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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.14 by root, Mon Oct 30 20:52:24 2006 UTC vs.
Revision 1.54 by root, Tue Apr 22 05:12:19 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	Event, Coro, Glib, Tk, Perl - various supported event loops	5	EV, Event, Coro::EV, Coro::Event, 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
14		14
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	15	my $w = AnyEvent->timer (after => $seconds, cb => sub {
16	...	16	...
17	});	17	});
18		18
19	my $w = AnyEvent->condvar; # stores wether a condition was flagged	19	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->wait; # enters "main loop" till $condvar gets ->broadcast	20	$w->wait; # enters "main loop" till $condvar gets ->broadcast
21	$w->broadcast; # wake up current and all future wait's	21	$w->broadcast; # wake up current and all future wait's
		22
		23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
		24
		25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
		26	nowadays. So what is different about AnyEvent?
		27
		28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
		29	policy> and AnyEvent is I<small and efficient>.
		30
		31	First and foremost, I<AnyEvent is not an event model> itself, it only
		32	interfaces to whatever event model the main program happens to use in a
		33	pragmatic way. For event models and certain classes of immortals alike,
		34	the statement "there can only be one" is a bitter reality: In general,
		35	only one event loop can be active at the same time in a process. AnyEvent
		36	helps hiding the differences between those event loops.
		37
		38	The goal of AnyEvent is to offer module authors the ability to do event
		39	programming (waiting for I/O or timer events) without subscribing to a
		40	religion, a way of living, and most importantly: without forcing your
		41	module users into the same thing by forcing them to use the same event
		42	model you use.
		43
		44	For modules like POE or IO::Async (which is a total misnomer as it is
		45	actually doing all I/O I<synchronously>...), using them in your module is
		46	like joining a cult: After you joined, you are dependent on them and you
		47	cannot use anything else, as it is simply incompatible to everything that
		48	isn't itself. What's worse, all the potential users of your module are
		49	I<also> forced to use the same event loop you use.
		50
		51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
		52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
		53	with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if
		54	your module uses one of those, every user of your module has to use it,
		55	too. But if your module uses AnyEvent, it works transparently with all
		56	event models it supports (including stuff like POE and IO::Async, as long
		57	as those use one of the supported event loops. It is trivial to add new
		58	event loops to AnyEvent, too, so it is future-proof).
		59
		60	In addition to being free of having to use I<the one and only true event
		61	model>, AnyEvent also is free of bloat and policy: with POE or similar
		62	modules, you get an enourmous amount of code and strict rules you have to
		63	follow. AnyEvent, on the other hand, is lean and up to the point, by only
		64	offering the functionality that is necessary, in as thin as a wrapper as
		65	technically possible.
		66
		67	Of course, if you want lots of policy (this can arguably be somewhat
		68	useful) and you want to force your users to use the one and only event
		69	model, you should I<not> use this module.
		70
22		71
23	=head1 DESCRIPTION	72	=head1 DESCRIPTION
24		73
25	L<AnyEvent> provides an identical interface to multiple event loops. This	74	L<AnyEvent> provides an identical interface to multiple event loops. This
26	allows module authors to utilise an event loop without forcing module	75	allows module authors to utilise an event loop without forcing module
27	users to use the same event loop (as only a single event loop can coexist	76	users to use the same event loop (as only a single event loop can coexist
28	peacefully at any one time).	77	peacefully at any one time).
29		78
30	The interface itself is vaguely similar but not identical to the Event	79	The interface itself is vaguely similar, but not identical to the L<Event>
31	module.	80	module.
32		81
33	On the first call of any method, the module tries to detect the currently	82	During the first call of any watcher-creation method, the module tries
34	loaded event loop by probing wether any of the following modules is	83	to detect the currently loaded event loop by probing whether one of the
35	loaded: L<Coro::Event>, L<Event>, L<Glib>, L<Tk>. The first one found is	84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,
36	used. If none is found, the module tries to load these modules in the	85	L<Event>, L<Glib>, L<Tk>. The first one found is used. If none are found,
37	order given. The first one that could be successfully loaded will be	86	the module tries to load these modules in the stated order. The first one
38	used. If still none could be found, AnyEvent will fall back to a pure-perl	87	that can be successfully loaded will be used. If, after this, still none
39	event loop, which is also not very efficient.	88	could be found, AnyEvent will fall back to a pure-perl event loop, which
		89	is not very efficient, but should work everywhere.
40		90
41	Because AnyEvent first checks for modules that are already loaded, loading	91	Because AnyEvent first checks for modules that are already loaded, loading
42	an Event model explicitly before first using AnyEvent will likely make	92	an event model explicitly before first using AnyEvent will likely make
43	that model the default. For example:	93	that model the default. For example:
44		94
45	use Tk;	95	use Tk;
46	use AnyEvent;	96	use AnyEvent;
47		97
48	# .. AnyEvent will likely default to Tk	98	# .. AnyEvent will likely default to Tk
		99
		100	The I<likely> means that, if any module loads another event model and
		101	starts using it, all bets are off. Maybe you should tell their authors to
		102	use AnyEvent so their modules work together with others seamlessly...
49		103
50	The pure-perl implementation of AnyEvent is called	104	The pure-perl implementation of AnyEvent is called
51	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	105	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
52	explicitly.	106	explicitly.
53		107
…		…
56	AnyEvent has the central concept of a I<watcher>, which is an object that	110	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	111	stores relevant data for each kind of event you are waiting for, such as
58	the callback to call, the filehandle to watch, etc.	112	the callback to call, the filehandle to watch, etc.
59		113
60	These watchers are normal Perl objects with normal Perl lifetime. After	114	These watchers are normal Perl objects with normal Perl lifetime. After
61	creating a watcher it will immediately "watch" for events and invoke	115	creating a watcher it will immediately "watch" for events and invoke the
		116	callback when the event occurs (of course, only when the event model
		117	is in control).
		118
62	the callback. To disable the watcher you have to destroy it (e.g. by	119	To disable the watcher you have to destroy it (e.g. by setting the
63	setting the variable that stores it to C<undef> or otherwise deleting all	120	variable you store it in to C<undef> or otherwise deleting all references
64	references to it).	121	to it).
65		122
66	All watchers are created by calling a method on the C<AnyEvent> class.	123	All watchers are created by calling a method on the C<AnyEvent> class.
67		124
		125	Many watchers either are used with "recursion" (repeating timers for
		126	example), or need to refer to their watcher object in other ways.
		127
		128	An any way to achieve that is this pattern:
		129
		130	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
		131	# you can use $w here, for example to undef it
		132	undef $w;
		133	});
		134
		135	Note that C<my $w; $w => combination. This is necessary because in Perl,
		136	my variables are only visible after the statement in which they are
		137	declared.
		138
68	=head2 IO WATCHERS	139	=head2 IO WATCHERS
69		140
70	You can create I/O watcher by calling the C<< AnyEvent->io >> method with	141	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
71	the following mandatory arguments:	142	with the following mandatory key-value pairs as arguments:
72		143
73	C<fh> the Perl I<filehandle> (not filedescriptor) to watch for	144	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for
74	events. C<poll> must be a string that is either C<r> or C<w>, that creates	145	events. C<poll> must be a string that is either C<r> or C<w>, which
75	a watcher waiting for "r"eadable or "w"ritable events. C<cb> teh callback	146	creates a watcher waiting for "r"eadable or "w"ritable events,
76	to invoke everytime the filehandle becomes ready.	147	respectively. C<cb> is the callback to invoke each time the file handle
		148	becomes ready.
77		149
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	150	File handles will be kept alive, so as long as the watcher exists, the
83	filehandle exists, too.	151	file handle exists, too.
		152
		153	It is not allowed to close a file handle as long as any watcher is active
		154	on the underlying file descriptor.
		155
		156	Some event loops issue spurious readyness notifications, so you should
		157	always use non-blocking calls when reading/writing from/to your file
		158	handles.
84		159
85	Example:	160	Example:
86		161
87	# wait for readability of STDIN, then read a line and disable the watcher	162	# 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 {	163	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
89	chomp (my $input = <STDIN>);	164	chomp (my $input = <STDIN>);
90	warn "read: $input\n";	165	warn "read: $input\n";
91	undef $w;	166	undef $w;
92	});	167	});
93		168
94	=head2 TIMER WATCHERS	169	=head2 TIME WATCHERS
95		170
96	You can create a timer watcher by calling the C<< AnyEvent->timer >>	171	You can create a time watcher by calling the C<< AnyEvent->timer >>
97	method with the following mandatory arguments:	172	method with the following mandatory arguments:
98		173
99	C<after> after how many seconds (fractions are supported) should the timer	174	C<after> specifies after how many seconds (fractional values are
100	activate. C<cb> the callback to invoke.	175	supported) should the timer activate. C<cb> the callback to invoke in that
		176	case.
101		177
102	The timer callback will be invoked at most once: if you want a repeating	178	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	179	timer you have to create a new watcher (this is a limitation by both Tk
104	and Glib).	180	and Glib).
105		181
…		…
109	my $w = AnyEvent->timer (after => 7.7, cb => sub {	185	my $w = AnyEvent->timer (after => 7.7, cb => sub {
110	warn "timeout\n";	186	warn "timeout\n";
111	});	187	});
112		188
113	# to cancel the timer:	189	# to cancel the timer:
114	undef $w	190	undef $w;
115		191
		192	Example 2:
		193
		194	# fire an event after 0.5 seconds, then roughly every second
		195	my $w;
		196
		197	my $cb = sub {
		198	# cancel the old timer while creating a new one
		199	$w = AnyEvent->timer (after => 1, cb => $cb);
		200	};
		201
		202	# start the "loop" by creating the first watcher
		203	$w = AnyEvent->timer (after => 0.5, cb => $cb);
		204
		205	=head3 TIMING ISSUES
		206
		207	There are two ways to handle timers: based on real time (relative, "fire
		208	in 10 seconds") and based on wallclock time (absolute, "fire at 12
		209	o'clock").
		210
		211	While most event loops expect timers to specified in a relative way, they use
		212	absolute time internally. This makes a difference when your clock "jumps",
		213	for example, when ntp decides to set your clock backwards from the wrong 2014-01-01 to
		214	2008-01-01, a watcher that you created to fire "after" a second might actually take
		215	six years to finally fire.
		216
		217	AnyEvent cannot compensate for this. The only event loop that is conscious
		218	about these issues is L<EV>, which offers both relative (ev_timer) and
		219	absolute (ev_periodic) timers.
		220
		221	AnyEvent always prefers relative timers, if available, matching the
		222	AnyEvent API.
		223
		224	=head2 SIGNAL WATCHERS
		225
		226	You can watch for signals using a signal watcher, C<signal> is the signal
		227	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
		228	be invoked whenever a signal occurs.
		229
		230	Multiple signals occurances can be clumped together into one callback
		231	invocation, and callback invocation will be synchronous. synchronous means
		232	that it might take a while until the signal gets handled by the process,
		233	but it is guarenteed not to interrupt any other callbacks.
		234
		235	The main advantage of using these watchers is that you can share a signal
		236	between multiple watchers.
		237
		238	This watcher might use C<%SIG>, so programs overwriting those signals
		239	directly will likely not work correctly.
		240
		241	Example: exit on SIGINT
		242
		243	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
		244
		245	=head2 CHILD PROCESS WATCHERS
		246
		247	You can also watch on a child process exit and catch its exit status.
		248
		249	The child process is specified by the C<pid> argument (if set to C<0>, it
		250	watches for any child process exit). The watcher will trigger as often
		251	as status change for the child are received. This works by installing a
		252	signal handler for C<SIGCHLD>. The callback will be called with the pid
		253	and exit status (as returned by waitpid).
		254
		255	Example: wait for pid 1333
		256
		257	my $w = AnyEvent->child (
		258	pid => 1333,
		259	cb => sub {
		260	my ($pid, $status) = @_;
		261	warn "pid $pid exited with status $status";
		262	},
		263	);
		264
116	=head2 CONDITION WATCHERS	265	=head2 CONDITION VARIABLES
117		266
118	Condition watchers can be created by calling the C<< AnyEvent->condvar >>	267	Condition variables can be created by calling the C<< AnyEvent->condvar >>
119	method without any arguments.	268	method without any arguments.
120		269
121	A condition watcher watches for a condition - precisely that the C<<	270	A condition variable waits for a condition - precisely that the C<<
122	->broadcast >> method has been called.	271	->broadcast >> method has been called.
123		272
124	The watcher has only two methods:	273	They are very useful to signal that a condition has been fulfilled, for
		274	example, if you write a module that does asynchronous http requests,
		275	then a condition variable would be the ideal candidate to signal the
		276	availability of results.
		277
		278	You can also use condition variables to block your main program until
		279	an event occurs - for example, you could C<< ->wait >> in your main
		280	program until the user clicks the Quit button in your app, which would C<<
		281	->broadcast >> the "quit" event.
		282
		283	Note that condition variables recurse into the event loop - if you have
		284	two pirces of code that call C<< ->wait >> in a round-robbin fashion, you
		285	lose. Therefore, condition variables are good to export to your caller, but
		286	you should avoid making a blocking wait yourself, at least in callbacks,
		287	as this asks for trouble.
		288
		289	This object has two methods:
125		290
126	=over 4	291	=over 4
127		292
128	=item $cv->wait	293	=item $cv->wait
129		294
130	Wait (blocking if necessary) until the C<< ->broadcast >> method has been	295	Wait (blocking if necessary) until the C<< ->broadcast >> method has been
131	called on c<$cv>, while servicing other watchers normally.	296	called on c<$cv>, while servicing other watchers normally.
132		297
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	298	You can only wait once on a condition - additional calls will return
141	immediately.	299	immediately.
142		300
		301	Not all event models support a blocking wait - some die in that case
		302	(programs might want to do that to stay interactive), so I<if you are
		303	using this from a module, never require a blocking wait>, but let the
		304	caller decide whether the call will block or not (for example, by coupling
		305	condition variables with some kind of request results and supporting
		306	callbacks so the caller knows that getting the result will not block,
		307	while still suppporting blocking waits if the caller so desires).
		308
		309	Another reason I<never> to C<< ->wait >> in a module is that you cannot
		310	sensibly have two C<< ->wait >>'s in parallel, as that would require
		311	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
		312	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and
		313	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
		314	from different coroutines, however).
		315
143	=item $cv->broadcast	316	=item $cv->broadcast
144		317
145	Flag the condition as ready - a running C<< ->wait >> and all further	318	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	319	calls to C<wait> will (eventually) return after this method has been
147	is waiting the broadcast will be remembered..	320	called. If nobody is waiting the broadcast will be remembered..
		321
		322	=back
148		323
149	Example:	324	Example:
150		325
151	# wait till the result is ready	326	# wait till the result is ready
152	my $result_ready = AnyEvent->condvar;	327	my $result_ready = AnyEvent->condvar;
153		328
154	# do something such as adding a timer	329	# do something such as adding a timer
155	# or socket watcher the calls $result_ready->broadcast	330	# or socket watcher the calls $result_ready->broadcast
156	# when the "result" is ready.	331	# when the "result" is ready.
		332	# in this case, we simply use a timer:
		333	my $w = AnyEvent->timer (
		334	after => 1,
		335	cb => sub { $result_ready->broadcast },
		336	);
157		337
		338	# this "blocks" (while handling events) till the watcher
		339	# calls broadcast
158	$result_ready->wait;	340	$result_ready->wait;
159		341
		342	=head1 GLOBAL VARIABLES AND FUNCTIONS
		343
		344	=over 4
		345
		346	=item $AnyEvent::MODEL
		347
		348	Contains C<undef> until the first watcher is being created. Then it
		349	contains the event model that is being used, which is the name of the
		350	Perl class implementing the model. This class is usually one of the
		351	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
		352	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
		353
		354	The known classes so far are:
		355
		356	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
		357	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
		358	AnyEvent::Impl::EV based on EV (an interface to libev, also best choice).
		359	AnyEvent::Impl::Event based on Event, also second best choice :)
		360	AnyEvent::Impl::Glib based on Glib, third-best choice.
		361	AnyEvent::Impl::Tk based on Tk, very bad choice.
		362	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
		363
		364	=item AnyEvent::detect
		365
		366	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
		367	if necessary. You should only call this function right before you would
		368	have created an AnyEvent watcher anyway, that is, as late as possible at
		369	runtime.
		370
160	=back	371	=back
161		372
162	=head1 WHAT TO DO IN A MODULE	373	=head1 WHAT TO DO IN A MODULE
163		374
164	As a module author, you should "use AnyEvent" and call AnyEvent methods	375	As a module author, you should C<use AnyEvent> and call AnyEvent methods
165	freely, but you should not load a specific event module or rely on it.	376	freely, but you should not load a specific event module or rely on it.
166		377
167	Be careful when you create watchers in the module body - Anyevent will	378	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	379	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	380	by calling AnyEvent in your module body you force the user of your module
170	to load the event module first.	381	to load the event module first.
171		382
		383	Never call C<< ->wait >> on a condition variable unless you I<know> that
		384	the C<< ->broadcast >> method has been called on it already. This is
		385	because it will stall the whole program, and the whole point of using
		386	events is to stay interactive.
		387
		388	It is fine, however, to call C<< ->wait >> when the user of your module
		389	requests it (i.e. if you create a http request object ad have a method
		390	called C<results> that returns the results, it should call C<< ->wait >>
		391	freely, as the user of your module knows what she is doing. always).
		392
172	=head1 WHAT TO DO IN THE MAIN PROGRAM	393	=head1 WHAT TO DO IN THE MAIN PROGRAM
173		394
174	There will always be a single main program - the only place that should	395	There will always be a single main program - the only place that should
175	dictate which event model to use.	396	dictate which event model to use.
176		397
177	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	398	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.	399	do anything special (it does not need to be event-based) and let AnyEvent
		400	decide which implementation to chose if some module relies on it.
179		401
180	If the main program relies on a specific event model (for example, in Gtk2	402	If the main program relies on a specific event model. For example, in
181	programs you have to rely on either Glib or Glib::Event), you should load	403	Gtk2 programs you have to rely on the Glib module. You should load the
182	it before loading AnyEvent or any module that uses it, generally, as early	404	event module before loading AnyEvent or any module that uses it: generally
183	as possible. The reason is that modules might create watchers when they	405	speaking, you should load it as early as possible. The reason is that
184	are loaded, and AnyEvent will decide on the event model to use as soon as	406	modules might create watchers when they are loaded, and AnyEvent will
185	it creates watchers, and it might chose the wrong one unless you load the	407	decide on the event model to use as soon as it creates watchers, and it
186	correct one yourself.	408	might chose the wrong one unless you load the correct one yourself.
187		409
188	You can chose to use a rather inefficient pure-perl implementation by	410	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	411	loading the C<AnyEvent::Impl::Perl> module, which gives you similar
190	generally better.	412	behaviour everywhere, but letting AnyEvent chose is generally better.
191		413
192	=cut	414	=cut
193		415
194	package AnyEvent;	416	package AnyEvent;
195		417
196	no warnings;	418	no warnings;
197	use strict 'vars';	419	use strict;
		420
198	use Carp;	421	use Carp;
199		422
200	our $VERSION = '1.02';	423	our $VERSION = '3.12';
201	our $MODEL;	424	our $MODEL;
202		425
203	our $AUTOLOAD;	426	our $AUTOLOAD;
204	our @ISA;	427	our @ISA;
205		428
206	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	429	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
207		430
208	our @REGISTRY;	431	our @REGISTRY;
209		432
210	my @models = (	433	my @models = (
		434	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
211	[Coro::Event:: => AnyEvent::Impl::Coro::],	435	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
		436	[EV:: => AnyEvent::Impl::EV::],
212	[Event:: => AnyEvent::Impl::Event::],	437	[Event:: => AnyEvent::Impl::Event::],
213	[Glib:: => AnyEvent::Impl::Glib::],	438	[Glib:: => AnyEvent::Impl::Glib::],
214	[Tk:: => AnyEvent::Impl::Tk::],	439	[Tk:: => AnyEvent::Impl::Tk::],
215	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	440	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
216	);	441	);
217		442
218	our %method = map +($_ => 1), qw(io timer condvar broadcast wait DESTROY);	443	our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY);
219		444
220	sub AUTOLOAD {	445	sub detect() {
221	$AUTOLOAD =~ s/.*://;
222
223	$method{$AUTOLOAD}
224	or croak "$AUTOLOAD: not a valid method for AnyEvent objects";
225
226	unless ($MODEL) {	446	unless ($MODEL) {
		447	no strict 'refs';
		448
227	# check for already loaded models	449	# check for already loaded models
228	for (@REGISTRY, @models) {	450	for (@REGISTRY, @models) {
229	my ($package, $model) = @$_;	451	my ($package, $model) = @$_;
230	if (${"$package\::VERSION"} > 0) {	452	if (${"$package\::VERSION"} > 0) {
231	if (eval "require $model") {	453	if (eval "require $model") {
…		…
239	unless ($MODEL) {	461	unless ($MODEL) {
240	# try to load a model	462	# try to load a model
241		463
242	for (@REGISTRY, @models) {	464	for (@REGISTRY, @models) {
243	my ($package, $model) = @$_;	465	my ($package, $model) = @$_;
		466	if (eval "require $package"
		467	and ${"$package\::VERSION"} > 0
244	if (eval "require $model") {	468	and eval "require $model") {
245	$MODEL = $model;	469	$MODEL = $model;
246	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;	470	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;
247	last;	471	last;
248	}	472	}
249	}	473	}
250		474
251	$MODEL	475	$MODEL
252	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Coro, Event, Glib or Tk.";	476	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event), Glib or Tk.";
253	}	477	}
		478
		479	unshift @ISA, $MODEL;
		480	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
254	}	481	}
255		482
256	@ISA = $MODEL;	483	$MODEL
		484	}
		485
		486	sub AUTOLOAD {
		487	(my $func = $AUTOLOAD) =~ s/.*://;
		488
		489	$method{$func}
		490	or croak "$func: not a valid method for AnyEvent objects";
		491
		492	detect unless $MODEL;
257		493
258	my $class = shift;	494	my $class = shift;
259	$class->$AUTOLOAD (@_);	495	$class->$func (@_);
		496	}
		497
		498	package AnyEvent::Base;
		499
		500	# default implementation for ->condvar, ->wait, ->broadcast
		501
		502	sub condvar {
		503	bless \my $flag, "AnyEvent::Base::CondVar"
		504	}
		505
		506	sub AnyEvent::Base::CondVar::broadcast {
		507	${$_[0]}++;
		508	}
		509
		510	sub AnyEvent::Base::CondVar::wait {
		511	AnyEvent->one_event while !${$_[0]};
		512	}
		513
		514	# default implementation for ->signal
		515
		516	our %SIG_CB;
		517
		518	sub signal {
		519	my (undef, %arg) = @_;
		520
		521	my $signal = uc $arg{signal}
		522	or Carp::croak "required option 'signal' is missing";
		523
		524	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		525	$SIG{$signal} \|\|= sub {
		526	$_->() for values %{ $SIG_CB{$signal} \|\| {} };
		527	};
		528
		529	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
		530	}
		531
		532	sub AnyEvent::Base::Signal::DESTROY {
		533	my ($signal, $cb) = @{$_[0]};
		534
		535	delete $SIG_CB{$signal}{$cb};
		536
		537	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };
		538	}
		539
		540	# default implementation for ->child
		541
		542	our %PID_CB;
		543	our $CHLD_W;
		544	our $CHLD_DELAY_W;
		545	our $PID_IDLE;
		546	our $WNOHANG;
		547
		548	sub _child_wait {
		549	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
		550	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
		551	(values %{ $PID_CB{0} \|\| {} });
		552	}
		553
		554	undef $PID_IDLE;
		555	}
		556
		557	sub _sigchld {
		558	# make sure we deliver these changes "synchronous" with the event loop.
		559	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
		560	undef $CHLD_DELAY_W;
		561	&_child_wait;
		562	});
		563	}
		564
		565	sub child {
		566	my (undef, %arg) = @_;
		567
		568	defined (my $pid = $arg{pid} + 0)
		569	or Carp::croak "required option 'pid' is missing";
		570
		571	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
		572
		573	unless ($WNOHANG) {
		574	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;
		575	}
		576
		577	unless ($CHLD_W) {
		578	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
		579	# child could be a zombie already, so make at least one round
		580	&_sigchld;
		581	}
		582
		583	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"
		584	}
		585
		586	sub AnyEvent::Base::Child::DESTROY {
		587	my ($pid, $cb) = @{$_[0]};
		588
		589	delete $PID_CB{$pid}{$cb};
		590	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
		591
		592	undef $CHLD_W unless keys %PID_CB;
260	}	593	}
261		594
262	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	595	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
		596
		597	This is an advanced topic that you do not normally need to use AnyEvent in
		598	a module. This section is only of use to event loop authors who want to
		599	provide AnyEvent compatibility.
263		600
264	If you need to support another event library which isn't directly	601	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	602	supported by AnyEvent, you can supply your own interface to it by
266	pushing, before the first watcher gets created, the package name of	603	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	604	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	605	C<@AnyEvent::REGISTRY>. You can do that before and even without loading
269	AnyEvent.	606	AnyEvent, so it is reasonably cheap.
270		607
271	Example:	608	Example:
272		609
273	push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::];	610	push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::];
274		611
275	This tells AnyEvent to (literally) use the C<urxvt::anyevent::>	612	This tells AnyEvent to (literally) use the C<urxvt::anyevent::>
276	package/class when it finds the C<urxvt> package/module is loaded. When	613	package/class when it finds the C<urxvt> package/module is already loaded.
		614
277	AnyEvent is loaded and asked to find a suitable event model, it will	615	When AnyEvent is loaded and asked to find a suitable event model, it
278	first check for the presence of urxvt.	616	will first check for the presence of urxvt by trying to C<use> the
		617	C<urxvt::anyevent> module.
279		618
280	The class should prove implementations for all watcher types (see	619	The class should provide implementations for all watcher types. See
281	L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib>	620	L<AnyEvent::Impl::EV> (source code), L<AnyEvent::Impl::Glib> (Source code)
282	(Source code) and so on for actual examples, use C<perldoc -m	621	and so on for actual examples. Use C<perldoc -m AnyEvent::Impl::Glib> to
283	AnyEvent::Impl::Glib> to see the sources).	622	see the sources.
284		623
		624	If you don't provide C<signal> and C<child> watchers than AnyEvent will
		625	provide suitable (hopefully) replacements.
		626
285	The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt)	627	The above example 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	628	terminal emulator uses the above line as-is. An interface isn't included
287	because it doesn't make sense outside the embedded interpreter inside	629	in AnyEvent because it doesn't make sense outside the embedded interpreter
288	I<rxvt-unicode>, and it is updated and maintained as part of the	630	inside I<rxvt-unicode>, and it is updated and maintained as part of the
289	I<rxvt-unicode> distribution.	631	I<rxvt-unicode> distribution.
290		632
291	I<rxvt-unicode> also cheats a bit by not providing blocking access to	633	I<rxvt-unicode> also cheats a bit by not providing blocking access to
292	condition variables: code blocking while waiting for a condition will	634	condition variables: code blocking while waiting for a condition will
293	C<die>. This still works with most modules/usages, and blocking calls must	635	C<die>. This still works with most modules/usages, and blocking calls must
294	not be in an interactive appliation, so it makes sense.	636	not be done in an interactive application, so it makes sense.
295		637
296	=head1 ENVIRONMENT VARIABLES	638	=head1 ENVIRONMENT VARIABLES
297		639
298	The following environment variables are used by this module:	640	The following environment variables are used by this module:
299		641
300	C<PERL_ANYEVENT_VERBOSE> when set to C<2> or higher, reports which event	642	C<PERL_ANYEVENT_VERBOSE> when set to C<2> or higher, cause AnyEvent to
301	model gets used.	643	report to STDERR which event model it chooses.
302		644
303	=head1 EXAMPLE	645	=head1 EXAMPLE PROGRAM
304		646
305	The following program uses an io watcher to read data from stdin, a timer	647	The following program uses an IO watcher to read data from STDIN, a timer
306	to display a message once per second, and a condvar to exit the program	648	to display a message once per second, and a condition variable to quit the
307	when the user enters quit:	649	program when the user enters quit:
308		650
309	use AnyEvent;	651	use AnyEvent;
310		652
311	my $cv = AnyEvent->condvar;	653	my $cv = AnyEvent->condvar;
312		654
313	my $io_watcher = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	655	my $io_watcher = AnyEvent->io (
		656	fh => \*STDIN,
		657	poll => 'r',
		658	cb => sub {
314	warn "io event <$_[0]>\n"; # will always output <r>	659	warn "io event <$_[0]>\n"; # will always output <r>
315	chomp (my $input = <STDIN>); # read a line	660	chomp (my $input = <STDIN>); # read a line
316	warn "read: $input\n"; # output what has been read	661	warn "read: $input\n"; # output what has been read
317	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	662	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i
		663	},
318	});	664	);
319		665
320	my $time_watcher; # can only be used once	666	my $time_watcher; # can only be used once
321		667
322	sub new_timer {	668	sub new_timer {
323	$timer = AnyEvent->timer (after => 1, cb => sub {	669	$timer = AnyEvent->timer (after => 1, cb => sub {
…		…
405	$txn->{finished}->wait;	751	$txn->{finished}->wait;
406	return $txn->{result};	752	return $txn->{result};
407		753
408	The actual code goes further and collects all errors (C<die>s, exceptions)	754	The actual code goes further and collects all errors (C<die>s, exceptions)
409	that occured during request processing. The C<result> method detects	755	that occured during request processing. The C<result> method detects
410	wether an exception as thrown (it is stored inside the $txn object)	756	whether an exception as thrown (it is stored inside the $txn object)
411	and just throws the exception, which means connection errors and other	757	and just throws the exception, which means connection errors and other
412	problems get reported tot he code that tries to use the result, not in a	758	problems get reported tot he code that tries to use the result, not in a
413	random callback.	759	random callback.
414		760
415	All of this enables the following usage styles:	761	All of this enables the following usage styles:
416		762
417	1. Blocking:	763	1. Blocking:
418		764
419	my $data = $fcp->client_get ($url);	765	my $data = $fcp->client_get ($url);
420		766
421	2. Blocking, but parallelizing:	767	2. Blocking, but running in parallel:
422		768
423	my @datas = map $_->result,	769	my @datas = map $_->result,
424	map $fcp->txn_client_get ($_),	770	map $fcp->txn_client_get ($_),
425	@urls;	771	@urls;
426		772
427	Both blocking examples work without the module user having to know	773	Both blocking examples work without the module user having to know
428	anything about events.	774	anything about events.
429		775
430	3a. Event-based in a main program, using any support Event module:	776	3a. Event-based in a main program, using any supported event module:
431		777
432	use Event;	778	use EV;
433		779
434	$fcp->txn_client_get ($url)->cb (sub {	780	$fcp->txn_client_get ($url)->cb (sub {
435	my $txn = shift;	781	my $txn = shift;
436	my $data = $txn->result;	782	my $data = $txn->result;
437	...	783	...
438	});	784	});
439		785
440	Event::loop;	786	EV::loop;
441		787
442	3b. The module user could use AnyEvent, too:	788	3b. The module user could use AnyEvent, too:
443		789
444	use AnyEvent;	790	use AnyEvent;
445		791
…		…
452		798
453	$quit->wait;	799	$quit->wait;
454		800
455	=head1 SEE ALSO	801	=head1 SEE ALSO
456		802
457	Event modules: L<Coro::Event>, L<Coro>, L<Event>, L<Glib::Event>, L<Glib>.	803	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,
		804	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>.
458		805
459	Implementations: L<AnyEvent::Impl::Coro>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>.	806	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,
		807	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>,
		808	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>.
460		809
461	Nontrivial usage example: L<Net::FCP>.	810	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.
462		811
463	=head1	812	=head1 AUTHOR
		813
		814	Marc Lehmann <schmorp@schmorp.de>
		815	http://home.schmorp.de/
464		816
465	=cut	817	=cut
466		818
467	1	819	1
468		820

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.14 by root, Mon Oct 30 20:52:24 2006 UTC vs. Revision 1.54 by root, Tue Apr 22 05:12:19 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.14 by root, Mon Oct 30 20:52:24 2006 UTC vs.
Revision 1.54 by root, Tue Apr 22 05:12:19 2008 UTC