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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.170 by root, Wed Jul 9 11:53:40 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 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	# not strictly required, as $^F is normally 2, but let's make sure...
		1093	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1094	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1095
		1096	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1097	}
		1098
1011	my $signal = uc $arg{signal}	1099	my $signal = uc $arg{signal}
1012	or Carp::croak "required option 'signal' is missing";	1100	or Carp::croak "required option 'signal' is missing";
1013		1101
1014	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1102	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1015	$SIG{$signal} \|\|= sub {	1103	$SIG{$signal} \|\|= sub {
1016	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1104	local $!;
		1105	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1106	undef $SIG_EV{$signal};
1017	};	1107	};
1018		1108
1019	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1109	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
1020	}	1110	}
1021		1111
…		…
1140		1230
1141	# undocumented/compatibility with pre-3.4	1231	# undocumented/compatibility with pre-3.4
1142	*broadcast = \&send;	1232	*broadcast = \&send;
1143	*wait = \&_wait;	1233	*wait = \&_wait;
1144		1234
		1235	=head1 ERROR AND EXCEPTION HANDLING
		1236
		1237	In general, AnyEvent does not do any error handling - it relies on the
		1238	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1239	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1240	checking of all AnyEvent methods, however, which is highly useful during
		1241	development.
		1242
		1243	As for exception handling (i.e. runtime errors and exceptions thrown while
		1244	executing a callback), this is not only highly event-loop specific, but
		1245	also not in any way wrapped by this module, as this is the job of the main
		1246	program.
		1247
		1248	The pure perl event loop simply re-throws the exception (usually
		1249	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1250	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1251	so on.
		1252
		1253	=head1 ENVIRONMENT VARIABLES
		1254
		1255	The following environment variables are used by this module or its
		1256	submodules:
		1257
		1258	=over 4
		1259
		1260	=item C<PERL_ANYEVENT_VERBOSE>
		1261
		1262	By default, AnyEvent will be completely silent except in fatal
		1263	conditions. You can set this environment variable to make AnyEvent more
		1264	talkative.
		1265
		1266	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1267	conditions, such as not being able to load the event model specified by
		1268	C<PERL_ANYEVENT_MODEL>.
		1269
		1270	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1271	model it chooses.
		1272
		1273	=item C<PERL_ANYEVENT_STRICT>
		1274
		1275	AnyEvent does not do much argument checking by default, as thorough
		1276	argument checking is very costly. Setting this variable to a true value
		1277	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1278	check the arguments passed to most method calls. If it finds any problems
		1279	it will croak.
		1280
		1281	In other words, enables "strict" mode.
		1282
		1283	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1284	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1285	developing programs can be very useful, however.
		1286
		1287	=item C<PERL_ANYEVENT_MODEL>
		1288
		1289	This can be used to specify the event model to be used by AnyEvent, before
		1290	auto detection and -probing kicks in. It must be a string consisting
		1291	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1292	and the resulting module name is loaded and if the load was successful,
		1293	used as event model. If it fails to load AnyEvent will proceed with
		1294	auto detection and -probing.
		1295
		1296	This functionality might change in future versions.
		1297
		1298	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1299	could start your program like this:
		1300
		1301	PERL_ANYEVENT_MODEL=Perl perl ...
		1302
		1303	=item C<PERL_ANYEVENT_PROTOCOLS>
		1304
		1305	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1306	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1307	of auto probing).
		1308
		1309	Must be set to a comma-separated list of protocols or address families,
		1310	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1311	used, and preference will be given to protocols mentioned earlier in the
		1312	list.
		1313
		1314	This variable can effectively be used for denial-of-service attacks
		1315	against local programs (e.g. when setuid), although the impact is likely
		1316	small, as the program has to handle conenction and other failures anyways.
		1317
		1318	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1319	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1320	- only support IPv4, never try to resolve or contact IPv6
		1321	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1322	IPv6, but prefer IPv6 over IPv4.
		1323
		1324	=item C<PERL_ANYEVENT_EDNS0>
		1325
		1326	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1327	for DNS. This extension is generally useful to reduce DNS traffic, but
		1328	some (broken) firewalls drop such DNS packets, which is why it is off by
		1329	default.
		1330
		1331	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1332	EDNS0 in its DNS requests.
		1333
		1334	=item C<PERL_ANYEVENT_MAX_FORKS>
		1335
		1336	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1337	will create in parallel.
		1338
		1339	=back
		1340
1145	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1341	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1146		1342
1147	This is an advanced topic that you do not normally need to use AnyEvent in	1343	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	1344	a module. This section is only of use to event loop authors who want to
1149	provide AnyEvent compatibility.	1345	provide AnyEvent compatibility.
…		…
1182		1378
1183	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1379	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1184	condition variables: code blocking while waiting for a condition will	1380	condition variables: code blocking while waiting for a condition will
1185	C<die>. This still works with most modules/usages, and blocking calls must	1381	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.	1382	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 load C<AnyEvent::Strict> and then to thoroughly
1212	check the arguments passed to most method calls. If it finds any problems
1213	it will croak.
1214
1215	In other words, enables "strict" mode.
1216
1217	Unlike C<use strict> it is definitely recommended ot keep it off in
1218	production.
1219
1220	=item C<PERL_ANYEVENT_MODEL>
1221
1222	This can be used to specify the event model to be used by AnyEvent, before
1223	auto detection and -probing kicks in. It must be a string consisting
1224	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1225	and the resulting module name is loaded and if the load was successful,
1226	used as event model. If it fails to load AnyEvent will proceed with
1227	auto detection and -probing.
1228
1229	This functionality might change in future versions.
1230
1231	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1232	could start your program like this:
1233
1234	PERL_ANYEVENT_MODEL=Perl perl ...
1235
1236	=item C<PERL_ANYEVENT_PROTOCOLS>
1237
1238	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1239	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1240	of auto probing).
1241
1242	Must be set to a comma-separated list of protocols or address families,
1243	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1244	used, and preference will be given to protocols mentioned earlier in the
1245	list.
1246
1247	This variable can effectively be used for denial-of-service attacks
1248	against local programs (e.g. when setuid), although the impact is likely
1249	small, as the program has to handle connection errors already-
1250
1251	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1252	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1253	- only support IPv4, never try to resolve or contact IPv6
1254	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1255	IPv6, but prefer IPv6 over IPv4.
1256
1257	=item C<PERL_ANYEVENT_EDNS0>
1258
1259	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1260	for DNS. This extension is generally useful to reduce DNS traffic, but
1261	some (broken) firewalls drop such DNS packets, which is why it is off by
1262	default.
1263
1264	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1265	EDNS0 in its DNS requests.
1266
1267	=item C<PERL_ANYEVENT_MAX_FORKS>
1268
1269	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1270	will create in parallel.
1271
1272	=back
1273		1383
1274	=head1 EXAMPLE PROGRAM	1384	=head1 EXAMPLE PROGRAM
1275		1385
1276	The following program uses an I/O watcher to read data from STDIN, a timer	1386	The following program uses an I/O watcher to read data from STDIN, a timer
1277	to display a message once per second, and a condition variable to quit the	1387	to display a message once per second, and a condition variable to quit the
…		…
1471	watcher.	1581	watcher.
1472		1582
1473	=head3 Results	1583	=head3 Results
1474		1584
1475	name watchers bytes create invoke destroy comment	1585	name watchers bytes create invoke destroy comment
1476	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1586	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1477	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1587	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1478	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1588	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1479	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1589	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1480	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1590	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1481	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1591	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1482	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1592	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1483	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1593	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1484	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1594	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1485	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1595	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1486		1596
1487	=head3 Discussion	1597	=head3 Discussion
1488		1598
1489	The benchmark does I<not> measure scalability of the event loop very	1599	The benchmark does I<not> measure scalability of the event loop very
1490	well. For example, a select-based event loop (such as the pure perl one)	1600	well. For example, a select-based event loop (such as the pure perl one)
…		…
1692	watchers, as the management overhead dominates.	1802	watchers, as the management overhead dominates.
1693		1803
1694	=back	1804	=back
1695		1805
1696		1806
		1807	=head1 SIGNALS
		1808
		1809	AnyEvent currently installs handlers for these signals:
		1810
		1811	=over 4
		1812
		1813	=item SIGCHLD
		1814
		1815	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1816	emulation for event loops that do not support them natively. Also, some
		1817	event loops install a similar handler.
		1818
		1819	=item SIGPIPE
		1820
		1821	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1822	when AnyEvent gets loaded.
		1823
		1824	The rationale for this is that AnyEvent users usually do not really depend
		1825	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1826	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1827	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1828	some random socket.
		1829
		1830	The rationale for installing a no-op handler as opposed to ignoring it is
		1831	that this way, the handler will be restored to defaults on exec.
		1832
		1833	Feel free to install your own handler, or reset it to defaults.
		1834
		1835	=back
		1836
		1837	=cut
		1838
		1839	$SIG{PIPE} = sub { }
		1840	unless defined $SIG{PIPE};
		1841
		1842
1697	=head1 FORK	1843	=head1 FORK
1698		1844
1699	Most event libraries are not fork-safe. The ones who are usually are	1845	Most event libraries are not fork-safe. The ones who are usually are
1700	because they rely on inefficient but fork-safe C<select> or C<poll>	1846	because they rely on inefficient but fork-safe C<select> or C<poll>
1701	calls. Only L<EV> is fully fork-aware.	1847	calls. Only L<EV> is fully fork-aware.
…		…
1729	=head1 BUGS	1875	=head1 BUGS
1730		1876
1731	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	1877	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1732	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	1878	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1733	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	1879	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1734	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	1880	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1735	pronounced).	1881	pronounced).
1736		1882
1737		1883
1738	=head1 SEE ALSO	1884	=head1 SEE ALSO
1739		1885

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.170 by root, Wed Jul 9 11:53:40 2008 UTC vs. Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.170 by root, Wed Jul 9 11:53:40 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC