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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.147 by root, Fri May 30 21:43:26 2008 UTC vs.
Revision 1.195 by root, Wed Mar 25 17:33:11 2009 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
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 });
		31
		32	=head1 INTRODUCTION/TUTORIAL
		33
		34	This manpage is mainly a reference manual. If you are interested
		35	in a tutorial or some gentle introduction, have a look at the
		36	L<AnyEvent::Intro> manpage.
22		37
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	38	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		39
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	40	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	41	nowadays. So what is different about AnyEvent?
27		42
28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
30		45
31	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
32	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
33	pragmatic way. For event models and certain classes of immortals alike,	48	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,	49	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	50	only one event loop can be active at the same time in a process. AnyEvent
36	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
37		53
38	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
39	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
40	religion, a way of living, and most importantly: without forcing your	56	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	57	module users into the same thing by forcing them to use the same event
42	model you use.	58	model you use.
43		59
44	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
45	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
46	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
47	cannot use anything else, as it is simply incompatible to everything that	63	cannot use anything else, as they are simply incompatible to everything
48	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
49	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.
50		66
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	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
53	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
54	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,
55	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
56	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
57	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
58	event loops to AnyEvent, too, so it is future-proof).	74	to AnyEvent, too, so it is future-proof).
59		75
60	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
61	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
62	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
63	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
132	Many watchers either are used with "recursion" (repeating timers for	148	Many watchers either are used with "recursion" (repeating timers for
133	example), or need to refer to their watcher object in other ways.	149	example), or need to refer to their watcher object in other ways.
134		150
135	An any way to achieve that is this pattern:	151	An any way to achieve that is this pattern:
136		152
137	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	153	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138	# you can use $w here, for example to undef it	154	# you can use $w here, for example to undef it
139	undef $w;	155	undef $w;
140	});	156	});
141		157
142	Note that C<my $w; $w => combination. This is necessary because in Perl,	158	Note that C<my $w; $w => combination. This is necessary because in Perl,
143	my variables are only visible after the statement in which they are	159	my variables are only visible after the statement in which they are
144	declared.	160	declared.
145		161
146	=head2 I/O WATCHERS	162	=head2 I/O WATCHERS
147		163
148	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
149	with the following mandatory key-value pairs as arguments:	165	with the following mandatory key-value pairs as arguments:
150		166
151	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
152	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>
153	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
154	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
155	becomes ready.	171	callback to invoke each time the file handle becomes ready.
156		172
157	Although the callback might get passed parameters, their value and	173	Although the callback might get passed parameters, their value and
158	presence is undefined and you cannot rely on them. Portable AnyEvent	174	presence is undefined and you cannot rely on them. Portable AnyEvent
159	callbacks cannot use arguments passed to I/O watcher callbacks.	175	callbacks cannot use arguments passed to I/O watcher callbacks.
160		176
…		…
164		180
165	Some event loops issue spurious readyness notifications, so you should	181	Some event loops issue spurious readyness notifications, so you should
166	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
167	handles.	183	handles.
168		184
169	Example:
170
171	# 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
172	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	188	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173	chomp (my $input = <STDIN>);	189	chomp (my $input = <STDIN>);
174	warn "read: $input\n";	190	warn "read: $input\n";
175	undef $w;	191	undef $w;
176	});	192	});
…		…
186		202
187	Although the callback might get passed parameters, their value and	203	Although the callback might get passed parameters, their value and
188	presence is undefined and you cannot rely on them. Portable AnyEvent	204	presence is undefined and you cannot rely on them. Portable AnyEvent
189	callbacks cannot use arguments passed to time watcher callbacks.	205	callbacks cannot use arguments passed to time watcher callbacks.
190		206
191	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
192	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
193	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.
194		212
195	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.
196		216
197	# fire an event after 7.7 seconds	217	Example: fire an event after 7.7 seconds.
		218
198	my $w = AnyEvent->timer (after => 7.7, cb => sub {	219	my $w = AnyEvent->timer (after => 7.7, cb => sub {
199	warn "timeout\n";	220	warn "timeout\n";
200	});	221	});
201		222
202	# to cancel the timer:	223	# to cancel the timer:
203	undef $w;	224	undef $w;
204		225
205	Example 2:
206
207	# 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.
208	my $w;
209		227
210	my $cb = sub {
211	# cancel the old timer while creating a new one
212	$w = AnyEvent->timer (after => 1, cb => $cb);	228	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		229	warn "timeout\n";
213	};	230	};
214
215	# start the "loop" by creating the first watcher
216	$w = AnyEvent->timer (after => 0.5, cb => $cb);
217		231
218	=head3 TIMING ISSUES	232	=head3 TIMING ISSUES
219		233
220	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
221	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
…		…
299	=back	313	=back
300		314
301	=head2 SIGNAL WATCHERS	315	=head2 SIGNAL WATCHERS
302		316
303	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
304	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
305	be invoked whenever a signal occurs.	319	callback to be invoked whenever a signal occurs.
306		320
307	Although the callback might get passed parameters, their value and	321	Although the callback might get passed parameters, their value and
308	presence is undefined and you cannot rely on them. Portable AnyEvent	322	presence is undefined and you cannot rely on them. Portable AnyEvent
309	callbacks cannot use arguments passed to signal watcher callbacks.	323	callbacks cannot use arguments passed to signal watcher callbacks.
310		324
…		…
326	=head2 CHILD PROCESS WATCHERS	340	=head2 CHILD PROCESS WATCHERS
327		341
328	You can also watch on a child process exit and catch its exit status.	342	You can also watch on a child process exit and catch its exit status.
329		343
330	The child process is specified by the C<pid> argument (if set to C<0>, it	344	The child process is specified by the C<pid> argument (if set to C<0>, it
331	watches for any child process exit). The watcher will trigger as often	345	watches for any child process exit). The watcher will triggered only when
332	as status change for the child are received. This works by installing a	346	the child process has finished and an exit status is available, not on
333	signal handler for C<SIGCHLD>. The callback will be called with the pid	347	any trace events (stopped/continued).
334	and exit status (as returned by waitpid), so unlike other watcher types,	348
335	you I<can> rely on child watcher callback arguments.	349	The callback will be called with the pid and exit status (as returned by
		350	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		351	callback arguments.
		352
		353	This watcher type works by installing a signal handler for C<SIGCHLD>,
		354	and since it cannot be shared, nothing else should use SIGCHLD or reap
		355	random child processes (waiting for specific child processes, e.g. inside
		356	C<system>, is just fine).
336		357
337	There is a slight catch to child watchers, however: you usually start them	358	There is a slight catch to child watchers, however: you usually start them
338	I<after> the child process was created, and this means the process could	359	I<after> the child process was created, and this means the process could
339	have exited already (and no SIGCHLD will be sent anymore).	360	have exited already (and no SIGCHLD will be sent anymore).
340		361
…		…
346	AnyEvent program, you I<have> to create at least one watcher before you	367	AnyEvent program, you I<have> to create at least one watcher before you
347	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	368	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
348		369
349	Example: fork a process and wait for it	370	Example: fork a process and wait for it
350		371
351	my $done = AnyEvent->condvar;	372	my $done = AnyEvent->condvar;
352		373
353	my $pid = fork or exit 5;	374	my $pid = fork or exit 5;
354		375
355	my $w = AnyEvent->child (	376	my $w = AnyEvent->child (
356	pid => $pid,	377	pid => $pid,
357	cb => sub {	378	cb => sub {
358	my ($pid, $status) = @_;	379	my ($pid, $status) = @_;
359	warn "pid $pid exited with status $status";	380	warn "pid $pid exited with status $status";
360	$done->send;	381	$done->send;
361	},	382	},
362	);	383	);
363		384
364	# do something else, then wait for process exit	385	# do something else, then wait for process exit
365	$done->recv;	386	$done->recv;
366		387
367	=head2 CONDITION VARIABLES	388	=head2 CONDITION VARIABLES
368		389
369	If you are familiar with some event loops you will know that all of them	390	If you are familiar with some event loops you will know that all of them
370	require you to run some blocking "loop", "run" or similar function that	391	require you to run some blocking "loop", "run" or similar function that
…		…
376	The instrument to do that is called a "condition variable", so called	397	The instrument to do that is called a "condition variable", so called
377	because they represent a condition that must become true.	398	because they represent a condition that must become true.
378		399
379	Condition variables can be created by calling the C<< AnyEvent->condvar	400	Condition variables can be created by calling the C<< AnyEvent->condvar
380	>> method, usually without arguments. The only argument pair allowed is	401	>> method, usually without arguments. The only argument pair allowed is
		402
381	C<cb>, which specifies a callback to be called when the condition variable	403	C<cb>, which specifies a callback to be called when the condition variable
382	becomes true.	404	becomes true, with the condition variable as the first argument (but not
		405	the results).
383		406
384	After creation, the condition variable is "false" until it becomes "true"	407	After creation, the condition variable is "false" until it becomes "true"
385	by calling the C<send> method (or calling the condition variable as if it	408	by calling the C<send> method (or calling the condition variable as if it
386	were a callback, read about the caveats in the description for the C<<	409	were a callback, read about the caveats in the description for the C<<
387	->send >> method).	410	->send >> method).
…		…
443		466
444	my $done = AnyEvent->condvar;	467	my $done = AnyEvent->condvar;
445	my $delay = AnyEvent->timer (after => 5, cb => $done);	468	my $delay = AnyEvent->timer (after => 5, cb => $done);
446	$done->recv;	469	$done->recv;
447		470
		471	Example: Imagine an API that returns a condvar and doesn't support
		472	callbacks. This is how you make a synchronous call, for example from
		473	the main program:
		474
		475	use AnyEvent::CouchDB;
		476
		477	...
		478
		479	my @info = $couchdb->info->recv;
		480
		481	And this is how you would just ste a callback to be called whenever the
		482	results are available:
		483
		484	$couchdb->info->cb (sub {
		485	my @info = $_[0]->recv;
		486	});
		487
448	=head3 METHODS FOR PRODUCERS	488	=head3 METHODS FOR PRODUCERS
449		489
450	These methods should only be used by the producing side, i.e. the	490	These methods should only be used by the producing side, i.e. the
451	code/module that eventually sends the signal. Note that it is also	491	code/module that eventually sends the signal. Note that it is also
452	the producer side which creates the condvar in most cases, but it isn't	492	the producer side which creates the condvar in most cases, but it isn't
…		…
585	=item $bool = $cv->ready	625	=item $bool = $cv->ready
586		626
587	Returns true when the condition is "true", i.e. whether C<send> or	627	Returns true when the condition is "true", i.e. whether C<send> or
588	C<croak> have been called.	628	C<croak> have been called.
589		629
590	=item $cb = $cv->cb ([new callback])	630	=item $cb = $cv->cb ($cb->($cv))
591		631
592	This is a mutator function that returns the callback set and optionally	632	This is a mutator function that returns the callback set and optionally
593	replaces it before doing so.	633	replaces it before doing so.
594		634
595	The callback will be called when the condition becomes "true", i.e. when	635	The callback will be called when the condition becomes "true", i.e. when
596	C<send> or C<croak> are called. Calling C<recv> inside the callback	636	C<send> or C<croak> are called, with the only argument being the condition
597	or at any later time is guaranteed not to block.	637	variable itself. Calling C<recv> inside the callback or at any later time
		638	is guaranteed not to block.
598		639
599	=back	640	=back
600		641
601	=head1 GLOBAL VARIABLES AND FUNCTIONS	642	=head1 GLOBAL VARIABLES AND FUNCTIONS
602		643
…		…
731	=item L<AnyEvent::Util>	772	=item L<AnyEvent::Util>
732		773
733	Contains various utility functions that replace often-used but blocking	774	Contains various utility functions that replace often-used but blocking
734	functions such as C<inet_aton> by event-/callback-based versions.	775	functions such as C<inet_aton> by event-/callback-based versions.
735		776
736	=item L<AnyEvent::Handle>
737
738	Provide read and write buffers and manages watchers for reads and writes.
739
740	=item L<AnyEvent::Socket>	777	=item L<AnyEvent::Socket>
741		778
742	Provides various utility functions for (internet protocol) sockets,	779	Provides various utility functions for (internet protocol) sockets,
743	addresses and name resolution. Also functions to create non-blocking tcp	780	addresses and name resolution. Also functions to create non-blocking tcp
744	connections or tcp servers, with IPv6 and SRV record support and more.	781	connections or tcp servers, with IPv6 and SRV record support and more.
745		782
		783	=item L<AnyEvent::Handle>
		784
		785	Provide read and write buffers, manages watchers for reads and writes,
		786	supports raw and formatted I/O, I/O queued and fully transparent and
		787	non-blocking SSL/TLS.
		788
746	=item L<AnyEvent::DNS>	789	=item L<AnyEvent::DNS>
747		790
748	Provides rich asynchronous DNS resolver capabilities.	791	Provides rich asynchronous DNS resolver capabilities.
749		792
		793	=item L<AnyEvent::HTTP>
		794
		795	A simple-to-use HTTP library that is capable of making a lot of concurrent
		796	HTTP requests.
		797
750	=item L<AnyEvent::HTTPD>	798	=item L<AnyEvent::HTTPD>
751		799
752	Provides a simple web application server framework.	800	Provides a simple web application server framework.
753		801
754	=item L<AnyEvent::FastPing>	802	=item L<AnyEvent::FastPing>
755		803
756	The fastest ping in the west.	804	The fastest ping in the west.
757		805
		806	=item L<AnyEvent::DBI>
		807
		808	Executes L<DBI> requests asynchronously in a proxy process.
		809
		810	=item L<AnyEvent::AIO>
		811
		812	Truly asynchronous I/O, should be in the toolbox of every event
		813	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		814	together.
		815
		816	=item L<AnyEvent::BDB>
		817
		818	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		819	L<BDB> and AnyEvent together.
		820
		821	=item L<AnyEvent::GPSD>
		822
		823	A non-blocking interface to gpsd, a daemon delivering GPS information.
		824
		825	=item L<AnyEvent::IGS>
		826
		827	A non-blocking interface to the Internet Go Server protocol (used by
		828	L<App::IGS>).
		829
758	=item L<Net::IRC3>	830	=item L<AnyEvent::IRC>
759		831
760	AnyEvent based IRC client module family.	832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
761		833
762	=item L<Net::XMPP2>	834	=item L<Net::XMPP2>
763		835
764	AnyEvent based XMPP (Jabber protocol) module family.	836	AnyEvent based XMPP (Jabber protocol) module family.
765		837
…		…
774		846
775	=item L<Coro>	847	=item L<Coro>
776		848
777	Has special support for AnyEvent via L<Coro::AnyEvent>.	849	Has special support for AnyEvent via L<Coro::AnyEvent>.
778		850
779	=item L<AnyEvent::AIO>, L<IO::AIO>
780
781	Truly asynchronous I/O, should be in the toolbox of every event
782	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
783	together.
784
785	=item L<AnyEvent::BDB>, L<BDB>
786
787	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
788	IO::AIO and AnyEvent together.
789
790	=item L<IO::Lambda>	851	=item L<IO::Lambda>
791		852
792	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	853	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
793		854
794	=back	855	=back
…		…
796	=cut	857	=cut
797		858
798	package AnyEvent;	859	package AnyEvent;
799		860
800	no warnings;	861	no warnings;
801	use strict;	862	use strict qw(vars subs);
802		863
803	use Carp;	864	use Carp;
804		865
805	our $VERSION = 4.11;	866	our $VERSION = 4.341;
806	our $MODEL;	867	our $MODEL;
807		868
808	our $AUTOLOAD;	869	our $AUTOLOAD;
809	our @ISA;	870	our @ISA;
810		871
…		…
913	$MODEL	974	$MODEL
914	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	975	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
915	}	976	}
916	}	977	}
917		978
		979	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		980
918	unshift @ISA, $MODEL;	981	unshift @ISA, $MODEL;
919	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	982
		983	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
920		984
921	(shift @post_detect)->() while @post_detect;	985	(shift @post_detect)->() while @post_detect;
922	}	986	}
923		987
924	$MODEL	988	$MODEL
…		…
934		998
935	my $class = shift;	999	my $class = shift;
936	$class->$func (@_);	1000	$class->$func (@_);
937	}	1001	}
938		1002
		1003	# utility function to dup a filehandle. this is used by many backends
		1004	# to support binding more than one watcher per filehandle (they usually
		1005	# allow only one watcher per fd, so we dup it to get a different one).
		1006	sub _dupfh($$$$) {
		1007	my ($poll, $fh, $r, $w) = @_;
		1008
		1009	# cygwin requires the fh mode to be matching, unix doesn't
		1010	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1011	: $poll eq "w" ? ($w, ">")
		1012	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1013
		1014	open my $fh2, "$mode&" . fileno $fh
		1015	or die "cannot dup() filehandle: $!";
		1016
		1017	# we assume CLOEXEC is already set by perl in all important cases
		1018
		1019	($fh2, $rw)
		1020	}
		1021
939	package AnyEvent::Base;	1022	package AnyEvent::Base;
940		1023
941	# default implementation for now and time	1024	# default implementation for now and time
942		1025
943	use Time::HiRes ();	1026	BEGIN {
		1027	if (eval "use Time::HiRes (); time (); 1") {
		1028	*_time = \&Time::HiRes::time;
		1029	# if (eval "use POSIX (); (POSIX::times())...
		1030	} else {
		1031	*_time = sub { time }; # epic fail
		1032	}
		1033	}
944		1034
945	sub time { Time::HiRes::time }	1035	sub time { _time }
946	sub now { Time::HiRes::time }	1036	sub now { _time }
947		1037
948	# default implementation for ->condvar	1038	# default implementation for ->condvar
949		1039
950	sub condvar {	1040	sub condvar {
951	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1041	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
952	}	1042	}
953		1043
954	# default implementation for ->signal	1044	# default implementation for ->signal
955		1045
956	our %SIG_CB;	1046	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1047
		1048	sub _signal_exec {
		1049	while (%SIG_EV) {
		1050	sysread $SIGPIPE_R, my $dummy, 4;
		1051	for (keys %SIG_EV) {
		1052	delete $SIG_EV{$_};
		1053	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1054	}
		1055	}
		1056	}
957		1057
958	sub signal {	1058	sub signal {
959	my (undef, %arg) = @_;	1059	my (undef, %arg) = @_;
960		1060
		1061	unless ($SIGPIPE_R) {
		1062	if (AnyEvent::WIN32) {
		1063	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1064	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1065	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1066	} else {
		1067	pipe $SIGPIPE_R, $SIGPIPE_W;
		1068	require Fcntl;
		1069	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1070	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1071	}
		1072
		1073	$SIGPIPE_R
		1074	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1075
		1076	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1077	}
		1078
961	my $signal = uc $arg{signal}	1079	my $signal = uc $arg{signal}
962	or Carp::croak "required option 'signal' is missing";	1080	or Carp::croak "required option 'signal' is missing";
963		1081
964	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1082	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
965	$SIG{$signal} \|\|= sub {	1083	$SIG{$signal} \|\|= sub {
966	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1084	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1085	undef $SIG_EV{$signal};
967	};	1086	};
968		1087
969	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1088	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
970	}	1089	}
971		1090
972	sub AnyEvent::Base::Signal::DESTROY {	1091	sub AnyEvent::Base::Signal::DESTROY {
973	my ($signal, $cb) = @{$_[0]};	1092	my ($signal, $cb) = @{$_[0]};
974		1093
975	delete $SIG_CB{$signal}{$cb};	1094	delete $SIG_CB{$signal}{$cb};
976		1095
977	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1096	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
978	}	1097	}
979		1098
980	# default implementation for ->child	1099	# default implementation for ->child
981		1100
982	our %PID_CB;	1101	our %PID_CB;
…		…
1090		1209
1091	# undocumented/compatibility with pre-3.4	1210	# undocumented/compatibility with pre-3.4
1092	*broadcast = \&send;	1211	*broadcast = \&send;
1093	*wait = \&_wait;	1212	*wait = \&_wait;
1094		1213
		1214	=head1 ERROR AND EXCEPTION HANDLING
		1215
		1216	In general, AnyEvent does not do any error handling - it relies on the
		1217	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1218	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1219	checking of all AnyEvent methods, however, which is highly useful during
		1220	development.
