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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.176 by root, Wed Aug 20 12:37:21 2008 UTC vs.
Revision 1.186 by root, Mon Oct 27 02:58:19 2008 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
…		…
818	=item L<AnyEvent::IGS>	825	=item L<AnyEvent::IGS>
819		826
820	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
821	L<App::IGS>).	828	L<App::IGS>).
822		829
823	=item L<Net::IRC3>	830	=item L<AnyEvent::IRC>
824		831
825	AnyEvent based IRC client module family.	832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
826		833
827	=item L<Net::XMPP2>	834	=item L<Net::XMPP2>
828		835
829	AnyEvent based XMPP (Jabber protocol) module family.	836	AnyEvent based XMPP (Jabber protocol) module family.
830		837
…		…
850	=cut	857	=cut
851		858
852	package AnyEvent;	859	package AnyEvent;
853		860
854	no warnings;	861	no warnings;
855	use strict;	862	use strict qw(vars subs);
856		863
857	use Carp;	864	use Carp;
858		865
859	our $VERSION = 4.231;	866	our $VERSION = 4.3;
860	our $MODEL;	867	our $MODEL;
861		868
862	our $AUTOLOAD;	869	our $AUTOLOAD;
863	our @ISA;	870	our @ISA;
864		871
…		…
1016		1023
1017	package AnyEvent::Base;	1024	package AnyEvent::Base;
1018		1025
1019	# default implementation for now and time	1026	# default implementation for now and time
1020		1027
1021	use Time::HiRes ();	1028	BEGIN {
		1029	if (eval "use Time::HiRes (); time (); 1") {
		1030	*_time = \&Time::HiRes::time;
		1031	# if (eval "use POSIX (); (POSIX::times())...
		1032	} else {
		1033	*_time = sub { time }; # epic fail
		1034	}
		1035	}
1022		1036
1023	sub time { Time::HiRes::time }	1037	sub time { _time }
1024	sub now { Time::HiRes::time }	1038	sub now { _time }
1025		1039
1026	# default implementation for ->condvar	1040	# default implementation for ->condvar
1027		1041
1028	sub condvar {	1042	sub condvar {
1029	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1043	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
1168		1182
1169	# undocumented/compatibility with pre-3.4	1183	# undocumented/compatibility with pre-3.4
1170	*broadcast = \&send;	1184	*broadcast = \&send;
1171	*wait = \&_wait;	1185	*wait = \&_wait;
1172		1186
		1187	=head1 ERROR AND EXCEPTION HANDLING
		1188
		1189	In general, AnyEvent does not do any error handling - it relies on the
		1190	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1191	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1192	checking of all AnyEvent methods, however, which is highly useful during
		1193	development.
		1194
		1195	As for exception handling (i.e. runtime errors and exceptions thrown while
		1196	executing a callback), this is not only highly event-loop specific, but
		1197	also not in any way wrapped by this module, as this is the job of the main
		1198	program.
		1199
		1200	The pure perl event loop simply re-throws the exception (usually
		1201	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1202	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1203	so on.
		1204
		1205	=head1 ENVIRONMENT VARIABLES
		1206
		1207	The following environment variables are used by this module or its
		1208	submodules:
		1209
		1210	=over 4
		1211
		1212	=item C<PERL_ANYEVENT_VERBOSE>
		1213
		1214	By default, AnyEvent will be completely silent except in fatal
		1215	conditions. You can set this environment variable to make AnyEvent more
		1216	talkative.
		1217
		1218	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1219	conditions, such as not being able to load the event model specified by
		1220	C<PERL_ANYEVENT_MODEL>.
		1221
		1222	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1223	model it chooses.
		1224
		1225	=item C<PERL_ANYEVENT_STRICT>
		1226
		1227	AnyEvent does not do much argument checking by default, as thorough
		1228	argument checking is very costly. Setting this variable to a true value
		1229	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1230	check the arguments passed to most method calls. If it finds any problems
		1231	it will croak.
		1232
		1233	In other words, enables "strict" mode.
		1234
		1235	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1236	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1237	developing programs can be very useful, however.
		1238
		1239	=item C<PERL_ANYEVENT_MODEL>
		1240
		1241	This can be used to specify the event model to be used by AnyEvent, before
		1242	auto detection and -probing kicks in. It must be a string consisting
		1243	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1244	and the resulting module name is loaded and if the load was successful,
		1245	used as event model. If it fails to load AnyEvent will proceed with
		1246	auto detection and -probing.
		1247
		1248	This functionality might change in future versions.
		1249
		1250	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1251	could start your program like this:
		1252
		1253	PERL_ANYEVENT_MODEL=Perl perl ...
		1254
		1255	=item C<PERL_ANYEVENT_PROTOCOLS>
		1256
		1257	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1258	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1259	of auto probing).
		1260
		1261	Must be set to a comma-separated list of protocols or address families,
		1262	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1263	used, and preference will be given to protocols mentioned earlier in the
		1264	list.
		1265
		1266	This variable can effectively be used for denial-of-service attacks
		1267	against local programs (e.g. when setuid), although the impact is likely
		1268	small, as the program has to handle connection errors already-
		1269
		1270	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1271	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1272	- only support IPv4, never try to resolve or contact IPv6
		1273	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1274	IPv6, but prefer IPv6 over IPv4.
		1275
		1276	=item C<PERL_ANYEVENT_EDNS0>
		1277
		1278	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1279	for DNS. This extension is generally useful to reduce DNS traffic, but
		1280	some (broken) firewalls drop such DNS packets, which is why it is off by
		1281	default.
		1282
		1283	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1284	EDNS0 in its DNS requests.
		1285
		1286	=item C<PERL_ANYEVENT_MAX_FORKS>
		1287
		1288	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1289	will create in parallel.
		1290
		1291	=back
		1292
1173	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1293	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1174		1294
1175	This is an advanced topic that you do not normally need to use AnyEvent in	1295	This is an advanced topic that you do not normally need to use AnyEvent in
1176	a module. This section is only of use to event loop authors who want to	1296	a module. This section is only of use to event loop authors who want to
1177	provide AnyEvent compatibility.	1297	provide AnyEvent compatibility.
…		…
1210		1330
1211	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1331	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1212	condition variables: code blocking while waiting for a condition will	1332	condition variables: code blocking while waiting for a condition will
1213	C<die>. This still works with most modules/usages, and blocking calls must	1333	C<die>. This still works with most modules/usages, and blocking calls must
1214	not be done in an interactive application, so it makes sense.	1334	not be done in an interactive application, so it makes sense.
1215
1216	=head1 ENVIRONMENT VARIABLES
1217
1218	The following environment variables are used by this module:
1219
1220	=over 4
1221
1222	=item C<PERL_ANYEVENT_VERBOSE>
1223
1224	By default, AnyEvent will be completely silent except in fatal
1225	conditions. You can set this environment variable to make AnyEvent more
1226	talkative.
1227
1228	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1229	conditions, such as not being able to load the event model specified by
1230	C<PERL_ANYEVENT_MODEL>.
1231
1232	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1233	model it chooses.
1234
1235	=item C<PERL_ANYEVENT_STRICT>
1236
1237	AnyEvent does not do much argument checking by default, as thorough
1238	argument checking is very costly. Setting this variable to a true value
1239	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1240	check the arguments passed to most method calls. If it finds any problems
1241	it will croak.
1242
1243	In other words, enables "strict" mode.
1244
1245	Unlike C<use strict> it is definitely recommended ot keep it off in
1246	production.
1247
1248	=item C<PERL_ANYEVENT_MODEL>
1249
1250	This can be used to specify the event model to be used by AnyEvent, before
1251	auto detection and -probing kicks in. It must be a string consisting
1252	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1253	and the resulting module name is loaded and if the load was successful,
1254	used as event model. If it fails to load AnyEvent will proceed with
1255	auto detection and -probing.
1256
1257	This functionality might change in future versions.
1258
1259	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1260	could start your program like this:
1261
1262	PERL_ANYEVENT_MODEL=Perl perl ...
1263
1264	=item C<PERL_ANYEVENT_PROTOCOLS>
1265
1266	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1267	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1268	of auto probing).
1269
1270	Must be set to a comma-separated list of protocols or address families,
1271	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1272	used, and preference will be given to protocols mentioned earlier in the
1273	list.
1274
1275	This variable can effectively be used for denial-of-service attacks
1276	against local programs (e.g. when setuid), although the impact is likely
1277	small, as the program has to handle connection errors already-
1278
1279	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1280	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1281	- only support IPv4, never try to resolve or contact IPv6
1282	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1283	IPv6, but prefer IPv6 over IPv4.
1284
1285	=item C<PERL_ANYEVENT_EDNS0>
1286
1287	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1288	for DNS. This extension is generally useful to reduce DNS traffic, but
1289	some (broken) firewalls drop such DNS packets, which is why it is off by
1290	default.
1291
1292	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1293	EDNS0 in its DNS requests.
1294
1295	=item C<PERL_ANYEVENT_MAX_FORKS>
1296
1297	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1298	will create in parallel.
1299
1300	=back
1301		1335
1302	=head1 EXAMPLE PROGRAM	1336	=head1 EXAMPLE PROGRAM
1303		1337
1304	The following program uses an I/O watcher to read data from STDIN, a timer	1338	The following program uses an I/O watcher to read data from STDIN, a timer
1305	to display a message once per second, and a condition variable to quit the	1339	to display a message once per second, and a condition variable to quit the
…		…
1499	watcher.	1533	watcher.
1500		1534
1501	=head3 Results	1535	=head3 Results
1502		1536
1503	name watchers bytes create invoke destroy comment	1537	name watchers bytes create invoke destroy comment
1504	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1538	EV/EV 400000 224 0.47 0.43 0.27 EV native interface
1505	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1539	EV/Any 100000 224 2.88 0.44 0.27 EV + AnyEvent watchers
1506	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1540	CoroEV/Any 100000 224 2.85 0.45 0.28 coroutines + Coro::Signal
1507	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1541	Perl/Any 100000 452 4.14 0.75 0.99 pure perl implementation
1508	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1542	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1509	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1543	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1510	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1544	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1511	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1545	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1512	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1546	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1513	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1547	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1514		1548
1515	=head3 Discussion	1549	=head3 Discussion
1516		1550
1517	The benchmark does I<not> measure scalability of the event loop very	1551	The benchmark does I<not> measure scalability of the event loop very
1518	well. For example, a select-based event loop (such as the pure perl one)	1552	well. For example, a select-based event loop (such as the pure perl one)
…		…
1720	watchers, as the management overhead dominates.	1754	watchers, as the management overhead dominates.
1721		1755
1722	=back	1756	=back
1723		1757
1724		1758
		1759	=head1 SIGNALS
		1760
		1761	AnyEvent currently installs handlers for these signals:
		1762
		1763	=over 4
		1764
		1765	=item SIGCHLD
		1766
		1767	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1768	emulation for event loops that do not support them natively. Also, some
		1769	event loops install a similar handler.
		1770
		1771	=item SIGPIPE
		1772
		1773	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1774	when AnyEvent gets loaded.
		1775
		1776	The rationale for this is that AnyEvent users usually do not really depend
		1777	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1778	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1779	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1780	some random socket.
		1781
		1782	The rationale for installing a no-op handler as opposed to ignoring it is
		1783	that this way, the handler will be restored to defaults on exec.
		1784
		1785	Feel free to install your own handler, or reset it to defaults.
		1786
		1787	=back
		1788
		1789	=cut
		1790
		1791	$SIG{PIPE} = sub { }
		1792	unless defined $SIG{PIPE};
		1793
		1794
1725	=head1 FORK	1795	=head1 FORK
1726		1796
1727	Most event libraries are not fork-safe. The ones who are usually are	1797	Most event libraries are not fork-safe. The ones who are usually are
1728	because they rely on inefficient but fork-safe C<select> or C<poll>	1798	because they rely on inefficient but fork-safe C<select> or C<poll>
1729	calls. Only L<EV> is fully fork-aware.	1799	calls. Only L<EV> is fully fork-aware.

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.176 by root, Wed Aug 20 12:37:21 2008 UTC vs. Revision 1.186 by root, Mon Oct 27 02:58:19 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.176 by root, Wed Aug 20 12:37:21 2008 UTC vs.
Revision 1.186 by root, Mon Oct 27 02:58:19 2008 UTC