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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC vs.
Revision 1.205 by root, Sun Apr 19 12:09:46 2009 UTC

…		…
137	These watchers are normal Perl objects with normal Perl lifetime. After	137	These watchers are normal Perl objects with normal Perl lifetime. After
138	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
139	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
140	is in control).	140	is in control).
141		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
142	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
143	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
144	to it).	150	to it).
145		151
146	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.
…		…
162	=head2 I/O WATCHERS	168	=head2 I/O WATCHERS
163		169
164	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
165	with the following mandatory key-value pairs as arguments:	171	with the following mandatory key-value pairs as arguments:
166		172
167	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
168	(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
169	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
170	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
171	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.
172		184
173	Although the callback might get passed parameters, their value and	185	Although the callback might get passed parameters, their value and
174	presence is undefined and you cannot rely on them. Portable AnyEvent	186	presence is undefined and you cannot rely on them. Portable AnyEvent
175	callbacks cannot use arguments passed to I/O watcher callbacks.	187	callbacks cannot use arguments passed to I/O watcher callbacks.
176		188
…		…
308	In either case, if you care (and in most cases, you don't), then you	320	In either case, if you care (and in most cases, you don't), then you
309	can get whatever behaviour you want with any event loop, by taking the	321	can get whatever behaviour you want with any event loop, by taking the
310	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	322	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
311	account.	323	account.
312		324
		325	=item AnyEvent->now_update
		326
		327	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		328	the current time for each loop iteration (see the discussion of L<<
		329	AnyEvent->now >>, above).
		330
		331	When a callback runs for a long time (or when the process sleeps), then
		332	this "current" time will differ substantially from the real time, which
		333	might affect timers and time-outs.
		334
		335	When this is the case, you can call this method, which will update the
		336	event loop's idea of "current time".
		337
		338	Note that updating the time I<might> cause some events to be handled.
		339
313	=back	340	=back
314		341
315	=head2 SIGNAL WATCHERS	342	=head2 SIGNAL WATCHERS
316		343
317	You can watch for signals using a signal watcher, C<signal> is the signal	344	You can watch for signals using a signal watcher, C<signal> is the signal
…		…
340	=head2 CHILD PROCESS WATCHERS	367	=head2 CHILD PROCESS WATCHERS
341		368
342	You can also watch on a child process exit and catch its exit status.	369	You can also watch on a child process exit and catch its exit status.
343		370
344	The child process is specified by the C<pid> argument (if set to C<0>, it	371	The child process is specified by the C<pid> argument (if set to C<0>, it
345	watches for any child process exit). The watcher will trigger as often	372	watches for any child process exit). The watcher will triggered only when
346	as status change for the child are received. This works by installing a	373	the child process has finished and an exit status is available, not on
347	signal handler for C<SIGCHLD>. The callback will be called with the pid	374	any trace events (stopped/continued).
348	and exit status (as returned by waitpid), so unlike other watcher types,	375
349	you I<can> rely on child watcher callback arguments.	376	The callback will be called with the pid and exit status (as returned by
		377	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		378	callback arguments.
		379
		380	This watcher type works by installing a signal handler for C<SIGCHLD>,
		381	and since it cannot be shared, nothing else should use SIGCHLD or reap
		382	random child processes (waiting for specific child processes, e.g. inside
		383	C<system>, is just fine).
350		384
351	There is a slight catch to child watchers, however: you usually start them	385	There is a slight catch to child watchers, however: you usually start them
352	I<after> the child process was created, and this means the process could	386	I<after> the child process was created, and this means the process could
353	have exited already (and no SIGCHLD will be sent anymore).	387	have exited already (and no SIGCHLD will be sent anymore).
354		388
…		…
389		423
390	The instrument to do that is called a "condition variable", so called	424	The instrument to do that is called a "condition variable", so called
391	because they represent a condition that must become true.	425	because they represent a condition that must become true.
392		426
393	Condition variables can be created by calling the C<< AnyEvent->condvar	427	Condition variables can be created by calling the C<< AnyEvent->condvar
394
395	>> method, usually without arguments. The only argument pair allowed is	428	>> method, usually without arguments. The only argument pair allowed is
396		429
397	C<cb>, which specifies a callback to be called when the condition variable	430	C<cb>, which specifies a callback to be called when the condition variable
398	becomes true, with the condition variable as the first argument (but not	431	becomes true, with the condition variable as the first argument (but not
399	the results).	432	the results).
…		…
819	=item L<AnyEvent::IGS>	852	=item L<AnyEvent::IGS>
820		853
821	A non-blocking interface to the Internet Go Server protocol (used by	854	A non-blocking interface to the Internet Go Server protocol (used by
822	L<App::IGS>).	855	L<App::IGS>).
823		856
824	=item L<Net::IRC3>	857	=item L<AnyEvent::IRC>
825		858
826	AnyEvent based IRC client module family.	859	AnyEvent based IRC client module family (replacing the older Net::IRC3).
827		860
828	=item L<Net::XMPP2>	861	=item L<Net::XMPP2>
829		862
830	AnyEvent based XMPP (Jabber protocol) module family.	863	AnyEvent based XMPP (Jabber protocol) module family.
831		864
…		…
851	=cut	884	=cut
852		885
853	package AnyEvent;	886	package AnyEvent;
854		887
855	no warnings;	888	no warnings;
856	use strict;	889	use strict qw(vars subs);
857		890
858	use Carp;	891	use Carp;
859		892
860	our $VERSION = 4.22;	893	our $VERSION = 4.351;
861	our $MODEL;	894	our $MODEL;
862		895
863	our $AUTOLOAD;	896	our $AUTOLOAD;
864	our @ISA;	897	our @ISA;
865		898
…		…
897	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	930	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
898	[Wx:: => AnyEvent::Impl::POE::],	931	[Wx:: => AnyEvent::Impl::POE::],
899	[Prima:: => AnyEvent::Impl::POE::],	932	[Prima:: => AnyEvent::Impl::POE::],
900	);	933	);
901		934
902	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	935	our %method = map +($_ => 1),
		936	qw(io timer time now now_update signal child condvar one_event DESTROY);
903		937
904	our @post_detect;	938	our @post_detect;
905		939
906	sub post_detect(&) {	940	sub post_detect(&) {
907	my ($cb) = @_;	941	my ($cb) = @_;
…		…
964	last;	998	last;
965	}	999	}
966	}	1000	}
967		1001
968	$MODEL	1002	$MODEL
969	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1003	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
970	}	1004	}
971	}	1005	}
972		1006
973	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1007	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
974		1008
…		…
998	# to support binding more than one watcher per filehandle (they usually	1032	# to support binding more than one watcher per filehandle (they usually
999	# allow only one watcher per fd, so we dup it to get a different one).	1033	# allow only one watcher per fd, so we dup it to get a different one).
1000	sub _dupfh($$$$) {	1034	sub _dupfh($$$$) {
1001	my ($poll, $fh, $r, $w) = @_;	1035	my ($poll, $fh, $r, $w) = @_;
1002		1036
1003	require Fcntl;
1004
1005	# cygwin requires the fh mode to be matching, unix doesn't	1037	# cygwin requires the fh mode to be matching, unix doesn't
1006	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1038	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
1007	: $poll eq "w" ? ($w, ">")	1039	: $poll eq "w" ? ($w, ">")
1008	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";	1040	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1009		1041
1010	open my $fh2, "$mode&" . fileno $fh	1042	open my $fh2, "$mode&" . fileno $fh
1011	or die "cannot dup() filehandle: $!";	1043	or die "cannot dup() filehandle: $!,";
1012		1044
1013	# we assume CLOEXEC is already set by perl in all important cases	1045	# we assume CLOEXEC is already set by perl in all important cases
1014		1046
1015	($fh2, $rw)	1047	($fh2, $rw)
1016	}	1048	}
1017		1049
1018	package AnyEvent::Base;	1050	package AnyEvent::Base;
1019		1051
1020	# default implementation for now and time	1052	# default implementations for many methods
1021		1053
1022	use Time::HiRes ();	1054	BEGIN {
		1055	if (eval "use Time::HiRes (); time (); 1") {
		1056	*_time = \&Time::HiRes::time;
		1057	# if (eval "use POSIX (); (POSIX::times())...
		1058	} else {
		1059	*_time = sub { time }; # epic fail
		1060	}
		1061	}
1023		1062
1024	sub time { Time::HiRes::time }	1063	sub time { _time }
1025	sub now { Time::HiRes::time }	1064	sub now { _time }
		1065	sub now_update { }
1026		1066
1027	# default implementation for ->condvar	1067	# default implementation for ->condvar
1028		1068
1029	sub condvar {	1069	sub condvar {
1030	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1070	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
1031	}	1071	}
1032		1072
1033	# default implementation for ->signal	1073	# default implementation for ->signal
1034		1074
1035	our %SIG_CB;	1075	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1076
		1077	sub _signal_exec {
		1078	sysread $SIGPIPE_R, my $dummy, 4;
		1079
		1080	while (%SIG_EV) {
		1081	for (keys %SIG_EV) {
		1082	delete $SIG_EV{$_};
		1083	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1084	}
		1085	}
		1086	}
1036		1087
1037	sub signal {	1088	sub signal {
1038	my (undef, %arg) = @_;	1089	my (undef, %arg) = @_;
1039		1090
		1091	unless ($SIGPIPE_R) {
		1092	require Fcntl;
		1093
		1094	if (AnyEvent::WIN32) {
		1095	require AnyEvent::Util;
		1096
		1097	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1098	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1099	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1100	} else {
		1101	pipe $SIGPIPE_R, $SIGPIPE_W;
		1102	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1103	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1104	}
		1105
		1106	$SIGPIPE_R
		1107	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1108
		1109	# not strictly required, as $^F is normally 2, but let's make sure...
		1110	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1111	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1112
		1113	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1114	}
		1115
1040	my $signal = uc $arg{signal}	1116	my $signal = uc $arg{signal}
1041	or Carp::croak "required option 'signal' is missing";	1117	or Carp::croak "required option 'signal' is missing";
1042		1118
1043	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1119	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1044	$SIG{$signal} \|\|= sub {	1120	$SIG{$signal} \|\|= sub {
1045	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1121	local $!;
		1122	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1123	undef $SIG_EV{$signal};
1046	};	1124	};
1047		1125
1048	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1126	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
1049	}	1127	}
1050		1128
…		…
1169		1247
1170	# undocumented/compatibility with pre-3.4	1248	# undocumented/compatibility with pre-3.4
1171	*broadcast = \&send;	1249	*broadcast = \&send;
1172	*wait = \&_wait;	1250	*wait = \&_wait;
1173		1251
		1252	=head1 ERROR AND EXCEPTION HANDLING
		1253
		1254	In general, AnyEvent does not do any error handling - it relies on the
		1255	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1256	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1257	checking of all AnyEvent methods, however, which is highly useful during
		1258	development.
		1259
		1260	As for exception handling (i.e. runtime errors and exceptions thrown while
		1261	executing a callback), this is not only highly event-loop specific, but
		1262	also not in any way wrapped by this module, as this is the job of the main
		1263	program.
		1264
		1265	The pure perl event loop simply re-throws the exception (usually
		1266	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1267	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1268	so on.
		1269
		1270	=head1 ENVIRONMENT VARIABLES
		1271
		1272	The following environment variables are used by this module or its
		1273	submodules:
		1274
		1275	=over 4
		1276
		1277	=item C<PERL_ANYEVENT_VERBOSE>
		1278
		1279	By default, AnyEvent will be completely silent except in fatal
		1280	conditions. You can set this environment variable to make AnyEvent more
		1281	talkative.
		1282
		1283	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1284	conditions, such as not being able to load the event model specified by
		1285	C<PERL_ANYEVENT_MODEL>.
		1286
		1287	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1288	model it chooses.
		1289
		1290	=item C<PERL_ANYEVENT_STRICT>
		1291
		1292	AnyEvent does not do much argument checking by default, as thorough
		1293	argument checking is very costly. Setting this variable to a true value
		1294	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1295	check the arguments passed to most method calls. If it finds any problems
		1296	it will croak.
		1297
		1298	In other words, enables "strict" mode.
		1299
		1300	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1301	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1302	developing programs can be very useful, however.
		1303
		1304	=item C<PERL_ANYEVENT_MODEL>
		1305
		1306	This can be used to specify the event model to be used by AnyEvent, before
		1307	auto detection and -probing kicks in. It must be a string consisting
		1308	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1309	and the resulting module name is loaded and if the load was successful,
		1310	used as event model. If it fails to load AnyEvent will proceed with
		1311	auto detection and -probing.
		1312
		1313	This functionality might change in future versions.
		1314
		1315	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1316	could start your program like this:
		1317
		1318	PERL_ANYEVENT_MODEL=Perl perl ...
		1319
		1320	=item C<PERL_ANYEVENT_PROTOCOLS>
		1321
		1322	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1323	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1324	of auto probing).
		1325
		1326	Must be set to a comma-separated list of protocols or address families,
		1327	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1328	used, and preference will be given to protocols mentioned earlier in the
		1329	list.
		1330
		1331	This variable can effectively be used for denial-of-service attacks
		1332	against local programs (e.g. when setuid), although the impact is likely
		1333	small, as the program has to handle conenction and other failures anyways.
		1334
		1335	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1336	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1337	- only support IPv4, never try to resolve or contact IPv6
		1338	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1339	IPv6, but prefer IPv6 over IPv4.
		1340
		1341	=item C<PERL_ANYEVENT_EDNS0>
		1342
		1343	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1344	for DNS. This extension is generally useful to reduce DNS traffic, but
		1345	some (broken) firewalls drop such DNS packets, which is why it is off by
		1346	default.
		1347
		1348	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1349	EDNS0 in its DNS requests.
		1350
		1351	=item C<PERL_ANYEVENT_MAX_FORKS>
		1352
		1353	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1354	will create in parallel.
		1355
		1356	=back
		1357
1174	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1358	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1175		1359
1176	This is an advanced topic that you do not normally need to use AnyEvent in	1360	This is an advanced topic that you do not normally need to use AnyEvent in
1177	a module. This section is only of use to event loop authors who want to	1361	a module. This section is only of use to event loop authors who want to
1178	provide AnyEvent compatibility.	1362	provide AnyEvent compatibility.
…		…
1211		1395
1212	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1396	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1213	condition variables: code blocking while waiting for a condition will	1397	condition variables: code blocking while waiting for a condition will
1214	C<die>. This still works with most modules/usages, and blocking calls must	1398	C<die>. This still works with most modules/usages, and blocking calls must
1215	not be done in an interactive application, so it makes sense.	1399	not be done in an interactive application, so it makes sense.
1216
1217	=head1 ENVIRONMENT VARIABLES
1218
1219	The following environment variables are used by this module:
1220
1221	=over 4
1222
1223	=item C<PERL_ANYEVENT_VERBOSE>
1224
1225	By default, AnyEvent will be completely silent except in fatal
1226	conditions. You can set this environment variable to make AnyEvent more
1227	talkative.
1228
1229	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1230	conditions, such as not being able to load the event model specified by
1231	C<PERL_ANYEVENT_MODEL>.
1232
1233	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1234	model it chooses.
1235
1236	=item C<PERL_ANYEVENT_STRICT>
1237
1238	AnyEvent does not do much argument checking by default, as thorough
1239	argument checking is very costly. Setting this variable to a true value
1240	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1241	check the arguments passed to most method calls. If it finds any problems
1242	it will croak.
1243
1244	In other words, enables "strict" mode.
1245
1246	Unlike C<use strict> it is definitely recommended ot keep it off in
1247	production.
1248
1249	=item C<PERL_ANYEVENT_MODEL>
1250
1251	This can be used to specify the event model to be used by AnyEvent, before
1252	auto detection and -probing kicks in. It must be a string consisting
1253	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1254	and the resulting module name is loaded and if the load was successful,
1255	used as event model. If it fails to load AnyEvent will proceed with
1256	auto detection and -probing.
1257
1258	This functionality might change in future versions.
1259
1260	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1261	could start your program like this:
1262
1263	PERL_ANYEVENT_MODEL=Perl perl ...
1264
1265	=item C<PERL_ANYEVENT_PROTOCOLS>
1266
1267	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1268	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1269	of auto probing).
1270
1271	Must be set to a comma-separated list of protocols or address families,
1272	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1273	used, and preference will be given to protocols mentioned earlier in the
1274	list.
1275
1276	This variable can effectively be used for denial-of-service attacks
1277	against local programs (e.g. when setuid), although the impact is likely
1278	small, as the program has to handle connection errors already-
1279
1280	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1281	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1282	- only support IPv4, never try to resolve or contact IPv6
1283	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1284	IPv6, but prefer IPv6 over IPv4.
1285
1286	=item C<PERL_ANYEVENT_EDNS0>
1287
1288	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1289	for DNS. This extension is generally useful to reduce DNS traffic, but
1290	some (broken) firewalls drop such DNS packets, which is why it is off by
1291	default.
1292
1293	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1294	EDNS0 in its DNS requests.
1295
1296	=item C<PERL_ANYEVENT_MAX_FORKS>
1297
1298	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1299	will create in parallel.
1300
1301	=back
1302		1400
1303	=head1 EXAMPLE PROGRAM	1401	=head1 EXAMPLE PROGRAM
1304		1402
1305	The following program uses an I/O watcher to read data from STDIN, a timer	1403	The following program uses an I/O watcher to read data from STDIN, a timer
1306	to display a message once per second, and a condition variable to quit the	1404	to display a message once per second, and a condition variable to quit the
…		…
1500	watcher.	1598	watcher.
1501		1599
1502	=head3 Results	1600	=head3 Results
1503		1601
1504	name watchers bytes create invoke destroy comment	1602	name watchers bytes create invoke destroy comment
1505	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1603	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1506	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1604	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1507	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1605	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1508	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1606	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1509	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1607	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1510	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1608	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1511	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1609	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1512	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1610	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1513	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1611	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1514	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1612	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1515		1613
1516	=head3 Discussion	1614	=head3 Discussion
1517		1615
1518	The benchmark does I<not> measure scalability of the event loop very	1616	The benchmark does I<not> measure scalability of the event loop very
1519	well. For example, a select-based event loop (such as the pure perl one)	1617	well. For example, a select-based event loop (such as the pure perl one)
…		…
1721	watchers, as the management overhead dominates.	1819	watchers, as the management overhead dominates.
1722		1820
1723	=back	1821	=back
1724		1822
1725		1823
		1824	=head1 SIGNALS
		1825
		1826	AnyEvent currently installs handlers for these signals:
		1827
		1828	=over 4
		1829
		1830	=item SIGCHLD
		1831
		1832	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1833	emulation for event loops that do not support them natively. Also, some
		1834	event loops install a similar handler.
		1835
		1836	=item SIGPIPE
		1837
		1838	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1839	when AnyEvent gets loaded.
		1840
		1841	The rationale for this is that AnyEvent users usually do not really depend
		1842	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1843	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1844	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1845	some random socket.
		1846
		1847	The rationale for installing a no-op handler as opposed to ignoring it is
		1848	that this way, the handler will be restored to defaults on exec.
		1849
		1850	Feel free to install your own handler, or reset it to defaults.
		1851
		1852	=back
		1853
		1854	=cut
		1855
		1856	$SIG{PIPE} = sub { }
		1857	unless defined $SIG{PIPE};
		1858
		1859
1726	=head1 FORK	1860	=head1 FORK
1727		1861
1728	Most event libraries are not fork-safe. The ones who are usually are	1862	Most event libraries are not fork-safe. The ones who are usually are
1729	because they rely on inefficient but fork-safe C<select> or C<poll>	1863	because they rely on inefficient but fork-safe C<select> or C<poll>
1730	calls. Only L<EV> is fully fork-aware.	1864	calls. Only L<EV> is fully fork-aware.
…		…
1758	=head1 BUGS	1892	=head1 BUGS
1759		1893
1760	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	1894	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1761	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	1895	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1762	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	1896	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1763	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	1897	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1764	pronounced).	1898	pronounced).
1765		1899
1766		1900
1767	=head1 SEE ALSO	1901	=head1 SEE ALSO
1768		1902

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC vs. Revision 1.205 by root, Sun Apr 19 12:09:46 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC vs.
Revision 1.205 by root, Sun Apr 19 12:09:46 2009 UTC