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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.161 by root, Wed Jul 2 12:27:42 2008 UTC vs.
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC

…		…
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });
12	...
13	});
14		12
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		15
		16	print AnyEvent->now; # prints current event loop time
		17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		18
		19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		20
		21	my $w = AnyEvent->child (pid => $pid, cb => sub {
		22	my ($pid, $status) = @_;
16	...	23	...
17	});	24	});
18		25
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	26	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	27	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	28	$w->recv; # enters "main loop" till $condvar gets ->send
		29	# use a condvar in callback mode:
		30	$w->cb (sub { $_[0]->recv });
22		31
23	=head1 INTRODUCTION/TUTORIAL	32	=head1 INTRODUCTION/TUTORIAL
24		33
25	This manpage is mainly a reference manual. If you are interested	34	This manpage is mainly a reference manual. If you are interested
26	in a tutorial or some gentle introduction, have a look at the	35	in a tutorial or some gentle introduction, have a look at the
…		…
33		42
34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
36		45
37	First and foremost, I<AnyEvent is not an event model> itself, it only	46	First and foremost, I<AnyEvent is not an event model> itself, it only
38	interfaces to whatever event model the main program happens to use in a	47	interfaces to whatever event model the main program happens to use, in a
39	pragmatic way. For event models and certain classes of immortals alike,	48	pragmatic way. For event models and certain classes of immortals alike,
40	the statement "there can only be one" is a bitter reality: In general,	49	the statement "there can only be one" is a bitter reality: In general,
41	only one event loop can be active at the same time in a process. AnyEvent	50	only one event loop can be active at the same time in a process. AnyEvent
42	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
43		53
44	The goal of AnyEvent is to offer module authors the ability to do event	54	The goal of AnyEvent is to offer module authors the ability to do event
45	programming (waiting for I/O or timer events) without subscribing to a	55	programming (waiting for I/O or timer events) without subscribing to a
46	religion, a way of living, and most importantly: without forcing your	56	religion, a way of living, and most importantly: without forcing your
47	module users into the same thing by forcing them to use the same event	57	module users into the same thing by forcing them to use the same event
48	model you use.	58	model you use.
49		59
50	For modules like POE or IO::Async (which is a total misnomer as it is	60	For modules like POE or IO::Async (which is a total misnomer as it is
51	actually doing all I/O I<synchronously>...), using them in your module is	61	actually doing all I/O I<synchronously>...), using them in your module is
52	like joining a cult: After you joined, you are dependent on them and you	62	like joining a cult: After you joined, you are dependent on them and you
53	cannot use anything else, as it is simply incompatible to everything that	63	cannot use anything else, as they are simply incompatible to everything
54	isn't itself. What's worse, all the potential users of your module are	64	that isn't them. What's worse, all the potential users of your
55	I<also> forced to use the same event loop you use.	65	module are I<also> forced to use the same event loop you use.
56		66
57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	68	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
59	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	69	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
60	your module uses one of those, every user of your module has to use it,	70	your module uses one of those, every user of your module has to use it,
61	too. But if your module uses AnyEvent, it works transparently with all	71	too. But if your module uses AnyEvent, it works transparently with all
62	event models it supports (including stuff like POE and IO::Async, as long	72	event models it supports (including stuff like IO::Async, as long as those
63	as those use one of the supported event loops. It is trivial to add new	73	use one of the supported event loops. It is trivial to add new event loops
64	event loops to AnyEvent, too, so it is future-proof).	74	to AnyEvent, too, so it is future-proof).
65		75
66	In addition to being free of having to use I<the one and only true event	76	In addition to being free of having to use I<the one and only true event
67	model>, AnyEvent also is free of bloat and policy: with POE or similar	77	model>, AnyEvent also is free of bloat and policy: with POE or similar
68	modules, you get an enormous amount of code and strict rules you have to	78	modules, you get an enormous amount of code and strict rules you have to
69	follow. AnyEvent, on the other hand, is lean and up to the point, by only	79	follow. AnyEvent, on the other hand, is lean and up to the point, by only
…		…
152	=head2 I/O WATCHERS	162	=head2 I/O WATCHERS
153		163
154	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	164	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
155	with the following mandatory key-value pairs as arguments:	165	with the following mandatory key-value pairs as arguments:
156		166
157	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	167	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
158	for events. C<poll> must be a string that is either C<r> or C<w>,	168	(AnyEvent might or might not keep a reference to this file handle). C<poll>
159	which creates a watcher waiting for "r"eadable or "w"ritable events,	169	must be a string that is either C<r> or C<w>, which creates a watcher
160	respectively. C<cb> is the callback to invoke each time the file handle	170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
161	becomes ready.	171	callback to invoke each time the file handle becomes ready.
162		172
163	Although the callback might get passed parameters, their value and	173	Although the callback might get passed parameters, their value and
164	presence is undefined and you cannot rely on them. Portable AnyEvent	174	presence is undefined and you cannot rely on them. Portable AnyEvent
165	callbacks cannot use arguments passed to I/O watcher callbacks.	175	callbacks cannot use arguments passed to I/O watcher callbacks.
166		176
…		…
170		180
171	Some event loops issue spurious readyness notifications, so you should	181	Some event loops issue spurious readyness notifications, so you should
172	always use non-blocking calls when reading/writing from/to your file	182	always use non-blocking calls when reading/writing from/to your file
173	handles.	183	handles.
174		184
175	Example:
176
177	# wait for readability of STDIN, then read a line and disable the watcher	185	Example: wait for readability of STDIN, then read a line and disable the
		186	watcher.
		187
178	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	188	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
179	chomp (my $input = <STDIN>);	189	chomp (my $input = <STDIN>);
180	warn "read: $input\n";	190	warn "read: $input\n";
181	undef $w;	191	undef $w;
182	});	192	});
…		…
192		202
193	Although the callback might get passed parameters, their value and	203	Although the callback might get passed parameters, their value and
194	presence is undefined and you cannot rely on them. Portable AnyEvent	204	presence is undefined and you cannot rely on them. Portable AnyEvent
195	callbacks cannot use arguments passed to time watcher callbacks.	205	callbacks cannot use arguments passed to time watcher callbacks.
196		206
197	The timer callback will be invoked at most once: if you want a repeating	207	The callback will normally be invoked once only. If you specify another
198	timer you have to create a new watcher (this is a limitation by both Tk	208	parameter, C<interval>, as a strictly positive number (> 0), then the
199	and Glib).	209	callback will be invoked regularly at that interval (in fractional
		210	seconds) after the first invocation. If C<interval> is specified with a
		211	false value, then it is treated as if it were missing.
200		212
201	Example:	213	The callback will be rescheduled before invoking the callback, but no
		214	attempt is done to avoid timer drift in most backends, so the interval is
		215	only approximate.
202		216
203	# fire an event after 7.7 seconds	217	Example: fire an event after 7.7 seconds.
		218
204	my $w = AnyEvent->timer (after => 7.7, cb => sub {	219	my $w = AnyEvent->timer (after => 7.7, cb => sub {
205	warn "timeout\n";	220	warn "timeout\n";
206	});	221	});
207		222
208	# to cancel the timer:	223	# to cancel the timer:
209	undef $w;	224	undef $w;
210		225
211	Example 2:
212
213	# fire an event after 0.5 seconds, then roughly every second	226	Example 2: fire an event after 0.5 seconds, then roughly every second.
214	my $w;
215		227
216	my $cb = sub {
217	# cancel the old timer while creating a new one
218	$w = AnyEvent->timer (after => 1, cb => $cb);	228	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		229	warn "timeout\n";
219	};	230	};
220
221	# start the "loop" by creating the first watcher
222	$w = AnyEvent->timer (after => 0.5, cb => $cb);
223		231
224	=head3 TIMING ISSUES	232	=head3 TIMING ISSUES
225		233
226	There are two ways to handle timers: based on real time (relative, "fire	234	There are two ways to handle timers: based on real time (relative, "fire
227	in 10 seconds") and based on wallclock time (absolute, "fire at 12	235	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
305	=back	313	=back
306		314
307	=head2 SIGNAL WATCHERS	315	=head2 SIGNAL WATCHERS
308		316
309	You can watch for signals using a signal watcher, C<signal> is the signal	317	You can watch for signals using a signal watcher, C<signal> is the signal
310	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	318	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
311	be invoked whenever a signal occurs.	319	callback to be invoked whenever a signal occurs.
312		320
313	Although the callback might get passed parameters, their value and	321	Although the callback might get passed parameters, their value and
314	presence is undefined and you cannot rely on them. Portable AnyEvent	322	presence is undefined and you cannot rely on them. Portable AnyEvent
315	callbacks cannot use arguments passed to signal watcher callbacks.	323	callbacks cannot use arguments passed to signal watcher callbacks.
316		324
…		…
381		389
382	The instrument to do that is called a "condition variable", so called	390	The instrument to do that is called a "condition variable", so called
383	because they represent a condition that must become true.	391	because they represent a condition that must become true.
384		392
385	Condition variables can be created by calling the C<< AnyEvent->condvar	393	Condition variables can be created by calling the C<< AnyEvent->condvar
		394
386	>> method, usually without arguments. The only argument pair allowed is	395	>> method, usually without arguments. The only argument pair allowed is
		396
387	C<cb>, which specifies a callback to be called when the condition variable	397	C<cb>, which specifies a callback to be called when the condition variable
388	becomes true.	398	becomes true, with the condition variable as the first argument (but not
		399	the results).
389		400
390	After creation, the condition variable is "false" until it becomes "true"	401	After creation, the condition variable is "false" until it becomes "true"
391	by calling the C<send> method (or calling the condition variable as if it	402	by calling the C<send> method (or calling the condition variable as if it
392	were a callback, read about the caveats in the description for the C<<	403	were a callback, read about the caveats in the description for the C<<
393	->send >> method).	404	->send >> method).
…		…
449		460
450	my $done = AnyEvent->condvar;	461	my $done = AnyEvent->condvar;
451	my $delay = AnyEvent->timer (after => 5, cb => $done);	462	my $delay = AnyEvent->timer (after => 5, cb => $done);
452	$done->recv;	463	$done->recv;
453		464
		465	Example: Imagine an API that returns a condvar and doesn't support
		466	callbacks. This is how you make a synchronous call, for example from
		467	the main program:
		468
		469	use AnyEvent::CouchDB;
		470
		471	...
		472
		473	my @info = $couchdb->info->recv;
		474
		475	And this is how you would just ste a callback to be called whenever the
		476	results are available:
		477
		478	$couchdb->info->cb (sub {
		479	my @info = $_[0]->recv;
		480	});
		481
454	=head3 METHODS FOR PRODUCERS	482	=head3 METHODS FOR PRODUCERS
455		483
456	These methods should only be used by the producing side, i.e. the	484	These methods should only be used by the producing side, i.e. the
457	code/module that eventually sends the signal. Note that it is also	485	code/module that eventually sends the signal. Note that it is also
458	the producer side which creates the condvar in most cases, but it isn't	486	the producer side which creates the condvar in most cases, but it isn't
…		…
591	=item $bool = $cv->ready	619	=item $bool = $cv->ready
592		620
593	Returns true when the condition is "true", i.e. whether C<send> or	621	Returns true when the condition is "true", i.e. whether C<send> or
594	C<croak> have been called.	622	C<croak> have been called.
595		623
596	=item $cb = $cv->cb ([new callback])	624	=item $cb = $cv->cb ($cb->($cv))
597		625
598	This is a mutator function that returns the callback set and optionally	626	This is a mutator function that returns the callback set and optionally
599	replaces it before doing so.	627	replaces it before doing so.
600		628
601	The callback will be called when the condition becomes "true", i.e. when	629	The callback will be called when the condition becomes "true", i.e. when
…		…
738	=item L<AnyEvent::Util>	766	=item L<AnyEvent::Util>
739		767
740	Contains various utility functions that replace often-used but blocking	768	Contains various utility functions that replace often-used but blocking
741	functions such as C<inet_aton> by event-/callback-based versions.	769	functions such as C<inet_aton> by event-/callback-based versions.
742		770
743	=item L<AnyEvent::Handle>
744
745	Provide read and write buffers and manages watchers for reads and writes.
746
747	=item L<AnyEvent::Socket>	771	=item L<AnyEvent::Socket>
748		772
749	Provides various utility functions for (internet protocol) sockets,	773	Provides various utility functions for (internet protocol) sockets,
750	addresses and name resolution. Also functions to create non-blocking tcp	774	addresses and name resolution. Also functions to create non-blocking tcp
751	connections or tcp servers, with IPv6 and SRV record support and more.	775	connections or tcp servers, with IPv6 and SRV record support and more.
752		776
		777	=item L<AnyEvent::Handle>
		778
		779	Provide read and write buffers, manages watchers for reads and writes,
		780	supports raw and formatted I/O, I/O queued and fully transparent and
		781	non-blocking SSL/TLS.
		782
753	=item L<AnyEvent::DNS>	783	=item L<AnyEvent::DNS>
754		784
755	Provides rich asynchronous DNS resolver capabilities.	785	Provides rich asynchronous DNS resolver capabilities.
756		786
757	=item L<AnyEvent::HTTP>	787	=item L<AnyEvent::HTTP>
…		…
767		797
768	The fastest ping in the west.	798	The fastest ping in the west.
769		799
770	=item L<AnyEvent::DBI>	800	=item L<AnyEvent::DBI>
771		801
772	Executes DBI requests asynchronously in a proxy process.	802	Executes L<DBI> requests asynchronously in a proxy process.
		803
		804	=item L<AnyEvent::AIO>
		805
		806	Truly asynchronous I/O, should be in the toolbox of every event
		807	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		808	together.
		809
		810	=item L<AnyEvent::BDB>
		811
		812	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		813	L<BDB> and AnyEvent together.
		814
		815	=item L<AnyEvent::GPSD>
		816
		817	A non-blocking interface to gpsd, a daemon delivering GPS information.
		818
		819	=item L<AnyEvent::IGS>
		820
		821	A non-blocking interface to the Internet Go Server protocol (used by
		822	L<App::IGS>).
773		823
774	=item L<Net::IRC3>	824	=item L<Net::IRC3>
775		825
776	AnyEvent based IRC client module family.	826	AnyEvent based IRC client module family.
777		827
…		…
790		840
791	=item L<Coro>	841	=item L<Coro>
792		842
793	Has special support for AnyEvent via L<Coro::AnyEvent>.	843	Has special support for AnyEvent via L<Coro::AnyEvent>.
794		844
795	=item L<AnyEvent::AIO>, L<IO::AIO>
796
797	Truly asynchronous I/O, should be in the toolbox of every event
798	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
799	together.
800
801	=item L<AnyEvent::BDB>, L<BDB>
802
803	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
804	IO::AIO and AnyEvent together.
805
806	=item L<IO::Lambda>	845	=item L<IO::Lambda>
807		846
808	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	847	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
809		848
810	=back	849	=back
…		…
816	no warnings;	855	no warnings;
817	use strict;	856	use strict;
818		857
819	use Carp;	858	use Carp;
820		859
821	our $VERSION = '4.160'; # temporary workaround for broken fedora	860	our $VERSION = 4.22;
822	our $MODEL;	861	our $MODEL;
823		862
824	our $AUTOLOAD;	863	our $AUTOLOAD;
825	our @ISA;	864	our @ISA;
826		865
…		…
929	$MODEL	968	$MODEL
930	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	969	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
931	}	970	}
932	}	971	}
933		972
		973	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		974
934	unshift @ISA, $MODEL;	975	unshift @ISA, $MODEL;
935	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	976
		977	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
936		978
937	(shift @post_detect)->() while @post_detect;	979	(shift @post_detect)->() while @post_detect;
938	}	980	}
939		981
940	$MODEL	982	$MODEL
…		…
948		990
949	detect unless $MODEL;	991	detect unless $MODEL;
950		992
951	my $class = shift;	993	my $class = shift;
952	$class->$func (@_);	994	$class->$func (@_);
		995	}
		996
		997	# utility function to dup a filehandle. this is used by many backends
		998	# to support binding more than one watcher per filehandle (they usually
		999	# allow only one watcher per fd, so we dup it to get a different one).
		1000	sub _dupfh($$$$) {
		1001	my ($poll, $fh, $r, $w) = @_;
		1002
		1003	require Fcntl;
		1004
		1005	# cygwin requires the fh mode to be matching, unix doesn't
		1006	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1007	: $poll eq "w" ? ($w, ">")
		1008	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1009
		1010	open my $fh2, "$mode&" . fileno $fh
		1011	or die "cannot dup() filehandle: $!";
		1012
		1013	# we assume CLOEXEC is already set by perl in all important cases
		1014
		1015	($fh2, $rw)
953	}	1016	}
954		1017
955	package AnyEvent::Base;	1018	package AnyEvent::Base;
956		1019
957	# default implementation for now and time	1020	# default implementation for now and time
…		…
1167	conditions, such as not being able to load the event model specified by	1230	conditions, such as not being able to load the event model specified by
1168	C<PERL_ANYEVENT_MODEL>.	1231	C<PERL_ANYEVENT_MODEL>.
1169		1232
1170	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1233	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1171	model it chooses.	1234	model it chooses.
		1235
		1236	=item C<PERL_ANYEVENT_STRICT>
		1237
		1238	AnyEvent does not do much argument checking by default, as thorough
		1239	argument checking is very costly. Setting this variable to a true value
		1240	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1241	check the arguments passed to most method calls. If it finds any problems
		1242	it will croak.
		1243
		1244	In other words, enables "strict" mode.
		1245
		1246	Unlike C<use strict> it is definitely recommended ot keep it off in
		1247	production.
1172		1248
1173	=item C<PERL_ANYEVENT_MODEL>	1249	=item C<PERL_ANYEVENT_MODEL>
1174		1250
1175	This can be used to specify the event model to be used by AnyEvent, before	1251	This can be used to specify the event model to be used by AnyEvent, before
1176	auto detection and -probing kicks in. It must be a string consisting	1252	auto detection and -probing kicks in. It must be a string consisting
…		…
1673		1749
1674	use AnyEvent;	1750	use AnyEvent;
1675		1751
1676	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1752	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1677	be used to probe what backend is used and gain other information (which is	1753	be used to probe what backend is used and gain other information (which is
1678	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1754	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1755	$ENV{PERL_ANYEGENT_STRICT}.
1679		1756
1680		1757
1681	=head1 BUGS	1758	=head1 BUGS
1682		1759
1683	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	1760	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.161 by root, Wed Jul 2 12:27:42 2008 UTC vs. Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.161 by root, Wed Jul 2 12:27:42 2008 UTC vs.
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC