[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 1.14 by root, Mon Oct 30 20:52:24 2006 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 TIMER WATCHERS
		95
		96	You can create a timer 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
		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	=head1 WHAT TO DO IN A MODULE
		163
		164	As a module author, you should "use AnyEvent" and call AnyEvent methods
		165	freely, but you should not load a specific event module or rely on it.
		166
		167	Be careful when you create watchers in the module body - Anyevent will
		168	decide which event module to use as soon as the first method is called, so
		169	by calling AnyEvent in your module body you force the user of your module
		170	to load the event module first.
		171
		172	=head1 WHAT TO DO IN THE MAIN PROGRAM
		173
		174	There will always be a single main program - the only place that should
		175	dictate which event model to use.
		176
		177	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
		178	do anything special and let AnyEvent decide which implementation to chose.
		179
		180	If the main program relies on a specific event model (for example, in Gtk2
		181	programs you have to rely on either Glib or Glib::Event), you should load
		182	it before loading AnyEvent or any module that uses it, generally, as early
		183	as possible. The reason is that modules might create watchers when they
		184	are loaded, and AnyEvent will decide on the event model to use as soon as
		185	it creates watchers, and it might chose the wrong one unless you load the
		186	correct one yourself.
		187
		188	You can chose to use a rather inefficient pure-perl implementation by
		189	loading the C<AnyEvent::Impl::Perl> module, but letting AnyEvent chose is
		190	generally better.
64		191
65	=cut	192	=cut
66		193
67	package AnyEvent;	194	package AnyEvent;
68		195
69	no warnings;	196	no warnings;
70	use strict 'vars';	197	use strict 'vars';
71	use Carp;	198	use Carp;
72		199
73	our $VERSION = '0.4';	200	our $VERSION = '1.02';
74	our $MODEL;	201	our $MODEL;
75		202
76	our $AUTOLOAD;	203	our $AUTOLOAD;
77	our @ISA;	204	our @ISA;
78		205
79	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	206	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
80		207
		208	our @REGISTRY;
		209
81	my @models = (	210	my @models = (
82	[Coro => Coro::Event::],	211	[Coro::Event:: => AnyEvent::Impl::Coro::],
83	[Event => Event::],	212	[Event:: => AnyEvent::Impl::Event::],
84	[Glib => Glib::],	213	[Glib:: => AnyEvent::Impl::Glib::],
85	[Tk => Tk::],	214	[Tk:: => AnyEvent::Impl::Tk::],
		215	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
86	);	216	);
87		217
88	our %method = map +($_ => 1), qw(io timer condvar broadcast wait cancel DESTROY);	218	our %method = map +($_ => 1), qw(io timer condvar broadcast wait DESTROY);
89		219
90	sub AUTOLOAD {	220	sub AUTOLOAD {
91	$AUTOLOAD =~ s/.*://;	221	$AUTOLOAD =~ s/.*://;
92		222
93	$method{$AUTOLOAD}	223	$method{$AUTOLOAD}
94	or croak "$AUTOLOAD: not a valid method for AnyEvent objects";	224	or croak "$AUTOLOAD: not a valid method for AnyEvent objects";
95		225
96	unless ($MODEL) {	226	unless ($MODEL) {
97	# check for already loaded models	227	# check for already loaded models
98	for (@models) {	228	for (@REGISTRY, @models) {
99	my ($model, $package) = @$_;	229	my ($package, $model) = @$_;
100	if (${"$package\::VERSION"} > 0) {	230	if (${"$package\::VERSION"} > 0) {
101	eval "require AnyEvent::Impl::$model";	231	if (eval "require $model") {
		232	$MODEL = $model;
102	warn "AnyEvent: found model '$model', using it.\n" if $MODEL && $verbose > 1;	233	warn "AnyEvent: found model '$model', using it.\n" if $verbose > 1;
103	last if $MODEL;	234	last;
		235	}
104	}	236	}
105	}	237	}
106		238
107	unless ($MODEL) {	239	unless ($MODEL) {
108	# try to load a model	240	# try to load a model
109		241
110	for (@models) {	242	for (@REGISTRY, @models) {
111	my ($model, $package) = @$_;	243	my ($package, $model) = @$_;
112	eval "require AnyEvent::Impl::$model";	244	if (eval "require $model") {
		245	$MODEL = $model;
113	warn "AnyEvent: autprobed and loaded model '$model', using it.\n" if $MODEL && $verbose > 1;	246	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;
114	last if $MODEL;	247	last;
		248	}
115	}	249	}
116		250
117	$MODEL	251	$MODEL
118	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Coro, Event, Glib or Tk.";	252	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Coro, Event, Glib or Tk.";
119	}	253	}
…		…
123		257
124	my $class = shift;	258	my $class = shift;
125	$class->$AUTOLOAD (@_);	259	$class->$AUTOLOAD (@_);
126	}	260	}
127		261
128	=back	262	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
		263
		264	If you need to support another event library which isn't directly
		265	supported by AnyEvent, you can supply your own interface to it by
		266	pushing, before the first watcher gets created, the package name of
		267	the event module and the package name of the interface to use onto
		268	C<@AnyEvent::REGISTRY>. You can do that before and even without loading
		269	AnyEvent.
		270
		271	Example:
		272
		273	push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::];
		274
		275	This tells AnyEvent to (literally) use the C<urxvt::anyevent::>
		276	package/class when it finds the C<urxvt> package/module is loaded. When
		277	AnyEvent is loaded and asked to find a suitable event model, it will
		278	first check for the presence of urxvt.
		279
		280	The class should prove implementations for all watcher types (see
		281	L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib>
		282	(Source code) and so on for actual examples, use C<perldoc -m
		283	AnyEvent::Impl::Glib> to see the sources).
		284
		285	The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt)
		286	uses the above line as-is. An interface isn't included in AnyEvent
		287	because it doesn't make sense outside the embedded interpreter inside
		288	I<rxvt-unicode>, and it is updated and maintained as part of the
		289	I<rxvt-unicode> distribution.
		290
		291	I<rxvt-unicode> also cheats a bit by not providing blocking access to
		292	condition variables: code blocking while waiting for a condition will
		293	C<die>. This still works with most modules/usages, and blocking calls must
		294	not be in an interactive appliation, so it makes sense.
129		295
130	=head1 ENVIRONMENT VARIABLES	296	=head1 ENVIRONMENT VARIABLES
131		297
132	The following environment variables are used by this module:	298	The following environment variables are used by this module:
133		299

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.7 by root, Fri Dec 30 01:28:31 2005 UTC vs. Revision 1.14 by root, Mon Oct 30 20:52:24 2006 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 1.14 by root, Mon Oct 30 20:52:24 2006 UTC