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Revision 1.295 by root, Wed Oct 28 02:42:06 2009 UTC vs.
Revision 1.305 by root, Sun Dec 13 05:13:15 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
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 $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
400 424
401=head3 Signal Races, Delays and Workarounds 425=head3 Signal Races, Delays and Workarounds
402 426
403Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404callbacks to signals in a generic way, which is a pity, as you cannot 428callbacks to signals in a generic way, which is a pity, as you cannot
942You should check C<$AnyEvent::MODEL> before adding to this array, though: 966You should check C<$AnyEvent::MODEL> before adding to this array, though:
943if it is defined then the event loop has already been detected, and the 967if it is defined then the event loop has already been detected, and the
944array will be ignored. 968array will be ignored.
945 969
946Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 970Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
947it,as it takes care of these details. 971it, as it takes care of these details.
948 972
949This variable is mainly useful for modules that can do something useful 973This variable is mainly useful for modules that can do something useful
950when AnyEvent is used and thus want to know when it is initialised, but do 974when AnyEvent is used and thus want to know when it is initialised, but do
951not need to even load it by default. This array provides the means to hook 975not need to even load it by default. This array provides the means to hook
952into AnyEvent passively, without loading it. 976into AnyEvent passively, without loading it.
977
978Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
979together, you could put this into Coro (this is the actual code used by
980Coro to accomplish this):
981
982 if (defined $AnyEvent::MODEL) {
983 # AnyEvent already initialised, so load Coro::AnyEvent
984 require Coro::AnyEvent;
985 } else {
986 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
987 # as soon as it is
988 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
989 }
953 990
954=back 991=back
955 992
956=head1 WHAT TO DO IN A MODULE 993=head1 WHAT TO DO IN A MODULE
957 994
1107package AnyEvent; 1144package AnyEvent;
1108 1145
1109# basically a tuned-down version of common::sense 1146# basically a tuned-down version of common::sense
1110sub common_sense { 1147sub common_sense {
1111 # from common:.sense 1.0 1148 # from common:.sense 1.0
1112 ${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03"; 1149 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1113 # use strict vars subs 1150 # use strict vars subs
1114 $^H |= 0x00000600; 1151 $^H |= 0x00000600;
1115} 1152}
1116 1153
1117BEGIN { AnyEvent::common_sense } 1154BEGIN { AnyEvent::common_sense }
1118 1155
1119use Carp (); 1156use Carp ();
1120 1157
1121our $VERSION = '5.202'; 1158our $VERSION = '5.22';
1122our $MODEL; 1159our $MODEL;
1123 1160
1124our $AUTOLOAD; 1161our $AUTOLOAD;
1125our @ISA; 1162our @ISA;
1126 1163
1127our @REGISTRY; 1164our @REGISTRY;
1128
1129our $WIN32;
1130 1165
1131our $VERBOSE; 1166our $VERBOSE;
1132 1167
1133BEGIN { 1168BEGIN {
1134 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1169 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
2426it's built-in modules) are required to use it. 2461it's built-in modules) are required to use it.
2427 2462
2428That does not mean that AnyEvent won't take advantage of some additional 2463That does not mean that AnyEvent won't take advantage of some additional
2429modules if they are installed. 2464modules if they are installed.
2430 2465
2431This section epxlains which additional modules will be used, and how they 2466This section explains which additional modules will be used, and how they
2432affect AnyEvent's operetion. 2467affect AnyEvent's operation.
2433 2468
2434=over 4 2469=over 4
2435 2470
2436=item L<Async::Interrupt> 2471=item L<Async::Interrupt>
2437 2472
2442catch the signals) with some delay (default is 10 seconds, look for 2477catch the signals) with some delay (default is 10 seconds, look for
2443C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2478C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2444 2479
2445If this module is available, then it will be used to implement signal 2480If 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 2481catching, which means that signals will not be delayed, and the event loop
2447will not be interrupted regularly, which is more efficient (And good for 2482will not be interrupted regularly, which is more efficient (and good for
2448battery life on laptops). 2483battery life on laptops).
2449 2484
2450This affects not just the pure-perl event loop, but also other event loops 2485This 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). 2486that have no signal handling on their own (e.g. Glib, Tk, Qt).
2452 2487
2502 2537
2503Most event libraries are not fork-safe. The ones who are usually are 2538Most 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> 2539because they rely on inefficient but fork-safe C<select> or C<poll>
2505calls. Only L<EV> is fully fork-aware. 2540calls. Only L<EV> is fully fork-aware.
2506 2541
2542This means that, in general, you cannot fork and do event processing
2543in the child if a watcher was created before the fork (which in turn
2544initialises the event library).
2545
2507If you have to fork, you must either do so I<before> creating your first 2546If 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 2547watcher OR you must not use AnyEvent at all in the child OR you must do
2509something completely out of the scope of AnyEvent. 2548something completely out of the scope of AnyEvent.
2549
2550The problem of doing event processing in the parent I<and> the child
2551is much more complicated: even for backends that I<are> fork-aware or
2552fork-safe, their behaviour is not usually what you want: fork clones all
2553watchers, that means all timers, I/O watchers etc. are active in both
2554parent and child, which is almost never what you want.
2510 2555
2511 2556
2512=head1 SECURITY CONSIDERATIONS 2557=head1 SECURITY CONSIDERATIONS
2513 2558
2514AnyEvent can be forced to load any event model via 2559AnyEvent can be forced to load any event model via

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