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Revision 1.385 by root, Mon Sep 5 08:51:14 2011 UTC vs.
Revision 1.398 by root, Tue Mar 27 16:21:11 2012 UTC

415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's 415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416pure perl implementation). 416pure perl implementation).
417 417
418=head3 Safe/Unsafe Signals 418=head3 Safe/Unsafe Signals
419 419
420Perl signals can be either "safe" (synchronous to opcode handling) or 420Perl signals can be either "safe" (synchronous to opcode handling)
421"unsafe" (asynchronous) - the former might get delayed indefinitely, the 421or "unsafe" (asynchronous) - the former might delay signal delivery
422latter might corrupt your memory. 422indefinitely, the latter might corrupt your memory.
423 423
424AnyEvent signal handlers are, in addition, synchronous to the event loop, 424AnyEvent signal handlers are, in addition, synchronous to the event loop,
425i.e. they will not interrupt your running perl program but will only be 425i.e. they will not interrupt your running perl program but will only be
426called as part of the normal event handling (just like timer, I/O etc. 426called as part of the normal event handling (just like timer, I/O etc.
427callbacks, too). 427callbacks, too).
428 428
429=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
430 430
431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support
432callbacks to signals in a generic way, which is a pity, as you cannot 432attaching callbacks to signals in a generic way, which is a pity,
433do race-free signal handling in perl, requiring C libraries for 433as you cannot do race-free signal handling in perl, requiring
434this. AnyEvent will try to do its best, which means in some cases, 434C libraries for this. AnyEvent will try to do its best, which
435signals will be delayed. The maximum time a signal might be delayed is 435means in some cases, signals will be delayed. The maximum time
436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436a signal might be delayed is 10 seconds by default, but can
437variable can be changed only before the first signal watcher is created, 437be overriden via C<$ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY}> or
438and should be left alone otherwise. This variable determines how often 438C<$AnyEvent::MAX_SIGNAL_LATENCY> - see the L<ENVIRONMENT VARIABLES>
439AnyEvent polls for signals (in case a wake-up was missed). Higher values 439section for details.
440will cause fewer spurious wake-ups, which is better for power and CPU
441saving.
442 440
443All these problems can be avoided by installing the optional 441All these problems can be avoided by installing the optional
444L<Async::Interrupt> module, which works with most event loops. It will not 442L<Async::Interrupt> module, which works with most event loops. It will not
445work with inherently broken event loops such as L<Event> or L<Event::Lib> 443work with inherently broken event loops such as L<Event> or L<Event::Lib>
446(and not with L<POE> currently, as POE does its own workaround with 444(and not with L<POE> currently). For those, you just have to suffer the
447one-second latency). For those, you just have to suffer the delays. 445delays.
448 446
449=head2 CHILD PROCESS WATCHERS 447=head2 CHILD PROCESS WATCHERS
450 448
451 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 449 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
452 450
1225 1223
1226package AnyEvent; 1224package AnyEvent;
1227 1225
1228# basically a tuned-down version of common::sense 1226# basically a tuned-down version of common::sense
1229sub common_sense { 1227sub common_sense {
1230 # from common:.sense 3.4 1228 # from common:.sense 3.5
1229 local $^W;
1231 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00"; 1230 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1232 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl) 1231 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1233 $^H |= 0x00000600; 1232 $^H |= 0x00000600;
1234} 1233}
1235 1234
1236BEGIN { AnyEvent::common_sense } 1235BEGIN { AnyEvent::common_sense }
1237 1236
1238use Carp (); 1237use Carp ();
1239 1238
1240our $VERSION = '6.02'; 1239our $VERSION = '6.14';
1241our $MODEL; 1240our $MODEL;
1242our @ISA; 1241our @ISA;
1243our @REGISTRY; 1242our @REGISTRY;
1244our $VERBOSE; 1243our $VERBOSE;
1245our $MAX_SIGNAL_LATENCY = 10;
1246our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1244our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1245our $MAX_SIGNAL_LATENCY = $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} || 10; # executes after the BEGIN block below (tainting!)
1247 1246
1248BEGIN { 1247BEGIN {
1249 require "AnyEvent/constants.pl"; 1248 require "AnyEvent/constants.pl";
1250 1249
1251 eval "sub TAINT (){" . (${^TAINT}*1) . "}"; 1250 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1304} 1303}
1305 1304
1306sub log($$;@) { 1305sub log($$;@) {
1307 # only load the big bloated module when we actually are about to log something 1306 # only load the big bloated module when we actually are about to log something
1308 if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal 1307 if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
1308 local ($!, $@);
1309 require AnyEvent::Log; # among other things, sets $VERBOSE to 9 1309 require AnyEvent::Log; # among other things, sets $VERBOSE to 9
1310 # AnyEvent::Log overwrites this function 1310 # AnyEvent::Log overwrites this function
1311 goto &log; 1311 goto &log;
1312 } 1312 }
1313 1313
1314 0 # not logged 1314 0 # not logged
1315} 1315}
1316 1316
1317sub logger($;$) { 1317sub _logger($;$) {
1318 package AnyEvent::Log;
1319
1320 my ($level, $renabled) = @_; 1318 my ($level, $renabled) = @_;
1321 1319
1322 $$renabled = $level <= $VERBOSE; 1320 $$renabled = $level <= $VERBOSE;
1323 1321
1324 my $pkg = (caller)[0];
1325
1326 my $logger = [$pkg, $level, $renabled]; 1322 my $logger = [(caller)[0], $level, $renabled];
1327 1323
1328 our %LOGGER;
1329 $LOGGER{$logger+0} = $logger; 1324 $AnyEvent::Log::LOGGER{$logger+0} = $logger;
1330 1325
1326# return unless defined wantarray;
1327#
1331 require AnyEvent::Util; 1328# require AnyEvent::Util;
1332 my $guard = AnyEvent::Util::guard (sub { 1329# my $guard = AnyEvent::Util::guard (sub {
1333 # "clean up" 1330# # "clean up"
1334 delete $LOGGER{$logger+0}; 1331# delete $LOGGER{$logger+0};
1335 }); 1332# });
1336 1333#
1337 sub { 1334# sub {
1338 return 0 unless $$renabled; 1335# return 0 unless $$renabled;
1339 1336#
1340 $guard if 0; # keep guard alive, but don't cause runtime overhead 1337# $guard if 0; # keep guard alive, but don't cause runtime overhead
1341 require AnyEvent::Log unless $AnyEvent::Log::VERSION; 1338# require AnyEvent::Log unless $AnyEvent::Log::VERSION;
1342 package AnyEvent::Log; 1339# package AnyEvent::Log;
1343 _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time 1340# _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
1344 } 1341# }
1345} 1342}
1346 1343
1347if (length $ENV{PERL_ANYEVENT_LOG}) { 1344if (length $ENV{PERL_ANYEVENT_LOG}) {
1348 require AnyEvent::Log; # AnyEvent::Log does the thing for us 1345 require AnyEvent::Log; # AnyEvent::Log does the thing for us
1349} 1346}
1395our @methods = qw(io timer time now now_update signal child idle condvar); 1392our @methods = qw(io timer time now now_update signal child idle condvar);
1396 1393
1397sub detect() { 1394sub detect() {
1398 return $MODEL if $MODEL; # some programs keep references to detect 1395 return $MODEL if $MODEL; # some programs keep references to detect
1399 1396
1397 # IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1398 # the author knows about the problems and what it does to AnyEvent as a whole
1399 # (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
1400 # anyway.
1401 AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - that module is broken by\n"
1402 . "design, abuses internals and breaks AnyEvent - will not continue."
1403 if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1404
1400 local $!; # for good measure 1405 local $!; # for good measure
1401 local $SIG{__DIE__}; # we use eval 1406 local $SIG{__DIE__}; # we use eval
1402 1407
1403 # free some memory 1408 # free some memory
1404 *detect = sub () { $MODEL }; 1409 *detect = sub () { $MODEL };
1428 if (${"$package\::VERSION"} > 0) { 1433 if (${"$package\::VERSION"} > 0) {
1429 if (eval "require $model") { 1434 if (eval "require $model") {
1430 AnyEvent::log 7 => "autodetected model '$model', using it."; 1435 AnyEvent::log 7 => "autodetected model '$model', using it.";
1431 $MODEL = $model; 1436 $MODEL = $model;
1432 last; 1437 last;
1438 } else {
1439 AnyEvent::log 8 => "detected event loop $package, but cannot load '$model', skipping: $@";
1433 } 1440 }
1434 } 1441 }
1435 } 1442 }
1436 1443
1437 unless ($MODEL) { 1444 unless ($MODEL) {
2067 2074
2068=over 4 2075=over 4
2069 2076
2070=item C<PERL_ANYEVENT_VERBOSE> 2077=item C<PERL_ANYEVENT_VERBOSE>
2071 2078
2072By default, AnyEvent will only log messages with loglevel C<3> 2079By default, AnyEvent will log messages with loglevel C<4> (C<error>) or
2073(C<critical>) or higher (see L<AnyEvent::Log>). You can set this 2080higher (see L<AnyEvent::Log>). You can set this environment variable to a
2074environment variable to a numerical loglevel to make AnyEvent more (or 2081numerical loglevel to make AnyEvent more (or less) talkative.
2075less) talkative.
2076 2082
2077If you want to do more than just set the global logging level 2083If you want to do more than just set the global logging level
2078you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more 2084you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
2079complex specifications. 2085complex specifications.
2080 2086
2081When set to C<0> (C<off>), then no messages whatsoever will be logged with 2087When set to C<0> (C<off>), then no messages whatsoever will be logged with
2082the default logging settings. 2088everything else at defaults.
2083 2089
2084When set to C<5> or higher (C<warn>), causes AnyEvent to warn about 2090When set to C<5> or higher (C<warn>), AnyEvent warns about unexpected
2085unexpected conditions, such as not being able to load the event model 2091conditions, such as not being able to load the event model specified by
2086specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an 2092C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an exception - this
2087exception - this is the minimum recommended level. 2093is the minimum recommended level for use during development.
2088 2094
2089When set to C<7> or higher (info), cause AnyEvent to report which event model it 2095When set to C<7> or higher (info), AnyEvent reports which event model it
2090chooses. 2096chooses.
2091 2097
2092When set to C<8> or higher (debug), then AnyEvent will report extra information on 2098When set to C<8> or higher (debug), then AnyEvent will report extra
2093which optional modules it loads and how it implements certain features. 2099information on which optional modules it loads and how it implements
2100certain features.
2094 2101
2095=item C<PERL_ANYEVENT_LOG> 2102=item C<PERL_ANYEVENT_LOG>
2096 2103
2097Accepts rather complex logging specifications. For example, you could log 2104Accepts rather complex logging specifications. For example, you could log
2098all C<debug> messages of some module to stderr, warnings and above to 2105all C<debug> messages of some module to stderr, warnings and above to
2105This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded, 2112This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
2106so will take effect even before AnyEvent has initialised itself. 2113so will take effect even before AnyEvent has initialised itself.
2107 2114
2108Note that specifying this environment variable causes the L<AnyEvent::Log> 2115Note that specifying this environment variable causes the L<AnyEvent::Log>
2109module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only 2116module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
2110using the latter saves a few hundred kB of memory until the first message 2117using the latter saves a few hundred kB of memory unless a module
2111is being logged. 2118explicitly needs the extra features of AnyEvent::Log.
2112 2119
2113=item C<PERL_ANYEVENT_STRICT> 2120=item C<PERL_ANYEVENT_STRICT>
2114 2121
2115AnyEvent does not do much argument checking by default, as thorough 2122AnyEvent does not do much argument checking by default, as thorough
2116argument checking is very costly. Setting this variable to a true value 2123argument checking is very costly. Setting this variable to a true value
2218=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> 2225=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
2219 2226
2220The default value for the C<max_outstanding> parameter for the default DNS 2227The default value for the C<max_outstanding> parameter for the default DNS
2221resolver - this is the maximum number of parallel DNS requests that are 2228resolver - this is the maximum number of parallel DNS requests that are
2222sent to the DNS server. 2229sent to the DNS server.
2230
2231=item C<PERL_ANYEVENT_MAX_SIGNAL_LATENCY>
2232
2233Perl has inherently racy signal handling (you can basically choose between
2234losing signals and memory corruption) - pure perl event loops (including
2235C<AnyEvent::Loop>, when C<Async::Interrupt> isn't available) therefore
2236have to poll regularly to avoid losing signals.
2237
2238Some event loops are racy, but don't poll regularly, and some event loops
2239are written in C but are still racy. For those event loops, AnyEvent
2240installs a timer that regularly wakes up the event loop.
2241
2242By default, the interval for this timer is C<10> seconds, but you can
2243override this delay with this environment variable (or by setting
2244the C<$AnyEvent::MAX_SIGNAL_LATENCY> variable before creating signal
2245watchers).
2246
2247Lower values increase CPU (and energy) usage, higher values can introduce
2248long delays when reaping children or waiting for signals.
2249
2250The L<AnyEvent::Async> module, if available, will be used to avoid this
2251polling (with most event loops).
2223 2252
2224=item C<PERL_ANYEVENT_RESOLV_CONF> 2253=item C<PERL_ANYEVENT_RESOLV_CONF>
2225 2254
2226The absolute path to a F<resolv.conf>-style file to use instead of 2255The absolute path to a F<resolv.conf>-style file to use instead of
2227F</etc/resolv.conf> (or the OS-specific configuration) in the default 2256F</etc/resolv.conf> (or the OS-specific configuration) in the default

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