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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.54 by root, Tue Apr 22 05:12:19 2008 UTC vs.
Revision 1.59 by root, Thu Apr 24 08:38:13 2008 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl - various supported event loops	5	EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt - various supported event loops
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
78		78
79	The interface itself is vaguely similar, but not identical to the L<Event>	79	The interface itself is vaguely similar, but not identical to the L<Event>
80	module.	80	module.
81		81
82	During the first call of any watcher-creation method, the module tries	82	During the first call of any watcher-creation method, the module tries
83	to detect the currently loaded event loop by probing whether one of the	83	to detect the currently loaded event loop by probing whether one of
84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	84	the following modules is already loaded: L<Coro::EV>, L<Coro::Event>,
85	L<Event>, L<Glib>, L<Tk>. The first one found is used. If none are found,	85	L<EV>, L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>. The first one
86	the module tries to load these modules in the stated order. The first one	86	found is used. If none are found, the module tries to load these modules
		87	(excluding Event::Lib and Qt) in the order given. The first one that can
87	that can be successfully loaded will be used. If, after this, still none	88	be successfully loaded will be used. If, after this, still none could be
88	could be found, AnyEvent will fall back to a pure-perl event loop, which	89	found, AnyEvent will fall back to a pure-perl event loop, which is not
89	is not very efficient, but should work everywhere.	90	very efficient, but should work everywhere.
90		91
91	Because AnyEvent first checks for modules that are already loaded, loading	92	Because AnyEvent first checks for modules that are already loaded, loading
92	an event model explicitly before first using AnyEvent will likely make	93	an event model explicitly before first using AnyEvent will likely make
93	that model the default. For example:	94	that model the default. For example:
94		95
…		…
145	events. C<poll> must be a string that is either C<r> or C<w>, which	146	events. C<poll> must be a string that is either C<r> or C<w>, which
146	creates a watcher waiting for "r"eadable or "w"ritable events,	147	creates a watcher waiting for "r"eadable or "w"ritable events,
147	respectively. C<cb> is the callback to invoke each time the file handle	148	respectively. C<cb> is the callback to invoke each time the file handle
148	becomes ready.	149	becomes ready.
149		150
150	File handles will be kept alive, so as long as the watcher exists, the	151	As long as the I/O watcher exists it will keep the file descriptor or a
151	file handle exists, too.	152	copy of it alive/open.
152		153
153	It is not allowed to close a file handle as long as any watcher is active	154	It is not allowed to close a file handle as long as any watcher is active
154	on the underlying file descriptor.	155	on the underlying file descriptor.
155		156
156	Some event loops issue spurious readyness notifications, so you should	157	Some event loops issue spurious readyness notifications, so you should
…		…
206		207
207	There are two ways to handle timers: based on real time (relative, "fire	208	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	in 10 seconds") and based on wallclock time (absolute, "fire at 12
209	o'clock").	210	o'clock").
210		211
211	While most event loops expect timers to specified in a relative way, they use	212	While most event loops expect timers to specified in a relative way, they
212	absolute time internally. This makes a difference when your clock "jumps",	213	use absolute time internally. This makes a difference when your clock
213	for example, when ntp decides to set your clock backwards from the wrong 2014-01-01 to	214	"jumps", for example, when ntp decides to set your clock backwards from
214	2008-01-01, a watcher that you created to fire "after" a second might actually take	215	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
215	six years to finally fire.	216	fire "after" a second might actually take six years to finally fire.
216		217
217	AnyEvent cannot compensate for this. The only event loop that is conscious	218	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	about these issues is L<EV>, which offers both relative (ev_timer, based
219	absolute (ev_periodic) timers.	220	on true relative time) and absolute (ev_periodic, based on wallclock time)
		221	timers.
220		222
221	AnyEvent always prefers relative timers, if available, matching the	223	AnyEvent always prefers relative timers, if available, matching the
222	AnyEvent API.	224	AnyEvent API.
223		225
224	=head2 SIGNAL WATCHERS	226	=head2 SIGNAL WATCHERS
225		227
226	You can watch for signals using a signal watcher, C<signal> is the signal	228	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	229	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
228	be invoked whenever a signal occurs.	230	be invoked whenever a signal occurs.
229		231
230	Multiple signals occurances can be clumped together into one callback	232	Multiple signal occurances can be clumped together into one callback
231	invocation, and callback invocation will be synchronous. synchronous means	233	invocation, and callback invocation will be synchronous. synchronous means
232	that it might take a while until the signal gets handled by the process,	234	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.	235	but it is guarenteed not to interrupt any other callbacks.
234		236
235	The main advantage of using these watchers is that you can share a signal	237	The main advantage of using these watchers is that you can share a signal
…		…
353		355
354	The known classes so far are:	356	The known classes so far are:
355		357
356	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.	358	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
357	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.	359	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
358	AnyEvent::Impl::EV based on EV (an interface to libev, also best choice).	360	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
359	AnyEvent::Impl::Event based on Event, also second best choice :)	361	AnyEvent::Impl::Event based on Event, second best choice.
360	AnyEvent::Impl::Glib based on Glib, third-best choice.	362	AnyEvent::Impl::Glib based on Glib, third-best choice.
361	AnyEvent::Impl::Tk based on Tk, very bad choice.	363	AnyEvent::Impl::Tk based on Tk, very bad choice.
362	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.	364	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
		365	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
		366	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
363		367
364	=item AnyEvent::detect	368	=item AnyEvent::detect
365		369
366	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	370	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
367	if necessary. You should only call this function right before you would	371	if necessary. You should only call this function right before you would
…		…
418	no warnings;	422	no warnings;
419	use strict;	423	use strict;
420		424
421	use Carp;	425	use Carp;
422		426
423	our $VERSION = '3.12';	427	our $VERSION = '3.2';
424	our $MODEL;	428	our $MODEL;
425		429
426	our $AUTOLOAD;	430	our $AUTOLOAD;
427	our @ISA;	431	our @ISA;
428		432
…		…
437	[Event:: => AnyEvent::Impl::Event::],	441	[Event:: => AnyEvent::Impl::Event::],
438	[Glib:: => AnyEvent::Impl::Glib::],	442	[Glib:: => AnyEvent::Impl::Glib::],
439	[Tk:: => AnyEvent::Impl::Tk::],	443	[Tk:: => AnyEvent::Impl::Tk::],
440	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	444	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
441	);	445	);
		446	my @models_detect = (
		447	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
		448	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		449	);
442		450
443	our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY);	451	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);
444		452
445	sub detect() {	453	sub detect() {
446	unless ($MODEL) {	454	unless ($MODEL) {
447	no strict 'refs';	455	no strict 'refs';
448		456
		457	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		458	my $model = "AnyEvent::Impl::$1";
		459	if (eval "require $model") {
		460	$MODEL = $model;
		461	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;
		462	}
		463	}
		464
449	# check for already loaded models	465	# check for already loaded models
		466	unless ($MODEL) {
450	for (@REGISTRY, @models) {	467	for (@REGISTRY, @models, @models_detect) {
451	my ($package, $model) = @$_;	468	my ($package, $model) = @$_;
452	if (${"$package\::VERSION"} > 0) {	469	if (${"$package\::VERSION"} > 0) {
453	if (eval "require $model") {	470	if (eval "require $model") {
454	$MODEL = $model;	471	$MODEL = $model;
455	warn "AnyEvent: found model '$model', using it.\n" if $verbose > 1;	472	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;
456	last;	473	last;
		474	}
457	}	475	}
458	}	476	}
459	}
460		477
461	unless ($MODEL) {	478	unless ($MODEL) {
462	# try to load a model	479	# try to load a model
463		480
464	for (@REGISTRY, @models) {	481	for (@REGISTRY, @models) {
465	my ($package, $model) = @$_;	482	my ($package, $model) = @$_;
466	if (eval "require $package"	483	if (eval "require $package"
467	and ${"$package\::VERSION"} > 0	484	and ${"$package\::VERSION"} > 0
468	and eval "require $model") {	485	and eval "require $model") {
469	$MODEL = $model;	486	$MODEL = $model;
470	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;	487	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
471	last;	488	last;
		489	}
472	}	490	}
		491
		492	$MODEL
		493	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) or Glib.";
473	}	494	}
474
475	$MODEL
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.";
477	}	495	}
478		496
479	unshift @ISA, $MODEL;	497	unshift @ISA, $MODEL;
480	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	498	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
481	}	499	}
…		…
637		655
638	=head1 ENVIRONMENT VARIABLES	656	=head1 ENVIRONMENT VARIABLES
639		657
640	The following environment variables are used by this module:	658	The following environment variables are used by this module:
641		659
642	C<PERL_ANYEVENT_VERBOSE> when set to C<2> or higher, cause AnyEvent to	660	=over 4
643	report to STDERR which event model it chooses.	661
		662	=item C<PERL_ANYEVENT_VERBOSE>
		663
		664	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		665	model it chooses.
		666
		667	=item C<PERL_ANYEVENT_MODEL>
		668
		669	This can be used to specify the event model to be used by AnyEvent, before
		670	autodetection and -probing kicks in. It must be a string consisting
		671	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		672	and the resulting module name is loaded and if the load was successful,
		673	used as event model. If it fails to load AnyEvent will proceed with
		674	autodetection and -probing.
		675
		676	This functionality might change in future versions.
		677
		678	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		679	could start your program like this:
		680
		681	PERL_ANYEVENT_MODEL=Perl perl ...
		682
		683	=back
644		684
645	=head1 EXAMPLE PROGRAM	685	=head1 EXAMPLE PROGRAM
646		686
647	The following program uses an IO watcher to read data from STDIN, a timer	687	The following program uses an IO watcher to read data from STDIN, a timer
648	to display a message once per second, and a condition variable to quit the	688	to display a message once per second, and a condition variable to quit the
…		…
796	$quit->broadcast;	836	$quit->broadcast;
797	});	837	});
798		838
799	$quit->wait;	839	$quit->wait;
800		840
		841	=head1 FORK
		842
		843	Most event libraries are not fork-safe. The ones who are usually are
		844	because they are so inefficient. Only L<EV> is fully fork-aware.
		845
		846	If you have to fork, you must either do so I<before> creating your first
		847	watcher OR you must not use AnyEvent at all in the child.
		848
		849	=head1 SECURITY CONSIDERATIONS
		850
		851	AnyEvent can be forced to load any event model via
		852	$ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used to
		853	execute arbitrary code or directly gain access, it can easily be used to
		854	make the program hang or malfunction in subtle ways, as AnyEvent watchers
		855	will not be active when the program uses a different event model than
		856	specified in the variable.
		857
		858	You can make AnyEvent completely ignore this variable by deleting it
		859	before the first watcher gets created, e.g. with a C<BEGIN> block:
		860
		861	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
		862
		863	use AnyEvent;
		864
801	=head1 SEE ALSO	865	=head1 SEE ALSO
802		866
803	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	867	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>.	868	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,
		869	L<Event::Lib>, L<Qt>.
805		870
806	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	871	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,
807	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>,	872	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,
808	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>.	873	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,
		874	L<AnyEvent::Impl::Qt>.
809		875
810	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	876	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.
811		877
812	=head1 AUTHOR	878	=head1 AUTHOR
813		879

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.54 by root, Tue Apr 22 05:12:19 2008 UTC vs. Revision 1.59 by root, Thu Apr 24 08:38:13 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.54 by root, Tue Apr 22 05:12:19 2008 UTC vs.
Revision 1.59 by root, Thu Apr 24 08:38:13 2008 UTC