[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 1.190 by root, Wed Nov 5 02:21:27 2008 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
…		…
331	=head2 CHILD PROCESS WATCHERS	340	=head2 CHILD PROCESS WATCHERS
332		341
333	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.
334		343
335	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
336	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
337	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
338	signal handler for C<SIGCHLD>. The callback will be called with the pid	347	any trace events (stopped/continued).
339	and exit status (as returned by waitpid), so unlike other watcher types,	348
340	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).
341		357
342	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
343	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
344	have exited already (and no SIGCHLD will be sent anymore).	360	have exited already (and no SIGCHLD will be sent anymore).
345		361
…		…
381	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
382	because they represent a condition that must become true.	398	because they represent a condition that must become true.
383		399
384	Condition variables can be created by calling the C<< AnyEvent->condvar	400	Condition variables can be created by calling the C<< AnyEvent->condvar
385	>> method, usually without arguments. The only argument pair allowed is	401	>> method, usually without arguments. The only argument pair allowed is
		402
386	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
387	becomes true.	404	becomes true, with the condition variable as the first argument (but not
		405	the results).
388		406
389	After creation, the condition variable is "false" until it becomes "true"	407	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	408	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<<	409	were a callback, read about the caveats in the description for the C<<
392	->send >> method).	410	->send >> method).
…		…
448		466
449	my $done = AnyEvent->condvar;	467	my $done = AnyEvent->condvar;
450	my $delay = AnyEvent->timer (after => 5, cb => $done);	468	my $delay = AnyEvent->timer (after => 5, cb => $done);
451	$done->recv;	469	$done->recv;
452		470
		471	Example: Imagine an API that returns a condvar and doesn't support
		472	callbacks. This is how you make a synchronous call, for example from
		473	the main program:
		474
		475	use AnyEvent::CouchDB;
		476
		477	...
		478
		479	my @info = $couchdb->info->recv;
		480
		481	And this is how you would just ste a callback to be called whenever the
		482	results are available:
		483
		484	$couchdb->info->cb (sub {
		485	my @info = $_[0]->recv;
		486	});
		487
453	=head3 METHODS FOR PRODUCERS	488	=head3 METHODS FOR PRODUCERS
454		489
455	These methods should only be used by the producing side, i.e. the	490	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	491	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	492	the producer side which creates the condvar in most cases, but it isn't
…		…
590	=item $bool = $cv->ready	625	=item $bool = $cv->ready
591		626
592	Returns true when the condition is "true", i.e. whether C<send> or	627	Returns true when the condition is "true", i.e. whether C<send> or
593	C<croak> have been called.	628	C<croak> have been called.
594		629
595	=item $cb = $cv->cb ([new callback])	630	=item $cb = $cv->cb ($cb->($cv))
596		631
597	This is a mutator function that returns the callback set and optionally	632	This is a mutator function that returns the callback set and optionally
598	replaces it before doing so.	633	replaces it before doing so.
599		634
600	The callback will be called when the condition becomes "true", i.e. when	635	The callback will be called when the condition becomes "true", i.e. when
…		…
790	=item L<AnyEvent::IGS>	825	=item L<AnyEvent::IGS>
791		826
792	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
793	L<App::IGS>).	828	L<App::IGS>).
794		829
795	=item L<Net::IRC3>	830	=item L<AnyEvent::IRC>
796		831
797	AnyEvent based IRC client module family.	832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
798		833
799	=item L<Net::XMPP2>	834	=item L<Net::XMPP2>
800		835
801	AnyEvent based XMPP (Jabber protocol) module family.	836	AnyEvent based XMPP (Jabber protocol) module family.
802		837
…		…
822	=cut	857	=cut
823		858
824	package AnyEvent;	859	package AnyEvent;
825		860
826	no warnings;	861	no warnings;
827	use strict;	862	use strict qw(vars subs);
828		863
829	use Carp;	864	use Carp;
830		865
831	our $VERSION = 4.2;	866	our $VERSION = 4.32;
832	our $MODEL;	867	our $MODEL;
833		868
834	our $AUTOLOAD;	869	our $AUTOLOAD;
835	our @ISA;	870	our @ISA;
836		871
…		…
988		1023
989	package AnyEvent::Base;	1024	package AnyEvent::Base;
990		1025
991	# default implementation for now and time	1026	# default implementation for now and time
992		1027
993	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	}
994		1036
995	sub time { Time::HiRes::time }	1037	sub time { _time }
996	sub now { Time::HiRes::time }	1038	sub now { _time }
997		1039
998	# default implementation for ->condvar	1040	# default implementation for ->condvar
999		1041
1000	sub condvar {	1042	sub condvar {
1001	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1043	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
1140		1182
1141	# undocumented/compatibility with pre-3.4	1183	# undocumented/compatibility with pre-3.4
1142	*broadcast = \&send;	1184	*broadcast = \&send;
1143	*wait = \&_wait;	1185	*wait = \&_wait;
1144		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
1145	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1293	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1146		1294
1147	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
1148	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
1149	provide AnyEvent compatibility.	1297	provide AnyEvent compatibility.
…		…
1182		1330
1183	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
1184	condition variables: code blocking while waiting for a condition will	1332	condition variables: code blocking while waiting for a condition will
1185	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
1186	not be done in an interactive application, so it makes sense.	1334	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		1335
1274	=head1 EXAMPLE PROGRAM	1336	=head1 EXAMPLE PROGRAM
1275		1337
1276	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
1277	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
…		…
1471	watcher.	1533	watcher.
1472		1534
1473	=head3 Results	1535	=head3 Results
1474		1536
1475	name watchers bytes create invoke destroy comment	1537	name watchers bytes create invoke destroy comment
1476	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1538	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	1539	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	1540	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	1541	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	1542	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	1543	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	1544	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	1545	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	1546	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	1547	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1486		1548
1487	=head3 Discussion	1549	=head3 Discussion
1488		1550
1489	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
1490	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)
…		…
1692	watchers, as the management overhead dominates.	1754	watchers, as the management overhead dominates.
1693		1755
1694	=back	1756	=back
1695		1757
1696		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
1697	=head1 FORK	1795	=head1 FORK
1698		1796
1699	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
1700	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>
1701	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 1.170 by root, Wed Jul 9 11:53:40 2008 UTC vs. Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.170 by root, Wed Jul 9 11:53:40 2008 UTC vs.
Revision 1.190 by root, Wed Nov 5 02:21:27 2008 UTC