[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 1.195 by root, Wed Mar 25 17:33:11 2009 UTC

…		…
340	=head2 CHILD PROCESS WATCHERS	340	=head2 CHILD PROCESS WATCHERS
341		341
342	You can also watch on a child process exit and catch its exit status.	342	You can also watch on a child process exit and catch its exit status.
343		343
344	The child process is specified by the C<pid> argument (if set to C<0>, it	344	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	345	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	346	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	347	any trace events (stopped/continued).
348	and exit status (as returned by waitpid), so unlike other watcher types,	348
349	you I<can> rely on child watcher callback arguments.	349	The callback will be called with the pid and exit status (as returned by
		350	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		351	callback arguments.
		352
		353	This watcher type works by installing a signal handler for C<SIGCHLD>,
		354	and since it cannot be shared, nothing else should use SIGCHLD or reap
		355	random child processes (waiting for specific child processes, e.g. inside
		356	C<system>, is just fine).
350		357
351	There is a slight catch to child watchers, however: you usually start them	358	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	359	I<after> the child process was created, and this means the process could
353	have exited already (and no SIGCHLD will be sent anymore).	360	have exited already (and no SIGCHLD will be sent anymore).
354		361
…		…
389		396
390	The instrument to do that is called a "condition variable", so called	397	The instrument to do that is called a "condition variable", so called
391	because they represent a condition that must become true.	398	because they represent a condition that must become true.
392		399
393	Condition variables can be created by calling the C<< AnyEvent->condvar	400	Condition variables can be created by calling the C<< AnyEvent->condvar
394
395	>> method, usually without arguments. The only argument pair allowed is	401	>> method, usually without arguments. The only argument pair allowed is
396		402
397	C<cb>, which specifies a callback to be called when the condition variable	403	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	404	becomes true, with the condition variable as the first argument (but not
399	the results).	405	the results).
…		…
819	=item L<AnyEvent::IGS>	825	=item L<AnyEvent::IGS>
820		826
821	A non-blocking interface to the Internet Go Server protocol (used by	827	A non-blocking interface to the Internet Go Server protocol (used by
822	L<App::IGS>).	828	L<App::IGS>).
823		829
824	=item L<Net::IRC3>	830	=item L<AnyEvent::IRC>
825		831
826	AnyEvent based IRC client module family.	832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
827		833
828	=item L<Net::XMPP2>	834	=item L<Net::XMPP2>
829		835
830	AnyEvent based XMPP (Jabber protocol) module family.	836	AnyEvent based XMPP (Jabber protocol) module family.
831		837
…		…
851	=cut	857	=cut
852		858
853	package AnyEvent;	859	package AnyEvent;
854		860
855	no warnings;	861	no warnings;
856	use strict;	862	use strict qw(vars subs);
857		863
858	use Carp;	864	use Carp;
859		865
860	our $VERSION = 4.22;	866	our $VERSION = 4.341;
861	our $MODEL;	867	our $MODEL;
862		868
863	our $AUTOLOAD;	869	our $AUTOLOAD;
864	our @ISA;	870	our @ISA;
865		871
…		…
998	# to support binding more than one watcher per filehandle (they usually	1004	# 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).	1005	# allow only one watcher per fd, so we dup it to get a different one).
1000	sub _dupfh($$$$) {	1006	sub _dupfh($$$$) {
1001	my ($poll, $fh, $r, $w) = @_;	1007	my ($poll, $fh, $r, $w) = @_;
1002		1008
1003	require Fcntl;
1004
1005	# cygwin requires the fh mode to be matching, unix doesn't	1009	# cygwin requires the fh mode to be matching, unix doesn't
1006	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1010	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
1007	: $poll eq "w" ? ($w, ">")	1011	: $poll eq "w" ? ($w, ">")
1008	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";	1012	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1009		1013
…		…
1017		1021
1018	package AnyEvent::Base;	1022	package AnyEvent::Base;
1019		1023
1020	# default implementation for now and time	1024	# default implementation for now and time
1021		1025
1022	use Time::HiRes ();	1026	BEGIN {
		1027	if (eval "use Time::HiRes (); time (); 1") {
		1028	*_time = \&Time::HiRes::time;
		1029	# if (eval "use POSIX (); (POSIX::times())...
		1030	} else {
		1031	*_time = sub { time }; # epic fail
		1032	}
		1033	}
1023		1034
1024	sub time { Time::HiRes::time }	1035	sub time { _time }
1025	sub now { Time::HiRes::time }	1036	sub now { _time }
1026		1037
1027	# default implementation for ->condvar	1038	# default implementation for ->condvar
1028		1039
1029	sub condvar {	1040	sub condvar {
1030	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1041	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
1031	}	1042	}
1032		1043
1033	# default implementation for ->signal	1044	# default implementation for ->signal
1034		1045
1035	our %SIG_CB;	1046	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1047
		1048	sub _signal_exec {
		1049	while (%SIG_EV) {
		1050	sysread $SIGPIPE_R, my $dummy, 4;
		1051	for (keys %SIG_EV) {
		1052	delete $SIG_EV{$_};
		1053	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1054	}
		1055	}
		1056	}
1036		1057
1037	sub signal {	1058	sub signal {
1038	my (undef, %arg) = @_;	1059	my (undef, %arg) = @_;
1039		1060
		1061	unless ($SIGPIPE_R) {
		1062	if (AnyEvent::WIN32) {
		1063	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1064	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1065	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1066	} else {
		1067	pipe $SIGPIPE_R, $SIGPIPE_W;
		1068	require Fcntl;
		1069	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1070	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1071	}
		1072
		1073	$SIGPIPE_R
		1074	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1075
		1076	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1077	}
		1078
1040	my $signal = uc $arg{signal}	1079	my $signal = uc $arg{signal}
1041	or Carp::croak "required option 'signal' is missing";	1080	or Carp::croak "required option 'signal' is missing";
1042		1081
1043	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1082	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1044	$SIG{$signal} \|\|= sub {	1083	$SIG{$signal} \|\|= sub {
1045	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1084	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1085	undef $SIG_EV{$signal};
1046	};	1086	};
1047		1087
1048	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1088	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
1049	}	1089	}
1050		1090
…		…
1169		1209
1170	# undocumented/compatibility with pre-3.4	1210	# undocumented/compatibility with pre-3.4
1171	*broadcast = \&send;	1211	*broadcast = \&send;
1172	*wait = \&_wait;	1212	*wait = \&_wait;
1173		1213
		1214	=head1 ERROR AND EXCEPTION HANDLING
		1215
		1216	In general, AnyEvent does not do any error handling - it relies on the
		1217	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1218	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1219	checking of all AnyEvent methods, however, which is highly useful during
		1220	development.
		1221
		1222	As for exception handling (i.e. runtime errors and exceptions thrown while
		1223	executing a callback), this is not only highly event-loop specific, but
		1224	also not in any way wrapped by this module, as this is the job of the main
		1225	program.
		1226
		1227	The pure perl event loop simply re-throws the exception (usually
		1228	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1229	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1230	so on.
		1231
		1232	=head1 ENVIRONMENT VARIABLES
		1233
		1234	The following environment variables are used by this module or its
		1235	submodules:
		1236
		1237	=over 4
		1238
		1239	=item C<PERL_ANYEVENT_VERBOSE>
		1240
		1241	By default, AnyEvent will be completely silent except in fatal
		1242	conditions. You can set this environment variable to make AnyEvent more
		1243	talkative.
		1244
		1245	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1246	conditions, such as not being able to load the event model specified by
		1247	C<PERL_ANYEVENT_MODEL>.
		1248
		1249	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1250	model it chooses.
		1251
		1252	=item C<PERL_ANYEVENT_STRICT>
		1253
		1254	AnyEvent does not do much argument checking by default, as thorough
		1255	argument checking is very costly. Setting this variable to a true value
		1256	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1257	check the arguments passed to most method calls. If it finds any problems
		1258	it will croak.
		1259
		1260	In other words, enables "strict" mode.
		1261
		1262	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1263	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1264	developing programs can be very useful, however.
		1265
		1266	=item C<PERL_ANYEVENT_MODEL>
		1267
		1268	This can be used to specify the event model to be used by AnyEvent, before
		1269	auto detection and -probing kicks in. It must be a string consisting
		1270	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1271	and the resulting module name is loaded and if the load was successful,
		1272	used as event model. If it fails to load AnyEvent will proceed with
		1273	auto detection and -probing.
		1274
		1275	This functionality might change in future versions.
		1276
		1277	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1278	could start your program like this:
		1279
		1280	PERL_ANYEVENT_MODEL=Perl perl ...
		1281
		1282	=item C<PERL_ANYEVENT_PROTOCOLS>
		1283
		1284	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1285	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1286	of auto probing).
		1287
		1288	Must be set to a comma-separated list of protocols or address families,
		1289	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1290	used, and preference will be given to protocols mentioned earlier in the
		1291	list.
		1292
		1293	This variable can effectively be used for denial-of-service attacks
		1294	against local programs (e.g. when setuid), although the impact is likely
		1295	small, as the program has to handle conenction and other failures anyways.
		1296
		1297	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1298	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1299	- only support IPv4, never try to resolve or contact IPv6
		1300	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1301	IPv6, but prefer IPv6 over IPv4.
		1302
		1303	=item C<PERL_ANYEVENT_EDNS0>
		1304
		1305	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1306	for DNS. This extension is generally useful to reduce DNS traffic, but
		1307	some (broken) firewalls drop such DNS packets, which is why it is off by
		1308	default.
		1309
		1310	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1311	EDNS0 in its DNS requests.
		1312
		1313	=item C<PERL_ANYEVENT_MAX_FORKS>
		1314
		1315	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1316	will create in parallel.
		1317
		1318	=back
		1319
1174	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1320	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1175		1321
1176	This is an advanced topic that you do not normally need to use AnyEvent in	1322	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	1323	a module. This section is only of use to event loop authors who want to
1178	provide AnyEvent compatibility.	1324	provide AnyEvent compatibility.
…		…
1211		1357
1212	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1358	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1213	condition variables: code blocking while waiting for a condition will	1359	condition variables: code blocking while waiting for a condition will
1214	C<die>. This still works with most modules/usages, and blocking calls must	1360	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.	1361	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		1362
1303	=head1 EXAMPLE PROGRAM	1363	=head1 EXAMPLE PROGRAM
1304		1364
1305	The following program uses an I/O watcher to read data from STDIN, a timer	1365	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	1366	to display a message once per second, and a condition variable to quit the
…		…
1500	watcher.	1560	watcher.
1501		1561
1502	=head3 Results	1562	=head3 Results
1503		1563
1504	name watchers bytes create invoke destroy comment	1564	name watchers bytes create invoke destroy comment
1505	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1565	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	1566	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	1567	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	1568	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	1569	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	1570	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	1571	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	1572	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	1573	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	1574	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1515		1575
1516	=head3 Discussion	1576	=head3 Discussion
1517		1577
1518	The benchmark does I<not> measure scalability of the event loop very	1578	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)	1579	well. For example, a select-based event loop (such as the pure perl one)
…		…
1721	watchers, as the management overhead dominates.	1781	watchers, as the management overhead dominates.
1722		1782
1723	=back	1783	=back
1724		1784
1725		1785
		1786	=head1 SIGNALS
		1787
		1788	AnyEvent currently installs handlers for these signals:
		1789
		1790	=over 4
		1791
		1792	=item SIGCHLD
		1793
		1794	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1795	emulation for event loops that do not support them natively. Also, some
		1796	event loops install a similar handler.
		1797
		1798	=item SIGPIPE
		1799
		1800	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1801	when AnyEvent gets loaded.
		1802
		1803	The rationale for this is that AnyEvent users usually do not really depend
		1804	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1805	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1806	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1807	some random socket.
		1808
		1809	The rationale for installing a no-op handler as opposed to ignoring it is
		1810	that this way, the handler will be restored to defaults on exec.
		1811
		1812	Feel free to install your own handler, or reset it to defaults.
		1813
		1814	=back
		1815
		1816	=cut
		1817
		1818	$SIG{PIPE} = sub { }
		1819	unless defined $SIG{PIPE};
		1820
		1821
1726	=head1 FORK	1822	=head1 FORK
1727		1823
1728	Most event libraries are not fork-safe. The ones who are usually are	1824	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>	1825	because they rely on inefficient but fork-safe C<select> or C<poll>
1730	calls. Only L<EV> is fully fork-aware.	1826	calls. Only L<EV> is fully fork-aware.

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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 1.195 by root, Wed Mar 25 17:33:11 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC vs.
Revision 1.195 by root, Wed Mar 25 17:33:11 2009 UTC