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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.169 by root, Wed Jul 9 10:36:22 2008 UTC vs.
Revision 1.200 by root, Wed Apr 1 14:02:27 2009 UTC

…		…
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });
12	...
13	});
14		12
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		15
		16	print AnyEvent->now; # prints current event loop time
		17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		18
		19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		20
		21	my $w = AnyEvent->child (pid => $pid, cb => sub {
		22	my ($pid, $status) = @_;
16	...	23	...
17	});	24	});
18		25
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	26	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	27	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	28	$w->recv; # enters "main loop" till $condvar gets ->send
		29	# use a condvar in callback mode:
		30	$w->cb (sub { $_[0]->recv });
22		31
23	=head1 INTRODUCTION/TUTORIAL	32	=head1 INTRODUCTION/TUTORIAL
24		33
25	This manpage is mainly a reference manual. If you are interested	34	This manpage is mainly a reference manual. If you are interested
26	in a tutorial or some gentle introduction, have a look at the	35	in a tutorial or some gentle introduction, have a look at the
…		…
128	These watchers are normal Perl objects with normal Perl lifetime. After	137	These watchers are normal Perl objects with normal Perl lifetime. After
129	creating a watcher it will immediately "watch" for events and invoke the	138	creating a watcher it will immediately "watch" for events and invoke the
130	callback when the event occurs (of course, only when the event model	139	callback when the event occurs (of course, only when the event model
131	is in control).	140	is in control).
132		141
		142	Note that B<callbacks must not permanently change global variables>
		143	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		144	callbacks must not C<die> >>. The former is good programming practise in
		145	Perl and the latter stems from the fact that exception handling differs
		146	widely between event loops.
		147
133	To disable the watcher you have to destroy it (e.g. by setting the	148	To disable the watcher you have to destroy it (e.g. by setting the
134	variable you store it in to C<undef> or otherwise deleting all references	149	variable you store it in to C<undef> or otherwise deleting all references
135	to it).	150	to it).
136		151
137	All watchers are created by calling a method on the C<AnyEvent> class.	152	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
153	=head2 I/O WATCHERS	168	=head2 I/O WATCHERS
154		169
155	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	170	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
156	with the following mandatory key-value pairs as arguments:	171	with the following mandatory key-value pairs as arguments:
157		172
158	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events	173	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch
159	(AnyEvent might or might not keep a reference to this file handle). C<poll>	174	for events (AnyEvent might or might not keep a reference to this file
		175	handle). Note that only file handles pointing to things for which
		176	non-blocking operation makes sense are allowed. This includes sockets,
		177	most character devices, pipes, fifos and so on, but not for example files
		178	or block devices.
		179
160	must be a string that is either C<r> or C<w>, which creates a watcher	180	C<poll> must be a string that is either C<r> or C<w>, which creates a
161	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the	181	watcher waiting for "r"eadable or "w"ritable events, respectively.
		182
162	callback to invoke each time the file handle becomes ready.	183	C<cb> is the callback to invoke each time the file handle becomes ready.
163		184
164	Although the callback might get passed parameters, their value and	185	Although the callback might get passed parameters, their value and
165	presence is undefined and you cannot rely on them. Portable AnyEvent	186	presence is undefined and you cannot rely on them. Portable AnyEvent
166	callbacks cannot use arguments passed to I/O watcher callbacks.	187	callbacks cannot use arguments passed to I/O watcher callbacks.
167		188
…		…
331	=head2 CHILD PROCESS WATCHERS	352	=head2 CHILD PROCESS WATCHERS
332		353
333	You can also watch on a child process exit and catch its exit status.	354	You can also watch on a child process exit and catch its exit status.
334		355
335	The child process is specified by the C<pid> argument (if set to C<0>, it	356	The child process is specified by the C<pid> argument (if set to C<0>, it
336	watches for any child process exit). The watcher will trigger as often	357	watches for any child process exit). The watcher will triggered only when
337	as status change for the child are received. This works by installing a	358	the child process has finished and an exit status is available, not on
338	signal handler for C<SIGCHLD>. The callback will be called with the pid	359	any trace events (stopped/continued).
339	and exit status (as returned by waitpid), so unlike other watcher types,	360
340	you I<can> rely on child watcher callback arguments.	361	The callback will be called with the pid and exit status (as returned by
		362	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		363	callback arguments.
		364
		365	This watcher type works by installing a signal handler for C<SIGCHLD>,
		366	and since it cannot be shared, nothing else should use SIGCHLD or reap
		367	random child processes (waiting for specific child processes, e.g. inside
		368	C<system>, is just fine).
341		369
342	There is a slight catch to child watchers, however: you usually start them	370	There is a slight catch to child watchers, however: you usually start them
343	I<after> the child process was created, and this means the process could	371	I<after> the child process was created, and this means the process could
344	have exited already (and no SIGCHLD will be sent anymore).	372	have exited already (and no SIGCHLD will be sent anymore).
345		373
…		…
381	The instrument to do that is called a "condition variable", so called	409	The instrument to do that is called a "condition variable", so called
382	because they represent a condition that must become true.	410	because they represent a condition that must become true.
383		411
384	Condition variables can be created by calling the C<< AnyEvent->condvar	412	Condition variables can be created by calling the C<< AnyEvent->condvar
385	>> method, usually without arguments. The only argument pair allowed is	413	>> method, usually without arguments. The only argument pair allowed is
		414
386	C<cb>, which specifies a callback to be called when the condition variable	415	C<cb>, which specifies a callback to be called when the condition variable
387	becomes true.	416	becomes true, with the condition variable as the first argument (but not
		417	the results).
388		418
389	After creation, the condition variable is "false" until it becomes "true"	419	After creation, the condition variable is "false" until it becomes "true"
390	by calling the C<send> method (or calling the condition variable as if it	420	by calling the C<send> method (or calling the condition variable as if it
391	were a callback, read about the caveats in the description for the C<<	421	were a callback, read about the caveats in the description for the C<<
392	->send >> method).	422	->send >> method).
…		…
448		478
449	my $done = AnyEvent->condvar;	479	my $done = AnyEvent->condvar;
450	my $delay = AnyEvent->timer (after => 5, cb => $done);	480	my $delay = AnyEvent->timer (after => 5, cb => $done);
451	$done->recv;	481	$done->recv;
452		482
		483	Example: Imagine an API that returns a condvar and doesn't support
		484	callbacks. This is how you make a synchronous call, for example from
		485	the main program:
		486
		487	use AnyEvent::CouchDB;
		488
		489	...
		490
		491	my @info = $couchdb->info->recv;
		492
		493	And this is how you would just ste a callback to be called whenever the
		494	results are available:
		495
		496	$couchdb->info->cb (sub {
		497	my @info = $_[0]->recv;
		498	});
		499
453	=head3 METHODS FOR PRODUCERS	500	=head3 METHODS FOR PRODUCERS
454		501
455	These methods should only be used by the producing side, i.e. the	502	These methods should only be used by the producing side, i.e. the
456	code/module that eventually sends the signal. Note that it is also	503	code/module that eventually sends the signal. Note that it is also
457	the producer side which creates the condvar in most cases, but it isn't	504	the producer side which creates the condvar in most cases, but it isn't
…		…
590	=item $bool = $cv->ready	637	=item $bool = $cv->ready
591		638
592	Returns true when the condition is "true", i.e. whether C<send> or	639	Returns true when the condition is "true", i.e. whether C<send> or
593	C<croak> have been called.	640	C<croak> have been called.
594		641
595	=item $cb = $cv->cb ([new callback])	642	=item $cb = $cv->cb ($cb->($cv))
596		643
597	This is a mutator function that returns the callback set and optionally	644	This is a mutator function that returns the callback set and optionally
598	replaces it before doing so.	645	replaces it before doing so.
599		646
600	The callback will be called when the condition becomes "true", i.e. when	647	The callback will be called when the condition becomes "true", i.e. when
…		…
790	=item L<AnyEvent::IGS>	837	=item L<AnyEvent::IGS>
791		838
792	A non-blocking interface to the Internet Go Server protocol (used by	839	A non-blocking interface to the Internet Go Server protocol (used by
793	L<App::IGS>).	840	L<App::IGS>).
794		841
795	=item L<Net::IRC3>	842	=item L<AnyEvent::IRC>
796		843
797	AnyEvent based IRC client module family.	844	AnyEvent based IRC client module family (replacing the older Net::IRC3).
798		845
799	=item L<Net::XMPP2>	846	=item L<Net::XMPP2>
800		847
801	AnyEvent based XMPP (Jabber protocol) module family.	848	AnyEvent based XMPP (Jabber protocol) module family.
802		849
…		…
822	=cut	869	=cut
823		870
824	package AnyEvent;	871	package AnyEvent;
825		872
826	no warnings;	873	no warnings;
827	use strict;	874	use strict qw(vars subs);
828		875
829	use Carp;	876	use Carp;
830		877
831	our $VERSION = 4.2;	878	our $VERSION = 4.35;
832	our $MODEL;	879	our $MODEL;
833		880
834	our $AUTOLOAD;	881	our $AUTOLOAD;
835	our @ISA;	882	our @ISA;
836		883
…		…
969	# to support binding more than one watcher per filehandle (they usually	1016	# to support binding more than one watcher per filehandle (they usually
970	# allow only one watcher per fd, so we dup it to get a different one).	1017	# allow only one watcher per fd, so we dup it to get a different one).
971	sub _dupfh($$$$) {	1018	sub _dupfh($$$$) {
972	my ($poll, $fh, $r, $w) = @_;	1019	my ($poll, $fh, $r, $w) = @_;
973		1020
974	require Fcntl;
975
976	# cygwin requires the fh mode to be matching, unix doesn't	1021	# cygwin requires the fh mode to be matching, unix doesn't
977	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1022	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
978	: $poll eq "w" ? ($w, ">")	1023	: $poll eq "w" ? ($w, ">")
979	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";	1024	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
980		1025
…		…
988		1033
989	package AnyEvent::Base;	1034	package AnyEvent::Base;
990		1035
991	# default implementation for now and time	1036	# default implementation for now and time
992		1037
993	use Time::HiRes ();	1038	BEGIN {
		1039	if (eval "use Time::HiRes (); time (); 1") {
		1040	*_time = \&Time::HiRes::time;
		1041	# if (eval "use POSIX (); (POSIX::times())...
		1042	} else {
		1043	*_time = sub { time }; # epic fail
		1044	}
		1045	}
994		1046
995	sub time { Time::HiRes::time }	1047	sub time { _time }
996	sub now { Time::HiRes::time }	1048	sub now { _time }
997		1049
998	# default implementation for ->condvar	1050	# default implementation for ->condvar
999		1051
1000	sub condvar {	1052	sub condvar {
1001	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1053	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
1002	}	1054	}
1003		1055
1004	# default implementation for ->signal	1056	# default implementation for ->signal
1005		1057
1006	our %SIG_CB;	1058	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1059
		1060	sub _signal_exec {
		1061	sysread $SIGPIPE_R, my $dummy, 4;
		1062
		1063	while (%SIG_EV) {
		1064	for (keys %SIG_EV) {
		1065	delete $SIG_EV{$_};
		1066	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1067	}
		1068	}
		1069	}
1007		1070
1008	sub signal {	1071	sub signal {
1009	my (undef, %arg) = @_;	1072	my (undef, %arg) = @_;
1010		1073
		1074	unless ($SIGPIPE_R) {
		1075	require Fcntl;
		1076
		1077	if (AnyEvent::WIN32) {
		1078	require AnyEvent::Util;
		1079
		1080	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1081	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1082	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1083	} else {
		1084	pipe $SIGPIPE_R, $SIGPIPE_W;
		1085	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1086	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1087	}
		1088
		1089	$SIGPIPE_R
		1090	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1091
		1092	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1093	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1094
		1095	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1096	}
		1097
1011	my $signal = uc $arg{signal}	1098	my $signal = uc $arg{signal}
1012	or Carp::croak "required option 'signal' is missing";	1099	or Carp::croak "required option 'signal' is missing";
1013		1100
1014	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1101	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1015	$SIG{$signal} \|\|= sub {	1102	$SIG{$signal} \|\|= sub {
1016	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1103	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1104	undef $SIG_EV{$signal};
1017	};	1105	};
1018		1106
1019	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1107	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
1020	}	1108	}
1021		1109
…		…
1140		1228
1141	# undocumented/compatibility with pre-3.4	1229	# undocumented/compatibility with pre-3.4
1142	*broadcast = \&send;	1230	*broadcast = \&send;
1143	*wait = \&_wait;	1231	*wait = \&_wait;
1144		1232
		1233	=head1 ERROR AND EXCEPTION HANDLING
		1234
		1235	In general, AnyEvent does not do any error handling - it relies on the
		1236	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1237	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1238	checking of all AnyEvent methods, however, which is highly useful during
		1239	development.
		1240
		1241	As for exception handling (i.e. runtime errors and exceptions thrown while
		1242	executing a callback), this is not only highly event-loop specific, but
		1243	also not in any way wrapped by this module, as this is the job of the main
		1244	program.
		1245
		1246	The pure perl event loop simply re-throws the exception (usually
		1247	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1248	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1249	so on.
		1250
		1251	=head1 ENVIRONMENT VARIABLES
		1252
		1253	The following environment variables are used by this module or its
		1254	submodules:
		1255
		1256	=over 4
		1257
		1258	=item C<PERL_ANYEVENT_VERBOSE>
		1259
		1260	By default, AnyEvent will be completely silent except in fatal
		1261	conditions. You can set this environment variable to make AnyEvent more
		1262	talkative.
		1263
		1264	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1265	conditions, such as not being able to load the event model specified by
		1266	C<PERL_ANYEVENT_MODEL>.
		1267
		1268	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1269	model it chooses.
		1270
		1271	=item C<PERL_ANYEVENT_STRICT>
		1272
		1273	AnyEvent does not do much argument checking by default, as thorough
		1274	argument checking is very costly. Setting this variable to a true value
		1275	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1276	check the arguments passed to most method calls. If it finds any problems
		1277	it will croak.
		1278
		1279	In other words, enables "strict" mode.
		1280
		1281	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1282	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1283	developing programs can be very useful, however.
		1284
		1285	=item C<PERL_ANYEVENT_MODEL>
		1286
		1287	This can be used to specify the event model to be used by AnyEvent, before
		1288	auto detection and -probing kicks in. It must be a string consisting
		1289	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1290	and the resulting module name is loaded and if the load was successful,
		1291	used as event model. If it fails to load AnyEvent will proceed with
		1292	auto detection and -probing.
		1293
		1294	This functionality might change in future versions.
		1295
		1296	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1297	could start your program like this:
		1298
		1299	PERL_ANYEVENT_MODEL=Perl perl ...
		1300
		1301	=item C<PERL_ANYEVENT_PROTOCOLS>
		1302
		1303	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1304	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1305	of auto probing).
		1306
		1307	Must be set to a comma-separated list of protocols or address families,
		1308	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1309	used, and preference will be given to protocols mentioned earlier in the
		1310	list.
		1311
		1312	This variable can effectively be used for denial-of-service attacks
		1313	against local programs (e.g. when setuid), although the impact is likely
		1314	small, as the program has to handle conenction and other failures anyways.
		1315
		1316	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1317	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1318	- only support IPv4, never try to resolve or contact IPv6
		1319	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1320	IPv6, but prefer IPv6 over IPv4.
		1321
		1322	=item C<PERL_ANYEVENT_EDNS0>
		1323
		1324	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1325	for DNS. This extension is generally useful to reduce DNS traffic, but
		1326	some (broken) firewalls drop such DNS packets, which is why it is off by
		1327	default.
		1328
		1329	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1330	EDNS0 in its DNS requests.
		1331
		1332	=item C<PERL_ANYEVENT_MAX_FORKS>
		1333
		1334	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1335	will create in parallel.
		1336
		1337	=back
		1338
1145	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1339	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1146		1340
1147	This is an advanced topic that you do not normally need to use AnyEvent in	1341	This is an advanced topic that you do not normally need to use AnyEvent in
1148	a module. This section is only of use to event loop authors who want to	1342	a module. This section is only of use to event loop authors who want to
1149	provide AnyEvent compatibility.	1343	provide AnyEvent compatibility.
…		…
1182		1376
1183	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1377	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1184	condition variables: code blocking while waiting for a condition will	1378	condition variables: code blocking while waiting for a condition will
1185	C<die>. This still works with most modules/usages, and blocking calls must	1379	C<die>. This still works with most modules/usages, and blocking calls must
1186	not be done in an interactive application, so it makes sense.	1380	not be done in an interactive application, so it makes sense.
1187
1188	=head1 ENVIRONMENT VARIABLES
1189
1190	The following environment variables are used by this module:
1191
1192	=over 4
1193
1194	=item C<PERL_ANYEVENT_VERBOSE>
1195
1196	By default, AnyEvent will be completely silent except in fatal
1197	conditions. You can set this environment variable to make AnyEvent more
1198	talkative.
1199
1200	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1201	conditions, such as not being able to load the event model specified by
1202	C<PERL_ANYEVENT_MODEL>.
1203
1204	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1205	model it chooses.
1206
1207	=item C<PERL_ANYEVENT_STRICT>
1208
1209	AnyEvent does not do much argument checking by default, as thorough
1210	argument checking is very costly. Setting this variable to a true value
1211	will cause AnyEvent to thoroughly check the arguments passed to most
1212	method calls and croaks if it finds any problems. In other words, enables
1213	"strict" mode. Unlike C<use strict> it is definitely recommended ot keep
1214	it off in production.
1215
1216	=item C<PERL_ANYEVENT_MODEL>
1217
1218	This can be used to specify the event model to be used by AnyEvent, before
1219	auto detection and -probing kicks in. It must be a string consisting
1220	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1221	and the resulting module name is loaded and if the load was successful,
1222	used as event model. If it fails to load AnyEvent will proceed with
1223	auto detection and -probing.
1224
1225	This functionality might change in future versions.
1226
1227	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1228	could start your program like this:
1229
1230	PERL_ANYEVENT_MODEL=Perl perl ...
1231
1232	=item C<PERL_ANYEVENT_PROTOCOLS>
1233
1234	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1235	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1236	of auto probing).
1237
1238	Must be set to a comma-separated list of protocols or address families,
1239	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1240	used, and preference will be given to protocols mentioned earlier in the
1241	list.
1242
1243	This variable can effectively be used for denial-of-service attacks
1244	against local programs (e.g. when setuid), although the impact is likely
1245	small, as the program has to handle connection errors already-
1246
1247	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1248	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1249	- only support IPv4, never try to resolve or contact IPv6
1250	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1251	IPv6, but prefer IPv6 over IPv4.
1252
1253	=item C<PERL_ANYEVENT_EDNS0>
1254
1255	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1256	for DNS. This extension is generally useful to reduce DNS traffic, but
1257	some (broken) firewalls drop such DNS packets, which is why it is off by
1258	default.
1259
1260	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1261	EDNS0 in its DNS requests.
1262
1263	=item C<PERL_ANYEVENT_MAX_FORKS>
1264
1265	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1266	will create in parallel.
1267
1268	=back
1269		1381
1270	=head1 EXAMPLE PROGRAM	1382	=head1 EXAMPLE PROGRAM
1271		1383
1272	The following program uses an I/O watcher to read data from STDIN, a timer	1384	The following program uses an I/O watcher to read data from STDIN, a timer
1273	to display a message once per second, and a condition variable to quit the	1385	to display a message once per second, and a condition variable to quit the
…		…
1467	watcher.	1579	watcher.
1468		1580
1469	=head3 Results	1581	=head3 Results
1470		1582
1471	name watchers bytes create invoke destroy comment	1583	name watchers bytes create invoke destroy comment
1472	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1584	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1473	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1585	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1474	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1586	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1475	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1587	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1476	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1588	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1477	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1589	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1478	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1590	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1479	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1591	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1480	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1592	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1481	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1593	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1482		1594
1483	=head3 Discussion	1595	=head3 Discussion
1484		1596
1485	The benchmark does I<not> measure scalability of the event loop very	1597	The benchmark does I<not> measure scalability of the event loop very
1486	well. For example, a select-based event loop (such as the pure perl one)	1598	well. For example, a select-based event loop (such as the pure perl one)
…		…
1688	watchers, as the management overhead dominates.	1800	watchers, as the management overhead dominates.
1689		1801
1690	=back	1802	=back
1691		1803
1692		1804
		1805	=head1 SIGNALS
		1806
		1807	AnyEvent currently installs handlers for these signals:
		1808
		1809	=over 4
		1810
		1811	=item SIGCHLD
		1812
		1813	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1814	emulation for event loops that do not support them natively. Also, some
		1815	event loops install a similar handler.
		1816
		1817	=item SIGPIPE
		1818
		1819	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1820	when AnyEvent gets loaded.
		1821
		1822	The rationale for this is that AnyEvent users usually do not really depend
		1823	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1824	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1825	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1826	some random socket.
		1827
		1828	The rationale for installing a no-op handler as opposed to ignoring it is
		1829	that this way, the handler will be restored to defaults on exec.
		1830
		1831	Feel free to install your own handler, or reset it to defaults.
		1832
		1833	=back
		1834
		1835	=cut
		1836
		1837	$SIG{PIPE} = sub { }
		1838	unless defined $SIG{PIPE};
		1839
		1840
1693	=head1 FORK	1841	=head1 FORK
1694		1842
1695	Most event libraries are not fork-safe. The ones who are usually are	1843	Most event libraries are not fork-safe. The ones who are usually are
1696	because they rely on inefficient but fork-safe C<select> or C<poll>	1844	because they rely on inefficient but fork-safe C<select> or C<poll>
1697	calls. Only L<EV> is fully fork-aware.	1845	calls. Only L<EV> is fully fork-aware.
…		…
1725	=head1 BUGS	1873	=head1 BUGS
1726		1874
1727	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	1875	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1728	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	1876	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1729	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	1877	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1730	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	1878	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1731	pronounced).	1879	pronounced).
1732		1880
1733		1881
1734	=head1 SEE ALSO	1882	=head1 SEE ALSO
1735		1883

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.169 by root, Wed Jul 9 10:36:22 2008 UTC vs. Revision 1.200 by root, Wed Apr 1 14:02:27 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.169 by root, Wed Jul 9 10:36:22 2008 UTC vs.
Revision 1.200 by root, Wed Apr 1 14:02:27 2009 UTC