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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.7 by root, Fri Dec 30 01:28:31 2005 UTC vs.
Revision 1.31 by root, Fri Nov 2 19:20:36 2007 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	Event, Coro, Glib, Tk - various supported event loops	5	Event, Coro, Glib, Tk, Perl - 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 => ..., poll => "[rw]+", cb => sub {	11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {
12	my ($poll_got) = @_;
13	...	12	...
14	});	13	});
15
16	* only one io watcher per $fh and $poll type is allowed (i.e. on a socket
17	you can have one r + one w or one rw watcher, not any more (limitation by
18	Tk).
19
20	* the C<$poll_got> passed to the handler needs to be checked by looking
21	for single characters (e.g. with a regex), as it can contain more event
22	types than were requested (e.g. a 'w' watcher might generate 'rw' events,
23	limitation by Glib).
24
25	* AnyEvent will keep filehandles alive, so as long as the watcher exists,
26	the filehandle exists.
27		14
28	my $w = AnyEvent->timer (after => $seconds, cb => sub {	15	my $w = AnyEvent->timer (after => $seconds, cb => sub {
29	...	16	...
30	});	17	});
31		18
32	* io and time watchers get canceled whenever $w is destroyed, so keep a copy	19	my $w = AnyEvent->condvar; # stores wether a condition was flagged
33
34	* timers can only be used once and must be recreated for repeated
35	operation (limitation by Glib and Tk).
36
37	my $w = AnyEvent->condvar; # kind of main loop replacement
38	$w->wait; # enters main loop till $condvar gets ->broadcast	20	$w->wait; # enters "main loop" till $condvar gets ->broadcast
39	$w->broadcast; # wake up current and all future wait's	21	$w->broadcast; # wake up current and all future wait's
40		22
41	* condvars are used to give blocking behaviour when neccessary. Create
42	a condvar for any "request" or "event" your module might create, C<<
43	->broadcast >> it when the event happens and provide a function that calls
44	C<< ->wait >> for it. See the examples below.
45
46	=head1 DESCRIPTION	23	=head1 DESCRIPTION
47		24
48	L<AnyEvent> provides an identical interface to multiple event loops. This	25	L<AnyEvent> provides an identical interface to multiple event loops. This
49	allows module authors to utilizy an event loop without forcing module	26	allows module authors to utilise an event loop without forcing module
50	users to use the same event loop (as only a single event loop can coexist	27	users to use the same event loop (as only a single event loop can coexist
51	peacefully at any one time).	28	peacefully at any one time).
52		29
53	The interface itself is vaguely similar but not identical to the Event	30	The interface itself is vaguely similar but not identical to the Event
54	module.	31	module.
56	On the first call of any method, the module tries to detect the currently	33	On the first call of any method, the module tries to detect the currently
57	loaded event loop by probing wether any of the following modules is	34	loaded event loop by probing wether any of the following modules is
58	loaded: L<Coro::Event>, L<Event>, L<Glib>, L<Tk>. The first one found is	35	loaded: L<Coro::Event>, L<Event>, L<Glib>, L<Tk>. The first one found is
59	used. If none is found, the module tries to load these modules in the	36	used. If none is found, the module tries to load these modules in the
60	order given. The first one that could be successfully loaded will be	37	order given. The first one that could be successfully loaded will be
61	used. If still none could be found, it will issue an error.	38	used. If still none could be found, AnyEvent will fall back to a pure-perl
		39	event loop, which is also not very efficient.
		40
		41	Because AnyEvent first checks for modules that are already loaded, loading
		42	an Event model explicitly before first using AnyEvent will likely make
		43	that model the default. For example:
		44
		45	use Tk;
		46	use AnyEvent;
		47
		48	# .. AnyEvent will likely default to Tk
		49
		50	The pure-perl implementation of AnyEvent is called
		51	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
		52	explicitly.
		53
		54	=head1 WATCHERS
		55
		56	AnyEvent has the central concept of a I<watcher>, which is an object that
		57	stores relevant data for each kind of event you are waiting for, such as
		58	the callback to call, the filehandle to watch, etc.
		59
		60	These watchers are normal Perl objects with normal Perl lifetime. After
		61	creating a watcher it will immediately "watch" for events and invoke
		62	the callback. To disable the watcher you have to destroy it (e.g. by
		63	setting the variable that stores it to C<undef> or otherwise deleting all
		64	references to it).
		65
		66	All watchers are created by calling a method on the C<AnyEvent> class.
		67
		68	=head2 IO WATCHERS
		69
		70	You can create I/O watcher by calling the C<< AnyEvent->io >> method with
		71	the following mandatory arguments:
		72
		73	C<fh> the Perl I<filehandle> (not filedescriptor) to watch for
		74	events. C<poll> must be a string that is either C<r> or C<w>, that creates
		75	a watcher waiting for "r"eadable or "w"ritable events. C<cb> teh callback
		76	to invoke everytime the filehandle becomes ready.
		77
		78	Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on
		79	a socket you can have one r + one w, not any more (limitation comes from
		80	Tk - if you are sure you are not using Tk this limitation is gone).
		81
		82	Filehandles will be kept alive, so as long as the watcher exists, the
		83	filehandle exists, too.
		84
		85	Example:
		86
		87	# wait for readability of STDIN, then read a line and disable the watcher
		88	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		89	chomp (my $input = <STDIN>);
		90	warn "read: $input\n";
		91	undef $w;
		92	});
		93
		94	=head2 TIME WATCHERS
		95
		96	You can create a time watcher by calling the C<< AnyEvent->timer >>
		97	method with the following mandatory arguments:
		98
		99	C<after> after how many seconds (fractions are supported) should the timer
		100	activate. C<cb> the callback to invoke.
		101
		102	The timer callback will be invoked at most once: if you want a repeating
		103	timer you have to create a new watcher (this is a limitation by both Tk
		104	and Glib).
		105
		106	Example:
		107
		108	# fire an event after 7.7 seconds
		109	my $w = AnyEvent->timer (after => 7.7, cb => sub {
		110	warn "timeout\n";
		111	});
		112
		113	# to cancel the timer:
		114	undef $w
		115
		116	=head2 CONDITION WATCHERS
		117
		118	Condition watchers can be created by calling the C<< AnyEvent->condvar >>
		119	method without any arguments.
		120
		121	A condition watcher watches for a condition - precisely that the C<<
		122	->broadcast >> method has been called.
		123
		124	The watcher has only two methods:
62		125
63	=over 4	126	=over 4
64		127
		128	=item $cv->wait
		129
		130	Wait (blocking if necessary) until the C<< ->broadcast >> method has been
		131	called on c<$cv>, while servicing other watchers normally.
		132
		133	Not all event models support a blocking wait - some die in that case, so
		134	if you are using this from a module, never require a blocking wait, but
		135	let the caller decide wether the call will block or not (for example,
		136	by coupling condition variables with some kind of request results and
		137	supporting callbacks so the caller knows that getting the result will not
		138	block, while still suppporting blockign waits if the caller so desires).
		139
		140	You can only wait once on a condition - additional calls will return
		141	immediately.
		142
		143	=item $cv->broadcast
		144
		145	Flag the condition as ready - a running C<< ->wait >> and all further
		146	calls to C<wait> will return after this method has been called. If nobody
		147	is waiting the broadcast will be remembered..
		148
		149	Example:
		150
		151	# wait till the result is ready
		152	my $result_ready = AnyEvent->condvar;
		153
		154	# do something such as adding a timer
		155	# or socket watcher the calls $result_ready->broadcast
		156	# when the "result" is ready.
		157
		158	$result_ready->wait;
		159
		160	=back
		161
		162	=head2 SIGNAL WATCHERS
		163
		164	You can listen for signals using a signal watcher, C<signal> is the signal
		165	I<name> without any C<SIG> prefix. Multiple signals events can be clumped
		166	together into one callback invocation, and callback invocation might or
		167	might not be asynchronous.
		168
		169	These watchers might use C<%SIG>, so programs overwriting those signals
		170	directly will likely not work correctly.
		171
		172	Example: exit on SIGINT
		173
		174	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		175
		176	=head2 CHILD PROCESS WATCHERS
		177
		178	You can also listen for the status of a child process specified by the
		179	C<pid> argument (or any child if the pid argument is 0). The watcher will
		180	trigger as often as status change for the child are received. This works
		181	by installing a signal handler for C<SIGCHLD>.
		182
		183	Example: wait for pid 1333
		184
		185	my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" });
		186
		187	=head1 GLOBALS
		188
		189	=over 4
		190
		191	=item $AnyEvent::MODEL
		192
		193	Contains C<undef> until the first watcher is being created. Then it
		194	contains the event model that is being used, which is the name of the
		195	Perl class implementing the model. This class is usually one of the
		196	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
		197	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
		198
		199	The known classes so far are:
		200
		201	EV::AnyEvent based on EV (an interface to libev, best choice)
		202	AnyEvent::Impl::Coro based on Coro::Event, second best choice.
		203	AnyEvent::Impl::Event based on Event, also second best choice :)
		204	AnyEvent::Impl::Glib based on Glib, second-best choice.
		205	AnyEvent::Impl::Tk based on Tk, very bad choice.
		206	AnyEvent::Impl::Perl pure-perl implementation, inefficient.
		207
		208	=item AnyEvent::detect
		209
		210	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if
		211	necessary. You should only call this function right before you would have
		212	created an AnyEvent watcher anyway, that is, very late at runtime.
		213
		214	=back
		215
		216	=head1 WHAT TO DO IN A MODULE
		217
		218	As a module author, you should "use AnyEvent" and call AnyEvent methods
		219	freely, but you should not load a specific event module or rely on it.
		220
		221	Be careful when you create watchers in the module body - Anyevent will
		222	decide which event module to use as soon as the first method is called, so
		223	by calling AnyEvent in your module body you force the user of your module
		224	to load the event module first.
		225
		226	=head1 WHAT TO DO IN THE MAIN PROGRAM
		227
		228	There will always be a single main program - the only place that should
		229	dictate which event model to use.
		230
		231	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
		232	do anything special and let AnyEvent decide which implementation to chose.
		233
		234	If the main program relies on a specific event model (for example, in Gtk2
		235	programs you have to rely on either Glib or Glib::Event), you should load
		236	it before loading AnyEvent or any module that uses it, generally, as early
		237	as possible. The reason is that modules might create watchers when they
		238	are loaded, and AnyEvent will decide on the event model to use as soon as
		239	it creates watchers, and it might chose the wrong one unless you load the
		240	correct one yourself.
		241
		242	You can chose to use a rather inefficient pure-perl implementation by
		243	loading the C<AnyEvent::Impl::Perl> module, but letting AnyEvent chose is
		244	generally better.
		245
65	=cut	246	=cut
66		247
67	package AnyEvent;	248	package AnyEvent;
68		249
69	no warnings;	250	no warnings;
70	use strict 'vars';	251	use strict;
		252
71	use Carp;	253	use Carp;
72		254
73	our $VERSION = '0.4';	255	our $VERSION = '2.55';
74	our $MODEL;	256	our $MODEL;
75		257
76	our $AUTOLOAD;	258	our $AUTOLOAD;
77	our @ISA;	259	our @ISA;
78		260
79	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	261	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
80		262
		263	our @REGISTRY;
		264
81	my @models = (	265	my @models = (
82	[Coro => Coro::Event::],	266	[Coro::Event:: => AnyEvent::Impl::Coro::],
83	[Event => Event::],	267	[EV:: => EV::AnyEvent::],
84	[Glib => Glib::],	268	[Event:: => AnyEvent::Impl::Event::],
85	[Tk => Tk::],	269	[Glib:: => AnyEvent::Impl::Glib::],
		270	[Tk:: => AnyEvent::Impl::Tk::],
		271	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
86	);	272	);
87		273
88	our %method = map +($_ => 1), qw(io timer condvar broadcast wait cancel DESTROY);	274	our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY);
89		275
90	sub AUTOLOAD {	276	sub detect() {
91	$AUTOLOAD =~ s/.*://;
92
93	$method{$AUTOLOAD}
94	or croak "$AUTOLOAD: not a valid method for AnyEvent objects";
95
96	unless ($MODEL) {	277	unless ($MODEL) {
		278	no strict 'refs';
		279
97	# check for already loaded models	280	# check for already loaded models
98	for (@models) {	281	for (@REGISTRY, @models) {
99	my ($model, $package) = @$_;	282	my ($package, $model) = @$_;
100	if (${"$package\::VERSION"} > 0) {	283	if (${"$package\::VERSION"} > 0) {
101	eval "require AnyEvent::Impl::$model";	284	if (eval "require $model") {
		285	$MODEL = $model;
102	warn "AnyEvent: found model '$model', using it.\n" if $MODEL && $verbose > 1;	286	warn "AnyEvent: found model '$model', using it.\n" if $verbose > 1;
103	last if $MODEL;	287	last;
		288	}
104	}	289	}
105	}	290	}
106		291
107	unless ($MODEL) {	292	unless ($MODEL) {
108	# try to load a model	293	# try to load a model
109		294
110	for (@models) {	295	for (@REGISTRY, @models) {
111	my ($model, $package) = @$_;	296	my ($package, $model) = @$_;
112	eval "require AnyEvent::Impl::$model";	297	if (eval "require $package"
		298	and ${"$package\::VERSION"} > 0
		299	and eval "require $model") {
		300	$MODEL = $model;
113	warn "AnyEvent: autprobed and loaded model '$model', using it.\n" if $MODEL && $verbose > 1;	301	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;
114	last if $MODEL;	302	last;
		303	}
115	}	304	}
116		305
117	$MODEL	306	$MODEL
118	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Coro, Event, Glib or Tk.";	307	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Event (or Coro+Event), Glib or Tk.";
119	}	308	}
		309
		310	unshift @ISA, $MODEL;
		311	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
120	}	312	}
121		313
122	@ISA = $MODEL;	314	$MODEL
		315	}
		316
		317	sub AUTOLOAD {
		318	(my $func = $AUTOLOAD) =~ s/.*://;
		319
		320	$method{$func}
		321	or croak "$func: not a valid method for AnyEvent objects";
		322
		323	detect unless $MODEL;
123		324
124	my $class = shift;	325	my $class = shift;
125	$class->$AUTOLOAD (@_);	326	$class->$func (@_);
126	}	327	}
127		328
128	=back	329	package AnyEvent::Base;
		330
		331	# default implementation for ->condvar, ->wait, ->broadcast
		332
		333	sub condvar {
		334	bless \my $flag, "AnyEvent::Base::CondVar"
		335	}
		336
		337	sub AnyEvent::Base::CondVar::broadcast {
		338	${$_[0]}++;
		339	}
		340
		341	sub AnyEvent::Base::CondVar::wait {
		342	AnyEvent->one_event while !${$_[0]};
		343	}
		344
		345	# default implementation for ->signal
		346
		347	our %SIG_CB;
		348
		349	sub signal {
		350	my (undef, %arg) = @_;
		351
		352	my $signal = uc $arg{signal}
		353	or Carp::croak "required option 'signal' is missing";
		354
		355	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		356	$SIG{$signal} \|\|= sub {
		357	$_->() for values %{ $SIG_CB{$signal} \|\| {} };
		358	};
		359
		360	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
		361	}
		362
		363	sub AnyEvent::Base::Signal::DESTROY {
		364	my ($signal, $cb) = @{$_[0]};
		365
		366	delete $SIG_CB{$signal}{$cb};
		367
		368	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };
		369	}
		370
		371	# default implementation for ->child
		372
		373	our %PID_CB;
		374	our $CHLD_W;
		375	our $PID_IDLE;
		376	our $WNOHANG;
		377
		378	sub _child_wait {
		379	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		380	$_->() for (values %{ $PID_CB{$pid} \|\| {} }),
		381	(values %{ $PID_CB{0} \|\| {} });
		382	}
		383
		384	undef $PID_IDLE;
		385	}
		386
		387	sub child {
		388	my (undef, %arg) = @_;
		389
		390	defined (my $pid = $arg{pid} + 0)
		391	or Carp::croak "required option 'pid' is missing";
		392
		393	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
		394
		395	unless ($WNOHANG) {
		396	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;
		397	}
		398
		399	unless ($CHLD_W) {
		400	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_child_wait);
		401	# child could be a zombie already
		402	$PID_IDLE \|\|= AnyEvent->timer (after => 0, cb => \&_child_wait);
		403	}
		404
		405	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"
		406	}
		407
		408	sub AnyEvent::Base::Child::DESTROY {
		409	my ($pid, $cb) = @{$_[0]};
		410
		411	delete $PID_CB{$pid}{$cb};
		412	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
		413
		414	undef $CHLD_W unless keys %PID_CB;
		415	}
		416
		417	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
		418
		419	If you need to support another event library which isn't directly
		420	supported by AnyEvent, you can supply your own interface to it by
		421	pushing, before the first watcher gets created, the package name of
		422	the event module and the package name of the interface to use onto
		423	C<@AnyEvent::REGISTRY>. You can do that before and even without loading
		424	AnyEvent.
		425
		426	Example:
		427
		428	push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::];
		429
		430	This tells AnyEvent to (literally) use the C<urxvt::anyevent::>
		431	package/class when it finds the C<urxvt> package/module is loaded. When
		432	AnyEvent is loaded and asked to find a suitable event model, it will
		433	first check for the presence of urxvt.
		434
		435	The class should provide implementations for all watcher types (see
		436	L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib>
		437	(Source code) and so on for actual examples, use C<perldoc -m
		438	AnyEvent::Impl::Glib> to see the sources).
		439
		440	The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt)
		441	uses the above line as-is. An interface isn't included in AnyEvent
		442	because it doesn't make sense outside the embedded interpreter inside
		443	I<rxvt-unicode>, and it is updated and maintained as part of the
		444	I<rxvt-unicode> distribution.
		445
		446	I<rxvt-unicode> also cheats a bit by not providing blocking access to
		447	condition variables: code blocking while waiting for a condition will
		448	C<die>. This still works with most modules/usages, and blocking calls must
		449	not be in an interactive application, so it makes sense.
129		450
130	=head1 ENVIRONMENT VARIABLES	451	=head1 ENVIRONMENT VARIABLES
131		452
132	The following environment variables are used by this module:	453	The following environment variables are used by this module:
133		454

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.7 by root, Fri Dec 30 01:28:31 2005 UTC vs. Revision 1.31 by root, Fri Nov 2 19:20:36 2007 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.7 by root, Fri Dec 30 01:28:31 2005 UTC vs.
Revision 1.31 by root, Fri Nov 2 19:20:36 2007 UTC