ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent/lib/AnyEvent.pm
(Generate patch)

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.284 by root, Sun Aug 16 16:54:51 2009 UTC vs.
Revision 1.306 by root, Tue Dec 15 05:49:13 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
592 after => 1, 616 after => 1,
593 cb => sub { $result_ready->send }, 617 cb => sub { $result_ready->send },
594 ); 618 );
595 619
596 # this "blocks" (while handling events) till the callback 620 # this "blocks" (while handling events) till the callback
597 # calls -<send 621 # calls ->send
598 $result_ready->recv; 622 $result_ready->recv;
599 623
600Example: wait for a timer, but take advantage of the fact that condition 624Example: wait for a timer, but take advantage of the fact that condition
601variables are also callable directly. 625variables are also callable directly.
602 626
942You should check C<$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
1106 1143
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 # no warnings 1148 # from common:.sense 1.0
1112 ${^WARNING_BITS} ^= ${^WARNING_BITS}; 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 - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
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 = '5.111'; 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) ." }";
1343 1378
1344package AnyEvent::Base; 1379package AnyEvent::Base;
1345 1380
1346# default implementations for many methods 1381# default implementations for many methods
1347 1382
1348sub _time { 1383sub _time() {
1349 # probe for availability of Time::HiRes 1384 # probe for availability of Time::HiRes
1350 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1385 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1351 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1386 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1352 *_time = \&Time::HiRes::time; 1387 *_time = \&Time::HiRes::time;
1353 # if (eval "use POSIX (); (POSIX::times())... 1388 # if (eval "use POSIX (); (POSIX::times())...
1373 1408
1374our $HAVE_ASYNC_INTERRUPT; 1409our $HAVE_ASYNC_INTERRUPT;
1375 1410
1376sub _have_async_interrupt() { 1411sub _have_async_interrupt() {
1377 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} 1412 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1378 && eval "use Async::Interrupt 1.0 (); 1") 1413 && eval "use Async::Interrupt 1.02 (); 1")
1379 unless defined $HAVE_ASYNC_INTERRUPT; 1414 unless defined $HAVE_ASYNC_INTERRUPT;
1380 1415
1381 $HAVE_ASYNC_INTERRUPT 1416 $HAVE_ASYNC_INTERRUPT
1382} 1417}
1383 1418
1386our ($SIG_COUNT, $SIG_TW); 1421our ($SIG_COUNT, $SIG_TW);
1387 1422
1388sub _signal_exec { 1423sub _signal_exec {
1389 $HAVE_ASYNC_INTERRUPT 1424 $HAVE_ASYNC_INTERRUPT
1390 ? $SIGPIPE_R->drain 1425 ? $SIGPIPE_R->drain
1391 : sysread $SIGPIPE_R, my $dummy, 9; 1426 : sysread $SIGPIPE_R, (my $dummy), 9;
1392 1427
1393 while (%SIG_EV) { 1428 while (%SIG_EV) {
1394 for (keys %SIG_EV) { 1429 for (keys %SIG_EV) {
1395 delete $SIG_EV{$_}; 1430 delete $SIG_EV{$_};
1396 $_->() for values %{ $SIG_CB{$_} || {} }; 1431 $_->() for values %{ $SIG_CB{$_} || {} };
1912 warn "read: $input\n"; # output what has been read 1947 warn "read: $input\n"; # output what has been read
1913 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1948 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1914 }, 1949 },
1915 ); 1950 );
1916 1951
1917 my $time_watcher; # can only be used once
1918
1919 sub new_timer {
1920 $timer = AnyEvent->timer (after => 1, cb => sub { 1952 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1921 warn "timeout\n"; # print 'timeout' about every second 1953 warn "timeout\n"; # print 'timeout' at most every second
1922 &new_timer; # and restart the time
1923 }); 1954 });
1924 }
1925
1926 new_timer; # create first timer
1927 1955
1928 $cv->recv; # wait until user enters /^q/i 1956 $cv->recv; # wait until user enters /^q/i
1929 1957
1930=head1 REAL-WORLD EXAMPLE 1958=head1 REAL-WORLD EXAMPLE
1931 1959
2375As you can see, the AnyEvent + EV combination even beats the 2403As you can see, the AnyEvent + EV combination even beats the
2376hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2404hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2377backend easily beats IO::Lambda and POE. 2405backend easily beats IO::Lambda and POE.
2378 2406
2379And even the 100% non-blocking version written using the high-level (and 2407And even the 100% non-blocking version written using the high-level (and
2380slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2408slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2381large margin, even though it does all of DNS, tcp-connect and socket I/O 2409higher level ("unoptimised") abstractions by a large margin, even though
2382in a non-blocking way. 2410it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2383 2411
2384The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2412The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2385F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2413F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2386part of the IO::lambda distribution and were used without any changes. 2414part of the IO::Lambda distribution and were used without any changes.
2387 2415
2388 2416
2389=head1 SIGNALS 2417=head1 SIGNALS
2390 2418
2391AnyEvent currently installs handlers for these signals: 2419AnyEvent currently installs handlers for these signals:
2433it's built-in modules) are required to use it. 2461it's built-in modules) are required to use it.
2434 2462
2435That 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
2436modules if they are installed. 2464modules if they are installed.
2437 2465
2438This section epxlains which additional modules will be used, and how they 2466This section explains which additional modules will be used, and how they
2439affect AnyEvent's operetion. 2467affect AnyEvent's operation.
2440 2468
2441=over 4 2469=over 4
2442 2470
2443=item L<Async::Interrupt> 2471=item L<Async::Interrupt>
2444 2472
2449catch the signals) with some delay (default is 10 seconds, look for 2477catch the signals) with some delay (default is 10 seconds, look for
2450C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2478C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451 2479
2452If 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
2453catching, 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
2454will not be interrupted regularly, which is more efficient (And good for 2482will not be interrupted regularly, which is more efficient (and good for
2455battery life on laptops). 2483battery life on laptops).
2456 2484
2457This 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
2458that 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).
2459 2487
2480lot less memory), but otherwise doesn't affect guard operation much. It is 2508lot less memory), but otherwise doesn't affect guard operation much. It is
2481purely used for performance. 2509purely used for performance.
2482 2510
2483=item L<JSON> and L<JSON::XS> 2511=item L<JSON> and L<JSON::XS>
2484 2512
2485This module is required when you want to read or write JSON data via 2513One of these modules is required when you want to read or write JSON data
2486L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2514via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2487advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2515advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488 2516
2489In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is 2517In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490installed. 2518installed.
2491 2519
2509 2537
2510Most 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
2511because 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>
2512calls. Only L<EV> is fully fork-aware. 2540calls. Only L<EV> is fully fork-aware.
2513 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
2514If 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
2515watcher 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
2516something 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.
2517 2555
2518 2556
2519=head1 SECURITY CONSIDERATIONS 2557=head1 SECURITY CONSIDERATIONS
2520 2558
2521AnyEvent can be forced to load any event model via 2559AnyEvent can be forced to load any event model via

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines