[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.296 by root, Tue Nov 17 01:19:49 2009 UTC vs.
Revision 1.328 by root, Tue Jun 8 10:06:15 2010 UTC

…		…
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
…		…
402	correctly.	405	correctly.
403		406
404	Example: exit on SIGINT	407	Example: exit on SIGINT
405		408
406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	409	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		410
		411	=head3 Restart Behaviour
		412
		413	While restart behaviour is up to the event loop implementation, most will
		414	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		415	pure perl implementation).
		416
		417	=head3 Safe/Unsafe Signals
		418
		419	Perl signals can be either "safe" (synchronous to opcode handling) or
		420	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		421	latter might corrupt your memory.
		422
		423	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		424	i.e. they will not interrupt your running perl program but will only be
		425	called as part of the normal event handling (just like timer, I/O etc.
		426	callbacks, too).
407		427
408	=head3 Signal Races, Delays and Workarounds	428	=head3 Signal Races, Delays and Workarounds
409		429
410	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
411	callbacks to signals in a generic way, which is a pity, as you cannot	431	callbacks to signals in a generic way, which is a pity, as you cannot
…		…
486		506
487	=head2 IDLE WATCHERS	507	=head2 IDLE WATCHERS
488		508
489	$w = AnyEvent->idle (cb => <callback>);	509	$w = AnyEvent->idle (cb => <callback>);
490		510
491	Sometimes there is a need to do something, but it is not so important	511	Repeatedly invoke the callback after the process becomes idle, until
492	to do it instantly, but only when there is nothing better to do. This	512	either the watcher is destroyed or new events have been detected.
493	"nothing better to do" is usually defined to be "no other events need
494	attention by the event loop".
495		513
496	Idle watchers ideally get invoked when the event loop has nothing	514	Idle watchers are useful when there is a need to do something, but it
497	better to do, just before it would block the process to wait for new	515	is not so important (or wise) to do it instantly. The callback will be
498	events. Instead of blocking, the idle watcher is invoked.	516	invoked only when there is "nothing better to do", which is usually
		517	defined as "all outstanding events have been handled and no new events
		518	have been detected". That means that idle watchers ideally get invoked
		519	when the event loop has just polled for new events but none have been
		520	detected. Instead of blocking to wait for more events, the idle watchers
		521	will be invoked.
499		522
500	Most event loops unfortunately do not really support idle watchers (only	523	Unfortunately, most event loops do not really support idle watchers (only
501	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	524	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
502	will simply call the callback "from time to time".	525	will simply call the callback "from time to time".
503		526
504	Example: read lines from STDIN, but only process them when the	527	Example: read lines from STDIN, but only process them when the
505	program is otherwise idle:	528	program is otherwise idle:
…		…
533	will actively watch for new events and call your callbacks.	556	will actively watch for new events and call your callbacks.
534		557
535	AnyEvent is slightly different: it expects somebody else to run the event	558	AnyEvent is slightly different: it expects somebody else to run the event
536	loop and will only block when necessary (usually when told by the user).	559	loop and will only block when necessary (usually when told by the user).
537		560
538	The instrument to do that is called a "condition variable", so called	561	The tool to do that is called a "condition variable", so called because
539	because they represent a condition that must become true.	562	they represent a condition that must become true.
540		563
541	Now is probably a good time to look at the examples further below.	564	Now is probably a good time to look at the examples further below.
542		565
543	Condition variables can be created by calling the C<< AnyEvent->condvar	566	Condition variables can be created by calling the C<< AnyEvent->condvar
544	>> method, usually without arguments. The only argument pair allowed is	567	>> method, usually without arguments. The only argument pair allowed is
…		…
549	After creation, the condition variable is "false" until it becomes "true"	572	After creation, the condition variable is "false" until it becomes "true"
550	by calling the C<send> method (or calling the condition variable as if it	573	by calling the C<send> method (or calling the condition variable as if it
551	were a callback, read about the caveats in the description for the C<<	574	were a callback, read about the caveats in the description for the C<<
552	->send >> method).	575	->send >> method).
553		576
554	Condition variables are similar to callbacks, except that you can	577	Since condition variables are the most complex part of the AnyEvent API, here are
555	optionally wait for them. They can also be called merge points - points	578	some different mental models of what they are - pick the ones you can connect to:
556	in time where multiple outstanding events have been processed. And yet	579
557	another way to call them is transactions - each condition variable can be	580	=over 4
558	used to represent a transaction, which finishes at some point and delivers	581
559	a result. And yet some people know them as "futures" - a promise to	582	=item * Condition variables are like callbacks - you can call them (and pass them instead
560	compute/deliver something that you can wait for.	583	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		584
		585	=item * Condition variables are signals - one side can emit or send them,
		586	the other side can wait for them, or install a handler that is called when
		587	the signal fires.
		588
		589	=item * Condition variables are like "Merge Points" - points in your program
		590	where you merge multiple independent results/control flows into one.
		591
		592	=item * Condition variables represent a transaction - function that start
		593	some kind of transaction can return them, leaving the caller the choice
		594	between waiting in a blocking fashion, or setting a callback.
		595
		596	=item * Condition variables represent future values, or promises to deliver
		597	some result, long before the result is available.
		598
		599	=back
561		600
562	Condition variables are very useful to signal that something has finished,	601	Condition variables are very useful to signal that something has finished,
563	for example, if you write a module that does asynchronous http requests,	602	for example, if you write a module that does asynchronous http requests,
564	then a condition variable would be the ideal candidate to signal the	603	then a condition variable would be the ideal candidate to signal the
565	availability of results. The user can either act when the callback is	604	availability of results. The user can either act when the callback is
…		…
586	eventually calls C<< -> send >>, and the "consumer side", which waits	625	eventually calls C<< -> send >>, and the "consumer side", which waits
587	for the send to occur.	626	for the send to occur.
588		627
589	Example: wait for a timer.	628	Example: wait for a timer.
590		629
591	# wait till the result is ready	630	# condition: "wait till the timer is fired"
592	my $result_ready = AnyEvent->condvar;	631	my $timer_fired = AnyEvent->condvar;
593		632
594	# do something such as adding a timer	633	# create the timer - we could wait for, say
595	# or socket watcher the calls $result_ready->send	634	# a handle becomign ready, or even an
596	# when the "result" is ready.	635	# AnyEvent::HTTP request to finish, but
597	# in this case, we simply use a timer:	636	# in this case, we simply use a timer:
598	my $w = AnyEvent->timer (	637	my $w = AnyEvent->timer (
599	after => 1,	638	after => 1,
600	cb => sub { $result_ready->send },	639	cb => sub { $timer_fired->send },
601	);	640	);
602		641
603	# this "blocks" (while handling events) till the callback	642	# this "blocks" (while handling events) till the callback
604	# calls ->send	643	# calls ->send
605	$result_ready->recv;	644	$timer_fired->recv;
606		645
607	Example: wait for a timer, but take advantage of the fact that condition	646	Example: wait for a timer, but take advantage of the fact that condition
608	variables are also callable directly.	647	variables are also callable directly.
609		648
610	my $done = AnyEvent->condvar;	649	my $done = AnyEvent->condvar;
…		…
949	You should check C<$AnyEvent::MODEL> before adding to this array, though:	988	You should check C<$AnyEvent::MODEL> before adding to this array, though:
950	if it is defined then the event loop has already been detected, and the	989	if it is defined then the event loop has already been detected, and the
951	array will be ignored.	990	array will be ignored.
952		991
953	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	992	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
954	it,as it takes care of these details.	993	it, as it takes care of these details.
955		994
956	This variable is mainly useful for modules that can do something useful	995	This variable is mainly useful for modules that can do something useful
957	when AnyEvent is used and thus want to know when it is initialised, but do	996	when AnyEvent is used and thus want to know when it is initialised, but do
958	not need to even load it by default. This array provides the means to hook	997	not need to even load it by default. This array provides the means to hook
959	into AnyEvent passively, without loading it.	998	into AnyEvent passively, without loading it.
		999
		1000	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1001	together, you could put this into Coro (this is the actual code used by
		1002	Coro to accomplish this):
		1003
		1004	if (defined $AnyEvent::MODEL) {
		1005	# AnyEvent already initialised, so load Coro::AnyEvent
		1006	require Coro::AnyEvent;
		1007	} else {
		1008	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1009	# as soon as it is
		1010	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1011	}
960		1012
961	=back	1013	=back
962		1014
963	=head1 WHAT TO DO IN A MODULE	1015	=head1 WHAT TO DO IN A MODULE
964		1016
…		…
1021	=head1 OTHER MODULES	1073	=head1 OTHER MODULES
1022		1074
1023	The following is a non-exhaustive list of additional modules that use	1075	The following is a non-exhaustive list of additional modules that use
1024	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1076	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1025	modules and other event loops in the same program. Some of the modules	1077	modules and other event loops in the same program. Some of the modules
1026	come with AnyEvent, most are available via CPAN.	1078	come as part of AnyEvent, the others are available via CPAN.
1027		1079
1028	=over 4	1080	=over 4
1029		1081
1030	=item L<AnyEvent::Util>	1082	=item L<AnyEvent::Util>
1031		1083
…		…
1046		1098
1047	=item L<AnyEvent::DNS>	1099	=item L<AnyEvent::DNS>
1048		1100
1049	Provides rich asynchronous DNS resolver capabilities.	1101	Provides rich asynchronous DNS resolver capabilities.
1050		1102
		1103	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1104
		1105	Implement event-based interfaces to the protocols of the same name (for
		1106	the curious, IGS is the International Go Server and FCP is the Freenet
		1107	Client Protocol).
		1108
		1109	=item L<AnyEvent::Handle::UDP>
		1110
		1111	Here be danger!
		1112
		1113	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1114	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1115	it's use of a stream-based API with a protocol that isn't streamable, that
		1116	the only way to improve it is to delete it.
		1117
		1118	It features data corruption (but typically only under load) and general
		1119	confusion. On top, the author is not only clueless about UDP but also
		1120	fact-resistant - some gems of his understanding: "connect doesn't work
		1121	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1122	packets", "I don't need to implement proper error checking as UDP doesn't
		1123	support error checking" and so on - he doesn't even understand what's
		1124	wrong with his module when it is explained to him.
		1125
1051	=item L<AnyEvent::HTTP>	1126	=item L<AnyEvent::DBI>
1052		1127
1053	A simple-to-use HTTP library that is capable of making a lot of concurrent	1128	Executes L<DBI> requests asynchronously in a proxy process for you,
1054	HTTP requests.	1129	notifying you in an event-bnased way when the operation is finished.
		1130
		1131	=item L<AnyEvent::AIO>
		1132
		1133	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1134	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1135	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1136	file I/O, and much more.
1055		1137
1056	=item L<AnyEvent::HTTPD>	1138	=item L<AnyEvent::HTTPD>
1057		1139
1058	Provides a simple web application server framework.	1140	A simple embedded webserver.
1059		1141
1060	=item L<AnyEvent::FastPing>	1142	=item L<AnyEvent::FastPing>
1061		1143
1062	The fastest ping in the west.	1144	The fastest ping in the west.
1063
1064	=item L<AnyEvent::DBI>
1065
1066	Executes L<DBI> requests asynchronously in a proxy process.
1067
1068	=item L<AnyEvent::AIO>
1069
1070	Truly asynchronous I/O, should be in the toolbox of every event
1071	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1072	together.
1073
1074	=item L<AnyEvent::BDB>
1075
1076	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1077	L<BDB> and AnyEvent together.
1078
1079	=item L<AnyEvent::GPSD>
1080
1081	A non-blocking interface to gpsd, a daemon delivering GPS information.
1082
1083	=item L<AnyEvent::IRC>
1084
1085	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1086
1087	=item L<AnyEvent::XMPP>
1088
1089	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1090	Net::XMPP2>.
1091
1092	=item L<AnyEvent::IGS>
1093
1094	A non-blocking interface to the Internet Go Server protocol (used by
1095	L<App::IGS>).
1096
1097	=item L<Net::FCP>
1098
1099	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1100	of AnyEvent.
1101
1102	=item L<Event::ExecFlow>
1103
1104	High level API for event-based execution flow control.
1105		1145
1106	=item L<Coro>	1146	=item L<Coro>
1107		1147
1108	Has special support for AnyEvent via L<Coro::AnyEvent>.	1148	Has special support for AnyEvent via L<Coro::AnyEvent>.
1109		1149
…		…
1114	package AnyEvent;	1154	package AnyEvent;
1115		1155
1116	# basically a tuned-down version of common::sense	1156	# basically a tuned-down version of common::sense
1117	sub common_sense {	1157	sub common_sense {
1118	# from common:.sense 1.0	1158	# from common:.sense 1.0
1119	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";	1159	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1120	# use strict vars subs	1160	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1121	$^H \|= 0x00000600;	1161	$^H \|= 0x00000600;
1122	}	1162	}
1123		1163
1124	BEGIN { AnyEvent::common_sense }	1164	BEGIN { AnyEvent::common_sense }
1125		1165
1126	use Carp ();	1166	use Carp ();
1127		1167
1128	our $VERSION = '5.202';	1168	our $VERSION = '5.271';
1129	our $MODEL;	1169	our $MODEL;
1130		1170
1131	our $AUTOLOAD;	1171	our $AUTOLOAD;
1132	our @ISA;	1172	our @ISA;
1133		1173
1134	our @REGISTRY;	1174	our @REGISTRY;
1135		1175
1136	our $WIN32;
1137
1138	our $VERBOSE;	1176	our $VERBOSE;
1139		1177
1140	BEGIN {	1178	BEGIN {
1141	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1179	require "AnyEvent/constants.pl";
		1180
1142	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1181	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1143		1182
1144	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1183	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1145	if ${^TAINT};	1184	if ${^TAINT};
1146		1185
1147	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1186	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1190	our @post_detect;	1229	our @post_detect;
1191		1230
1192	sub post_detect(&) {	1231	sub post_detect(&) {
1193	my ($cb) = @_;	1232	my ($cb) = @_;
1194		1233
1195	if ($MODEL) {
1196	$cb->();
1197
1198	undef
1199	} else {
1200	push @post_detect, $cb;	1234	push @post_detect, $cb;
1201		1235
1202	defined wantarray	1236	defined wantarray
1203	? bless \$cb, "AnyEvent::Util::postdetect"	1237	? bless \$cb, "AnyEvent::Util::postdetect"
1204	: ()	1238	: ()
1205	}
1206	}	1239	}
1207		1240
1208	sub AnyEvent::Util::postdetect::DESTROY {	1241	sub AnyEvent::Util::postdetect::DESTROY {
1209	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1242	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1210	}	1243	}
1211		1244
1212	sub detect() {	1245	sub detect() {
		1246	# free some memory
		1247	*detect = sub () { $MODEL };
		1248
		1249	local $!; # for good measure
		1250	local $SIG{__DIE__};
		1251
		1252	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1253	my $model = "AnyEvent::Impl::$1";
		1254	if (eval "require $model") {
		1255	$MODEL = $model;
		1256	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1257	} else {
		1258	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1259	}
		1260	}
		1261
		1262	# check for already loaded models
1213	unless ($MODEL) {	1263	unless ($MODEL) {
1214	local $SIG{__DIE__};	1264	for (@REGISTRY, @models) {
1215		1265	my ($package, $model) = @$_;
1216	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1266	if (${"$package\::VERSION"} > 0) {
1217	my $model = "AnyEvent::Impl::$1";
1218	if (eval "require $model") {	1267	if (eval "require $model") {
1219	$MODEL = $model;	1268	$MODEL = $model;
1220	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1269	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1221	} else {	1270	last;
1222	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1271	}
1223	}	1272	}
1224	}	1273	}
1225		1274
1226	# check for already loaded models
1227	unless ($MODEL) {	1275	unless ($MODEL) {
		1276	# try to autoload a model
1228	for (@REGISTRY, @models) {	1277	for (@REGISTRY, @models) {
1229	my ($package, $model) = @$_;	1278	my ($package, $model, $autoload) = @$_;
		1279	if (
		1280	$autoload
		1281	and eval "require $package"
1230	if (${"$package\::VERSION"} > 0) {	1282	and ${"$package\::VERSION"} > 0
1231	if (eval "require $model") {	1283	and eval "require $model"
		1284	) {
1232	$MODEL = $model;	1285	$MODEL = $model;
1233	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1286	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1234	last;	1287	last;
1235	}
1236	}	1288	}
1237	}	1289	}
1238		1290
1239	unless ($MODEL) {
1240	# try to autoload a model
1241	for (@REGISTRY, @models) {
1242	my ($package, $model, $autoload) = @$_;
1243	if (
1244	$autoload
1245	and eval "require $package"
1246	and ${"$package\::VERSION"} > 0
1247	and eval "require $model"
1248	) {
1249	$MODEL = $model;
1250	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1251	last;
1252	}
1253	}
1254
1255	$MODEL	1291	$MODEL
1256	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1292	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1257	}
1258	}	1293	}
1259
1260	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1261
1262	unshift @ISA, $MODEL;
1263
1264	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1265
1266	(shift @post_detect)->() while @post_detect;
1267	}	1294	}
		1295
		1296	@models = (); # free probe data
		1297
		1298	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1299	unshift @ISA, $MODEL;
		1300
		1301	# now nuke some methods that are overriden by the backend.
		1302	# SUPER is not allowed.
		1303	for (qw(time signal child idle)) {
		1304	undef &{"AnyEvent::Base::$_"}
		1305	if defined &{"$MODEL\::$_"};
		1306	}
		1307
		1308	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
		1309
		1310	(shift @post_detect)->() while @post_detect;
		1311
		1312	*post_detect = sub(&) {
		1313	shift->();
		1314
		1315	undef
		1316	};
1268		1317
1269	$MODEL	1318	$MODEL
1270	}	1319	}
1271		1320
1272	sub AUTOLOAD {	1321	sub AUTOLOAD {
1273	(my $func = $AUTOLOAD) =~ s/.*://;	1322	(my $func = $AUTOLOAD) =~ s/.*://;
1274		1323
1275	$method{$func}	1324	$method{$func}
1276	or Carp::croak "$func: not a valid method for AnyEvent objects";	1325	or Carp::croak "$func: not a valid AnyEvent class method";
1277		1326
1278	detect unless $MODEL;	1327	detect;
1279		1328
1280	my $class = shift;	1329	my $class = shift;
1281	$class->$func (@_);	1330	$class->$func (@_);
1282	}	1331	}
1283		1332
…		…
1300		1349
1301	=head1 SIMPLIFIED AE API	1350	=head1 SIMPLIFIED AE API
1302		1351
1303	Starting with version 5.0, AnyEvent officially supports a second, much	1352	Starting with version 5.0, AnyEvent officially supports a second, much
1304	simpler, API that is designed to reduce the calling, typing and memory	1353	simpler, API that is designed to reduce the calling, typing and memory
1305	overhead.	1354	overhead by using function call syntax and a fixed number of parameters.
1306		1355
1307	See the L<AE> manpage for details.	1356	See the L<AE> manpage for details.
1308		1357
1309	=cut	1358	=cut
1310		1359
1311	package AE;	1360	package AE;
1312		1361
1313	our $VERSION = $AnyEvent::VERSION;	1362	our $VERSION = $AnyEvent::VERSION;
		1363
		1364	# fall back to the main API by default - backends and AnyEvent::Base
		1365	# implementations can overwrite these.
1314		1366
1315	sub io($$$) {	1367	sub io($$$) {
1316	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1368	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317	}	1369	}
1318		1370
…		…
1350		1402
1351	package AnyEvent::Base;	1403	package AnyEvent::Base;
1352		1404
1353	# default implementations for many methods	1405	# default implementations for many methods
1354		1406
1355	sub _time() {	1407	sub time {
		1408	eval q{ # poor man's autoloading {}
1356	# probe for availability of Time::HiRes	1409	# probe for availability of Time::HiRes
1357	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1410	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1411	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1359	*_time = \&Time::HiRes::time;	1412	*AE::time = \&Time::HiRes::time;
1360	# if (eval "use POSIX (); (POSIX::times())...	1413	# if (eval "use POSIX (); (POSIX::times())...
1361	} else {	1414	} else {
1362	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1415	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1363	*_time = sub { time }; # epic fail	1416	*AE::time = sub (){ time }; # epic fail
		1417	}
		1418
		1419	*time = sub { AE::time }; # different prototypes
1364	}	1420	};
		1421	die if $@;
1365		1422
1366	&_time	1423	&time
1367	}	1424	}
1368		1425
1369	sub time { _time }	1426	*now = \&time;
1370	sub now { _time }	1427
1371	sub now_update { }	1428	sub now_update { }
1372		1429
1373	# default implementation for ->condvar	1430	# default implementation for ->condvar
1374		1431
1375	sub condvar {	1432	sub condvar {
		1433	eval q{ # poor man's autoloading {}
		1434	*condvar = sub {
1376	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1435	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1436	};
		1437
		1438	*AE::cv = sub (;&) {
		1439	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1440	};
		1441	};
		1442	die if $@;
		1443
		1444	&condvar
1377	}	1445	}
1378		1446
1379	# default implementation for ->signal	1447	# default implementation for ->signal
1380		1448
1381	our $HAVE_ASYNC_INTERRUPT;	1449	our $HAVE_ASYNC_INTERRUPT;
…		…
1390		1458
1391	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1459	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392	our (%SIG_ASY, %SIG_ASY_W);	1460	our (%SIG_ASY, %SIG_ASY_W);
1393	our ($SIG_COUNT, $SIG_TW);	1461	our ($SIG_COUNT, $SIG_TW);
1394		1462
1395	sub _signal_exec {
1396	$HAVE_ASYNC_INTERRUPT
1397	? $SIGPIPE_R->drain
1398	: sysread $SIGPIPE_R, (my $dummy), 9;
1399
1400	while (%SIG_EV) {
1401	for (keys %SIG_EV) {
1402	delete $SIG_EV{$_};
1403	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1404	}
1405	}
1406	}
1407
1408	# install a dummy wakeup watcher to reduce signal catching latency	1463	# install a dummy wakeup watcher to reduce signal catching latency
		1464	# used by Impls
1409	sub _sig_add() {	1465	sub _sig_add() {
1410	unless ($SIG_COUNT++) {	1466	unless ($SIG_COUNT++) {
1411	# try to align timer on a full-second boundary, if possible	1467	# try to align timer on a full-second boundary, if possible
1412	my $NOW = AE::now;	1468	my $NOW = AE::now;
1413		1469
…		…
1423	undef $SIG_TW	1479	undef $SIG_TW
1424	unless --$SIG_COUNT;	1480	unless --$SIG_COUNT;
1425	}	1481	}
1426		1482
1427	our $_sig_name_init; $_sig_name_init = sub {	1483	our $_sig_name_init; $_sig_name_init = sub {
1428	eval q{ # poor man's autoloading	1484	eval q{ # poor man's autoloading {}
1429	undef $_sig_name_init;	1485	undef $_sig_name_init;
1430		1486
1431	if (_have_async_interrupt) {	1487	if (_have_async_interrupt) {
1432	*sig2num = \&Async::Interrupt::sig2num;	1488	*sig2num = \&Async::Interrupt::sig2num;
1433	*sig2name = \&Async::Interrupt::sig2name;	1489	*sig2name = \&Async::Interrupt::sig2name;
…		…
1465	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1521	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1466		1522
1467	} else {	1523	} else {
1468	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1524	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1469		1525
1470	require Fcntl;
1471
1472	if (AnyEvent::WIN32) {	1526	if (AnyEvent::WIN32) {
1473	require AnyEvent::Util;	1527	require AnyEvent::Util;
1474		1528
1475	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1529	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1530	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1531	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478	} else {	1532	} else {
1479	pipe $SIGPIPE_R, $SIGPIPE_W;	1533	pipe $SIGPIPE_R, $SIGPIPE_W;
1480	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1534	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1481	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1535	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1482		1536
1483	# not strictly required, as $^F is normally 2, but let's make sure...	1537	# not strictly required, as $^F is normally 2, but let's make sure...
1484	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1538	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1485	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1539	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1486	}	1540	}
1487		1541
1488	$SIGPIPE_R	1542	$SIGPIPE_R
1489	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1543	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490		1544
1491	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1545	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1492	}	1546	}
1493		1547
1494	*signal = sub {	1548	*signal = $HAVE_ASYNC_INTERRUPT
		1549	? sub {
1495	my (undef, %arg) = @_;	1550	my (undef, %arg) = @_;
1496		1551
1497	my $signal = uc $arg{signal}
1498	or Carp::croak "required option 'signal' is missing";
1499
1500	if ($HAVE_ASYNC_INTERRUPT) {
1501	# async::interrupt	1552	# async::interrupt
1502
1503	$signal = sig2num $signal;	1553	my $signal = sig2num $arg{signal};
1504	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1554	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505		1555
1506	$SIG_ASY{$signal} \|\|= new Async::Interrupt	1556	$SIG_ASY{$signal} \|\|= new Async::Interrupt
1507	cb => sub { undef $SIG_EV{$signal} },	1557	cb => sub { undef $SIG_EV{$signal} },
1508	signal => $signal,	1558	signal => $signal,
1509	pipe => [$SIGPIPE_R->filenos],	1559	pipe => [$SIGPIPE_R->filenos],
1510	pipe_autodrain => 0,	1560	pipe_autodrain => 0,
1511	;	1561	;
1512		1562
1513	} else {	1563	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1564	}
		1565	: sub {
		1566	my (undef, %arg) = @_;
		1567
1514	# pure perl	1568	# pure perl
1515
1516	# AE::Util has been loaded in signal
1517	$signal = sig2name $signal;	1569	my $signal = sig2name $arg{signal};
1518	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1570	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519		1571
1520	$SIG{$signal} \|\|= sub {	1572	$SIG{$signal} \|\|= sub {
1521	local $!;	1573	local $!;
1522	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1574	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1523	undef $SIG_EV{$signal};	1575	undef $SIG_EV{$signal};
1524	};	1576	};
1525		1577
1526	# can't do signal processing without introducing races in pure perl,	1578	# can't do signal processing without introducing races in pure perl,
1527	# so limit the signal latency.	1579	# so limit the signal latency.
1528	_sig_add;	1580	_sig_add;
1529	}
1530		1581
1531	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1582	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1583	}
1532	};	1584	;
1533		1585
1534	*AnyEvent::Base::signal::DESTROY = sub {	1586	*AnyEvent::Base::signal::DESTROY = sub {
1535	my ($signal, $cb) = @{$_[0]};	1587	my ($signal, $cb) = @{$_[0]};
1536		1588
1537	_sig_del;	1589	_sig_del;
…		…
1544	# print weird messages, or just unconditionally exit	1596	# print weird messages, or just unconditionally exit
1545	# instead of getting the default action.	1597	# instead of getting the default action.
1546	undef $SIG{$signal}	1598	undef $SIG{$signal}
1547	unless keys %{ $SIG_CB{$signal} };	1599	unless keys %{ $SIG_CB{$signal} };
1548	};	1600	};
		1601
		1602	*_signal_exec = sub {
		1603	$HAVE_ASYNC_INTERRUPT
		1604	? $SIGPIPE_R->drain
		1605	: sysread $SIGPIPE_R, (my $dummy), 9;
		1606
		1607	while (%SIG_EV) {
		1608	for (keys %SIG_EV) {
		1609	delete $SIG_EV{$_};
		1610	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1611	}
		1612	}
		1613	};
1549	};	1614	};
1550	die if $@;	1615	die if $@;
		1616
1551	&signal	1617	&signal
1552	}	1618	}
1553		1619
1554	# default implementation for ->child	1620	# default implementation for ->child
1555		1621
1556	our %PID_CB;	1622	our %PID_CB;
1557	our $CHLD_W;	1623	our $CHLD_W;
1558	our $CHLD_DELAY_W;	1624	our $CHLD_DELAY_W;
1559	our $WNOHANG;	1625	our $WNOHANG;
1560		1626
		1627	# used by many Impl's
1561	sub _emit_childstatus($$) {	1628	sub _emit_childstatus($$) {
1562	my (undef, $rpid, $rstatus) = @_;	1629	my (undef, $rpid, $rstatus) = @_;
1563		1630
1564	$_->($rpid, $rstatus)	1631	$_->($rpid, $rstatus)
1565	for values %{ $PID_CB{$rpid} \|\| {} },	1632	for values %{ $PID_CB{$rpid} \|\| {} },
1566	values %{ $PID_CB{0} \|\| {} };	1633	values %{ $PID_CB{0} \|\| {} };
1567	}	1634	}
1568		1635
1569	sub _sigchld {
1570	my $pid;
1571
1572	AnyEvent->_emit_childstatus ($pid, $?)
1573	while ($pid = waitpid -1, $WNOHANG) > 0;
1574	}
1575
1576	sub child {	1636	sub child {
		1637	eval q{ # poor man's autoloading {}
		1638	*_sigchld = sub {
		1639	my $pid;
		1640
		1641	AnyEvent->_emit_childstatus ($pid, $?)
		1642	while ($pid = waitpid -1, $WNOHANG) > 0;
		1643	};
		1644
		1645	*child = sub {
1577	my (undef, %arg) = @_;	1646	my (undef, %arg) = @_;
1578		1647
1579	defined (my $pid = $arg{pid} + 0)	1648	defined (my $pid = $arg{pid} + 0)
1580	or Carp::croak "required option 'pid' is missing";	1649	or Carp::croak "required option 'pid' is missing";
1581		1650
1582	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1651	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1583		1652
1584	# WNOHANG is almost cetrainly 1 everywhere	1653	# WNOHANG is almost cetrainly 1 everywhere
1585	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/	1654	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
1586	? 1	1655	? 1
1587	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1656	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1588		1657
1589	unless ($CHLD_W) {	1658	unless ($CHLD_W) {
1590	$CHLD_W = AE::signal CHLD => \&_sigchld;	1659	$CHLD_W = AE::signal CHLD => \&_sigchld;
1591	# child could be a zombie already, so make at least one round	1660	# child could be a zombie already, so make at least one round
1592	&_sigchld;	1661	&_sigchld;
1593	}	1662	}
1594		1663
1595	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1664	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1596	}	1665	};
1597		1666
1598	sub AnyEvent::Base::child::DESTROY {	1667	*AnyEvent::Base::child::DESTROY = sub {
1599	my ($pid, $cb) = @{$_[0]};	1668	my ($pid, $cb) = @{$_[0]};
1600		1669
1601	delete $PID_CB{$pid}{$cb};	1670	delete $PID_CB{$pid}{$cb};
1602	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1671	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1603		1672
1604	undef $CHLD_W unless keys %PID_CB;	1673	undef $CHLD_W unless keys %PID_CB;
		1674	};
		1675	};
		1676	die if $@;
		1677
		1678	&child
1605	}	1679	}
1606		1680
1607	# idle emulation is done by simply using a timer, regardless	1681	# idle emulation is done by simply using a timer, regardless
1608	# of whether the process is idle or not, and not letting	1682	# of whether the process is idle or not, and not letting
1609	# the callback use more than 50% of the time.	1683	# the callback use more than 50% of the time.
1610	sub idle {	1684	sub idle {
		1685	eval q{ # poor man's autoloading {}
		1686	*idle = sub {
1611	my (undef, %arg) = @_;	1687	my (undef, %arg) = @_;
1612		1688
1613	my ($cb, $w, $rcb) = $arg{cb};	1689	my ($cb, $w, $rcb) = $arg{cb};
1614		1690
1615	$rcb = sub {	1691	$rcb = sub {
1616	if ($cb) {	1692	if ($cb) {
1617	$w = _time;	1693	$w = _time;
1618	&$cb;	1694	&$cb;
1619	$w = _time - $w;	1695	$w = _time - $w;
1620		1696
1621	# never use more then 50% of the time for the idle watcher,	1697	# never use more then 50% of the time for the idle watcher,
1622	# within some limits	1698	# within some limits
1623	$w = 0.0001 if $w < 0.0001;	1699	$w = 0.0001 if $w < 0.0001;
1624	$w = 5 if $w > 5;	1700	$w = 5 if $w > 5;
1625		1701
1626	$w = AE::timer $w, 0, $rcb;	1702	$w = AE::timer $w, 0, $rcb;
1627	} else {	1703	} else {
1628	# clean up...	1704	# clean up...
1629	undef $w;	1705	undef $w;
1630	undef $rcb;	1706	undef $rcb;
		1707	}
		1708	};
		1709
		1710	$w = AE::timer 0.05, 0, $rcb;
		1711
		1712	bless \\$cb, "AnyEvent::Base::idle"
1631	}	1713	};
		1714
		1715	*AnyEvent::Base::idle::DESTROY = sub {
		1716	undef $${$_[0]};
		1717	};
1632	};	1718	};
		1719	die if $@;
1633		1720
1634	$w = AE::timer 0.05, 0, $rcb;	1721	&idle
1635
1636	bless \\$cb, "AnyEvent::Base::idle"
1637	}
1638
1639	sub AnyEvent::Base::idle::DESTROY {
1640	undef $${$_[0]};
1641	}	1722	}
1642		1723
1643	package AnyEvent::CondVar;	1724	package AnyEvent::CondVar;
1644		1725
1645	our @ISA = AnyEvent::CondVar::Base::;	1726	our @ISA = AnyEvent::CondVar::Base::;
…		…
2004		2085
2005	The actual code goes further and collects all errors (C<die>s, exceptions)	2086	The actual code goes further and collects all errors (C<die>s, exceptions)
2006	that occurred during request processing. The C<result> method detects	2087	that occurred during request processing. The C<result> method detects
2007	whether an exception as thrown (it is stored inside the $txn object)	2088	whether an exception as thrown (it is stored inside the $txn object)
2008	and just throws the exception, which means connection errors and other	2089	and just throws the exception, which means connection errors and other
2009	problems get reported tot he code that tries to use the result, not in a	2090	problems get reported to the code that tries to use the result, not in a
2010	random callback.	2091	random callback.
2011		2092
2012	All of this enables the following usage styles:	2093	All of this enables the following usage styles:
2013		2094
2014	1. Blocking:	2095	1. Blocking:
…		…
2433	it's built-in modules) are required to use it.	2514	it's built-in modules) are required to use it.
2434		2515
2435	That does not mean that AnyEvent won't take advantage of some additional	2516	That does not mean that AnyEvent won't take advantage of some additional
2436	modules if they are installed.	2517	modules if they are installed.
2437		2518
2438	This section epxlains which additional modules will be used, and how they	2519	This section explains which additional modules will be used, and how they
2439	affect AnyEvent's operetion.	2520	affect AnyEvent's operation.
2440		2521
2441	=over 4	2522	=over 4
2442		2523
2443	=item L<Async::Interrupt>	2524	=item L<Async::Interrupt>
2444		2525
…		…
2449	catch the signals) with some delay (default is 10 seconds, look for	2530	catch the signals) with some delay (default is 10 seconds, look for
2450	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2531	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451		2532
2452	If this module is available, then it will be used to implement signal	2533	If this module is available, then it will be used to implement signal
2453	catching, which means that signals will not be delayed, and the event loop	2534	catching, which means that signals will not be delayed, and the event loop
2454	will not be interrupted regularly, which is more efficient (And good for	2535	will not be interrupted regularly, which is more efficient (and good for
2455	battery life on laptops).	2536	battery life on laptops).
2456		2537
2457	This affects not just the pure-perl event loop, but also other event loops	2538	This affects not just the pure-perl event loop, but also other event loops
2458	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2539	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459		2540
…		…
2471	automatic timer adjustments even when no monotonic clock is available,	2552	automatic timer adjustments even when no monotonic clock is available,
2472	can take avdantage of advanced kernel interfaces such as C<epoll> and	2553	can take avdantage of advanced kernel interfaces such as C<epoll> and
2473	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2554	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2474	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2555	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475		2556
		2557	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2558	then this module will do nothing for you.
		2559
2476	=item L<Guard>	2560	=item L<Guard>
2477		2561
2478	The guard module, when used, will be used to implement	2562	The guard module, when used, will be used to implement
2479	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2563	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480	lot less memory), but otherwise doesn't affect guard operation much. It is	2564	lot less memory), but otherwise doesn't affect guard operation much. It is
2481	purely used for performance.	2565	purely used for performance.
2482		2566
2483	=item L<JSON> and L<JSON::XS>	2567	=item L<JSON> and L<JSON::XS>
2484		2568
2485	One of these modules is required when you want to read or write JSON data	2569	One of these modules is required when you want to read or write JSON data
2486	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2570	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2487	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2571	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488
2489	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490	installed.
2491		2572
2492	=item L<Net::SSLeay>	2573	=item L<Net::SSLeay>
2493		2574
2494	Implementing TLS/SSL in Perl is certainly interesting, but not very	2575	Implementing TLS/SSL in Perl is certainly interesting, but not very
2495	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2576	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
…		…
2506		2587
2507		2588
2508	=head1 FORK	2589	=head1 FORK
2509		2590
2510	Most event libraries are not fork-safe. The ones who are usually are	2591	Most event libraries are not fork-safe. The ones who are usually are
2511	because they rely on inefficient but fork-safe C<select> or C<poll>	2592	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2512	calls. Only L<EV> is fully fork-aware.	2593	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2594	are usually badly thought-out hacks that are incompatible with fork in
		2595	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2596	continue event-processing in both parent and child (or both, if you know
		2597	what you are doing).
		2598
		2599	This means that, in general, you cannot fork and do event processing in
		2600	the child if the event library was initialised before the fork (which
		2601	usually happens when the first AnyEvent watcher is created, or the library
		2602	is loaded).
2513		2603
2514	If you have to fork, you must either do so I<before> creating your first	2604	If you have to fork, you must either do so I<before> creating your first
2515	watcher OR you must not use AnyEvent at all in the child OR you must do	2605	watcher OR you must not use AnyEvent at all in the child OR you must do
2516	something completely out of the scope of AnyEvent.	2606	something completely out of the scope of AnyEvent.
		2607
		2608	The problem of doing event processing in the parent I<and> the child
		2609	is much more complicated: even for backends that I<are> fork-aware or
		2610	fork-safe, their behaviour is not usually what you want: fork clones all
		2611	watchers, that means all timers, I/O watchers etc. are active in both
		2612	parent and child, which is almost never what you want. USing C<exec>
		2613	to start worker children from some kind of manage rprocess is usually
		2614	preferred, because it is much easier and cleaner, at the expense of having
		2615	to have another binary.
2517		2616
2518		2617
2519	=head1 SECURITY CONSIDERATIONS	2618	=head1 SECURITY CONSIDERATIONS
2520		2619
2521	AnyEvent can be forced to load any event model via	2620	AnyEvent can be forced to load any event model via

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.296 by root, Tue Nov 17 01:19:49 2009 UTC vs. Revision 1.328 by root, Tue Jun 8 10:06:15 2010 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.296 by root, Tue Nov 17 01:19:49 2009 UTC vs.
Revision 1.328 by root, Tue Jun 8 10:06:15 2010 UTC