		1221
		1222	As for exception handling (i.e. runtime errors and exceptions thrown while
		1223	executing a callback), this is not only highly event-loop specific, but
		1224	also not in any way wrapped by this module, as this is the job of the main
		1225	program.
		1226
		1227	The pure perl event loop simply re-throws the exception (usually
		1228	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1229	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1230	so on.
		1231
		1232	=head1 ENVIRONMENT VARIABLES
		1233
		1234	The following environment variables are used by this module or its
		1235	submodules:
		1236
		1237	=over 4
		1238
		1239	=item C<PERL_ANYEVENT_VERBOSE>
		1240
		1241	By default, AnyEvent will be completely silent except in fatal
		1242	conditions. You can set this environment variable to make AnyEvent more
		1243	talkative.
		1244
		1245	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1246	conditions, such as not being able to load the event model specified by
		1247	C<PERL_ANYEVENT_MODEL>.
		1248
		1249	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1250	model it chooses.
		1251
		1252	=item C<PERL_ANYEVENT_STRICT>
		1253
		1254	AnyEvent does not do much argument checking by default, as thorough
		1255	argument checking is very costly. Setting this variable to a true value
		1256	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1257	check the arguments passed to most method calls. If it finds any problems
		1258	it will croak.
		1259
		1260	In other words, enables "strict" mode.
		1261
		1262	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1263	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1264	developing programs can be very useful, however.
		1265
		1266	=item C<PERL_ANYEVENT_MODEL>
		1267
		1268	This can be used to specify the event model to be used by AnyEvent, before
		1269	auto detection and -probing kicks in. It must be a string consisting
		1270	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1271	and the resulting module name is loaded and if the load was successful,
		1272	used as event model. If it fails to load AnyEvent will proceed with
		1273	auto detection and -probing.
		1274
		1275	This functionality might change in future versions.
		1276
		1277	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1278	could start your program like this:
		1279
		1280	PERL_ANYEVENT_MODEL=Perl perl ...
		1281
		1282	=item C<PERL_ANYEVENT_PROTOCOLS>
		1283
		1284	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1285	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1286	of auto probing).
		1287
		1288	Must be set to a comma-separated list of protocols or address families,
		1289	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1290	used, and preference will be given to protocols mentioned earlier in the
		1291	list.
		1292
		1293	This variable can effectively be used for denial-of-service attacks
		1294	against local programs (e.g. when setuid), although the impact is likely
		1295	small, as the program has to handle conenction and other failures anyways.
		1296
		1297	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1298	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1299	- only support IPv4, never try to resolve or contact IPv6
		1300	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1301	IPv6, but prefer IPv6 over IPv4.
		1302
		1303	=item C<PERL_ANYEVENT_EDNS0>
		1304
		1305	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1306	for DNS. This extension is generally useful to reduce DNS traffic, but
		1307	some (broken) firewalls drop such DNS packets, which is why it is off by
		1308	default.
		1309
		1310	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1311	EDNS0 in its DNS requests.
		1312
		1313	=item C<PERL_ANYEVENT_MAX_FORKS>
		1314
		1315	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1316	will create in parallel.
		1317
		1318	=back
		1319
1095	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1320	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1096		1321
1097	This is an advanced topic that you do not normally need to use AnyEvent in	1322	This is an advanced topic that you do not normally need to use AnyEvent in
1098	a module. This section is only of use to event loop authors who want to	1323	a module. This section is only of use to event loop authors who want to
1099	provide AnyEvent compatibility.	1324	provide AnyEvent compatibility.
…		…
1132		1357
1133	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1358	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1134	condition variables: code blocking while waiting for a condition will	1359	condition variables: code blocking while waiting for a condition will
1135	C<die>. This still works with most modules/usages, and blocking calls must	1360	C<die>. This still works with most modules/usages, and blocking calls must
1136	not be done in an interactive application, so it makes sense.	1361	not be done in an interactive application, so it makes sense.
1137
1138	=head1 ENVIRONMENT VARIABLES
1139
1140	The following environment variables are used by this module:
1141
1142	=over 4
1143
1144	=item C<PERL_ANYEVENT_VERBOSE>
1145
1146	By default, AnyEvent will be completely silent except in fatal
1147	conditions. You can set this environment variable to make AnyEvent more
1148	talkative.
1149
1150	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1151	conditions, such as not being able to load the event model specified by
1152	C<PERL_ANYEVENT_MODEL>.
1153
1154	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1155	model it chooses.
1156
1157	=item C<PERL_ANYEVENT_MODEL>
1158
1159	This can be used to specify the event model to be used by AnyEvent, before
1160	auto detection and -probing kicks in. It must be a string consisting
1161	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1162	and the resulting module name is loaded and if the load was successful,
1163	used as event model. If it fails to load AnyEvent will proceed with
1164	auto detection and -probing.
1165
1166	This functionality might change in future versions.
1167
1168	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1169	could start your program like this:
1170
1171	PERL_ANYEVENT_MODEL=Perl perl ...
1172
1173	=item C<PERL_ANYEVENT_PROTOCOLS>
1174
1175	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1176	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1177	of auto probing).
1178
1179	Must be set to a comma-separated list of protocols or address families,
1180	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1181	used, and preference will be given to protocols mentioned earlier in the
1182	list.
1183
1184	This variable can effectively be used for denial-of-service attacks
1185	against local programs (e.g. when setuid), although the impact is likely
1186	small, as the program has to handle connection errors already-
1187
1188	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1189	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1190	- only support IPv4, never try to resolve or contact IPv6
1191	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1192	IPv6, but prefer IPv6 over IPv4.
1193
1194	=item C<PERL_ANYEVENT_EDNS0>
1195
1196	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1197	for DNS. This extension is generally useful to reduce DNS traffic, but
1198	some (broken) firewalls drop such DNS packets, which is why it is off by
1199	default.
1200
1201	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1202	EDNS0 in its DNS requests.
1203
1204	=item C<PERL_ANYEVENT_MAX_FORKS>
1205
1206	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1207	will create in parallel.
1208
1209	=back
1210		1362
1211	=head1 EXAMPLE PROGRAM	1363	=head1 EXAMPLE PROGRAM
1212		1364
1213	The following program uses an I/O watcher to read data from STDIN, a timer	1365	The following program uses an I/O watcher to read data from STDIN, a timer
1214	to display a message once per second, and a condition variable to quit the	1366	to display a message once per second, and a condition variable to quit the
…		…
1408	watcher.	1560	watcher.
1409		1561
1410	=head3 Results	1562	=head3 Results
1411		1563
1412	name watchers bytes create invoke destroy comment	1564	name watchers bytes create invoke destroy comment
1413	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1565	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1414	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1566	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1415	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1567	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1416	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1568	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1417	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1569	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1418	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1570	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1419	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1571	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1420	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1572	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1421	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1573	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1422	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1574	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1423		1575
1424	=head3 Discussion	1576	=head3 Discussion
1425		1577
1426	The benchmark does I<not> measure scalability of the event loop very	1578	The benchmark does I<not> measure scalability of the event loop very
1427	well. For example, a select-based event loop (such as the pure perl one)	1579	well. For example, a select-based event loop (such as the pure perl one)
…		…
1629	watchers, as the management overhead dominates.	1781	watchers, as the management overhead dominates.
1630		1782
1631	=back	1783	=back
1632		1784
1633		1785
		1786	=head1 SIGNALS
		1787
		1788	AnyEvent currently installs handlers for these signals:
		1789
		1790	=over 4
		1791
		1792	=item SIGCHLD
		1793
		1794	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1795	emulation for event loops that do not support them natively. Also, some
		1796	event loops install a similar handler.
		1797
		1798	=item SIGPIPE
		1799
		1800	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1801	when AnyEvent gets loaded.
		1802
		1803	The rationale for this is that AnyEvent users usually do not really depend
		1804	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1805	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1806	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1807	some random socket.
		1808
		1809	The rationale for installing a no-op handler as opposed to ignoring it is
		1810	that this way, the handler will be restored to defaults on exec.
		1811
		1812	Feel free to install your own handler, or reset it to defaults.
		1813
		1814	=back
		1815
		1816	=cut
		1817
		1818	$SIG{PIPE} = sub { }
		1819	unless defined $SIG{PIPE};
		1820
		1821
1634	=head1 FORK	1822	=head1 FORK
1635		1823
1636	Most event libraries are not fork-safe. The ones who are usually are	1824	Most event libraries are not fork-safe. The ones who are usually are
1637	because they rely on inefficient but fork-safe C<select> or C<poll>	1825	because they rely on inefficient but fork-safe C<select> or C<poll>
1638	calls. Only L<EV> is fully fork-aware.	1826	calls. Only L<EV> is fully fork-aware.
…		…
1651	specified in the variable.	1839	specified in the variable.
1652		1840
1653	You can make AnyEvent completely ignore this variable by deleting it	1841	You can make AnyEvent completely ignore this variable by deleting it
1654	before the first watcher gets created, e.g. with a C<BEGIN> block:	1842	before the first watcher gets created, e.g. with a C<BEGIN> block:
1655		1843
1656	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1844	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1657		1845
1658	use AnyEvent;	1846	use AnyEvent;
1659		1847
1660	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1848	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1661	be used to probe what backend is used and gain other information (which is	1849	be used to probe what backend is used and gain other information (which is
1662	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1850	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1851	$ENV{PERL_ANYEGENT_STRICT}.
		1852
		1853
		1854	=head1 BUGS
		1855
		1856	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1857	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1858	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1859	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1860	pronounced).
1663		1861
1664		1862
1665	=head1 SEE ALSO	1863	=head1 SEE ALSO
1666		1864
1667	Utility functions: L<AnyEvent::Util>.	1865	Utility functions: L<AnyEvent::Util>.
…		…
1684	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1882	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1685		1883
1686		1884
1687	=head1 AUTHOR	1885	=head1 AUTHOR
1688		1886
1689	Marc Lehmann <schmorp@schmorp.de>	1887	Marc Lehmann <schmorp@schmorp.de>
1690	http://home.schmorp.de/	1888	http://home.schmorp.de/
1691		1889
1692	=cut	1890	=cut
1693		1891
1694	1	1892	1
1695		1893

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.147 by root, Fri May 30 21:43:26 2008 UTC vs. Revision 1.195 by root, Wed Mar 25 17:33:11 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.147 by root, Fri May 30 21:43:26 2008 UTC vs.
Revision 1.195 by root, Wed Mar 25 17:33:11 2009 UTC