event loop has polled for new
211events. Sometiems useful as a generation counter. 283events. Sometimes useful as a generation counter.
212 284
213=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 285=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
214 286
215=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) 287=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
216 288
… …
227timeout. Otherwise a EV::timer with this value will be started. 299timeout. Otherwise a EV::timer with this value will be started.
228 300
229When an error occurs or either the timeout or I/O watcher triggers, then 301When an error occurs or either the timeout or I/O watcher triggers, then
230the callback will be called with the received event set (in general 302the callback will be called with the received event set (in general
231you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, 303you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
232C<EV::WRITE> and C<EV::TIMEOUT>). 304C<EV::WRITE> and C<EV::TIMER>).
233 305
234EV::once doesn't return anything: the watchers stay active till either 306EV::once doesn't return anything: the watchers stay active till either
235of them triggers, then they will be stopped and freed, and the callback 307of them triggers, then they will be stopped and freed, and the callback
236invoked. 308invoked.
237 309
… …
256 328
257=item $loop->set_timeout_collect_interval ($time) 329=item $loop->set_timeout_collect_interval ($time)
258 330
259These advanced functions set the minimum block interval when polling for I/O events and the minimum 331These advanced functions set the minimum block interval when polling for I/O events and the minimum
260wait interval for timer events. See the libev documentation at 332wait interval for timer events. See the libev documentation at
261L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for 333L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
262a more detailed discussion. 334(locally installed as F<EV::libev>) for a more detailed discussion.
335
336=item $count = EV::pending_count
337
338=item $count = $loop->pending_count
339
340Returns the number of currently pending watchers.
341
342=item EV::invoke_pending
343
344=item $loop->invoke_pending
345
346Invoke all currently pending watchers.
263 347
264=back 348=back
265 349
266 350
267=head1 WATCHER OBJECTS 351=head1 WATCHER OBJECTS
268 352
269A watcher is an object that gets created to record your interest in some 353A watcher is an object that gets created to record your interest in some
270event. For instance, if you want to wait for STDIN to become readable, you 354event. For instance, if you want to wait for STDIN to become readable, you
271would create an EV::io watcher for that: 355would create an EV::io watcher for that:
272 356
273 my $watcher = EV::io *STDIN, EV::READ, sub { 357 my $watcher = EV::io *STDIN, EV::READ, sub {
274 my ($watcher, $revents) = @_; 358 my ($watcher, $revents) = @_;
275 warn "yeah, STDIN should now be readable without blocking!\n" 359 warn "yeah, STDIN should now be readable without blocking!\n"
276 }; 360 };
277 361
278All watchers can be active (waiting for events) or inactive (paused). Only 362All watchers can be active (waiting for events) or inactive (paused). Only
279active watchers will have their callbacks invoked. All callbacks will be 363active watchers will have their callbacks invoked. All callbacks will be
280called with at least two arguments: the watcher and a bitmask of received 364called with at least two arguments: the watcher and a bitmask of received
281events. 365events.
282 366
283Each watcher type has its associated bit in revents, so you can use the 367Each watcher type has its associated bit in revents, so you can use the
284same callback for multiple watchers. The event mask is named after the 368same callback for multiple watchers. The event mask is named after the
285type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 369type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
286EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 370EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
287(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 371(which can set both EV::READ and EV::WRITE bits).
288uses EV::TIMEOUT).
289 372
290In the rare case where one wants to create a watcher but not start it at 373In the rare case where one wants to create a watcher but not start it at
291the same time, each constructor has a variant with a trailing C<_ns> in 374the same time, each constructor has a variant with a trailing C<_ns> in
292its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 375its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
293 376
… …
372 455
373=item $previous_state = $w->keepalive ($bool) 456=item $previous_state = $w->keepalive ($bool)
374 457
375Normally, C<EV::loop> will return when there are no active watchers 458Normally, C<EV::loop> will return when there are no active watchers
376(which is a "deadlock" because no progress can be made anymore). This is 459(which is a "deadlock" because no progress can be made anymore). This is
377convinient because it allows you to start your watchers (and your jobs), 460convenient because it allows you to start your watchers (and your jobs),
378call C<EV::loop> once and when it returns you know that all your jobs are 461call C<EV::loop> once and when it returns you know that all your jobs are
379finished (or they forgot to register some watchers for their task :). 462finished (or they forgot to register some watchers for their task :).
380 463
381Sometimes, however, this gets in your way, for example when the module 464Sometimes, however, this gets in your way, for example when the module
382that calls C<EV::loop> (usually the main program) is not the same module 465that calls C<EV::loop> (usually the main program) is not the same module
… …
386because you happen to have this long-running UDP port watcher. 469because you happen to have this long-running UDP port watcher.
387 470
388In this case you can clear the keepalive status, which means that even 471In this case you can clear the keepalive status, which means that even
389though your watcher is active, it won't keep C<EV::loop> from returning. 472though your watcher is active, it won't keep C<EV::loop> from returning.
390 473
391The initial value for keepalive is true (enabled), and you cna change it 474The initial value for keepalive is true (enabled), and you can change it
392any time. 475any time.
393 476
394Example: Register an I/O watcher for some UDP socket but do not keep the 477Example: Register an I/O watcher for some UDP socket but do not keep the
395event loop from running just because of that watcher. 478event loop from running just because of that watcher.
396 479
397 my $udp_socket = ... 480 my $udp_socket = ...
398 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 481 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
399 $1000udp_watcher->keepalive (0); 482 $udp_watcher->keepalive (0);
400 483
401=item $loop = $w->loop 484=item $loop = $w->loop
402 485
403Return the loop that this watcher is attached to. 486Return the loop that this watcher is attached to.
404 487
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533This time simply fires at the wallclock time C<$at> and doesn't repeat. It 616This time simply fires at the wallclock time C<$at> and doesn't repeat. It
534will not adjust when a time jump occurs, that is, if it is to be run 617will not adjust when a time jump occurs, that is, if it is to be run
535at January 1st 2011 then it will run when the system time reaches or 618at January 1st 2011 then it will run when the system time reaches or
536surpasses this time. 619surpasses this time.
537 620
538=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 621=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
539 622
540In this mode the watcher will always be scheduled to time out at the 623In this mode the watcher will always be scheduled to time out at the
541next C<$at + N * $interval> time (for some integer N) and then repeat, 624next C<$at + N * $interval> time (for some integer N) and then repeat,
542regardless of any time jumps. 625regardless of any time jumps.
543 626
… …
561time the periodic watcher gets scheduled, the reschedule callback 644time the periodic watcher gets scheduled, the reschedule callback
562($reschedule_cb) will be called with the watcher as first, and the current 645($reschedule_cb) will be called with the watcher as first, and the current
563time as second argument. 646time as second argument.
564 647
565I<This callback MUST NOT stop or destroy this or any other periodic 648I<This callback MUST NOT stop or destroy this or any other periodic
566watcher, ever>. If you need to stop it, return 1e30 and stop it 649watcher, ever, and MUST NOT call any event loop functions or methods>. If
567afterwards. 650you need to stop it, return 1e30 and stop it afterwards. You may create
651and start a C<EV::prepare> watcher for this task.
568 652
569It must return the next time to trigger, based on the passed time value 653It must return the next time to trigger, based on the passed time value
570(that is, the lowest time value larger than to the second argument). It 654(that is, the lowest time value larger than or equal to to the second
571will usually be called just before the callback will be triggered, but 655argument). It will usually be called just before the callback will be
572might be called at other times, too. 656triggered, but might be called at other times, too.
573 657
574This can be used to create very complex timers, such as a timer that 658This can be used to create very complex timers, such as a timer that
575triggers on each midnight, local time (actually 24 hours after the last 659triggers on each midnight, local time (actually 24 hours after the last
576midnight, to keep the example simple. If you know a way to do it correctly 660midnight, to keep the example simple. If you know a way to do it correctly
577in about the same space (without requiring elaborate modules), drop me a 661in about the same space (without requiring elaborate modules), drop me a
… …
613 697
614=item $w = EV::signal $signal, $callback 698=item $w = EV::signal $signal, $callback
615 699
616=item $w = EV::signal_ns $signal, $callback 700=item $w = EV::signal_ns $signal, $callback
617 701
702=item $w = $loop->signal ($signal, $callback)
703
704=item $w = $loop->signal_ns ($signal, $callback)
705
618Call the callback when $signal is received (the signal can be specified by 706Call the callback when $signal is received (the signal can be specified by
619number or by name, just as with C<kill> or C<%SIG>). 707number or by name, just as with C<kill> or C<%SIG>).
708
709Only one event loop can grab a given signal - attempting to grab the same
710signal from two EV loops will crash the program immediately or cause data
711corruption.
620 712
621EV will grab the signal for the process (the kernel only allows one 713EV will grab the signal for the process (the kernel only allows one
622component to receive a signal at a time) when you start a signal watcher, 714component to receive a signal at a time) when you start a signal watcher,
623and removes it again when you stop it. Perl does the same when you 715and removes it again when you stop it. Perl does the same when you
624add/remove callbacks to C<%SIG>, so watch out. 716add/remove callbacks to C<%SIG>, so watch out.
… …
644 736
645=head3 CHILD WATCHERS - watch out for process status changes 737=head3 CHILD WATCHERS - watch out for process status changes
646 738
647=over 4 739=over 4
648 740
649=item $w = EV::child $pid, $callback 741=item $w = EV::child $pid, $trace, $callback
650 742
651=item $w = EV::child_ns $pid, $callback 743=item $w = EV::child_ns $pid, $trace, $callback
652 744
653=item $w = $loop->child ($pid, $callback) 745=item $w = $loop->child ($pid, $trace, $callback)
654 746
655=item $w = $loop->child_ns ($pid, $callback) 747=item $w = $loop->child_ns ($pid, $trace, $callback)
656 748
657Call the callback when a status change for pid C<$pid> (or any pid if 749Call the callback when a status change for pid C<$pid> (or any pid
658C<$pid> is 0) has been received. More precisely: when the process receives 750if C<$pid> is 0) has been received (a status change happens when the
751process terminates or is killed, or, when trace is true, additionally when
752it is stopped or continued). More precisely: when the process receives
659a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 753a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
660changed/zombie children and call the callback. 754changed/zombie children and call the callback.
661 755
662It is valid (and fully supported) to install a child watcher after a child 756It is valid (and fully supported) to install a child watcher after a child
663has exited but before the event loop has started its next iteration (for 757has exited but before the event loop has started its next iteration (for
… …
670You can have as many pid watchers per pid as you want, they will all be 764You can have as many pid watchers per pid as you want, they will all be
671called. 765called.
672 766
673The C<child_ns> variant doesn't start (activate) the newly created watcher. 767The C<child_ns> variant doesn't start (activate) the newly created watcher.
674 768
675=item $w->set ($pid) 769=item $w->set ($pid, $trace)
676 770
677Reconfigures the watcher, see the constructor above for details. Can be called at 771Reconfigures the watcher, see the constructor above for details. Can be called at
678any time. 772any time.
679 773
680=item $current_pid = $w->pid 774=item $current_pid = $w->pid
681
682=item $old_pid = $w->pid ($new_pid)
683 775
684Returns the previously set process id and optionally set a new one. 776Returns the previously set process id and optionally set a new one.
685 777
686=item $exit_status = $w->rstatus 778=item $exit_status = $w->rstatus
687 779
… …
889 # make the dispatcher handle any new stuff 981 # make the dispatcher handle any new stuff
890 ... not shown 982 ... not shown
891 }; 983 };
892 984
893The callbacks of the created watchers will not be called as the watchers 985The callbacks of the created watchers will not be called as the watchers
894are destroyed before this cna happen (remember EV::check gets called 986are destroyed before this can happen (remember EV::check gets called
895first). 987first).
896 988
897The C<check_ns> variant doesn't start (activate) the newly created watcher. 989The C<check_ns> variant doesn't start (activate) the newly created watcher.
898 990
899=back 991=back
… …
930loop, other types of watchers might be handled in a delayed or incorrect 1022loop, other types of watchers might be handled in a delayed or incorrect
931fashion and must not be used). 1023fashion and must not be used).
932 1024
933See the libev documentation at 1025See the libev documentation at
934L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> 1026L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
935for more details. 1027(locally installed as F<EV::libev>) for more details.
936 1028
937In short, this watcher is most useful on BSD systems without working 1029In short, this watcher is most useful on BSD systems without working
938kqueue to still be able to handle a large number of sockets: 1030kqueue to still be able to handle a large number of sockets:
939 1031
940 my $socket_loop; 1032 my $socket_loop;
941 1033
942 # check wether we use SELECT or POLL _and_ KQUEUE is supported 1034 # check wether we use SELECT or POLL _and_ KQUEUE is supported
943 if ( 1035 if (
944 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) 1036 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
945 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) 1037 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
946 ) { 1038 ) {
947 # use kqueue for sockets 1039 # use kqueue for sockets
948 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; 1040 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
949 } 1041 }
950 1042
951 # use the default loop otherwise 1043 # use the default loop otherwise
952 $socket_loop ||= EV::default_loop; 1044 $socket_loop ||= EV::default_loop;
953 1045
954=over 4 1046=over 4
955 1047
956=item $w = EV::embed $otherloop, $callback 1048=item $w = EV::embed $otherloop[, $callback]
957 1049
958=item $w = EV::embed_ns $otherloop, $callback 1050=item $w = EV::embed_ns $otherloop[, $callback]
959 1051
960=item $w = $loop->embed ($otherloop, $callback) 1052=item $w = $loop->embed ($otherloop[, $callback])
961 1053
962=item $w = $loop->embed_ns ($otherloop, $callback) 1054=item $w = $loop->embed_ns ($otherloop[, $callback])
963 1055
964Call the callback when the embedded event loop (C<$otherloop>) has any 1056Call the callback when the embedded event loop (C<$otherloop>) has any
965I/O activity. The C<$callback> should alwas be specified as C<undef> in 1057I/O activity. The C<$callback> is optional: if it is missing, then the
966this version of EV, which means the embedded event loop will be managed 1058embedded event loop will be managed automatically (which is recommended),
967automatically. 1059otherwise you have to invoke C<sweep> yourself.
968 1060
969The C<embed_ns> variant doesn't start (activate) the newly created watcher. 1061The C<embed_ns> variant doesn't start (activate) the newly created watcher.
1062
1063=back
1064
1065=head3 ASYNC WATCHERS - how to wake up another event loop
1066
1067Async watchers are provided by EV, but have little use in perl directly,
1068as perl neither supports threads running in parallel nor direct access to
1069signal handlers or other contexts where they could be of value.
1070
1071It is, however, possible to use them from the XS level.
1072
1073Please see the libev documentation for further details.
1074
1075=over 4
1076
1077=item $w = EV::async $callback
1078
1079=item $w = EV::async_ns $callback
1080
1081=item $w->send
1082
1083=item $bool = $w->async_pending
970 1084
971=back 1085=back
972 1086
973 1087
974=head1 PERL SIGNALS 1088=head1 PERL SIGNALS
… …
988 my $async_check = EV::check sub { }; 1102 my $async_check = EV::check sub { };
989 1103
990This ensures that perl gets into control for a short time to handle any 1104This ensures that perl gets into control for a short time to handle any
991pending signals, and also ensures (slightly) slower overall operation. 1105pending signals, and also ensures (slightly) slower overall operation.
992 1106
993=head1 THREADS 1107=head1 ITHREADS
994 1108
995Threads are not supported by this module in any way. Perl pseudo-threads 1109Ithreads are not supported by this module in any way. Perl pseudo-threads
996is evil stuff and must die. As soon as Perl gains real threads I will work 1110is evil stuff and must die. Real threads as provided by Coro are fully
997on thread support for it. 1111supported (and enhanced support is available via L<Coro::EV>).
998 1112
999=head1 FORK 1113=head1 FORK
1000 1114
1001Most of the "improved" event delivering mechanisms of modern operating 1115Most of the "improved" event delivering mechanisms of modern operating
1002systems have quite a few problems with fork(2) (to put it bluntly: it is 1116systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
1026 1140
1027=head1 SEE ALSO 1141=head1 SEE ALSO
1028 1142
1029L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as 1143L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
1030event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient 1144event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
1031coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). 1145coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1146event-loop agnostic and portable event driven programming.
1032 1147
1033=head1 AUTHOR 1148=head1 AUTHOR
1034 1149
1035 Marc Lehmann <schmorp@schmorp.de> 1150 Marc Lehmann <schmorp@schmorp.de>
1036 http://home.schmorp.de/ 1151 http://home.schmorp.de/
1037 1152
1038=cut 1153=cut
1039 1154

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