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Revision 1.291 by root, Thu Sep 3 13:59:20 2009 UTC vs.
Revision 1.302 by root, Fri Dec 4 16:31:57 2009 UTC

… …
363might affect timers and time-outs. 363might affect timers and time-outs.
364 364
365When this is the case, you can call this method, which will update the 365When this is the case, you can call this method, which will update the
366event loop's idea of "current time". 366event loop's idea of "current time".
367 367
368A typical example would be a script in a web server (e.g. C<mod_perl>) -
369when mod_perl executes the script, then the event loop will have the wrong
370idea about the "current time" (being potentially far in the past, when the
371script ran the last time). In that case you should arrange a call to C<<
372AnyEvent->now_update >> each time the web server process wakes up again
373(e.g. at the start of your script, or in a handler).
374
368Note that updating the time I<might> cause some events to be handled. 375Note that updating the time I<might> cause some events to be handled.
369 376
370=back 377=back
371 378
372=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
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395correctly. 402correctly.
396 403
397Example: exit on SIGINT 404Example: exit on SIGINT
398 405
399 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
400 424
401=head3 Signal Races, Delays and Workarounds 425=head3 Signal Races, Delays and Workarounds
402 426
403Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404callbacks to signals in a generic way, which is a pity, as you cannot 428callbacks to signals in a generic way, which is a pity, as you cannot
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1107package AnyEvent; 1131package AnyEvent;
1108 1132
1109# basically a tuned-down version of common::sense 1133# basically a tuned-down version of common::sense
1110sub common_sense { 1134sub common_sense {
1111 # from common:.sense 1.0 1135 # from common:.sense 1.0
1112 ${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03"; 1136 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";
1113 # use strict vars subs 1137 # use strict vars subs
1114 $^H |= 0x00000600; 1138 $^H |= 0x00000600;
1115} 1139}
1116 1140
1117BEGIN { AnyEvent::common_sense } 1141BEGIN { AnyEvent::common_sense }
1118 1142
1119use Carp (); 1143use Carp ();
1120 1144
1121our $VERSION = '5.12'; 1145our $VERSION = '5.21';
1122our $MODEL; 1146our $MODEL;
1123 1147
1124our $AUTOLOAD; 1148our $AUTOLOAD;
1125our @ISA; 1149our @ISA;
1126 1150
1127our @REGISTRY; 1151our @REGISTRY;
1128
1129our $WIN32;
1130 1152
1131our $VERBOSE; 1153our $VERBOSE;
1132 1154
1133BEGIN { 1155BEGIN {
1134 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1156 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
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1386our ($SIG_COUNT, $SIG_TW); 1408our ($SIG_COUNT, $SIG_TW);
1387 1409
1388sub _signal_exec { 1410sub _signal_exec {
1389 $HAVE_ASYNC_INTERRUPT 1411 $HAVE_ASYNC_INTERRUPT
1390 ? $SIGPIPE_R->drain 1412 ? $SIGPIPE_R->drain
1391 : sysread $SIGPIPE_R, my $dummy, 9; 1413 : sysread $SIGPIPE_R, (my $dummy), 9;
1392 1414
1393 while (%SIG_EV) { 1415 while (%SIG_EV) {
1394 for (keys %SIG_EV) { 1416 for (keys %SIG_EV) {
1395 delete $SIG_EV{$_}; 1417 delete $SIG_EV{$_};
1396 $_->() for values %{ $SIG_CB{$_} || {} }; 1418 $_->() for values %{ $SIG_CB{$_} || {} };
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2426it's built-in modules) are required to use it. 2448it's built-in modules) are required to use it.
2427 2449
2428That does not mean that AnyEvent won't take advantage of some additional 2450That does not mean that AnyEvent won't take advantage of some additional
2429modules if they are installed. 2451modules if they are installed.
2430 2452
2431This section epxlains which additional modules will be used, and how they 2453This section explains which additional modules will be used, and how they
2432affect AnyEvent's operetion. 2454affect AnyEvent's operation.
2433 2455
2434=over 4 2456=over 4
2435 2457
2436=item L<Async::Interrupt> 2458=item L<Async::Interrupt>
2437 2459
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2442catch the signals) with some delay (default is 10 seconds, look for 2464catch the signals) with some delay (default is 10 seconds, look for
2443C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2465C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2444 2466
2445If this module is available, then it will be used to implement signal 2467If this module is available, then it will be used to implement signal
2446catching, which means that signals will not be delayed, and the event loop 2468catching, which means that signals will not be delayed, and the event loop
2447will not be interrupted regularly, which is more efficient (And good for 2469will not be interrupted regularly, which is more efficient (and good for
2448battery life on laptops). 2470battery life on laptops).
2449 2471
2450This affects not just the pure-perl event loop, but also other event loops 2472This affects not just the pure-perl event loop, but also other event loops
2451that have no signal handling on their own (e.g. Glib, Tk, Qt). 2473that have no signal handling on their own (e.g. Glib, Tk, Qt).
2452 2474
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2502 2524
2503Most event libraries are not fork-safe. The ones who are usually are 2525Most event libraries are not fork-safe. The ones who are usually are
2504because they rely on inefficient but fork-safe C<select> or C<poll> 2526because they rely on inefficient but fork-safe C<select> or C<poll>
2505calls. Only L<EV> is fully fork-aware. 2527calls. Only L<EV> is fully fork-aware.
2506 2528
2529This means that, in general, you cannot fork and do event processing
2530in the child if a watcher was created before the fork (which in turn
2531initialises the event library).
2532
2507If you have to fork, you must either do so I<before> creating your first 2533If you have to fork, you must either do so I<before> creating your first
2508watcher OR you must not use AnyEvent at all in the child OR you must do 2534watcher OR you must not use AnyEvent at all in the child OR you must do
2509something completely out of the scope of AnyEvent. 2535something completely out of the scope of AnyEvent.
2536
2537The problem of doing event processing in the parent I<and> the child
2538is much more complicated: even for backends that I<are> fork-aware or
2539fork-safe, their behaviour is not usually what you want: fork clones all
2540watchers, that means all timers, I/O watchers etc. are active in both
2541parent and child, which is almost never what you want.
2510 2542
2511 2543
2512=head1 SECURITY CONSIDERATIONS 2544=head1 SECURITY CONSIDERATIONS
2513 2545
2514AnyEvent can be forced to load any event model via 2546AnyEvent can be forced to load any event model via

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