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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC vs.
Revision 1.182 by root, Sun Sep 7 15:27:17 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
…		…
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 = 4.234;
832	our $MODEL;	867	our $MODEL;
833		868
834	our $AUTOLOAD;	869	our $AUTOLOAD;
835	our @ISA;	870	our @ISA;
836		871
…		…
963		998
964	my $class = shift;	999	my $class = shift;
965	$class->$func (@_);	1000	$class->$func (@_);
966	}	1001	}
967		1002
		1003	# utility function to dup a filehandle. this is used by many backends
		1004	# to support binding more than one watcher per filehandle (they usually
		1005	# allow only one watcher per fd, so we dup it to get a different one).
		1006	sub _dupfh($$$$) {
		1007	my ($poll, $fh, $r, $w) = @_;
		1008
		1009	require Fcntl;
		1010
		1011	# cygwin requires the fh mode to be matching, unix doesn't
		1012	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1013	: $poll eq "w" ? ($w, ">")
		1014	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1015
		1016	open my $fh2, "$mode&" . fileno $fh
		1017	or die "cannot dup() filehandle: $!";
		1018
		1019	# we assume CLOEXEC is already set by perl in all important cases
		1020
		1021	($fh2, $rw)
		1022	}
		1023
968	package AnyEvent::Base;	1024	package AnyEvent::Base;
969		1025
970	# default implementation for now and time	1026	# default implementation for now and time
971		1027
972	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	}
973		1036
974	sub time { Time::HiRes::time }	1037	sub time { _time }
975	sub now { Time::HiRes::time }	1038	sub now { _time }
976		1039
977	# default implementation for ->condvar	1040	# default implementation for ->condvar
978		1041
979	sub condvar {	1042	sub condvar {
980	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1043	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
1119		1182
1120	# undocumented/compatibility with pre-3.4	1183	# undocumented/compatibility with pre-3.4
1121	*broadcast = \&send;	1184	*broadcast = \&send;
1122	*wait = \&_wait;	1185	*wait = \&_wait;
1123		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
1124	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1293	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1125		1294
1126	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
1127	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
1128	provide AnyEvent compatibility.	1297	provide AnyEvent compatibility.
…		…
1161		1330
1162	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
1163	condition variables: code blocking while waiting for a condition will	1332	condition variables: code blocking while waiting for a condition will
1164	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
1165	not be done in an interactive application, so it makes sense.	1334	not be done in an interactive application, so it makes sense.
1166
1167	=head1 ENVIRONMENT VARIABLES
1168
1169	The following environment variables are used by this module:
1170
1171	=over 4
1172
1173	=item C<PERL_ANYEVENT_VERBOSE>
1174
1175	By default, AnyEvent will be completely silent except in fatal
1176	conditions. You can set this environment variable to make AnyEvent more
1177	talkative.
1178
1179	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1180	conditions, such as not being able to load the event model specified by
1181	C<PERL_ANYEVENT_MODEL>.
1182
1183	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1184	model it chooses.
1185
1186	=item C<PERL_ANYEVENT_STRICT>
1187
1188	AnyEvent does not do much argument checking by default, as thorough
1189	argument checking is very costly. Setting this variable to a true value
1190	will cause AnyEvent to thoroughly check the arguments passed to most
1191	method calls and croaks if it finds any problems. In other words, enables
1192	"strict" mode. Unlike C<use strict> it is definitely recommended ot keep
1193	it off in production.
1194
1195	=item C<PERL_ANYEVENT_MODEL>
1196
1197	This can be used to specify the event model to be used by AnyEvent, before
1198	auto detection and -probing kicks in. It must be a string consisting
1199	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1200	and the resulting module name is loaded and if the load was successful,
1201	used as event model. If it fails to load AnyEvent will proceed with
1202	auto detection and -probing.
1203
1204	This functionality might change in future versions.
1205
1206	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1207	could start your program like this:
1208
1209	PERL_ANYEVENT_MODEL=Perl perl ...
1210
1211	=item C<PERL_ANYEVENT_PROTOCOLS>
1212
1213	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1214	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1215	of auto probing).
1216
1217	Must be set to a comma-separated list of protocols or address families,
1218	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1219	used, and preference will be given to protocols mentioned earlier in the
1220	list.
1221
1222	This variable can effectively be used for denial-of-service attacks
1223	against local programs (e.g. when setuid), although the impact is likely
1224	small, as the program has to handle connection errors already-
1225
1226	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1227	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1228	- only support IPv4, never try to resolve or contact IPv6
1229	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1230	IPv6, but prefer IPv6 over IPv4.
1231
1232	=item C<PERL_ANYEVENT_EDNS0>
1233
1234	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1235	for DNS. This extension is generally useful to reduce DNS traffic, but
1236	some (broken) firewalls drop such DNS packets, which is why it is off by
1237	default.
1238
1239	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1240	EDNS0 in its DNS requests.
1241
1242	=item C<PERL_ANYEVENT_MAX_FORKS>
1243
1244	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1245	will create in parallel.
1246
1247	=back
1248		1335
1249	=head1 EXAMPLE PROGRAM	1336	=head1 EXAMPLE PROGRAM
1250		1337
1251	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
1252	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

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC vs. Revision 1.182 by root, Sun Sep 7 15:27:17 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC vs.
Revision 1.182 by root, Sun Sep 7 15:27:17 2008 UTC