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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs.
Revision 1.168 by root, Tue Jul 8 23:53:37 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, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
6		6
33		33
34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35	policy> and AnyEvent is I<small and efficient>.	35	policy> and AnyEvent is I<small and efficient>.
36		36
37	First and foremost, I<AnyEvent is not an event model> itself, it only	37	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	38	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,	39	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,	40	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	41	only one event loop can be active at the same time in a process. AnyEvent
42	helps hiding the differences between those event loops.	42	cannot change this, but it can hide the differences between those event
		43	loops.
43		44
44	The goal of AnyEvent is to offer module authors the ability to do event	45	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	46	programming (waiting for I/O or timer events) without subscribing to a
46	religion, a way of living, and most importantly: without forcing your	47	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	48	module users into the same thing by forcing them to use the same event
48	model you use.	49	model you use.
49		50
50	For modules like POE or IO::Async (which is a total misnomer as it is	51	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	52	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	53	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	54	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	55	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.	56	module are I<also> forced to use the same event loop you use.
56		57
57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	58	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	59	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	60	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,	61	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	62	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	63	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	64	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).	65	to AnyEvent, too, so it is future-proof).
65		66
66	In addition to being free of having to use I<the one and only true event	67	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	68	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	69	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	70	follow. AnyEvent, on the other hand, is lean and up to the point, by only
…		…
138	Many watchers either are used with "recursion" (repeating timers for	139	Many watchers either are used with "recursion" (repeating timers for
139	example), or need to refer to their watcher object in other ways.	140	example), or need to refer to their watcher object in other ways.
140		141
141	An any way to achieve that is this pattern:	142	An any way to achieve that is this pattern:
142		143
143	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	144	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
144	# you can use $w here, for example to undef it	145	# you can use $w here, for example to undef it
145	undef $w;	146	undef $w;
146	});	147	});
147		148
148	Note that C<my $w; $w => combination. This is necessary because in Perl,	149	Note that C<my $w; $w => combination. This is necessary because in Perl,
149	my variables are only visible after the statement in which they are	150	my variables are only visible after the statement in which they are
150	declared.	151	declared.
151		152
152	=head2 I/O WATCHERS	153	=head2 I/O WATCHERS
153		154
154	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	155	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
155	with the following mandatory key-value pairs as arguments:	156	with the following mandatory key-value pairs as arguments:
156		157
157	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	158	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>,	159	(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,	160	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	161	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
161	becomes ready.	162	callback to invoke each time the file handle becomes ready.
162		163
163	Although the callback might get passed parameters, their value and	164	Although the callback might get passed parameters, their value and
164	presence is undefined and you cannot rely on them. Portable AnyEvent	165	presence is undefined and you cannot rely on them. Portable AnyEvent
165	callbacks cannot use arguments passed to I/O watcher callbacks.	166	callbacks cannot use arguments passed to I/O watcher callbacks.
166		167
…		…
170		171
171	Some event loops issue spurious readyness notifications, so you should	172	Some event loops issue spurious readyness notifications, so you should
172	always use non-blocking calls when reading/writing from/to your file	173	always use non-blocking calls when reading/writing from/to your file
173	handles.	174	handles.
174		175
175	Example:
176
177	# wait for readability of STDIN, then read a line and disable the watcher	176	Example: wait for readability of STDIN, then read a line and disable the
		177	watcher.
		178
178	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	179	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
179	chomp (my $input = <STDIN>);	180	chomp (my $input = <STDIN>);
180	warn "read: $input\n";	181	warn "read: $input\n";
181	undef $w;	182	undef $w;
182	});	183	});
…		…
192		193
193	Although the callback might get passed parameters, their value and	194	Although the callback might get passed parameters, their value and
194	presence is undefined and you cannot rely on them. Portable AnyEvent	195	presence is undefined and you cannot rely on them. Portable AnyEvent
195	callbacks cannot use arguments passed to time watcher callbacks.	196	callbacks cannot use arguments passed to time watcher callbacks.
196		197
197	The timer callback will be invoked at most once: if you want a repeating	198	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	199	parameter, C<interval>, as a strictly positive number (> 0), then the
199	and Glib).	200	callback will be invoked regularly at that interval (in fractional
		201	seconds) after the first invocation. If C<interval> is specified with a
		202	false value, then it is treated as if it were missing.
200		203
201	Example:	204	The callback will be rescheduled before invoking the callback, but no
		205	attempt is done to avoid timer drift in most backends, so the interval is
		206	only approximate.
202		207
203	# fire an event after 7.7 seconds	208	Example: fire an event after 7.7 seconds.
		209
204	my $w = AnyEvent->timer (after => 7.7, cb => sub {	210	my $w = AnyEvent->timer (after => 7.7, cb => sub {
205	warn "timeout\n";	211	warn "timeout\n";
206	});	212	});
207		213
208	# to cancel the timer:	214	# to cancel the timer:
209	undef $w;	215	undef $w;
210		216
211	Example 2:
212
213	# fire an event after 0.5 seconds, then roughly every second	217	Example 2: fire an event after 0.5 seconds, then roughly every second.
214	my $w;
215		218
216	my $cb = sub {
217	# cancel the old timer while creating a new one
218	$w = AnyEvent->timer (after => 1, cb => $cb);	219	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		220	warn "timeout\n";
219	};	221	};
220
221	# start the "loop" by creating the first watcher
222	$w = AnyEvent->timer (after => 0.5, cb => $cb);
223		222
224	=head3 TIMING ISSUES	223	=head3 TIMING ISSUES
225		224
226	There are two ways to handle timers: based on real time (relative, "fire	225	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	226	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
305	=back	304	=back
306		305
307	=head2 SIGNAL WATCHERS	306	=head2 SIGNAL WATCHERS
308		307
309	You can watch for signals using a signal watcher, C<signal> is the signal	308	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	309	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
311	be invoked whenever a signal occurs.	310	callback to be invoked whenever a signal occurs.
312		311
313	Although the callback might get passed parameters, their value and	312	Although the callback might get passed parameters, their value and
314	presence is undefined and you cannot rely on them. Portable AnyEvent	313	presence is undefined and you cannot rely on them. Portable AnyEvent
315	callbacks cannot use arguments passed to signal watcher callbacks.	314	callbacks cannot use arguments passed to signal watcher callbacks.
316		315
…		…
352	AnyEvent program, you I<have> to create at least one watcher before you	351	AnyEvent program, you I<have> to create at least one watcher before you
353	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	352	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
354		353
355	Example: fork a process and wait for it	354	Example: fork a process and wait for it
356		355
357	my $done = AnyEvent->condvar;	356	my $done = AnyEvent->condvar;
358		357
359	my $pid = fork or exit 5;	358	my $pid = fork or exit 5;
360		359
361	my $w = AnyEvent->child (	360	my $w = AnyEvent->child (
362	pid => $pid,	361	pid => $pid,
363	cb => sub {	362	cb => sub {
364	my ($pid, $status) = @_;	363	my ($pid, $status) = @_;
365	warn "pid $pid exited with status $status";	364	warn "pid $pid exited with status $status";
366	$done->send;	365	$done->send;
367	},	366	},
368	);	367	);
369		368
370	# do something else, then wait for process exit	369	# do something else, then wait for process exit
371	$done->recv;	370	$done->recv;
372		371
373	=head2 CONDITION VARIABLES	372	=head2 CONDITION VARIABLES
374		373
375	If you are familiar with some event loops you will know that all of them	374	If you are familiar with some event loops you will know that all of them
376	require you to run some blocking "loop", "run" or similar function that	375	require you to run some blocking "loop", "run" or similar function that
…		…
738	=item L<AnyEvent::Util>	737	=item L<AnyEvent::Util>
739		738
740	Contains various utility functions that replace often-used but blocking	739	Contains various utility functions that replace often-used but blocking
741	functions such as C<inet_aton> by event-/callback-based versions.	740	functions such as C<inet_aton> by event-/callback-based versions.
742		741
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>	742	=item L<AnyEvent::Socket>
748		743
749	Provides various utility functions for (internet protocol) sockets,	744	Provides various utility functions for (internet protocol) sockets,
750	addresses and name resolution. Also functions to create non-blocking tcp	745	addresses and name resolution. Also functions to create non-blocking tcp
751	connections or tcp servers, with IPv6 and SRV record support and more.	746	connections or tcp servers, with IPv6 and SRV record support and more.
752		747
		748	=item L<AnyEvent::Handle>
		749
		750	Provide read and write buffers, manages watchers for reads and writes,
		751	supports raw and formatted I/O, I/O queued and fully transparent and
		752	non-blocking SSL/TLS.
		753
753	=item L<AnyEvent::DNS>	754	=item L<AnyEvent::DNS>
754		755
755	Provides rich asynchronous DNS resolver capabilities.	756	Provides rich asynchronous DNS resolver capabilities.
756		757
		758	=item L<AnyEvent::HTTP>
		759
		760	A simple-to-use HTTP library that is capable of making a lot of concurrent
		761	HTTP requests.
		762
757	=item L<AnyEvent::HTTPD>	763	=item L<AnyEvent::HTTPD>
758		764
759	Provides a simple web application server framework.	765	Provides a simple web application server framework.
760		766
761	=item L<AnyEvent::FastPing>	767	=item L<AnyEvent::FastPing>
762		768
763	The fastest ping in the west.	769	The fastest ping in the west.
		770
		771	=item L<AnyEvent::DBI>
		772
		773	Executes L<DBI> requests asynchronously in a proxy process.
		774
		775	=item L<AnyEvent::AIO>
		776
		777	Truly asynchronous I/O, should be in the toolbox of every event
		778	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		779	together.
		780
		781	=item L<AnyEvent::BDB>
		782
		783	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		784	L<BDB> and AnyEvent together.
		785
		786	=item L<AnyEvent::GPSD>
		787
		788	A non-blocking interface to gpsd, a daemon delivering GPS information.
		789
		790	=item L<AnyEvent::IGS>
		791
		792	A non-blocking interface to the Internet Go Server protocol (used by
		793	L<App::IGS>).
764		794
765	=item L<Net::IRC3>	795	=item L<Net::IRC3>
766		796
767	AnyEvent based IRC client module family.	797	AnyEvent based IRC client module family.
768		798
…		…
781		811
782	=item L<Coro>	812	=item L<Coro>
783		813
784	Has special support for AnyEvent via L<Coro::AnyEvent>.	814	Has special support for AnyEvent via L<Coro::AnyEvent>.
785		815
786	=item L<AnyEvent::AIO>, L<IO::AIO>
787
788	Truly asynchronous I/O, should be in the toolbox of every event
789	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
790	together.
791
792	=item L<AnyEvent::BDB>, L<BDB>
793
794	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
795	IO::AIO and AnyEvent together.
796
797	=item L<IO::Lambda>	816	=item L<IO::Lambda>
798		817
799	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	818	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
800		819
801	=back	820	=back
…		…
807	no warnings;	826	no warnings;
808	use strict;	827	use strict;
809		828
810	use Carp;	829	use Carp;
811		830
812	our $VERSION = 4.11;	831	our $VERSION = 4.2;
813	our $MODEL;	832	our $MODEL;
814		833
815	our $AUTOLOAD;	834	our $AUTOLOAD;
816	our @ISA;	835	our @ISA;
817		836
…		…
920	$MODEL	939	$MODEL
921	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	940	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
922	}	941	}
923	}	942	}
924		943
		944	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		945
925	unshift @ISA, $MODEL;	946	unshift @ISA, $MODEL;
926	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	947
		948	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
927		949
928	(shift @post_detect)->() while @post_detect;	950	(shift @post_detect)->() while @post_detect;
929	}	951	}
930		952
931	$MODEL	953	$MODEL
…		…
979	sub AnyEvent::Base::Signal::DESTROY {	1001	sub AnyEvent::Base::Signal::DESTROY {
980	my ($signal, $cb) = @{$_[0]};	1002	my ($signal, $cb) = @{$_[0]};
981		1003
982	delete $SIG_CB{$signal}{$cb};	1004	delete $SIG_CB{$signal}{$cb};
983		1005
984	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1006	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
985	}	1007	}
986		1008
987	# default implementation for ->child	1009	# default implementation for ->child
988		1010
989	our %PID_CB;	1011	our %PID_CB;
…		…
1159	C<PERL_ANYEVENT_MODEL>.	1181	C<PERL_ANYEVENT_MODEL>.
1160		1182
1161	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1183	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1162	model it chooses.	1184	model it chooses.
1163		1185
		1186	=item C<PERL_ANYEVENT_STRICT>
		1187
		1188	AnyEvent does not do much argument checking by default, as thorough
		1189	argument checking is very costly. Setting this variable to a true value
		1190	will cause AnyEvent to thoroughly check the arguments passed to most
		1191	method calls and croaks if it finds any problems. In other words, enables
		1192	"strict" mode. Unlike C<use strict> it is definitely recommended ot keep
		1193	it off in production.
		1194
1164	=item C<PERL_ANYEVENT_MODEL>	1195	=item C<PERL_ANYEVENT_MODEL>
1165		1196
1166	This can be used to specify the event model to be used by AnyEvent, before	1197	This can be used to specify the event model to be used by AnyEvent, before
1167	auto detection and -probing kicks in. It must be a string consisting	1198	auto detection and -probing kicks in. It must be a string consisting
1168	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1199	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
…		…
1173	This functionality might change in future versions.	1204	This functionality might change in future versions.
1174		1205
1175	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1206	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1176	could start your program like this:	1207	could start your program like this:
1177		1208
1178	PERL_ANYEVENT_MODEL=Perl perl ...	1209	PERL_ANYEVENT_MODEL=Perl perl ...
1179		1210
1180	=item C<PERL_ANYEVENT_PROTOCOLS>	1211	=item C<PERL_ANYEVENT_PROTOCOLS>
1181		1212
1182	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	1213	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1183	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	1214	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1658	specified in the variable.	1689	specified in the variable.
1659		1690
1660	You can make AnyEvent completely ignore this variable by deleting it	1691	You can make AnyEvent completely ignore this variable by deleting it
1661	before the first watcher gets created, e.g. with a C<BEGIN> block:	1692	before the first watcher gets created, e.g. with a C<BEGIN> block:
1662		1693
1663	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1694	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1664		1695
1665	use AnyEvent;	1696	use AnyEvent;
1666		1697
1667	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1698	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1668	be used to probe what backend is used and gain other information (which is	1699	be used to probe what backend is used and gain other information (which is
1669	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1700	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1701	$ENV{PERL_ANYEGENT_STRICT}.
		1702
		1703
		1704	=head1 BUGS
		1705
		1706	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1707	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1708	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1709	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1710	pronounced).
1670		1711
1671		1712
1672	=head1 SEE ALSO	1713	=head1 SEE ALSO
1673		1714
1674	Utility functions: L<AnyEvent::Util>.	1715	Utility functions: L<AnyEvent::Util>.
…		…
1691	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1732	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1692		1733
1693		1734
1694	=head1 AUTHOR	1735	=head1 AUTHOR
1695		1736
1696	Marc Lehmann <schmorp@schmorp.de>	1737	Marc Lehmann <schmorp@schmorp.de>
1697	http://home.schmorp.de/	1738	http://home.schmorp.de/
1698		1739
1699	=cut	1740	=cut
1700		1741
1701	1	1742	1
1702		1743

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs. Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs.
Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC