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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs.
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC

…		…
1	=head1 => NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
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
33		42
34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
36		45
37	First and foremost, I<AnyEvent is not an event model> itself, it only	46	First and foremost, I<AnyEvent is not an event model> itself, it only
38	interfaces to whatever event model the main program happens to use in a	47	interfaces to whatever event model the main program happens to use, in a
39	pragmatic way. For event models and certain classes of immortals alike,	48	pragmatic way. For event models and certain classes of immortals alike,
40	the statement "there can only be one" is a bitter reality: In general,	49	the statement "there can only be one" is a bitter reality: In general,
41	only one event loop can be active at the same time in a process. AnyEvent	50	only one event loop can be active at the same time in a process. AnyEvent
42	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
43		53
44	The goal of AnyEvent is to offer module authors the ability to do event	54	The goal of AnyEvent is to offer module authors the ability to do event
45	programming (waiting for I/O or timer events) without subscribing to a	55	programming (waiting for I/O or timer events) without subscribing to a
46	religion, a way of living, and most importantly: without forcing your	56	religion, a way of living, and most importantly: without forcing your
47	module users into the same thing by forcing them to use the same event	57	module users into the same thing by forcing them to use the same event
48	model you use.	58	model you use.
49		59
50	For modules like POE or IO::Async (which is a total misnomer as it is	60	For modules like POE or IO::Async (which is a total misnomer as it is
51	actually doing all I/O I<synchronously>...), using them in your module is	61	actually doing all I/O I<synchronously>...), using them in your module is
52	like joining a cult: After you joined, you are dependent on them and you	62	like joining a cult: After you joined, you are dependent on them and you
53	cannot use anything else, as it is simply incompatible to everything that	63	cannot use anything else, as they are simply incompatible to everything
54	isn't itself. What's worse, all the potential users of your module are	64	that isn't them. What's worse, all the potential users of your
55	I<also> forced to use the same event loop you use.	65	module are I<also> forced to use the same event loop you use.
56		66
57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	68	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
59	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	69	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
60	your module uses one of those, every user of your module has to use it,	70	your module uses one of those, every user of your module has to use it,
61	too. But if your module uses AnyEvent, it works transparently with all	71	too. But if your module uses AnyEvent, it works transparently with all
62	event models it supports (including stuff like POE and IO::Async, as long	72	event models it supports (including stuff like IO::Async, as long as those
63	as those use one of the supported event loops. It is trivial to add new	73	use one of the supported event loops. It is trivial to add new event loops
64	event loops to AnyEvent, too, so it is future-proof).	74	to AnyEvent, too, so it is future-proof).
65		75
66	In addition to being free of having to use I<the one and only true event	76	In addition to being free of having to use I<the one and only true event
67	model>, AnyEvent also is free of bloat and policy: with POE or similar	77	model>, AnyEvent also is free of bloat and policy: with POE or similar
68	modules, you get an enormous amount of code and strict rules you have to	78	modules, you get an enormous amount of code and strict rules you have to
69	follow. AnyEvent, on the other hand, is lean and up to the point, by only	79	follow. AnyEvent, on the other hand, is lean and up to the point, by only
…		…
138	Many watchers either are used with "recursion" (repeating timers for	148	Many watchers either are used with "recursion" (repeating timers for
139	example), or need to refer to their watcher object in other ways.	149	example), or need to refer to their watcher object in other ways.
140		150
141	An any way to achieve that is this pattern:	151	An any way to achieve that is this pattern:
142		152
143	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	153	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
144	# you can use $w here, for example to undef it	154	# you can use $w here, for example to undef it
145	undef $w;	155	undef $w;
146	});	156	});
147		157
148	Note that C<my $w; $w => combination. This is necessary because in Perl,	158	Note that C<my $w; $w => combination. This is necessary because in Perl,
149	my variables are only visible after the statement in which they are	159	my variables are only visible after the statement in which they are
150	declared.	160	declared.
151		161
152	=head2 I/O WATCHERS	162	=head2 I/O WATCHERS
153		163
154	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	164	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
155	with the following mandatory key-value pairs as arguments:	165	with the following mandatory key-value pairs as arguments:
156		166
157	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	167	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
158	for events. C<poll> must be a string that is either C<r> or C<w>,	168	(AnyEvent might or might not keep a reference to this file handle). C<poll>
159	which creates a watcher waiting for "r"eadable or "w"ritable events,	169	must be a string that is either C<r> or C<w>, which creates a watcher
160	respectively. C<cb> is the callback to invoke each time the file handle	170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
161	becomes ready.	171	callback to invoke each time the file handle becomes ready.
162		172
163	Although the callback might get passed parameters, their value and	173	Although the callback might get passed parameters, their value and
164	presence is undefined and you cannot rely on them. Portable AnyEvent	174	presence is undefined and you cannot rely on them. Portable AnyEvent
165	callbacks cannot use arguments passed to I/O watcher callbacks.	175	callbacks cannot use arguments passed to I/O watcher callbacks.
166		176
…		…
170		180
171	Some event loops issue spurious readyness notifications, so you should	181	Some event loops issue spurious readyness notifications, so you should
172	always use non-blocking calls when reading/writing from/to your file	182	always use non-blocking calls when reading/writing from/to your file
173	handles.	183	handles.
174		184
175	Example:
176
177	# wait for readability of STDIN, then read a line and disable the watcher	185	Example: wait for readability of STDIN, then read a line and disable the
		186	watcher.
		187
178	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	188	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
179	chomp (my $input = <STDIN>);	189	chomp (my $input = <STDIN>);
180	warn "read: $input\n";	190	warn "read: $input\n";
181	undef $w;	191	undef $w;
182	});	192	});
…		…
192		202
193	Although the callback might get passed parameters, their value and	203	Although the callback might get passed parameters, their value and
194	presence is undefined and you cannot rely on them. Portable AnyEvent	204	presence is undefined and you cannot rely on them. Portable AnyEvent
195	callbacks cannot use arguments passed to time watcher callbacks.	205	callbacks cannot use arguments passed to time watcher callbacks.
196		206
197	The timer callback will be invoked at most once: if you want a repeating	207	The callback will normally be invoked once only. If you specify another
198	timer you have to create a new watcher (this is a limitation by both Tk	208	parameter, C<interval>, as a strictly positive number (> 0), then the
199	and Glib).	209	callback will be invoked regularly at that interval (in fractional
		210	seconds) after the first invocation. If C<interval> is specified with a
		211	false value, then it is treated as if it were missing.
200		212
201	Example:	213	The callback will be rescheduled before invoking the callback, but no
		214	attempt is done to avoid timer drift in most backends, so the interval is
		215	only approximate.
202		216
203	# fire an event after 7.7 seconds	217	Example: fire an event after 7.7 seconds.
		218
204	my $w = AnyEvent->timer (after => 7.7, cb => sub {	219	my $w = AnyEvent->timer (after => 7.7, cb => sub {
205	warn "timeout\n";	220	warn "timeout\n";
206	});	221	});
207		222
208	# to cancel the timer:	223	# to cancel the timer:
209	undef $w;	224	undef $w;
210		225
211	Example 2:
212
213	# fire an event after 0.5 seconds, then roughly every second	226	Example 2: fire an event after 0.5 seconds, then roughly every second.
214	my $w;
215		227
216	my $cb = sub {
217	# cancel the old timer while creating a new one
218	$w = AnyEvent->timer (after => 1, cb => $cb);	228	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		229	warn "timeout\n";
219	};	230	};
220
221	# start the "loop" by creating the first watcher
222	$w = AnyEvent->timer (after => 0.5, cb => $cb);
223		231
224	=head3 TIMING ISSUES	232	=head3 TIMING ISSUES
225		233
226	There are two ways to handle timers: based on real time (relative, "fire	234	There are two ways to handle timers: based on real time (relative, "fire
227	in 10 seconds") and based on wallclock time (absolute, "fire at 12	235	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
305	=back	313	=back
306		314
307	=head2 SIGNAL WATCHERS	315	=head2 SIGNAL WATCHERS
308		316
309	You can watch for signals using a signal watcher, C<signal> is the signal	317	You can watch for signals using a signal watcher, C<signal> is the signal
310	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	318	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
311	be invoked whenever a signal occurs.	319	callback to be invoked whenever a signal occurs.
312		320
313	Although the callback might get passed parameters, their value and	321	Although the callback might get passed parameters, their value and
314	presence is undefined and you cannot rely on them. Portable AnyEvent	322	presence is undefined and you cannot rely on them. Portable AnyEvent
315	callbacks cannot use arguments passed to signal watcher callbacks.	323	callbacks cannot use arguments passed to signal watcher callbacks.
316		324
…		…
352	AnyEvent program, you I<have> to create at least one watcher before you	360	AnyEvent program, you I<have> to create at least one watcher before you
353	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	361	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
354		362
355	Example: fork a process and wait for it	363	Example: fork a process and wait for it
356		364
357	my $done = AnyEvent->condvar;	365	my $done = AnyEvent->condvar;
358		366
359	my $pid = fork or exit 5;	367	my $pid = fork or exit 5;
360		368
361	my $w = AnyEvent->child (	369	my $w = AnyEvent->child (
362	pid => $pid,	370	pid => $pid,
363	cb => sub {	371	cb => sub {
364	my ($pid, $status) = @_;	372	my ($pid, $status) = @_;
365	warn "pid $pid exited with status $status";	373	warn "pid $pid exited with status $status";
366	$done->send;	374	$done->send;
367	},	375	},
368	);	376	);
369		377
370	# do something else, then wait for process exit	378	# do something else, then wait for process exit
371	$done->recv;	379	$done->recv;
372		380
373	=head2 CONDITION VARIABLES	381	=head2 CONDITION VARIABLES
374		382
375	If you are familiar with some event loops you will know that all of them	383	If you are familiar with some event loops you will know that all of them
376	require you to run some blocking "loop", "run" or similar function that	384	require you to run some blocking "loop", "run" or similar function that
…		…
382	The instrument to do that is called a "condition variable", so called	390	The instrument to do that is called a "condition variable", so called
383	because they represent a condition that must become true.	391	because they represent a condition that must become true.
384		392
385	Condition variables can be created by calling the C<< AnyEvent->condvar	393	Condition variables can be created by calling the C<< AnyEvent->condvar
386	>> method, usually without arguments. The only argument pair allowed is	394	>> method, usually without arguments. The only argument pair allowed is
		395
387	C<cb>, which specifies a callback to be called when the condition variable	396	C<cb>, which specifies a callback to be called when the condition variable
388	becomes true.	397	becomes true, with the condition variable as the first argument (but not
		398	the results).
389		399
390	After creation, the condition variable is "false" until it becomes "true"	400	After creation, the condition variable is "false" until it becomes "true"
391	by calling the C<send> method (or calling the condition variable as if it	401	by calling the C<send> method (or calling the condition variable as if it
392	were a callback, read about the caveats in the description for the C<<	402	were a callback, read about the caveats in the description for the C<<
393	->send >> method).	403	->send >> method).
…		…
449		459
450	my $done = AnyEvent->condvar;	460	my $done = AnyEvent->condvar;
451	my $delay = AnyEvent->timer (after => 5, cb => $done);	461	my $delay = AnyEvent->timer (after => 5, cb => $done);
452	$done->recv;	462	$done->recv;
453		463
		464	Example: Imagine an API that returns a condvar and doesn't support
		465	callbacks. This is how you make a synchronous call, for example from
		466	the main program:
		467
		468	use AnyEvent::CouchDB;
		469
		470	...
		471
		472	my @info = $couchdb->info->recv;
		473
		474	And this is how you would just ste a callback to be called whenever the
		475	results are available:
		476
		477	$couchdb->info->cb (sub {
		478	my @info = $_[0]->recv;
		479	});
		480
454	=head3 METHODS FOR PRODUCERS	481	=head3 METHODS FOR PRODUCERS
455		482
456	These methods should only be used by the producing side, i.e. the	483	These methods should only be used by the producing side, i.e. the
457	code/module that eventually sends the signal. Note that it is also	484	code/module that eventually sends the signal. Note that it is also
458	the producer side which creates the condvar in most cases, but it isn't	485	the producer side which creates the condvar in most cases, but it isn't
…		…
591	=item $bool = $cv->ready	618	=item $bool = $cv->ready
592		619
593	Returns true when the condition is "true", i.e. whether C<send> or	620	Returns true when the condition is "true", i.e. whether C<send> or
594	C<croak> have been called.	621	C<croak> have been called.
595		622
596	=item $cb = $cv->cb ([new callback])	623	=item $cb = $cv->cb ($cb->($cv))
597		624
598	This is a mutator function that returns the callback set and optionally	625	This is a mutator function that returns the callback set and optionally
599	replaces it before doing so.	626	replaces it before doing so.
600		627
601	The callback will be called when the condition becomes "true", i.e. when	628	The callback will be called when the condition becomes "true", i.e. when
…		…
738	=item L<AnyEvent::Util>	765	=item L<AnyEvent::Util>
739		766
740	Contains various utility functions that replace often-used but blocking	767	Contains various utility functions that replace often-used but blocking
741	functions such as C<inet_aton> by event-/callback-based versions.	768	functions such as C<inet_aton> by event-/callback-based versions.
742		769
743	=item L<AnyEvent::Handle>
744
745	Provide read and write buffers and manages watchers for reads and writes.
746
747	=item L<AnyEvent::Socket>	770	=item L<AnyEvent::Socket>
748		771
749	Provides various utility functions for (internet protocol) sockets,	772	Provides various utility functions for (internet protocol) sockets,
750	addresses and name resolution. Also functions to create non-blocking tcp	773	addresses and name resolution. Also functions to create non-blocking tcp
751	connections or tcp servers, with IPv6 and SRV record support and more.	774	connections or tcp servers, with IPv6 and SRV record support and more.
752		775
		776	=item L<AnyEvent::Handle>
		777
		778	Provide read and write buffers, manages watchers for reads and writes,
		779	supports raw and formatted I/O, I/O queued and fully transparent and
		780	non-blocking SSL/TLS.
		781
753	=item L<AnyEvent::DNS>	782	=item L<AnyEvent::DNS>
754		783
755	Provides rich asynchronous DNS resolver capabilities.	784	Provides rich asynchronous DNS resolver capabilities.
756		785
		786	=item L<AnyEvent::HTTP>
		787
		788	A simple-to-use HTTP library that is capable of making a lot of concurrent
		789	HTTP requests.
		790
757	=item L<AnyEvent::HTTPD>	791	=item L<AnyEvent::HTTPD>
758		792
759	Provides a simple web application server framework.	793	Provides a simple web application server framework.
760		794
761	=item L<AnyEvent::FastPing>	795	=item L<AnyEvent::FastPing>
762		796
763	The fastest ping in the west.	797	The fastest ping in the west.
		798
		799	=item L<AnyEvent::DBI>
		800
		801	Executes L<DBI> requests asynchronously in a proxy process.
		802
		803	=item L<AnyEvent::AIO>
		804
		805	Truly asynchronous I/O, should be in the toolbox of every event
		806	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		807	together.
		808
		809	=item L<AnyEvent::BDB>
		810
		811	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		812	L<BDB> and AnyEvent together.
		813
		814	=item L<AnyEvent::GPSD>
		815
		816	A non-blocking interface to gpsd, a daemon delivering GPS information.
		817
		818	=item L<AnyEvent::IGS>
		819
		820	A non-blocking interface to the Internet Go Server protocol (used by
		821	L<App::IGS>).
764		822
765	=item L<Net::IRC3>	823	=item L<Net::IRC3>
766		824
767	AnyEvent based IRC client module family.	825	AnyEvent based IRC client module family.
768		826
…		…
781		839
782	=item L<Coro>	840	=item L<Coro>
783		841
784	Has special support for AnyEvent via L<Coro::AnyEvent>.	842	Has special support for AnyEvent via L<Coro::AnyEvent>.
785		843
786	=item L<AnyEvent::AIO>, L<IO::AIO>
787
788	Truly asynchronous I/O, should be in the toolbox of every event
789	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
790	together.
791
792	=item L<AnyEvent::BDB>, L<BDB>
793
794	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
795	IO::AIO and AnyEvent together.
796
797	=item L<IO::Lambda>	844	=item L<IO::Lambda>
798		845
799	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	846	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
800		847
801	=back	848	=back
…		…
803	=cut	850	=cut
804		851
805	package AnyEvent;	852	package AnyEvent;
806		853
807	no warnings;	854	no warnings;
808	use strict;	855	use strict qw(vars subs);
809		856
810	use Carp;	857	use Carp;
811		858
812	our $VERSION = 4.11;	859	our $VERSION = 4.233;
813	our $MODEL;	860	our $MODEL;
814		861
815	our $AUTOLOAD;	862	our $AUTOLOAD;
816	our @ISA;	863	our @ISA;
817		864
…		…
920	$MODEL	967	$MODEL
921	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	968	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
922	}	969	}
923	}	970	}
924		971
		972	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		973
925	unshift @ISA, $MODEL;	974	unshift @ISA, $MODEL;
926	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	975
		976	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
927		977
928	(shift @post_detect)->() while @post_detect;	978	(shift @post_detect)->() while @post_detect;
929	}	979	}
930		980
931	$MODEL	981	$MODEL
…		…
941		991
942	my $class = shift;	992	my $class = shift;
943	$class->$func (@_);	993	$class->$func (@_);
944	}	994	}
945		995
		996	# utility function to dup a filehandle. this is used by many backends
		997	# to support binding more than one watcher per filehandle (they usually
		998	# allow only one watcher per fd, so we dup it to get a different one).
		999	sub _dupfh($$$$) {
		1000	my ($poll, $fh, $r, $w) = @_;
		1001
		1002	require Fcntl;
		1003
		1004	# cygwin requires the fh mode to be matching, unix doesn't
		1005	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1006	: $poll eq "w" ? ($w, ">")
		1007	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1008
		1009	open my $fh2, "$mode&" . fileno $fh
		1010	or die "cannot dup() filehandle: $!";
		1011
		1012	# we assume CLOEXEC is already set by perl in all important cases
		1013
		1014	($fh2, $rw)
		1015	}
		1016
946	package AnyEvent::Base;	1017	package AnyEvent::Base;
947		1018
948	# default implementation for now and time	1019	# default implementation for now and time
949		1020
950	use Time::HiRes ();	1021	BEGIN {
		1022	if (eval "use Time::HiRes (); time (); 1") {
		1023	*_time = \&Time::HiRes::time;
		1024	# if (eval "use POSIX (); (POSIX::times())...
		1025	} else {
		1026	*_time = \&CORE::time; # epic fail
		1027	}
		1028	}
951		1029
952	sub time { Time::HiRes::time }	1030	sub time { _time }
953	sub now { Time::HiRes::time }	1031	sub now { _time }
954		1032
955	# default implementation for ->condvar	1033	# default implementation for ->condvar
956		1034
957	sub condvar {	1035	sub condvar {
958	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1036	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
979	sub AnyEvent::Base::Signal::DESTROY {	1057	sub AnyEvent::Base::Signal::DESTROY {
980	my ($signal, $cb) = @{$_[0]};	1058	my ($signal, $cb) = @{$_[0]};
981		1059
982	delete $SIG_CB{$signal}{$cb};	1060	delete $SIG_CB{$signal}{$cb};
983		1061
984	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1062	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
985	}	1063	}
986		1064
987	# default implementation for ->child	1065	# default implementation for ->child
988		1066
989	our %PID_CB;	1067	our %PID_CB;
…		…
1097		1175
1098	# undocumented/compatibility with pre-3.4	1176	# undocumented/compatibility with pre-3.4
1099	*broadcast = \&send;	1177	*broadcast = \&send;
1100	*wait = \&_wait;	1178	*wait = \&_wait;
1101		1179
		1180	=head1 ERROR AND EXCEPTION HANDLING
		1181
		1182	In general, AnyEvent does not do any error handling - it relies on the
		1183	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1184	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1185	checking of all AnyEvent methods, however, which is highly useful during
		1186	development.
		1187
		1188	As for exception handling (i.e. runtime errors and exceptions thrown while
		1189	executing a callback), this is not only highly event-loop specific, but
		1190	also not in any way wrapped by this module, as this is the job of the main
		1191	program.
		1192
		1193	The pure perl event loop simply re-throws the exception (usually
		1194	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1195	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1196	so on.
		1197
		1198	=head1 ENVIRONMENT VARIABLES
		1199
		1200	The following environment variables are used by this module or its
		1201	submodules:
		1202
		1203	=over 4
		1204
		1205	=item C<PERL_ANYEVENT_VERBOSE>
		1206
		1207	By default, AnyEvent will be completely silent except in fatal
		1208	conditions. You can set this environment variable to make AnyEvent more
		1209	talkative.
		1210
		1211	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1212	conditions, such as not being able to load the event model specified by
		1213	C<PERL_ANYEVENT_MODEL>.
		1214
		1215	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1216	model it chooses.
		1217
		1218	=item C<PERL_ANYEVENT_STRICT>
		1219
		1220	AnyEvent does not do much argument checking by default, as thorough
		1221	argument checking is very costly. Setting this variable to a true value
		1222	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1223	check the arguments passed to most method calls. If it finds any problems
		1224	it will croak.
		1225
		1226	In other words, enables "strict" mode.
		1227
		1228	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1229	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1230	developing programs can be very useful, however.
		1231
		1232	=item C<PERL_ANYEVENT_MODEL>
		1233
		1234	This can be used to specify the event model to be used by AnyEvent, before
		1235	auto detection and -probing kicks in. It must be a string consisting
		1236	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1237	and the resulting module name is loaded and if the load was successful,
		1238	used as event model. If it fails to load AnyEvent will proceed with
		1239	auto detection and -probing.
		1240
		1241	This functionality might change in future versions.
		1242
		1243	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1244	could start your program like this:
		1245
		1246	PERL_ANYEVENT_MODEL=Perl perl ...
		1247
		1248	=item C<PERL_ANYEVENT_PROTOCOLS>
		1249
		1250	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1251	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1252	of auto probing).
		1253
		1254	Must be set to a comma-separated list of protocols or address families,
		1255	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1256	used, and preference will be given to protocols mentioned earlier in the
		1257	list.
		1258
		1259	This variable can effectively be used for denial-of-service attacks
		1260	against local programs (e.g. when setuid), although the impact is likely
		1261	small, as the program has to handle connection errors already-
		1262
		1263	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1264	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1265	- only support IPv4, never try to resolve or contact IPv6
		1266	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1267	IPv6, but prefer IPv6 over IPv4.
		1268
		1269	=item C<PERL_ANYEVENT_EDNS0>
		1270
		1271	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1272	for DNS. This extension is generally useful to reduce DNS traffic, but
		1273	some (broken) firewalls drop such DNS packets, which is why it is off by
		1274	default.
		1275
		1276	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1277	EDNS0 in its DNS requests.
		1278
		1279	=item C<PERL_ANYEVENT_MAX_FORKS>
		1280
		1281	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1282	will create in parallel.
		1283
		1284	=back
		1285
1102	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1286	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1103		1287
1104	This is an advanced topic that you do not normally need to use AnyEvent in	1288	This is an advanced topic that you do not normally need to use AnyEvent in
1105	a module. This section is only of use to event loop authors who want to	1289	a module. This section is only of use to event loop authors who want to
1106	provide AnyEvent compatibility.	1290	provide AnyEvent compatibility.
…		…
1139		1323
1140	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1324	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1141	condition variables: code blocking while waiting for a condition will	1325	condition variables: code blocking while waiting for a condition will
1142	C<die>. This still works with most modules/usages, and blocking calls must	1326	C<die>. This still works with most modules/usages, and blocking calls must
1143	not be done in an interactive application, so it makes sense.	1327	not be done in an interactive application, so it makes sense.
1144
1145	=head1 ENVIRONMENT VARIABLES
1146
1147	The following environment variables are used by this module:
1148
1149	=over 4
1150
1151	=item C<PERL_ANYEVENT_VERBOSE>
1152
1153	By default, AnyEvent will be completely silent except in fatal
1154	conditions. You can set this environment variable to make AnyEvent more
1155	talkative.
1156
1157	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1158	conditions, such as not being able to load the event model specified by
1159	C<PERL_ANYEVENT_MODEL>.
1160
1161	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1162	model it chooses.
1163
1164	=item C<PERL_ANYEVENT_MODEL>
1165
1166	This can be used to specify the event model to be used by AnyEvent, before
1167	auto detection and -probing kicks in. It must be a string consisting
1168	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1169	and the resulting module name is loaded and if the load was successful,
1170	used as event model. If it fails to load AnyEvent will proceed with
1171	auto detection and -probing.
1172
1173	This functionality might change in future versions.
1174
1175	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1176	could start your program like this:
1177
1178	PERL_ANYEVENT_MODEL=Perl perl ...
1179
1180	=item C<PERL_ANYEVENT_PROTOCOLS>
1181
1182	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1183	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1184	of auto probing).
1185
1186	Must be set to a comma-separated list of protocols or address families,
1187	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1188	used, and preference will be given to protocols mentioned earlier in the
1189	list.
1190
1191	This variable can effectively be used for denial-of-service attacks
1192	against local programs (e.g. when setuid), although the impact is likely
1193	small, as the program has to handle connection errors already-
1194
1195	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1196	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1197	- only support IPv4, never try to resolve or contact IPv6
1198	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1199	IPv6, but prefer IPv6 over IPv4.
1200
1201	=item C<PERL_ANYEVENT_EDNS0>
1202
1203	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1204	for DNS. This extension is generally useful to reduce DNS traffic, but
1205	some (broken) firewalls drop such DNS packets, which is why it is off by
1206	default.
1207
1208	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1209	EDNS0 in its DNS requests.
1210
1211	=item C<PERL_ANYEVENT_MAX_FORKS>
1212
1213	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1214	will create in parallel.
1215
1216	=back
1217		1328
1218	=head1 EXAMPLE PROGRAM	1329	=head1 EXAMPLE PROGRAM
1219		1330
1220	The following program uses an I/O watcher to read data from STDIN, a timer	1331	The following program uses an I/O watcher to read data from STDIN, a timer
1221	to display a message once per second, and a condition variable to quit the	1332	to display a message once per second, and a condition variable to quit the
…		…
1658	specified in the variable.	1769	specified in the variable.
1659		1770
1660	You can make AnyEvent completely ignore this variable by deleting it	1771	You can make AnyEvent completely ignore this variable by deleting it
1661	before the first watcher gets created, e.g. with a C<BEGIN> block:	1772	before the first watcher gets created, e.g. with a C<BEGIN> block:
1662		1773
1663	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1774	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1664		1775
1665	use AnyEvent;	1776	use AnyEvent;
1666		1777
1667	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1778	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1668	be used to probe what backend is used and gain other information (which is	1779	be used to probe what backend is used and gain other information (which is
1669	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1780	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1781	$ENV{PERL_ANYEGENT_STRICT}.
		1782
		1783
		1784	=head1 BUGS
		1785
		1786	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1787	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1788	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1789	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1790	pronounced).
1670		1791
1671		1792
1672	=head1 SEE ALSO	1793	=head1 SEE ALSO
1673		1794
1674	Utility functions: L<AnyEvent::Util>.	1795	Utility functions: L<AnyEvent::Util>.
…		…
1691	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1812	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1692		1813
1693		1814
1694	=head1 AUTHOR	1815	=head1 AUTHOR
1695		1816
1696	Marc Lehmann <schmorp@schmorp.de>	1817	Marc Lehmann <schmorp@schmorp.de>
1697	http://home.schmorp.de/	1818	http://home.schmorp.de/
1698		1819
1699	=cut	1820	=cut
1700		1821
1701	1	1822	1
1702		1823

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs. Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs.
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC