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Revision 1.72 by root, Thu Dec 20 07:12:57 2007 UTC vs.
Revision 1.140 by root, Wed Apr 3 23:47:06 2013 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::run; # 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::run EV::RUN_ONCE; # 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::run EV::RUN_NOWAIT; # try to handle same events, but do not block
55
56=head1 BEFORE YOU START USING THIS MODULE
57
58If you only need timer, I/O, signal, child and idle watchers and not the
59advanced functionality of this module, consider using L<AnyEvent> instead,
60specifically the simplified API described in L<AE>.
61
62When used with EV as backend, the L<AE> API is as fast as the native L<EV>
63API, but your programs/modules will still run with many other event loops.
55 64
56=head1 DESCRIPTION 65=head1 DESCRIPTION
57 66
58This module provides an interface to libev 67This module provides an interface to libev
59(L<http://software.schmorp.de/pkg/libev.html>). While the documentation 68(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60below is comprehensive, one might also consult the documentation of libev 69below is comprehensive, one might also consult the documentation of
61itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on 70libev 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 71F<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 72discussion on the available backends, or how to force a specific backend
64because it has much more detailed information. 73with C<LIBEV_FLAGS>, or just about in any case because it has much more
74detailed information.
75
76This module is very fast and scalable. It is actually so fast that you
77can use it through the L<AnyEvent> module, stay portable to other event
78loops (if you don't rely on any watcher types not available through it)
79and still be faster than with any other event loop currently supported in
80Perl.
81
82=head2 PORTING FROM EV 3.X to 4.X
83
84EV version 4 introduces a number of incompatible changes summarised
85here. According to the depreciation strategy used by libev, there is a
86compatibility layer in place so programs should continue to run unchanged
87(the XS interface lacks this layer, so programs using that one need to be
88updated).
89
90This compatibility layer will be switched off in some future release.
91
92All changes relevant to Perl are renames of symbols, functions and
93methods:
94
95 EV::loop => EV::run
96 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
97 EV::LOOP_ONESHOT => EV::RUN_ONCE
98
99 EV::unloop => EV::break
100 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
101 EV::UNLOOP_ONE => EV::BREAK_ONE
102 EV::UNLOOP_ALL => EV::BREAK_ALL
103
104 EV::TIMEOUT => EV::TIMER
105
106 EV::loop_count => EV::iteration
107 EV::loop_depth => EV::depth
108 EV::loop_verify => EV::verify
109
110The loop object methods corresponding to the functions above have been
111similarly renamed.
112
113=head2 MODULE EXPORTS
114
115This module does not export any symbols.
65 116
66=cut 117=cut
67 118
68package EV; 119package EV;
69 120
70use strict; 121use common::sense;
71 122
72BEGIN { 123BEGIN {
73 our $VERSION = '2.0'; 124 our $VERSION = '4.15';
74 use XSLoader; 125 use XSLoader;
126 local $^W = 0; # avoid spurious warning
75 XSLoader::load "EV", $VERSION; 127 XSLoader::load "EV", $VERSION;
76} 128}
77 129
78@EV::IO::ISA = 130@EV::IO::ISA =
79@EV::Timer::ISA = 131@EV::Timer::ISA =
… …
84@EV::Idle::ISA = 136@EV::Idle::ISA =
85@EV::Prepare::ISA = 137@EV::Prepare::ISA =
86@EV::Check::ISA = 138@EV::Check::ISA =
87@EV::Embed::ISA = 139@EV::Embed::ISA =
88@EV::Fork::ISA = 140@EV::Fork::ISA =
141@EV::Async::ISA =
89 "EV::Watcher"; 142 "EV::Watcher";
90 143
91@EV::Loop::Default::ISA = "EV::Loop"; 144@EV::Loop::Default::ISA = "EV::Loop";
145
146=head1 EVENT LOOPS
147
148EV supports multiple event loops: There is a single "default event loop"
149that can handle everything including signals and child watchers, and any
150number of "dynamic event loops" that can use different backends (with
151various limitations), but no child and signal watchers.
152
153You do not have to do anything to create the default event loop: When
154the module is loaded a suitable backend is selected on the premise of
155selecting a working backend (which for example rules out kqueue on most
156BSDs). Modules should, unless they have "special needs" always use the
157default loop as this is fastest (perl-wise), best supported by other
158modules (e.g. AnyEvent or Coro) and most portable event loop.
159
160For specific programs you can create additional event loops dynamically.
161
162If you want to take advantage of kqueue (which often works properly for
163sockets only) even though the default loop doesn't enable it, you can
164I<embed> a kqueue loop into the default loop: running the default loop
165will then also service the kqueue loop to some extent. See the example in
166the section about embed watchers for an example on how to achieve that.
167
168=over 4
169
170=item $loop = new EV::Loop [$flags]
171
172Create a new event loop as per the specified flags. Please refer to
173the C<ev_loop_new ()> function description in the libev documentation
174(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
175or locally-installed as F<EV::libev> manpage) for more info.
176
177The loop will automatically be destroyed when it is no longer referenced
178by any watcher and the loop object goes out of scope.
179
180If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
181is recommended, as only the default event loop is protected by this
182module. If you I<are> embedding this loop in the default loop, this is not
183necessary, as C<EV::embed> automatically does the right thing on fork.
184
185=item $loop->loop_fork
186
187Must be called after a fork in the child, before entering or continuing
188the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
189this function automatically, at some performance loss (refer to the libev
190documentation).
191
192=item $loop->verify
193
194Calls C<ev_verify> to make internal consistency checks (for debugging
195libev) and abort the program if any data structures were found to be
196corrupted.
197
198=item $loop = EV::default_loop [$flags]
199
200Return the default loop (which is a singleton object). Since this module
201already creates the default loop with default flags, specifying flags here
202will not have any effect unless you destroy the default loop first, which
203isn't supported. So in short: don't do it, and if you break it, you get to
204keep the pieces.
205
206=back
207
92 208
93=head1 BASIC INTERFACE 209=head1 BASIC INTERFACE
94 210
95=over 4 211=over 4
96 212
… …
100throws an exception (with $@ containing the error). The default prints an 216throws an exception (with $@ containing the error). The default prints an
101informative message and continues. 217informative message and continues.
102 218
103If this callback throws an exception it will be silently ignored. 219If this callback throws an exception it will be silently ignored.
104 220
221=item $flags = EV::supported_backends
222
223=item $flags = EV::recommended_backends
224
225=item $flags = EV::embeddable_backends
226
227Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
228instance of EV, the set of recommended backends (supposed to be good) for
229this platform and the set of embeddable backends (see EMBED WATCHERS).
230
231=item EV::sleep $seconds
232
233Block the process for the given number of (fractional) seconds.
234
105=item $time = EV::time 235=item $time = EV::time
106 236
107Returns the current time in (fractional) seconds since the epoch. 237Returns the current time in (fractional) seconds since the epoch.
108 238
109=item $time = EV::now 239=item $time = EV::now
110 240
241=item $time = $loop->now
242
111Returns the time the last event loop iteration has been started. This 243Returns the time the last event loop iteration has been started. This
112is the time that (relative) timers are based on, and refering to it is 244is the time that (relative) timers are based on, and referring to it is
113usually faster then calling EV::time. 245usually faster then calling EV::time.
114 246
115=item $method = EV::method 247=item EV::now_update
116 248
249=item $loop->now_update
250
251Establishes the current time by querying the kernel, updating the time
252returned by C<EV::now> in the progress. This is a costly operation and
253is usually done automatically within C<EV::loop>.
254
255This function is rarely useful, but when some event callback runs for a
256very long time without entering the event loop, updating libev's idea of
257the current time is a good idea.
258
259=item EV::suspend
260
261=item $loop->suspend
262
263=item EV::resume
264
265=item $loop->resume
266
267These two functions suspend and resume a loop, for use when the loop is
268not used for a while and timeouts should not be processed.
269
270A typical use case would be an interactive program such as a game: When
271the user presses C<^Z> to suspend the game and resumes it an hour later it
272would be best to handle timeouts as if no time had actually passed while
273the program was suspended. This can be achieved by calling C<suspend>
274in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
275C<resume> directly afterwards to resume timer processing.
276
277Effectively, all C<timer> watchers will be delayed by the time spend
278between C<suspend> and C<resume>, and all C<periodic> watchers
279will be rescheduled (that is, they will lose any events that would have
280occured while suspended).
281
282After calling C<suspend> you B<must not> call I<any> function on the given
283loop other than C<resume>, and you B<must not> call C<resume>
284without a previous call to C<suspend>.
285
286Calling C<suspend>/C<resume> has the side effect of updating the event
287loop time (see C<now_update>).
288
289=item $backend = EV::backend
290
291=item $backend = $loop->backend
292
117Returns an integer describing the backend used by libev (EV::METHOD_SELECT 293Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
118or EV::METHOD_EPOLL). 294or EV::BACKEND_EPOLL).
119 295
120=item EV::loop [$flags] 296=item $active = EV::run [$flags]
297
298=item $active = $loop->run ([$flags])
121 299
122Begin checking for events and calling callbacks. It returns when a 300Begin checking for events and calling callbacks. It returns when a
123callback calls EV::unloop. 301callback calls EV::unloop or the flasg are nonzero (in which case the
302return value is true) or when there are no active watchers which reference
303the loop (keepalive is true), in which case the return value will be
304false. The returnv alue can generally be interpreted as "if true, there is
305more work left to do".
124 306
125The $flags argument can be one of the following: 307The $flags argument can be one of the following:
126 308
127 0 as above 309 0 as above
128 EV::LOOP_ONESHOT block at most once (wait, but do not loop) 310 EV::RUN_ONCE block at most once (wait, but do not loop)
129 EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) 311 EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
130 312
131=item EV::unloop [$how] 313=item EV::break [$how]
132 314
315=item $loop->break ([$how])
316
133When called with no arguments or an argument of EV::UNLOOP_ONE, makes the 317When called with no arguments or an argument of EV::BREAK_ONE, makes the
134innermost call to EV::loop return. 318innermost call to EV::loop return.
135 319
136When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as 320When called with an argument of EV::BREAK_ALL, all calls to EV::loop will
137fast as possible. 321return as fast as possible.
138 322
139=item $count = EV::loop_count 323When called with an argument of EV::BREAK_CANCEL, any pending break will
324be cancelled.
325
326=item $count = EV::iteration
327
328=item $count = $loop->iteration
140 329
141Return the number of times the event loop has polled for new 330Return the number of times the event loop has polled for new
142events. Sometiems useful as a generation counter. 331events. Sometimes useful as a generation counter.
143 332
144=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) 333=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
334
335=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
145 336
146This function rolls together an I/O and a timer watcher for a single 337This function rolls together an I/O and a timer watcher for a single
147one-shot event without the need for managing a watcher object. 338one-shot event without the need for managing a watcher object.
148 339
149If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> 340If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
… …
155If timeout is C<undef> or negative, then there will be no 346If timeout is C<undef> or negative, then there will be no
156timeout. Otherwise a EV::timer with this value will be started. 347timeout. Otherwise a EV::timer with this value will be started.
157 348
158When an error occurs or either the timeout or I/O watcher triggers, then 349When an error occurs or either the timeout or I/O watcher triggers, then
159the callback will be called with the received event set (in general 350the callback will be called with the received event set (in general
160you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, 351you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
161C<EV::WRITE> and C<EV::TIMEOUT>). 352C<EV::WRITE> and C<EV::TIMER>).
162 353
163EV::once doesn't return anything: the watchers stay active till either 354EV::once doesn't return anything: the watchers stay active till either
164of them triggers, then they will be stopped and freed, and the callback 355of them triggers, then they will be stopped and freed, and the callback
165invoked. 356invoked.
166 357
167=item EV::feed_fd_event ($fd, $revents) 358=item EV::feed_fd_event $fd, $revents
359
360=item $loop->feed_fd_event ($fd, $revents)
168 361
169Feed an event on a file descriptor into EV. EV will react to this call as 362Feed an event on a file descriptor into EV. EV will react to this call as
170if the readyness notifications specified by C<$revents> (a combination of 363if the readyness notifications specified by C<$revents> (a combination of
171C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. 364C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
172 365
173=item EV::feed_signal_event ($signal) 366=item EV::feed_signal_event $signal
174 367
175Feed a signal event into EV. EV will react to this call as if the signal 368Feed a signal event into the default loop. EV will react to this call as
176specified by C<$signal> had occured. 369if the signal specified by C<$signal> had occured.
177 370
178=back 371=item EV::feed_signal $signal
179 372
373Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
374regardless of which loop has registered the signal, and is mainly useful
375fro custom signal implementations.
180 376
377=item EV::set_io_collect_interval $time
378
379=item $loop->set_io_collect_interval ($time)
380
381=item EV::set_timeout_collect_interval $time
382
383=item $loop->set_timeout_collect_interval ($time)
384
385These advanced functions set the minimum block interval when polling for I/O events and the minimum
386wait interval for timer events. See the libev documentation at
387L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
388(locally installed as F<EV::libev>) for a more detailed discussion.
389
390=item $count = EV::pending_count
391
392=item $count = $loop->pending_count
393
394Returns the number of currently pending watchers.
395
396=item EV::invoke_pending
397
398=item $loop->invoke_pending
399
400Invoke all currently pending watchers.
401
402=back
403
404
181=head2 WATCHER OBJECTS 405=head1 WATCHER OBJECTS
182 406
183A watcher is an object that gets created to record your interest in some 407A watcher is an object that gets created to record your interest in some
184event. For instance, if you want to wait for STDIN to become readable, you 408event. For instance, if you want to wait for STDIN to become readable, you
185would create an EV::io watcher for that: 409would create an EV::io watcher for that:
186 410
187 my $watcher = EV::io *STDIN, EV::READ, sub { 411 my $watcher = EV::io *STDIN, EV::READ, sub {
188 my ($watcher, $revents) = @_; 412 my ($watcher, $revents) = @_;
189 warn "yeah, STDIN should not be readable without blocking!\n" 413 warn "yeah, STDIN should now be readable without blocking!\n"
190 }; 414 };
191 415
192All watchers can be active (waiting for events) or inactive (paused). Only 416All watchers can be active (waiting for events) or inactive (paused). Only
193active watchers will have their callbacks invoked. All callbacks will be 417active watchers will have their callbacks invoked. All callbacks will be
194called with at least two arguments: the watcher and a bitmask of received 418called with at least two arguments: the watcher and a bitmask of received
195events. 419events.
196 420
197Each watcher type has its associated bit in revents, so you can use the 421Each watcher type has its associated bit in revents, so you can use the
198same callback for multiple watchers. The event mask is named after the 422same callback for multiple watchers. The event mask is named after the
199type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 423type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
200EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events 424EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
201(which can set both EV::READ and EV::WRITE bits), and EV::timer (which 425(which can set both EV::READ and EV::WRITE bits).
202uses EV::TIMEOUT).
203 426
204In the rare case where one wants to create a watcher but not start it at 427In the rare case where one wants to create a watcher but not start it at
205the same time, each constructor has a variant with a trailing C<_ns> in 428the same time, each constructor has a variant with a trailing C<_ns> in
206its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 429its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
207 430
… …
278Feed some events on this watcher into EV. EV will react to this call as if 501Feed some events on this watcher into EV. EV will react to this call as if
279the watcher had received the given C<$revents> mask. 502the watcher had received the given C<$revents> mask.
280 503
281=item $revents = $w->clear_pending 504=item $revents = $w->clear_pending
282 505
283If the watcher is pending, this function returns clears its pending status 506If the watcher is pending, this function clears its pending status and
284and returns its C<$revents> bitset (as if its callback was invoked). If the 507returns its C<$revents> bitset (as if its callback was invoked). If the
285watcher isn't pending it does nothing and returns C<0>. 508watcher isn't pending it does nothing and returns C<0>.
286 509
287=item $previous_state = $w->keepalive ($bool) 510=item $previous_state = $w->keepalive ($bool)
288 511
289Normally, C<EV::loop> will return when there are no active watchers 512Normally, C<EV::loop> will return when there are no active watchers
290(which is a "deadlock" because no progress can be made anymore). This is 513(which is a "deadlock" because no progress can be made anymore). This is
291convinient because it allows you to start your watchers (and your jobs), 514convenient because it allows you to start your watchers (and your jobs),
292call C<EV::loop> once and when it returns you know that all your jobs are 515call C<EV::loop> once and when it returns you know that all your jobs are
293finished (or they forgot to register some watchers for their task :). 516finished (or they forgot to register some watchers for their task :).
294 517
295Sometimes, however, this gets in your way, for example when you the module 518Sometimes, however, this gets in your way, for example when the module
296that calls C<EV::loop> (usually the main program) is not the same module 519that calls C<EV::loop> (usually the main program) is not the same module
297as a long-living watcher (for example a DNS client module written by 520as a long-living watcher (for example a DNS client module written by
298somebody else even). Then you might want any outstanding requests to be 521somebody else even). Then you might want any outstanding requests to be
299handled, but you would not want to keep C<EV::loop> from returning just 522handled, but you would not want to keep C<EV::loop> from returning just
300because you happen to have this long-running UDP port watcher. 523because you happen to have this long-running UDP port watcher.
301 524
302In this case you can clear the keepalive status, which means that even 525In this case you can clear the keepalive status, which means that even
303though your watcher is active, it won't keep C<EV::loop> from returning. 526though your watcher is active, it won't keep C<EV::loop> from returning.
304 527
305The initial value for keepalive is true (enabled), and you cna change it 528The initial value for keepalive is true (enabled), and you can change it
306any time. 529any time.
307 530
308Example: Register an I/O watcher for some UDP socket but do not keep the 531Example: Register an I/O watcher for some UDP socket but do not keep the
309event loop from running just because of that watcher. 532event loop from running just because of that watcher.
310 533
311 my $udp_socket = ... 534 my $udp_socket = ...
312 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 535 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
313 $udp_watcher->keepalive (0); 536 $udp_watcher->keepalive (0);
314 537
315=back 538=item $loop = $w->loop
316 539
540Return the loop that this watcher is attached to.
317 541
542=back
543
544
318=head2 WATCHER TYPES 545=head1 WATCHER TYPES
319 546
320Each of the following subsections describes a single watcher type. 547Each of the following subsections describes a single watcher type.
321 548
322=head3 I/O WATCHERS - is this file descriptor readable or writable? 549=head3 I/O WATCHERS - is this file descriptor readable or writable?
323 550
324=over 4 551=over 4
325 552
326=item $w = EV::io $fileno_or_fh, $eventmask, $callback 553=item $w = EV::io $fileno_or_fh, $eventmask, $callback
327 554
328=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 555=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
556
557=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
558
559=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
329 560
330As long as the returned watcher object is alive, call the C<$callback> 561As long as the returned watcher object is alive, call the C<$callback>
331when at least one of events specified in C<$eventmask> occurs. 562when at least one of events specified in C<$eventmask> occurs.
332 563
333The $eventmask can be one or more of these constants ORed together: 564The $eventmask can be one or more of these constants ORed together:
… …
362=over 4 593=over 4
363 594
364=item $w = EV::timer $after, $repeat, $callback 595=item $w = EV::timer $after, $repeat, $callback
365 596
366=item $w = EV::timer_ns $after, $repeat, $callback 597=item $w = EV::timer_ns $after, $repeat, $callback
598
599=item $w = $loop->timer ($after, $repeat, $callback)
600
601=item $w = $loop->timer_ns ($after, $repeat, $callback)
367 602
368Calls the callback after C<$after> seconds (which may be fractional). If 603Calls the callback after C<$after> seconds (which may be fractional). If
369C<$repeat> is non-zero, the timer will be restarted (with the $repeat 604C<$repeat> is non-zero, the timer will be restarted (with the $repeat
370value as $after) after the callback returns. 605value as $after) after the callback returns.
371 606
… …
412=over 4 647=over 4
413 648
414=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 649=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
415 650
416=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 651=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
652
653=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
654
655=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
417 656
418Similar to EV::timer, but is not based on relative timeouts but on 657Similar to EV::timer, but is not based on relative timeouts but on
419absolute times. Apart from creating "simple" timers that trigger "at" the 658absolute times. Apart from creating "simple" timers that trigger "at" the
420specified time, it can also be used for non-drifting absolute timers and 659specified time, it can also be used for non-drifting absolute timers and
421more complex, cron-like, setups that are not adversely affected by time 660more complex, cron-like, setups that are not adversely affected by time
… …
431This time simply fires at the wallclock time C<$at> and doesn't repeat. It 670This time simply fires at the wallclock time C<$at> and doesn't repeat. It
432will not adjust when a time jump occurs, that is, if it is to be run 671will not adjust when a time jump occurs, that is, if it is to be run
433at January 1st 2011 then it will run when the system time reaches or 672at January 1st 2011 then it will run when the system time reaches or
434surpasses this time. 673surpasses this time.
435 674
436=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) 675=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
437 676
438In this mode the watcher will always be scheduled to time out at the 677In this mode the watcher will always be scheduled to time out at the
439next C<$at + N * $interval> time (for some integer N) and then repeat, 678next C<$at + N * $interval> time (for some integer N) and then repeat,
440regardless of any time jumps. 679regardless of any time jumps.
441 680
… …
459time the periodic watcher gets scheduled, the reschedule callback 698time the periodic watcher gets scheduled, the reschedule callback
460($reschedule_cb) will be called with the watcher as first, and the current 699($reschedule_cb) will be called with the watcher as first, and the current
461time as second argument. 700time as second argument.
462 701
463I<This callback MUST NOT stop or destroy this or any other periodic 702I<This callback MUST NOT stop or destroy this or any other periodic
464watcher, ever>. If you need to stop it, return 1e30 and stop it 703watcher, ever, and MUST NOT call any event loop functions or methods>. If
465afterwards. 704you need to stop it, return 1e30 and stop it afterwards. You may create
705and start a C<EV::prepare> watcher for this task.
466 706
467It must return the next time to trigger, based on the passed time value 707It must return the next time to trigger, based on the passed time value
468(that is, the lowest time value larger than to the second argument). It 708(that is, the lowest time value larger than or equal to to the second
469will usually be called just before the callback will be triggered, but 709argument). It will usually be called just before the callback will be
470might be called at other times, too. 710triggered, but might be called at other times, too.
471 711
472This can be used to create very complex timers, such as a timer that 712This can be used to create very complex timers, such as a timer that
473triggers on each midnight, local time (actually 24 hours after the last 713triggers on each midnight, local time (actually 24 hours after the last
474midnight, to keep the example simple. If you know a way to do it correctly 714midnight, to keep the example simple. If you know a way to do it correctly
475in about the same space (without requiring elaborate modules), drop me a 715in about the same space (without requiring elaborate modules), drop me a
… …
511 751
512=item $w = EV::signal $signal, $callback 752=item $w = EV::signal $signal, $callback
513 753
514=item $w = EV::signal_ns $signal, $callback 754=item $w = EV::signal_ns $signal, $callback
515 755
756=item $w = $loop->signal ($signal, $callback)
757
758=item $w = $loop->signal_ns ($signal, $callback)
759
516Call the callback when $signal is received (the signal can be specified by 760Call the callback when $signal is received (the signal can be specified by
517number or by name, just as with C<kill> or C<%SIG>). 761number or by name, just as with C<kill> or C<%SIG>).
762
763Only one event loop can grab a given signal - attempting to grab the same
764signal from two EV loops will crash the program immediately or cause data
765corruption.
518 766
519EV will grab the signal for the process (the kernel only allows one 767EV will grab the signal for the process (the kernel only allows one
520component to receive a signal at a time) when you start a signal watcher, 768component to receive a signal at a time) when you start a signal watcher,
521and removes it again when you stop it. Perl does the same when you 769and removes it again when you stop it. Perl does the same when you
522add/remove callbacks to C<%SIG>, so watch out. 770add/remove callbacks to C<%SIG>, so watch out.
… …
542 790
543=head3 CHILD WATCHERS - watch out for process status changes 791=head3 CHILD WATCHERS - watch out for process status changes
544 792
545=over 4 793=over 4
546 794
547=item $w = EV::child $pid, $callback 795=item $w = EV::child $pid, $trace, $callback
548 796
549=item $w = EV::child_ns $pid, $callback 797=item $w = EV::child_ns $pid, $trace, $callback
550 798
799=item $w = $loop->child ($pid, $trace, $callback)
800
801=item $w = $loop->child_ns ($pid, $trace, $callback)
802
551Call the callback when a status change for pid C<$pid> (or any pid if 803Call the callback when a status change for pid C<$pid> (or any pid
552C<$pid> is 0) has been received. More precisely: when the process receives 804if C<$pid> is 0) has been received (a status change happens when the
805process terminates or is killed, or, when trace is true, additionally when
806it is stopped or continued). More precisely: when the process receives
553a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all 807a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
554changed/zombie children and call the callback. 808changed/zombie children and call the callback.
555 809
556It is valid (and fully supported) to install a child watcher after a child 810It is valid (and fully supported) to install a child watcher after a child
557has exited but before the event loop has started its next iteration (for 811has exited but before the event loop has started its next iteration (for
… …
564You can have as many pid watchers per pid as you want, they will all be 818You can have as many pid watchers per pid as you want, they will all be
565called. 819called.
566 820
567The C<child_ns> variant doesn't start (activate) the newly created watcher. 821The C<child_ns> variant doesn't start (activate) the newly created watcher.
568 822
569=item $w->set ($pid) 823=item $w->set ($pid, $trace)
570 824
571Reconfigures the watcher, see the constructor above for details. Can be called at 825Reconfigures the watcher, see the constructor above for details. Can be called at
572any time. 826any time.
573 827
574=item $current_pid = $w->pid 828=item $current_pid = $w->pid
575 829
576=item $old_pid = $w->pid ($new_pid)
577
578Returns the previously set process id and optionally set a new one. 830Returns the previously set process id and optionally set a new one.
579 831
580=item $exit_status = $w->rstatus 832=item $exit_status = $w->rstatus
581 833
582Return the exit/wait status (as returned by waitpid, see the waitpid entry 834Return the exit/wait status (as returned by waitpid, see the waitpid entry
… …
595=over 4 847=over 4
596 848
597=item $w = EV::stat $path, $interval, $callback 849=item $w = EV::stat $path, $interval, $callback
598 850
599=item $w = EV::stat_ns $path, $interval, $callback 851=item $w = EV::stat_ns $path, $interval, $callback
852
853=item $w = $loop->stat ($path, $interval, $callback)
854
855=item $w = $loop->stat_ns ($path, $interval, $callback)
600 856
601Call the callback when a file status change has been detected on 857Call the callback when a file status change has been detected on
602C<$path>. The C<$path> does not need to exist, changing from "path exists" 858C<$path>. The C<$path> does not need to exist, changing from "path exists"
603to "path does not exist" is a status change like any other. 859to "path does not exist" is a status change like any other.
604 860
… …
674=over 4 930=over 4
675 931
676=item $w = EV::idle $callback 932=item $w = EV::idle $callback
677 933
678=item $w = EV::idle_ns $callback 934=item $w = EV::idle_ns $callback
935
936=item $w = $loop->idle ($callback)
937
938=item $w = $loop->idle_ns ($callback)
679 939
680Call the callback when there are no other pending watchers of the same or 940Call the callback when there are no other pending watchers of the same or
681higher priority (excluding check, prepare and other idle watchers of the 941higher priority (excluding check, prepare and other idle watchers of the
682same or lower priority, of course). They are called idle watchers because 942same or lower priority, of course). They are called idle watchers because
683when the watcher is the highest priority pending event in the process, the 943when the watcher is the highest priority pending event in the process, the
… …
706 966
707=item $w = EV::prepare $callback 967=item $w = EV::prepare $callback
708 968
709=item $w = EV::prepare_ns $callback 969=item $w = EV::prepare_ns $callback
710 970
971=item $w = $loop->prepare ($callback)
972
973=item $w = $loop->prepare_ns ($callback)
974
711Call the callback just before the process would block. You can still 975Call the callback just before the process would block. You can still
712create/modify any watchers at this point. 976create/modify any watchers at this point.
713 977
714See the EV::check watcher, below, for explanations and an example. 978See the EV::check watcher, below, for explanations and an example.
715 979
… …
724 988
725=item $w = EV::check $callback 989=item $w = EV::check $callback
726 990
727=item $w = EV::check_ns $callback 991=item $w = EV::check_ns $callback
728 992
993=item $w = $loop->check ($callback)
994
995=item $w = $loop->check_ns ($callback)
996
729Call the callback just after the process wakes up again (after it has 997Call the callback just after the process wakes up again (after it has
730gathered events), but before any other callbacks have been invoked. 998gathered events), but before any other callbacks have been invoked.
731 999
732This is used to integrate other event-based software into the EV 1000This can be used to integrate other event-based software into the EV
733mainloop: You register a prepare callback and in there, you create io and 1001mainloop: You register a prepare callback and in there, you create io and
734timer watchers as required by the other software. Here is a real-world 1002timer watchers as required by the other software. Here is a real-world
735example of integrating Net::SNMP (with some details left out): 1003example of integrating Net::SNMP (with some details left out):
736 1004
737 our @snmp_watcher; 1005 our @snmp_watcher;
… …
767 # make the dispatcher handle any new stuff 1035 # make the dispatcher handle any new stuff
768 ... not shown 1036 ... not shown
769 }; 1037 };
770 1038
771The callbacks of the created watchers will not be called as the watchers 1039The callbacks of the created watchers will not be called as the watchers
772are destroyed before this cna happen (remember EV::check gets called 1040are destroyed before this can happen (remember EV::check gets called
773first). 1041first).
774 1042
775The C<check_ns> variant doesn't start (activate) the newly created watcher. 1043The C<check_ns> variant doesn't start (activate) the newly created watcher.
1044
1045=item EV::CHECK constant issues
1046
1047Like all other watcher types, there is a bitmask constant for use in
1048C<$revents> and other places. The C<EV::CHECK> is special as it has
1049the same name as the C<CHECK> sub called by Perl. This doesn't cause
1050big issues on newer perls (beginning with 5.8.9), but it means thatthe
1051constant must be I<inlined>, i.e. runtime calls will not work. That means
1052that as long as you always C<use EV> and then C<EV::CHECK> you are on the
1053safe side.
776 1054
777=back 1055=back
778 1056
779 1057
780=head3 FORK WATCHERS - the audacity to resume the event loop after a fork 1058=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
… …
787 1065
788=item $w = EV::fork $callback 1066=item $w = EV::fork $callback
789 1067
790=item $w = EV::fork_ns $callback 1068=item $w = EV::fork_ns $callback
791 1069
1070=item $w = $loop->fork ($callback)
1071
1072=item $w = $loop->fork_ns ($callback)
1073
792Call the callback before the event loop is resumed in the child process 1074Call the callback before the event loop is resumed in the child process
793after a fork. 1075after a fork.
794 1076
795The C<fork_ns> variant doesn't start (activate) the newly created watcher. 1077The C<fork_ns> variant doesn't start (activate) the newly created watcher.
796 1078
797=back 1079=back
1080
1081
1082=head3 EMBED WATCHERS - when one backend isn't enough...
1083
1084This is a rather advanced watcher type that lets you embed one event loop
1085into another (currently only IO events are supported in the embedded
1086loop, other types of watchers might be handled in a delayed or incorrect
1087fashion and must not be used).
1088
1089See the libev documentation at
1090L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
1091(locally installed as F<EV::libev>) for more details.
1092
1093In short, this watcher is most useful on BSD systems without working
1094kqueue to still be able to handle a large number of sockets:
1095
1096 my $socket_loop;
1097
1098 # check wether we use SELECT or POLL _and_ KQUEUE is supported
1099 if (
1100 (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT))
1101 && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
1102 ) {
1103 # use kqueue for sockets
1104 $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV;
1105 }
1106
1107 # use the default loop otherwise
1108 $socket_loop ||= EV::default_loop;
1109
1110=over 4
1111
1112=item $w = EV::embed $otherloop[, $callback]
1113
1114=item $w = EV::embed_ns $otherloop[, $callback]
1115
1116=item $w = $loop->embed ($otherloop[, $callback])
1117
1118=item $w = $loop->embed_ns ($otherloop[, $callback])
1119
1120Call the callback when the embedded event loop (C<$otherloop>) has any
1121I/O activity. The C<$callback> is optional: if it is missing, then the
1122embedded event loop will be managed automatically (which is recommended),
1123otherwise you have to invoke C<sweep> yourself.
1124
1125The C<embed_ns> variant doesn't start (activate) the newly created watcher.
1126
1127=back
1128
1129=head3 ASYNC WATCHERS - how to wake up another event loop
1130
1131Async watchers are provided by EV, but have little use in perl directly,
1132as perl neither supports threads running in parallel nor direct access to
1133signal handlers or other contexts where they could be of value.
1134
1135It is, however, possible to use them from the XS level.
1136
1137Please see the libev documentation for further details.
1138
1139=over 4
1140
1141=item $w = EV::async $callback
1142
1143=item $w = EV::async_ns $callback
1144
1145=item $w = $loop->async ($callback)
1146
1147=item $w = $loop->async_ns ($callback)
1148
1149=item $w->send
1150
1151=item $bool = $w->async_pending
1152
1153=back
1154
1155=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
1156
1157Cleanup watchers are not supported on the Perl level, they can only be
1158used via XS currently.
798 1159
799 1160
800=head1 PERL SIGNALS 1161=head1 PERL SIGNALS
801 1162
802While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour 1163While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
… …
811to be called on every event loop iteration by installing a C<EV::check> 1172to be called on every event loop iteration by installing a C<EV::check>
812watcher: 1173watcher:
813 1174
814 my $async_check = EV::check sub { }; 1175 my $async_check = EV::check sub { };
815 1176
816This ensures that perl shortly gets into control for a short time, and 1177This ensures that perl gets into control for a short time to handle any
817also ensures slower overall operation. 1178pending signals, and also ensures (slightly) slower overall operation.
818 1179
819=head1 THREADS 1180=head1 ITHREADS
820 1181
821Threads are not supported by this module in any way. Perl pseudo-threads 1182Ithreads are not supported by this module in any way. Perl pseudo-threads
822is evil stuff and must die. As soon as Perl gains real threads I will work 1183is evil stuff and must die. Real threads as provided by Coro are fully
823on thread support for it. 1184supported (and enhanced support is available via L<Coro::EV>).
824 1185
825=head1 FORK 1186=head1 FORK
826 1187
827Most of the "improved" event delivering mechanisms of modern operating 1188Most of the "improved" event delivering mechanisms of modern operating
828systems have quite a few problems with fork(2) (to put it bluntly: it is 1189systems have quite a few problems with fork(2) (to put it bluntly: it is
… …
850 1211
8511; 12121;
852 1213
853=head1 SEE ALSO 1214=head1 SEE ALSO
854 1215
1216L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
855L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as 1217(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
856event loop), L<Coro::EV> (efficient coroutines with EV). 1218loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
1219integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
1220event-loop agnostic and portable event driven programming.
857 1221
858=head1 AUTHOR 1222=head1 AUTHOR
859 1223
860 Marc Lehmann <schmorp@schmorp.de> 1224 Marc Lehmann <schmorp@schmorp.de>
861 http://home.schmorp.de/ 1225 http://home.schmorp.de/
862 1226
863=cut 1227=cut
864 1228

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