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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.165 by root, Tue Jul 8 23:07:26 2008 UTC vs.
Revision 1.210 by root, Wed May 13 15:19:43 2009 UTC

…		…
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
		11	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	12	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
		13
		14	# one-shot or repeating timers
		15	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		16	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		17
		18	print AnyEvent->now; # prints current event loop time
		19	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		20
		21	# POSIX signal
		22	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		23
		24	# child process exit
		25	my $w = AnyEvent->child (pid => $pid, cb => sub {
		26	my ($pid, $status) = @_;
12	...	27	...
13	});	28	});
14		29
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	30	# called when event loop idle (if applicable)
16	...	31	my $w = AnyEvent->idle (cb => sub { ... });
17	});
18		32
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	33	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	34	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	35	$w->recv; # enters "main loop" till $condvar gets ->send
		36	# use a condvar in callback mode:
		37	$w->cb (sub { $_[0]->recv });
22		38
23	=head1 INTRODUCTION/TUTORIAL	39	=head1 INTRODUCTION/TUTORIAL
24		40
25	This manpage is mainly a reference manual. If you are interested	41	This manpage is mainly a reference manual. If you are interested
26	in a tutorial or some gentle introduction, have a look at the	42	in a tutorial or some gentle introduction, have a look at the
…		…
33		49
34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	50	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35	policy> and AnyEvent is I<small and efficient>.	51	policy> and AnyEvent is I<small and efficient>.
36		52
37	First and foremost, I<AnyEvent is not an event model> itself, it only	53	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	54	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,	55	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,	56	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	57	only one event loop can be active at the same time in a process. AnyEvent
42	helps hiding the differences between those event loops.	58	cannot change this, but it can hide the differences between those event
		59	loops.
43		60
44	The goal of AnyEvent is to offer module authors the ability to do event	61	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	62	programming (waiting for I/O or timer events) without subscribing to a
46	religion, a way of living, and most importantly: without forcing your	63	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	64	module users into the same thing by forcing them to use the same event
48	model you use.	65	model you use.
49		66
50	For modules like POE or IO::Async (which is a total misnomer as it is	67	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	68	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	69	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	70	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	71	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.	72	module are I<also> forced to use the same event loop you use.
56		73
57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	74	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	75	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	76	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,	77	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	78	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	79	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	80	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).	81	to AnyEvent, too, so it is future-proof).
65		82
66	In addition to being free of having to use I<the one and only true event	83	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	84	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	85	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	86	follow. AnyEvent, on the other hand, is lean and up to the point, by only
…		…
127	These watchers are normal Perl objects with normal Perl lifetime. After	144	These watchers are normal Perl objects with normal Perl lifetime. After
128	creating a watcher it will immediately "watch" for events and invoke the	145	creating a watcher it will immediately "watch" for events and invoke the
129	callback when the event occurs (of course, only when the event model	146	callback when the event occurs (of course, only when the event model
130	is in control).	147	is in control).
131		148
		149	Note that B<callbacks must not permanently change global variables>
		150	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		151	callbacks must not C<die> >>. The former is good programming practise in
		152	Perl and the latter stems from the fact that exception handling differs
		153	widely between event loops.
		154
132	To disable the watcher you have to destroy it (e.g. by setting the	155	To disable the watcher you have to destroy it (e.g. by setting the
133	variable you store it in to C<undef> or otherwise deleting all references	156	variable you store it in to C<undef> or otherwise deleting all references
134	to it).	157	to it).
135		158
136	All watchers are created by calling a method on the C<AnyEvent> class.	159	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
152	=head2 I/O WATCHERS	175	=head2 I/O WATCHERS
153		176
154	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	177	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
155	with the following mandatory key-value pairs as arguments:	178	with the following mandatory key-value pairs as arguments:
156		179
157	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	180	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch
		181	for events (AnyEvent might or might not keep a reference to this file
		182	handle). Note that only file handles pointing to things for which
		183	non-blocking operation makes sense are allowed. This includes sockets,
		184	most character devices, pipes, fifos and so on, but not for example files
		185	or block devices.
		186
158	for events. C<poll> must be a string that is either C<r> or C<w>,	187	C<poll> must be a string that is either C<r> or C<w>, which creates a
159	which creates a watcher waiting for "r"eadable or "w"ritable events,	188	watcher waiting for "r"eadable or "w"ritable events, respectively.
		189
160	respectively. C<cb> is the callback to invoke each time the file handle	190	C<cb> is the callback to invoke each time the file handle becomes ready.
161	becomes ready.
162		191
163	Although the callback might get passed parameters, their value and	192	Although the callback might get passed parameters, their value and
164	presence is undefined and you cannot rely on them. Portable AnyEvent	193	presence is undefined and you cannot rely on them. Portable AnyEvent
165	callbacks cannot use arguments passed to I/O watcher callbacks.	194	callbacks cannot use arguments passed to I/O watcher callbacks.
166		195
…		…
298	In either case, if you care (and in most cases, you don't), then you	327	In either case, if you care (and in most cases, you don't), then you
299	can get whatever behaviour you want with any event loop, by taking the	328	can get whatever behaviour you want with any event loop, by taking the
300	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	329	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
301	account.	330	account.
302		331
		332	=item AnyEvent->now_update
		333
		334	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		335	the current time for each loop iteration (see the discussion of L<<
		336	AnyEvent->now >>, above).
		337
		338	When a callback runs for a long time (or when the process sleeps), then
		339	this "current" time will differ substantially from the real time, which
		340	might affect timers and time-outs.
		341
		342	When this is the case, you can call this method, which will update the
		343	event loop's idea of "current time".
		344
		345	Note that updating the time I<might> cause some events to be handled.
		346
303	=back	347	=back
304		348
305	=head2 SIGNAL WATCHERS	349	=head2 SIGNAL WATCHERS
306		350
307	You can watch for signals using a signal watcher, C<signal> is the signal	351	You can watch for signals using a signal watcher, C<signal> is the signal
308	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	352	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
309	be invoked whenever a signal occurs.	353	callback to be invoked whenever a signal occurs.
310		354
311	Although the callback might get passed parameters, their value and	355	Although the callback might get passed parameters, their value and
312	presence is undefined and you cannot rely on them. Portable AnyEvent	356	presence is undefined and you cannot rely on them. Portable AnyEvent
313	callbacks cannot use arguments passed to signal watcher callbacks.	357	callbacks cannot use arguments passed to signal watcher callbacks.
314		358
…		…
330	=head2 CHILD PROCESS WATCHERS	374	=head2 CHILD PROCESS WATCHERS
331		375
332	You can also watch on a child process exit and catch its exit status.	376	You can also watch on a child process exit and catch its exit status.
333		377
334	The child process is specified by the C<pid> argument (if set to C<0>, it	378	The child process is specified by the C<pid> argument (if set to C<0>, it
335	watches for any child process exit). The watcher will trigger as often	379	watches for any child process exit). The watcher will triggered only when
336	as status change for the child are received. This works by installing a	380	the child process has finished and an exit status is available, not on
337	signal handler for C<SIGCHLD>. The callback will be called with the pid	381	any trace events (stopped/continued).
338	and exit status (as returned by waitpid), so unlike other watcher types,	382
339	you I<can> rely on child watcher callback arguments.	383	The callback will be called with the pid and exit status (as returned by
		384	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		385	callback arguments.
		386
		387	This watcher type works by installing a signal handler for C<SIGCHLD>,
		388	and since it cannot be shared, nothing else should use SIGCHLD or reap
		389	random child processes (waiting for specific child processes, e.g. inside
		390	C<system>, is just fine).
340		391
341	There is a slight catch to child watchers, however: you usually start them	392	There is a slight catch to child watchers, however: you usually start them
342	I<after> the child process was created, and this means the process could	393	I<after> the child process was created, and this means the process could
343	have exited already (and no SIGCHLD will be sent anymore).	394	have exited already (and no SIGCHLD will be sent anymore).
344		395
…		…
366	);	417	);
367		418
368	# do something else, then wait for process exit	419	# do something else, then wait for process exit
369	$done->recv;	420	$done->recv;
370		421
		422	=head2 IDLE WATCHERS
		423
		424	Sometimes there is a need to do something, but it is not so important
		425	to do it instantly, but only when there is nothing better to do. This
		426	"nothing better to do" is usually defined to be "no other events need
		427	attention by the event loop".
		428
		429	Idle watchers ideally get invoked when the event loop has nothing
		430	better to do, just before it would block the process to wait for new
		431	events. Instead of blocking, the idle watcher is invoked.
		432
		433	Most event loops unfortunately do not really support idle watchers (only
		434	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		435	will simply call the callback "from time to time".
		436
		437	Example: read lines from STDIN, but only process them when the
		438	program is otherwise idle:
		439
		440	my @lines; # read data
		441	my $idle_w;
		442	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		443	push @lines, scalar <STDIN>;
		444
		445	# start an idle watcher, if not already done
		446	$idle_w \|\|= AnyEvent->idle (cb => sub {
		447	# handle only one line, when there are lines left
		448	if (my $line = shift @lines) {
		449	print "handled when idle: $line";
		450	} else {
		451	# otherwise disable the idle watcher again
		452	undef $idle_w;
		453	}
		454	});
		455	});
		456
371	=head2 CONDITION VARIABLES	457	=head2 CONDITION VARIABLES
372		458
373	If you are familiar with some event loops you will know that all of them	459	If you are familiar with some event loops you will know that all of them
374	require you to run some blocking "loop", "run" or similar function that	460	require you to run some blocking "loop", "run" or similar function that
375	will actively watch for new events and call your callbacks.	461	will actively watch for new events and call your callbacks.
…		…
380	The instrument to do that is called a "condition variable", so called	466	The instrument to do that is called a "condition variable", so called
381	because they represent a condition that must become true.	467	because they represent a condition that must become true.
382		468
383	Condition variables can be created by calling the C<< AnyEvent->condvar	469	Condition variables can be created by calling the C<< AnyEvent->condvar
384	>> method, usually without arguments. The only argument pair allowed is	470	>> method, usually without arguments. The only argument pair allowed is
		471
385	C<cb>, which specifies a callback to be called when the condition variable	472	C<cb>, which specifies a callback to be called when the condition variable
386	becomes true.	473	becomes true, with the condition variable as the first argument (but not
		474	the results).
387		475
388	After creation, the condition variable is "false" until it becomes "true"	476	After creation, the condition variable is "false" until it becomes "true"
389	by calling the C<send> method (or calling the condition variable as if it	477	by calling the C<send> method (or calling the condition variable as if it
390	were a callback, read about the caveats in the description for the C<<	478	were a callback, read about the caveats in the description for the C<<
391	->send >> method).	479	->send >> method).
…		…
447		535
448	my $done = AnyEvent->condvar;	536	my $done = AnyEvent->condvar;
449	my $delay = AnyEvent->timer (after => 5, cb => $done);	537	my $delay = AnyEvent->timer (after => 5, cb => $done);
450	$done->recv;	538	$done->recv;
451		539
		540	Example: Imagine an API that returns a condvar and doesn't support
		541	callbacks. This is how you make a synchronous call, for example from
		542	the main program:
		543
		544	use AnyEvent::CouchDB;
		545
		546	...
		547
		548	my @info = $couchdb->info->recv;
		549
		550	And this is how you would just ste a callback to be called whenever the
		551	results are available:
		552
		553	$couchdb->info->cb (sub {
		554	my @info = $_[0]->recv;
		555	});
		556
452	=head3 METHODS FOR PRODUCERS	557	=head3 METHODS FOR PRODUCERS
453		558
454	These methods should only be used by the producing side, i.e. the	559	These methods should only be used by the producing side, i.e. the
455	code/module that eventually sends the signal. Note that it is also	560	code/module that eventually sends the signal. Note that it is also
456	the producer side which creates the condvar in most cases, but it isn't	561	the producer side which creates the condvar in most cases, but it isn't
…		…
589	=item $bool = $cv->ready	694	=item $bool = $cv->ready
590		695
591	Returns true when the condition is "true", i.e. whether C<send> or	696	Returns true when the condition is "true", i.e. whether C<send> or
592	C<croak> have been called.	697	C<croak> have been called.
593		698
594	=item $cb = $cv->cb ([new callback])	699	=item $cb = $cv->cb ($cb->($cv))
595		700
596	This is a mutator function that returns the callback set and optionally	701	This is a mutator function that returns the callback set and optionally
597	replaces it before doing so.	702	replaces it before doing so.
598		703
599	The callback will be called when the condition becomes "true", i.e. when	704	The callback will be called when the condition becomes "true", i.e. when
…		…
789	=item L<AnyEvent::IGS>	894	=item L<AnyEvent::IGS>
790		895
791	A non-blocking interface to the Internet Go Server protocol (used by	896	A non-blocking interface to the Internet Go Server protocol (used by
792	L<App::IGS>).	897	L<App::IGS>).
793		898
794	=item L<Net::IRC3>	899	=item L<AnyEvent::IRC>
795		900
796	AnyEvent based IRC client module family.	901	AnyEvent based IRC client module family (replacing the older Net::IRC3).
797		902
798	=item L<Net::XMPP2>	903	=item L<Net::XMPP2>
799		904
800	AnyEvent based XMPP (Jabber protocol) module family.	905	AnyEvent based XMPP (Jabber protocol) module family.
801		906
…		…
821	=cut	926	=cut
822		927
823	package AnyEvent;	928	package AnyEvent;
824		929
825	no warnings;	930	no warnings;
826	use strict;	931	use strict qw(vars subs);
827		932
828	use Carp;	933	use Carp;
829		934
830	our $VERSION = 4.2;	935	our $VERSION = 4.41;
831	our $MODEL;	936	our $MODEL;
832		937
833	our $AUTOLOAD;	938	our $AUTOLOAD;
834	our @ISA;	939	our @ISA;
835		940
…		…
867	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	972	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
868	[Wx:: => AnyEvent::Impl::POE::],	973	[Wx:: => AnyEvent::Impl::POE::],
869	[Prima:: => AnyEvent::Impl::POE::],	974	[Prima:: => AnyEvent::Impl::POE::],
870	);	975	);
871		976
872	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	977	our %method = map +($_ => 1),
		978	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
873		979
874	our @post_detect;	980	our @post_detect;
875		981
876	sub post_detect(&) {	982	sub post_detect(&) {
877	my ($cb) = @_;	983	my ($cb) = @_;
…		…
882	1	988	1
883	} else {	989	} else {
884	push @post_detect, $cb;	990	push @post_detect, $cb;
885		991
886	defined wantarray	992	defined wantarray
887	? bless \$cb, "AnyEvent::Util::PostDetect"	993	? bless \$cb, "AnyEvent::Util::postdetect"
888	: ()	994	: ()
889	}	995	}
890	}	996	}
891		997
892	sub AnyEvent::Util::PostDetect::DESTROY {	998	sub AnyEvent::Util::postdetect::DESTROY {
893	@post_detect = grep $_ != ${$_[0]}, @post_detect;	999	@post_detect = grep $_ != ${$_[0]}, @post_detect;
894	}	1000	}
895		1001
896	sub detect() {	1002	sub detect() {
897	unless ($MODEL) {	1003	unless ($MODEL) {
…		…
934	last;	1040	last;
935	}	1041	}
936	}	1042	}
937		1043
938	$MODEL	1044	$MODEL
939	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1045	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
940	}	1046	}
941	}	1047	}
942		1048
		1049	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1050
943	unshift @ISA, $MODEL;	1051	unshift @ISA, $MODEL;
944	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1052
		1053	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
945		1054
946	(shift @post_detect)->() while @post_detect;	1055	(shift @post_detect)->() while @post_detect;
947	}	1056	}
948		1057
949	$MODEL	1058	$MODEL
…		…
959		1068
960	my $class = shift;	1069	my $class = shift;
961	$class->$func (@_);	1070	$class->$func (@_);
962	}	1071	}
963		1072
		1073	# utility function to dup a filehandle. this is used by many backends
		1074	# to support binding more than one watcher per filehandle (they usually
		1075	# allow only one watcher per fd, so we dup it to get a different one).
		1076	sub _dupfh($$$$) {
		1077	my ($poll, $fh, $r, $w) = @_;
		1078
		1079	# cygwin requires the fh mode to be matching, unix doesn't
		1080	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1081	: $poll eq "w" ? ($w, ">")
		1082	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1083
		1084	open my $fh2, "$mode&" . fileno $fh
		1085	or die "cannot dup() filehandle: $!,";
		1086
		1087	# we assume CLOEXEC is already set by perl in all important cases
		1088
		1089	($fh2, $rw)
		1090	}
		1091
964	package AnyEvent::Base;	1092	package AnyEvent::Base;
965		1093
966	# default implementation for now and time	1094	# default implementations for many methods
967		1095
968	use Time::HiRes ();	1096	BEGIN {
		1097	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1098	*_time = \&Time::HiRes::time;
		1099	# if (eval "use POSIX (); (POSIX::times())...
		1100	} else {
		1101	*_time = sub { time }; # epic fail
		1102	}
		1103	}
969		1104
970	sub time { Time::HiRes::time }	1105	sub time { _time }
971	sub now { Time::HiRes::time }	1106	sub now { _time }
		1107	sub now_update { }
972		1108
973	# default implementation for ->condvar	1109	# default implementation for ->condvar
974		1110
975	sub condvar {	1111	sub condvar {
976	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1112	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
977	}	1113	}
978		1114
979	# default implementation for ->signal	1115	# default implementation for ->signal
980		1116
981	our %SIG_CB;	1117	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1118
		1119	sub _signal_exec {
		1120	sysread $SIGPIPE_R, my $dummy, 4;
		1121
		1122	while (%SIG_EV) {
		1123	for (keys %SIG_EV) {
		1124	delete $SIG_EV{$_};
		1125	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1126	}
		1127	}
		1128	}
982		1129
983	sub signal {	1130	sub signal {
984	my (undef, %arg) = @_;	1131	my (undef, %arg) = @_;
985		1132
		1133	unless ($SIGPIPE_R) {
		1134	require Fcntl;
		1135
		1136	if (AnyEvent::WIN32) {
		1137	require AnyEvent::Util;
		1138
		1139	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1140	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1141	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1142	} else {
		1143	pipe $SIGPIPE_R, $SIGPIPE_W;
		1144	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1145	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1146	}
		1147
		1148	$SIGPIPE_R
		1149	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1150
		1151	# not strictly required, as $^F is normally 2, but let's make sure...
		1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1154
		1155	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1156	}
		1157
986	my $signal = uc $arg{signal}	1158	my $signal = uc $arg{signal}
987	or Carp::croak "required option 'signal' is missing";	1159	or Carp::croak "required option 'signal' is missing";
988		1160
989	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1161	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
990	$SIG{$signal} \|\|= sub {	1162	$SIG{$signal} \|\|= sub {
991	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1163	local $!;
		1164	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1165	undef $SIG_EV{$signal};
992	};	1166	};
993		1167
994	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1168	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
995	}	1169	}
996		1170
997	sub AnyEvent::Base::Signal::DESTROY {	1171	sub AnyEvent::Base::signal::DESTROY {
998	my ($signal, $cb) = @{$_[0]};	1172	my ($signal, $cb) = @{$_[0]};
999		1173
1000	delete $SIG_CB{$signal}{$cb};	1174	delete $SIG_CB{$signal}{$cb};
1001		1175
		1176	# delete doesn't work with older perls - they then
		1177	# print weird messages, or just unconditionally exit
		1178	# instead of getting the default action.
1002	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1179	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1003	}	1180	}
1004		1181
1005	# default implementation for ->child	1182	# default implementation for ->child
1006		1183
1007	our %PID_CB;	1184	our %PID_CB;
1008	our $CHLD_W;	1185	our $CHLD_W;
1009	our $CHLD_DELAY_W;	1186	our $CHLD_DELAY_W;
1010	our $PID_IDLE;
1011	our $WNOHANG;	1187	our $WNOHANG;
1012		1188
1013	sub _child_wait {	1189	sub _sigchld {
1014	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1190	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1015	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1191	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1016	(values %{ $PID_CB{0} \|\| {} });	1192	(values %{ $PID_CB{0} \|\| {} });
1017	}	1193	}
1018
1019	undef $PID_IDLE;
1020	}
1021
1022	sub _sigchld {
1023	# make sure we deliver these changes "synchronous" with the event loop.
1024	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1025	undef $CHLD_DELAY_W;
1026	&_child_wait;
1027	});
1028	}	1194	}
1029		1195
1030	sub child {	1196	sub child {
1031	my (undef, %arg) = @_;	1197	my (undef, %arg) = @_;
1032		1198
1033	defined (my $pid = $arg{pid} + 0)	1199	defined (my $pid = $arg{pid} + 0)
1034	or Carp::croak "required option 'pid' is missing";	1200	or Carp::croak "required option 'pid' is missing";
1035		1201
1036	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1202	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1037		1203
1038	unless ($WNOHANG) {
1039	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1204	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1040	}
1041		1205
1042	unless ($CHLD_W) {	1206	unless ($CHLD_W) {
1043	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1207	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1044	# child could be a zombie already, so make at least one round	1208	# child could be a zombie already, so make at least one round
1045	&_sigchld;	1209	&_sigchld;
1046	}	1210	}
1047		1211
1048	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1212	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1049	}	1213	}
1050		1214
1051	sub AnyEvent::Base::Child::DESTROY {	1215	sub AnyEvent::Base::child::DESTROY {
1052	my ($pid, $cb) = @{$_[0]};	1216	my ($pid, $cb) = @{$_[0]};
1053		1217
1054	delete $PID_CB{$pid}{$cb};	1218	delete $PID_CB{$pid}{$cb};
1055	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1219	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1056		1220
1057	undef $CHLD_W unless keys %PID_CB;	1221	undef $CHLD_W unless keys %PID_CB;
		1222	}
		1223
		1224	# idle emulation is done by simply using a timer, regardless
		1225	# of whether the process is idle or not, and not letting
		1226	# the callback use more than 50% of the time.
		1227	sub idle {
		1228	my (undef, %arg) = @_;
		1229
		1230	my ($cb, $w, $rcb) = $arg{cb};
		1231
		1232	$rcb = sub {
		1233	if ($cb) {
		1234	$w = _time;
		1235	&$cb;
		1236	$w = _time - $w;
		1237
		1238	# never use more then 50% of the time for the idle watcher,
		1239	# within some limits
		1240	$w = 0.0001 if $w < 0.0001;
		1241	$w = 5 if $w > 5;
		1242
		1243	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1244	} else {
		1245	# clean up...
		1246	undef $w;
		1247	undef $rcb;
		1248	}
		1249	};
		1250
		1251	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1252
		1253	bless \\$cb, "AnyEvent::Base::idle"
		1254	}
		1255
		1256	sub AnyEvent::Base::idle::DESTROY {
		1257	undef $${$_[0]};
1058	}	1258	}
1059		1259
1060	package AnyEvent::CondVar;	1260	package AnyEvent::CondVar;
1061		1261
1062	our @ISA = AnyEvent::CondVar::Base::;	1262	our @ISA = AnyEvent::CondVar::Base::;
…		…
1114	}	1314	}
1115		1315
1116	# undocumented/compatibility with pre-3.4	1316	# undocumented/compatibility with pre-3.4
1117	*broadcast = \&send;	1317	*broadcast = \&send;
1118	*wait = \&_wait;	1318	*wait = \&_wait;
		1319
		1320	=head1 ERROR AND EXCEPTION HANDLING
		1321
		1322	In general, AnyEvent does not do any error handling - it relies on the
		1323	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1324	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1325	checking of all AnyEvent methods, however, which is highly useful during
		1326	development.
		1327
		1328	As for exception handling (i.e. runtime errors and exceptions thrown while
		1329	executing a callback), this is not only highly event-loop specific, but
		1330	also not in any way wrapped by this module, as this is the job of the main
		1331	program.
		1332
		1333	The pure perl event loop simply re-throws the exception (usually
		1334	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1335	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1336	so on.
		1337
		1338	=head1 ENVIRONMENT VARIABLES
		1339
		1340	The following environment variables are used by this module or its
		1341	submodules:
		1342
		1343	=over 4
		1344
		1345	=item C<PERL_ANYEVENT_VERBOSE>
		1346
		1347	By default, AnyEvent will be completely silent except in fatal
		1348	conditions. You can set this environment variable to make AnyEvent more
		1349	talkative.
		1350
		1351	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1352	conditions, such as not being able to load the event model specified by
		1353	C<PERL_ANYEVENT_MODEL>.
		1354
		1355	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1356	model it chooses.
		1357
		1358	=item C<PERL_ANYEVENT_STRICT>
		1359
		1360	AnyEvent does not do much argument checking by default, as thorough
		1361	argument checking is very costly. Setting this variable to a true value
		1362	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1363	check the arguments passed to most method calls. If it finds any problems
		1364	it will croak.
		1365
		1366	In other words, enables "strict" mode.
		1367
		1368	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1369	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1370	developing programs can be very useful, however.
		1371
		1372	=item C<PERL_ANYEVENT_MODEL>
		1373
		1374	This can be used to specify the event model to be used by AnyEvent, before
		1375	auto detection and -probing kicks in. It must be a string consisting
		1376	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1377	and the resulting module name is loaded and if the load was successful,
		1378	used as event model. If it fails to load AnyEvent will proceed with
		1379	auto detection and -probing.
		1380
		1381	This functionality might change in future versions.
		1382
		1383	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1384	could start your program like this:
		1385
		1386	PERL_ANYEVENT_MODEL=Perl perl ...
		1387
		1388	=item C<PERL_ANYEVENT_PROTOCOLS>
		1389
		1390	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1391	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1392	of auto probing).
		1393
		1394	Must be set to a comma-separated list of protocols or address families,
		1395	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1396	used, and preference will be given to protocols mentioned earlier in the
		1397	list.
		1398
		1399	This variable can effectively be used for denial-of-service attacks
		1400	against local programs (e.g. when setuid), although the impact is likely
		1401	small, as the program has to handle conenction and other failures anyways.
		1402
		1403	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1404	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1405	- only support IPv4, never try to resolve or contact IPv6
		1406	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1407	IPv6, but prefer IPv6 over IPv4.
		1408
		1409	=item C<PERL_ANYEVENT_EDNS0>
		1410
		1411	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1412	for DNS. This extension is generally useful to reduce DNS traffic, but
		1413	some (broken) firewalls drop such DNS packets, which is why it is off by
		1414	default.
		1415
		1416	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1417	EDNS0 in its DNS requests.
		1418
		1419	=item C<PERL_ANYEVENT_MAX_FORKS>
		1420
		1421	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1422	will create in parallel.
		1423
		1424	=back
1119		1425
1120	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1426	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1121		1427
1122	This is an advanced topic that you do not normally need to use AnyEvent in	1428	This is an advanced topic that you do not normally need to use AnyEvent in
1123	a module. This section is only of use to event loop authors who want to	1429	a module. This section is only of use to event loop authors who want to
…		…
1157		1463
1158	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1464	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1159	condition variables: code blocking while waiting for a condition will	1465	condition variables: code blocking while waiting for a condition will
1160	C<die>. This still works with most modules/usages, and blocking calls must	1466	C<die>. This still works with most modules/usages, and blocking calls must
1161	not be done in an interactive application, so it makes sense.	1467	not be done in an interactive application, so it makes sense.
1162
1163	=head1 ENVIRONMENT VARIABLES
1164
1165	The following environment variables are used by this module:
1166
1167	=over 4
1168
1169	=item C<PERL_ANYEVENT_VERBOSE>
1170
1171	By default, AnyEvent will be completely silent except in fatal
1172	conditions. You can set this environment variable to make AnyEvent more
1173	talkative.
1174
1175	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1176	conditions, such as not being able to load the event model specified by
1177	C<PERL_ANYEVENT_MODEL>.
1178
1179	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1180	model it chooses.
1181
1182	=item C<PERL_ANYEVENT_MODEL>
1183
1184	This can be used to specify the event model to be used by AnyEvent, before
1185	auto detection and -probing kicks in. It must be a string consisting
1186	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1187	and the resulting module name is loaded and if the load was successful,
1188	used as event model. If it fails to load AnyEvent will proceed with
1189	auto detection and -probing.
1190
1191	This functionality might change in future versions.
1192
1193	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1194	could start your program like this:
1195
1196	PERL_ANYEVENT_MODEL=Perl perl ...
1197
1198	=item C<PERL_ANYEVENT_PROTOCOLS>
1199
1200	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1201	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1202	of auto probing).
1203
1204	Must be set to a comma-separated list of protocols or address families,
1205	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1206	used, and preference will be given to protocols mentioned earlier in the
1207	list.
1208
1209	This variable can effectively be used for denial-of-service attacks
1210	against local programs (e.g. when setuid), although the impact is likely
1211	small, as the program has to handle connection errors already-
1212
1213	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1214	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1215	- only support IPv4, never try to resolve or contact IPv6
1216	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1217	IPv6, but prefer IPv6 over IPv4.
1218
1219	=item C<PERL_ANYEVENT_EDNS0>
1220
1221	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1222	for DNS. This extension is generally useful to reduce DNS traffic, but
1223	some (broken) firewalls drop such DNS packets, which is why it is off by
1224	default.
1225
1226	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1227	EDNS0 in its DNS requests.
1228
1229	=item C<PERL_ANYEVENT_MAX_FORKS>
1230
1231	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1232	will create in parallel.
1233
1234	=back
1235		1468
1236	=head1 EXAMPLE PROGRAM	1469	=head1 EXAMPLE PROGRAM
1237		1470
1238	The following program uses an I/O watcher to read data from STDIN, a timer	1471	The following program uses an I/O watcher to read data from STDIN, a timer
1239	to display a message once per second, and a condition variable to quit the	1472	to display a message once per second, and a condition variable to quit the
…		…
1433	watcher.	1666	watcher.
1434		1667
1435	=head3 Results	1668	=head3 Results
1436		1669
1437	name watchers bytes create invoke destroy comment	1670	name watchers bytes create invoke destroy comment
1438	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1671	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1439	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1672	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1440	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1673	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1441	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1674	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1442	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1675	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1443	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1676	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1444	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1677	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1445	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1678	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1446	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1679	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1447	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1680	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1448		1681
1449	=head3 Discussion	1682	=head3 Discussion
1450		1683
1451	The benchmark does I<not> measure scalability of the event loop very	1684	The benchmark does I<not> measure scalability of the event loop very
1452	well. For example, a select-based event loop (such as the pure perl one)	1685	well. For example, a select-based event loop (such as the pure perl one)
…		…
1654	watchers, as the management overhead dominates.	1887	watchers, as the management overhead dominates.
1655		1888
1656	=back	1889	=back
1657		1890
1658		1891
		1892	=head1 SIGNALS
		1893
		1894	AnyEvent currently installs handlers for these signals:
		1895
		1896	=over 4
		1897
		1898	=item SIGCHLD
		1899
		1900	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1901	emulation for event loops that do not support them natively. Also, some
		1902	event loops install a similar handler.
		1903
		1904	=item SIGPIPE
		1905
		1906	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1907	when AnyEvent gets loaded.
		1908
		1909	The rationale for this is that AnyEvent users usually do not really depend
		1910	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1911	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1912	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1913	some random socket.
		1914
		1915	The rationale for installing a no-op handler as opposed to ignoring it is
		1916	that this way, the handler will be restored to defaults on exec.
		1917
		1918	Feel free to install your own handler, or reset it to defaults.
		1919
		1920	=back
		1921
		1922	=cut
		1923
		1924	$SIG{PIPE} = sub { }
		1925	unless defined $SIG{PIPE};
		1926
		1927
1659	=head1 FORK	1928	=head1 FORK
1660		1929
1661	Most event libraries are not fork-safe. The ones who are usually are	1930	Most event libraries are not fork-safe. The ones who are usually are
1662	because they rely on inefficient but fork-safe C<select> or C<poll>	1931	because they rely on inefficient but fork-safe C<select> or C<poll>
1663	calls. Only L<EV> is fully fork-aware.	1932	calls. Only L<EV> is fully fork-aware.
…		…
1682		1951
1683	use AnyEvent;	1952	use AnyEvent;
1684		1953
1685	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1954	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1686	be used to probe what backend is used and gain other information (which is	1955	be used to probe what backend is used and gain other information (which is
1687	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1956	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1957	$ENV{PERL_ANYEGENT_STRICT}.
1688		1958
1689		1959
1690	=head1 BUGS	1960	=head1 BUGS
1691		1961
1692	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	1962	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1693	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	1963	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1694	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	1964	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1695	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	1965	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1696	pronounced).	1966	pronounced).
1697		1967
1698		1968
1699	=head1 SEE ALSO	1969	=head1 SEE ALSO
1700		1970

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.165 by root, Tue Jul 8 23:07:26 2008 UTC vs. Revision 1.210 by root, Wed May 13 15:19:43 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.165 by root, Tue Jul 8 23:07:26 2008 UTC vs.
Revision 1.210 by root, Wed May 13 15:19:43 2009 UTC