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Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs.
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC

38 # CHILD/PID STATUS CHANGES 38 # CHILD/PID STATUS CHANGES
39 39
40 my $w = EV::child 666, sub { 40 my $w = EV::child 666, sub {
41 my ($w, $revents) = @_; 41 my ($w, $revents) = @_;
42 my $status = $w->rstatus; 42 my $status = $w->rstatus;
43 };
44
45 # STAT CHANGES
46 my $w = EV::stat "/etc/passwd", 10, sub {
47 my ($w, $revents) = @_;
48 warn $w->path, " has changed somehow.\n";
43 }; 49 };
44 50
45 # MAINLOOP 51 # MAINLOOP
46 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
47 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
61package EV; 67package EV;
62 68
63use strict; 69use strict;
64 70
65BEGIN { 71BEGIN {
66 our $VERSION = '1.3'; 72 our $VERSION = '1.4';
67 use XSLoader; 73 use XSLoader;
68 XSLoader::load "EV", $VERSION; 74 XSLoader::load "EV", $VERSION;
69} 75}
70 76
71@EV::IO::ISA = 77@EV::IO::ISA =
73@EV::Periodic::ISA = 79@EV::Periodic::ISA =
74@EV::Signal::ISA = 80@EV::Signal::ISA =
75@EV::Idle::ISA = 81@EV::Idle::ISA =
76@EV::Prepare::ISA = 82@EV::Prepare::ISA =
77@EV::Check::ISA = 83@EV::Check::ISA =
84@EV::Child::ISA =
85@EV::Embed::ISA =
78@EV::Child::ISA = "EV::Watcher"; 86@EV::Stat::ISA = "EV::Watcher";
79 87
80=head1 BASIC INTERFACE 88=head1 BASIC INTERFACE
81 89
82=over 4 90=over 4
83 91
146of them triggers, then they will be stopped and freed, and the callback 154of them triggers, then they will be stopped and freed, and the callback
147invoked. 155invoked.
148 156
149=back 157=back
150 158
151=head2 WATCHER 159=head2 WATCHER OBJECTS
152 160
153A watcher is an object that gets created to record your interest in some 161A watcher is an object that gets created to record your interest in some
154event. For instance, if you want to wait for STDIN to become readable, you 162event. For instance, if you want to wait for STDIN to become readable, you
155would create an EV::io watcher for that: 163would create an EV::io watcher for that:
156 164
181 189
182Also, all methods changing some aspect of a watcher (->set, ->priority, 190Also, all methods changing some aspect of a watcher (->set, ->priority,
183->fh and so on) automatically stop and start it again if it is active, 191->fh and so on) automatically stop and start it again if it is active,
184which means pending events get lost. 192which means pending events get lost.
185 193
186=head2 WATCHER TYPES 194=head2 COMMON WATCHER METHODS
187 195
188Now lets move to the existing watcher types and asociated methods. 196This section lists methods common to all watchers.
189
190The following methods are available for all watchers. Then followes a
191description of each watcher constructor (EV::io, EV::timer, EV::periodic,
192EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
193any type-specific methods (if any).
194 197
195=over 4 198=over 4
196 199
197=item $w->start 200=item $w->start
198 201
274 277
275 my $udp_socket = ... 278 my $udp_socket = ...
276 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; 279 my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
277 $udp_watcher->keepalive (0); 280 $udp_watcher->keepalive (0);
278 281
282=back
283
284
285=head2 WATCHER TYPES
286
287Each of the following subsections describes a single watcher type.
288
289=head3 IO WATCHERS - is this file descriptor readable or writable?
290
291=over 4
292
279=item $w = EV::io $fileno_or_fh, $eventmask, $callback 293=item $w = EV::io $fileno_or_fh, $eventmask, $callback
280 294
281=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback 295=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
282 296
283As long as the returned watcher object is alive, call the C<$callback> 297As long as the returned watcher object is alive, call the C<$callback>
284when the events specified in C<$eventmask>. 298when at least one of events specified in C<$eventmask> occurs.
285 299
286The $eventmask can be one or more of these constants ORed together: 300The $eventmask can be one or more of these constants ORed together:
287 301
288 EV::READ wait until read() wouldn't block anymore 302 EV::READ wait until read() wouldn't block anymore
289 EV::WRITE wait until write() wouldn't block anymore 303 EV::WRITE wait until write() wouldn't block anymore
305 319
306=item $old_eventmask = $w->events ($new_eventmask) 320=item $old_eventmask = $w->events ($new_eventmask)
307 321
308Returns the previously set event mask and optionally set a new one. 322Returns the previously set event mask and optionally set a new one.
309 323
324=back
325
326
327=head3 TIMER WATCHERS - relative and optionally repeating timeouts
328
329=over 4
310 330
311=item $w = EV::timer $after, $repeat, $callback 331=item $w = EV::timer $after, $repeat, $callback
312 332
313=item $w = EV::timer_ns $after, $repeat, $callback 333=item $w = EV::timer_ns $after, $repeat, $callback
314 334
328 348
329The C<timer_ns> variant doesn't start (activate) the newly created watcher. 349The C<timer_ns> variant doesn't start (activate) the newly created watcher.
330 350
331=item $w->set ($after, $repeat) 351=item $w->set ($after, $repeat)
332 352
333Reconfigures the watcher, see the constructor above for details. Can be at 353Reconfigures the watcher, see the constructor above for details. Can be called at
334any time. 354any time.
335 355
336=item $w->again 356=item $w->again
337 357
338Similar to the C<start> method, but has special semantics for repeating timers: 358Similar to the C<start> method, but has special semantics for repeating timers:
349This behaviour is useful when you have a timeout for some IO 369This behaviour is useful when you have a timeout for some IO
350operation. You create a timer object with the same value for C<$after> and 370operation. You create a timer object with the same value for C<$after> and
351C<$repeat>, and then, in the read/write watcher, run the C<again> method 371C<$repeat>, and then, in the read/write watcher, run the C<again> method
352on the timeout. 372on the timeout.
353 373
374=back
375
376
377=head3 PERIODIC WATCHERS - to cron or not to cron?
378
379=over 4
354 380
355=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback 381=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
356 382
357=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback 383=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
358 384
430 456
431The C<periodic_ns> variant doesn't start (activate) the newly created watcher. 457The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
432 458
433=item $w->set ($at, $interval, $reschedule_cb) 459=item $w->set ($at, $interval, $reschedule_cb)
434 460
435Reconfigures the watcher, see the constructor above for details. Can be at 461Reconfigures the watcher, see the constructor above for details. Can be called at
436any time. 462any time.
437 463
438=item $w->again 464=item $w->again
439 465
440Simply stops and starts the watcher again. 466Simply stops and starts the watcher again.
441 467
468=back
469
470
471=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472
473=over 4
442 474
443=item $w = EV::signal $signal, $callback 475=item $w = EV::signal $signal, $callback
444 476
445=item $w = EV::signal_ns $signal, $callback 477=item $w = EV::signal_ns $signal, $callback
446 478
447Call the callback when $signal is received (the signal can be specified 479Call the callback when $signal is received (the signal can be specified by
448by number or by name, just as with kill or %SIG). 480number or by name, just as with C<kill> or C<%SIG>).
449 481
450EV will grab the signal for the process (the kernel only allows one 482EV will grab the signal for the process (the kernel only allows one
451component to receive a signal at a time) when you start a signal watcher, 483component to receive a signal at a time) when you start a signal watcher,
452and removes it again when you stop it. Perl does the same when you 484and removes it again when you stop it. Perl does the same when you
453add/remove callbacks to %SIG, so watch out. 485add/remove callbacks to C<%SIG>, so watch out.
454 486
455You can have as many signal watchers per signal as you want. 487You can have as many signal watchers per signal as you want.
456 488
457The C<signal_ns> variant doesn't start (activate) the newly created watcher. 489The C<signal_ns> variant doesn't start (activate) the newly created watcher.
458 490
459=item $w->set ($signal) 491=item $w->set ($signal)
460 492
461Reconfigures the watcher, see the constructor above for details. Can be at 493Reconfigures the watcher, see the constructor above for details. Can be
462any time. 494called at any time.
463 495
464=item $current_signum = $w->signal 496=item $current_signum = $w->signal
465 497
466=item $old_signum = $w->signal ($new_signal) 498=item $old_signum = $w->signal ($new_signal)
467 499
468Returns the previously set signal (always as a number not name) and 500Returns the previously set signal (always as a number not name) and
469optionally set a new one. 501optionally set a new one.
470 502
503=back
504
505
506=head3 CHILD WATCHERS - watch out for process status changes
507
508=over 4
471 509
472=item $w = EV::child $pid, $callback 510=item $w = EV::child $pid, $callback
473 511
474=item $w = EV::child_ns $pid, $callback 512=item $w = EV::child_ns $pid, $callback
475 513
476Call the callback when a status change for pid C<$pid> (or any pid 514Call the callback when a status change for pid C<$pid> (or any pid if
477if C<$pid> is 0) has been received. More precisely: when the process 515C<$pid> is 0) has been received. More precisely: when the process receives
478receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all 516a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
479changed/zombie children and call the callback. 517changed/zombie children and call the callback.
480 518
481You can access both status and pid by using the C<rstatus> and C<rpid> 519It is valid (and fully supported) to install a child watcher after a child
482methods on the watcher object. 520has exited but before the event loop has started its next iteration (for
521example, first you C<fork>, then the new child process might exit, and
522only then do you install a child watcher in the parent for the new pid).
483 523
524You can access both exit (or tracing) status and pid by using the
525C<rstatus> and C<rpid> methods on the watcher object.
526
484You can have as many pid watchers per pid as you want. 527You can have as many pid watchers per pid as you want, they will all be
528called.
485 529
486The C<child_ns> variant doesn't start (activate) the newly created watcher. 530The C<child_ns> variant doesn't start (activate) the newly created watcher.
487 531
488=item $w->set ($pid) 532=item $w->set ($pid)
489 533
490Reconfigures the watcher, see the constructor above for details. Can be at 534Reconfigures the watcher, see the constructor above for details. Can be called at
491any time. 535any time.
492 536
493=item $current_pid = $w->pid 537=item $current_pid = $w->pid
494 538
495=item $old_pid = $w->pid ($new_pid) 539=item $old_pid = $w->pid ($new_pid)
504=item $pid = $w->rpid 548=item $pid = $w->rpid
505 549
506Return the pid of the awaited child (useful when you have installed a 550Return the pid of the awaited child (useful when you have installed a
507watcher for all pids). 551watcher for all pids).
508 552
553=back
554
555
556=head3 IDLE WATCHERS - when you've got nothing better to do...
557
558=over 4
509 559
510=item $w = EV::idle $callback 560=item $w = EV::idle $callback
511 561
512=item $w = EV::idle_ns $callback 562=item $w = EV::idle_ns $callback
513 563
517The process will not block as long as any idle watchers are active, and 567The process will not block as long as any idle watchers are active, and
518they will be called repeatedly until stopped. 568they will be called repeatedly until stopped.
519 569
520The C<idle_ns> variant doesn't start (activate) the newly created watcher. 570The C<idle_ns> variant doesn't start (activate) the newly created watcher.
521 571
572=back
573
574
575=head3 PREPARE WATCHERS - customise your event loop!
576
577=over 4
522 578
523=item $w = EV::prepare $callback 579=item $w = EV::prepare $callback
524 580
525=item $w = EV::prepare_ns $callback 581=item $w = EV::prepare_ns $callback
526 582
529 585
530See the EV::check watcher, below, for explanations and an example. 586See the EV::check watcher, below, for explanations and an example.
531 587
532The C<prepare_ns> variant doesn't start (activate) the newly created watcher. 588The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
533 589
590=back
591
592
593=head3 CHECK WATCHERS - customise your event loop even more!
594
595=over 4
534 596
535=item $w = EV::check $callback 597=item $w = EV::check $callback
536 598
537=item $w = EV::check_ns $callback 599=item $w = EV::check_ns $callback
538 600
583first). 645first).
584 646
585The C<check_ns> variant doesn't start (activate) the newly created watcher. 647The C<check_ns> variant doesn't start (activate) the newly created watcher.
586 648
587=back 649=back
650
651=head3 STAT WATCHERS - did the file stats just change?
652
653=over 4
654
655=item $w = EV::stat $path, $interval, $callback
656
657=item $w = EV::stat_ns $path, $interval, $callback
658
659Call the callback when a file status change has been detected on
660C<$path>. The C<$path> does not need to exist, changing from "path exists"
661to "path does not exist" is a status change like any other.
662
663The C<$interval> is a recommended polling interval for systems where
664OS-supported change notifications don't exist or are not supported. If
665you use C<0> then an unspecified default is used (which is highly
666recommended!), which is to be expected to be around five seconds usually.
667
668This watcher type is not meant for massive numbers of stat watchers,
669as even with OS-supported change notifications, this can be
670resource-intensive.
671
672The C<stat_ns> variant doesn't start (activate) the newly created watcher.
673
674=item $w->set ($path, $interval)
675
676Reconfigures the watcher, see the constructor above for details. Can be
677called at any time.
678
679=item $current_path = $w->path
680
681=item $old_path = $w->path ($new_path)
682
683Returns the previously set path and optionally set a new one.
684
685=item $current_interval = $w->interval
686
687=item $old_interval = $w->interval ($new_interval)
688
689Returns the previously set interval and optionally set a new one. Can be
690used to query the actual interval used.
691
692=back
693
588 694
589=head1 THREADS 695=head1 THREADS
590 696
591Threads are not supported by this module in any way. Perl pseudo-threads 697Threads are not supported by this module in any way. Perl pseudo-threads
592is evil stuff and must die. As soon as Perl gains real threads I will work 698is evil stuff and must die. As soon as Perl gains real threads I will work
620 726
6211; 7271;
622 728
623=head1 SEE ALSO 729=head1 SEE ALSO
624 730
625 L<EV::DNS>. 731L<EV::DNS>.
626 732
627=head1 AUTHOR 733=head1 AUTHOR
628 734
629 Marc Lehmann <schmorp@schmorp.de> 735 Marc Lehmann <schmorp@schmorp.de>
630 http://home.schmorp.de/ 736 http://home.schmorp.de/

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