[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 1.61 by root, Fri Apr 25 01:55:25 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, POE - various supported event loops
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
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 the
84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	84	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,
85	L<Event>, L<Glib>, L<Tk>. The first one found is used. If none are found,	85	L<Event>, L<Glib>, L<Tk>, L<AnyEvent::Impl::Perl>, L<Event::Lib>, L<Qt>,
86	the module tries to load these modules in the stated order. The first one	86	L<POE>. The first one found is used. If none are found, the module tries
		87	to load these modules (excluding Event::Lib, Qt and POE as the pure perl
		88	adaptor should always succeed) in the order given. The first one that can
87	that can be successfully loaded will be used. If, after this, still none	89	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	90	found, AnyEvent will fall back to a pure-perl event loop, which is not
89	is not very efficient, but should work everywhere.	91	very efficient, but should work everywhere.
90		92
91	Because AnyEvent first checks for modules that are already loaded, loading	93	Because AnyEvent first checks for modules that are already loaded, loading
92	an event model explicitly before first using AnyEvent will likely make	94	an event model explicitly before first using AnyEvent will likely make
93	that model the default. For example:	95	that model the default. For example:
94		96
…		…
145	events. C<poll> must be a string that is either C<r> or C<w>, which	147	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,	148	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	149	respectively. C<cb> is the callback to invoke each time the file handle
148	becomes ready.	150	becomes ready.
149		151
150	File handles will be kept alive, so as long as the watcher exists, the	152	As long as the I/O watcher exists it will keep the file descriptor or a
151	file handle exists, too.	153	copy of it alive/open.
152		154
153	It is not allowed to close a file handle as long as any watcher is active	155	It is not allowed to close a file handle as long as any watcher is active
154	on the underlying file descriptor.	156	on the underlying file descriptor.
155		157
156	Some event loops issue spurious readyness notifications, so you should	158	Some event loops issue spurious readyness notifications, so you should
…		…
206		208
207	There are two ways to handle timers: based on real time (relative, "fire	209	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	210	in 10 seconds") and based on wallclock time (absolute, "fire at 12
209	o'clock").	211	o'clock").
210		212
211	While most event loops expect timers to specified in a relative way, they use	213	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",	214	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	215	"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	216	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
215	six years to finally fire.	217	fire "after" a second might actually take six years to finally fire.
216		218
217	AnyEvent cannot compensate for this. The only event loop that is conscious	219	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	220	about these issues is L<EV>, which offers both relative (ev_timer, based
219	absolute (ev_periodic) timers.	221	on true relative time) and absolute (ev_periodic, based on wallclock time)
		222	timers.
220		223
221	AnyEvent always prefers relative timers, if available, matching the	224	AnyEvent always prefers relative timers, if available, matching the
222	AnyEvent API.	225	AnyEvent API.
223		226
224	=head2 SIGNAL WATCHERS	227	=head2 SIGNAL WATCHERS
225		228
226	You can watch for signals using a signal watcher, C<signal> is the signal	229	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	230	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
228	be invoked whenever a signal occurs.	231	be invoked whenever a signal occurs.
229		232
230	Multiple signals occurances can be clumped together into one callback	233	Multiple signal occurances can be clumped together into one callback
231	invocation, and callback invocation will be synchronous. synchronous means	234	invocation, and callback invocation will be synchronous. synchronous means
232	that it might take a while until the signal gets handled by the process,	235	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.	236	but it is guarenteed not to interrupt any other callbacks.
234		237
235	The main advantage of using these watchers is that you can share a signal	238	The main advantage of using these watchers is that you can share a signal
…		…
353		356
354	The known classes so far are:	357	The known classes so far are:
355		358
356	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.	359	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
357	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.	360	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
358	AnyEvent::Impl::EV based on EV (an interface to libev, also best choice).	361	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
359	AnyEvent::Impl::Event based on Event, also second best choice :)	362	AnyEvent::Impl::Event based on Event, second best choice.
360	AnyEvent::Impl::Glib based on Glib, third-best choice.	363	AnyEvent::Impl::Glib based on Glib, third-best choice.
361	AnyEvent::Impl::Tk based on Tk, very bad choice.	364	AnyEvent::Impl::Tk based on Tk, very bad choice.
362	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.	365	AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable.
		366	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
		367	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		368	AnyEvent::Impl::POE based on POE, not generic enough for full support.
		369
		370	There is no support for WxWidgets, as WxWidgets has no support for
		371	watching file handles. However, you can use WxWidgets through the
		372	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
		373	second, which was considered to be too horrible to even consider for
		374	AnyEvent. Likewise, other POE backends can be used by Anyevent by using
		375	it's adaptor.
363		376
364	=item AnyEvent::detect	377	=item AnyEvent::detect
365		378
366	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	379	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
367	if necessary. You should only call this function right before you would	380	if necessary. You should only call this function right before you would
…		…
418	no warnings;	431	no warnings;
419	use strict;	432	use strict;
420		433
421	use Carp;	434	use Carp;
422		435
423	our $VERSION = '3.12';	436	our $VERSION = '3.2';
424	our $MODEL;	437	our $MODEL;
425		438
426	our $AUTOLOAD;	439	our $AUTOLOAD;
427	our @ISA;	440	our @ISA;
428		441
…		…
436	[EV:: => AnyEvent::Impl::EV::],	449	[EV:: => AnyEvent::Impl::EV::],
437	[Event:: => AnyEvent::Impl::Event::],	450	[Event:: => AnyEvent::Impl::Event::],
438	[Glib:: => AnyEvent::Impl::Glib::],	451	[Glib:: => AnyEvent::Impl::Glib::],
439	[Tk:: => AnyEvent::Impl::Tk::],	452	[Tk:: => AnyEvent::Impl::Tk::],
440	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	453	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
		454	# everything below here will not be autoprobed as the pureperl backend should work everywhere
		455	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		456	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
		457	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
441	);	458	);
442		459
443	our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY);	460	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);
444		461
445	sub detect() {	462	sub detect() {
446	unless ($MODEL) {	463	unless ($MODEL) {
447	no strict 'refs';	464	no strict 'refs';
448		465
		466	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		467	my $model = "AnyEvent::Impl::$1";
		468	if (eval "require $model") {
		469	$MODEL = $model;
		470	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;
		471	} else {
		472	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;
		473	}
		474	}
		475
449	# check for already loaded models	476	# check for already loaded models
		477	unless ($MODEL) {
450	for (@REGISTRY, @models) {	478	for (@REGISTRY, @models) {
451	my ($package, $model) = @$_;	479	my ($package, $model) = @$_;
452	if (${"$package\::VERSION"} > 0) {	480	if (${"$package\::VERSION"} > 0) {
453	if (eval "require $model") {	481	if (eval "require $model") {
454	$MODEL = $model;	482	$MODEL = $model;
455	warn "AnyEvent: found model '$model', using it.\n" if $verbose > 1;	483	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;
456	last;	484	last;
		485	}
457	}	486	}
458	}	487	}
459	}
460		488
461	unless ($MODEL) {	489	unless ($MODEL) {
462	# try to load a model	490	# try to load a model
463		491
464	for (@REGISTRY, @models) {	492	for (@REGISTRY, @models) {
465	my ($package, $model) = @$_;	493	my ($package, $model) = @$_;
466	if (eval "require $package"	494	if (eval "require $package"
467	and ${"$package\::VERSION"} > 0	495	and ${"$package\::VERSION"} > 0
468	and eval "require $model") {	496	and eval "require $model") {
469	$MODEL = $model;	497	$MODEL = $model;
470	warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1;	498	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
471	last;	499	last;
		500	}
472	}	501	}
		502
		503	$MODEL
		504	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	}	505	}
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	}	506	}
478		507
479	unshift @ISA, $MODEL;	508	unshift @ISA, $MODEL;
480	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	509	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
481	}	510	}
…		…
637		666
638	=head1 ENVIRONMENT VARIABLES	667	=head1 ENVIRONMENT VARIABLES
639		668
640	The following environment variables are used by this module:	669	The following environment variables are used by this module:
641		670
642	C<PERL_ANYEVENT_VERBOSE> when set to C<2> or higher, cause AnyEvent to	671	=over 4
643	report to STDERR which event model it chooses.	672
		673	=item C<PERL_ANYEVENT_VERBOSE>
		674
		675	By default, AnyEvent will be completely silent except in fatal
		676	conditions. You can set this environment variable to make AnyEvent more
		677	talkative.
		678
		679	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		680	conditions, such as not being able to load the event model specified by
		681	C<PERL_ANYEVENT_MODEL>.
		682
		683	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		684	model it chooses.
		685
		686	=item C<PERL_ANYEVENT_MODEL>
		687
		688	This can be used to specify the event model to be used by AnyEvent, before
		689	autodetection and -probing kicks in. It must be a string consisting
		690	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		691	and the resulting module name is loaded and if the load was successful,
		692	used as event model. If it fails to load AnyEvent will proceed with
		693	autodetection and -probing.
		694
		695	This functionality might change in future versions.
		696
		697	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		698	could start your program like this:
		699
		700	PERL_ANYEVENT_MODEL=Perl perl ...
		701
		702	=back
644		703
645	=head1 EXAMPLE PROGRAM	704	=head1 EXAMPLE PROGRAM
646		705
647	The following program uses an IO watcher to read data from STDIN, a timer	706	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	707	to display a message once per second, and a condition variable to quit the
…		…
796	$quit->broadcast;	855	$quit->broadcast;
797	});	856	});
798		857
799	$quit->wait;	858	$quit->wait;
800		859
		860	=head1 FORK
		861
		862	Most event libraries are not fork-safe. The ones who are usually are
		863	because they are so inefficient. Only L<EV> is fully fork-aware.
		864
		865	If you have to fork, you must either do so I<before> creating your first
		866	watcher OR you must not use AnyEvent at all in the child.
		867
		868	=head1 SECURITY CONSIDERATIONS
		869
		870	AnyEvent can be forced to load any event model via
		871	$ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used to
		872	execute arbitrary code or directly gain access, it can easily be used to
		873	make the program hang or malfunction in subtle ways, as AnyEvent watchers
		874	will not be active when the program uses a different event model than
		875	specified in the variable.
		876
		877	You can make AnyEvent completely ignore this variable by deleting it
		878	before the first watcher gets created, e.g. with a C<BEGIN> block:
		879
		880	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
		881
		882	use AnyEvent;
		883
801	=head1 SEE ALSO	884	=head1 SEE ALSO
802		885
803	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	886	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>.	887	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,
		888	L<Event::Lib>, L<Qt>, L<POE>.
805		889
806	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	890	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,
		891	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,
		892	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,
807	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>,	893	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.
808	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>.
809		894
810	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	895	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.
811		896
812	=head1 AUTHOR	897	=head1 AUTHOR
813		898

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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 1.61 by root, Fri Apr 25 01:55:25 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 1.61 by root, Fri Apr 25 01:55:25 2008 UTC