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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs.
Revision 1.197 by root, Thu Mar 26 15:51:44 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
121	These watchers are normal Perl objects with normal Perl lifetime. After	137	These watchers are normal Perl objects with normal Perl lifetime. After
122	creating a watcher it will immediately "watch" for events and invoke the	138	creating a watcher it will immediately "watch" for events and invoke the
123	callback when the event occurs (of course, only when the event model	139	callback when the event occurs (of course, only when the event model
124	is in control).	140	is in control).
125		141
		142	Note that B<callbacks must not permanently change global variables>
		143	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		144	callbacks must not C<die> >>. The former is good programming practise in
		145	Perl and the latter stems from the fact that exception handling differs
		146	widely between event loops.
		147
126	To disable the watcher you have to destroy it (e.g. by setting the	148	To disable the watcher you have to destroy it (e.g. by setting the
127	variable you store it in to C<undef> or otherwise deleting all references	149	variable you store it in to C<undef> or otherwise deleting all references
128	to it).	150	to it).
129		151
130	All watchers are created by calling a method on the C<AnyEvent> class.	152	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
132	Many watchers either are used with "recursion" (repeating timers for	154	Many watchers either are used with "recursion" (repeating timers for
133	example), or need to refer to their watcher object in other ways.	155	example), or need to refer to their watcher object in other ways.
134		156
135	An any way to achieve that is this pattern:	157	An any way to achieve that is this pattern:
136		158
137	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	159	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138	# you can use $w here, for example to undef it	160	# you can use $w here, for example to undef it
139	undef $w;	161	undef $w;
140	});	162	});
141		163
142	Note that C<my $w; $w => combination. This is necessary because in Perl,	164	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	165	my variables are only visible after the statement in which they are
144	declared.	166	declared.
145		167
146	=head2 I/O WATCHERS	168	=head2 I/O WATCHERS
147		169
148	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	170	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
149	with the following mandatory key-value pairs as arguments:	171	with the following mandatory key-value pairs as arguments:
150		172
151	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	173	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>,	174	(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,	175	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	176	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
155	becomes ready.	177	callback to invoke each time the file handle becomes ready.
156		178
157	Although the callback might get passed parameters, their value and	179	Although the callback might get passed parameters, their value and
158	presence is undefined and you cannot rely on them. Portable AnyEvent	180	presence is undefined and you cannot rely on them. Portable AnyEvent
159	callbacks cannot use arguments passed to I/O watcher callbacks.	181	callbacks cannot use arguments passed to I/O watcher callbacks.
160		182
…		…
164		186
165	Some event loops issue spurious readyness notifications, so you should	187	Some event loops issue spurious readyness notifications, so you should
166	always use non-blocking calls when reading/writing from/to your file	188	always use non-blocking calls when reading/writing from/to your file
167	handles.	189	handles.
168		190
169	Example:
170
171	# wait for readability of STDIN, then read a line and disable the watcher	191	Example: wait for readability of STDIN, then read a line and disable the
		192	watcher.
		193
172	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	194	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173	chomp (my $input = <STDIN>);	195	chomp (my $input = <STDIN>);
174	warn "read: $input\n";	196	warn "read: $input\n";
175	undef $w;	197	undef $w;
176	});	198	});
…		…
186		208
187	Although the callback might get passed parameters, their value and	209	Although the callback might get passed parameters, their value and
188	presence is undefined and you cannot rely on them. Portable AnyEvent	210	presence is undefined and you cannot rely on them. Portable AnyEvent
189	callbacks cannot use arguments passed to time watcher callbacks.	211	callbacks cannot use arguments passed to time watcher callbacks.
190		212
191	The timer callback will be invoked at most once: if you want a repeating	213	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	214	parameter, C<interval>, as a strictly positive number (> 0), then the
193	and Glib).	215	callback will be invoked regularly at that interval (in fractional
		216	seconds) after the first invocation. If C<interval> is specified with a
		217	false value, then it is treated as if it were missing.
194		218
195	Example:	219	The callback will be rescheduled before invoking the callback, but no
		220	attempt is done to avoid timer drift in most backends, so the interval is
		221	only approximate.
196		222
197	# fire an event after 7.7 seconds	223	Example: fire an event after 7.7 seconds.
		224
198	my $w = AnyEvent->timer (after => 7.7, cb => sub {	225	my $w = AnyEvent->timer (after => 7.7, cb => sub {
199	warn "timeout\n";	226	warn "timeout\n";
200	});	227	});
201		228
202	# to cancel the timer:	229	# to cancel the timer:
203	undef $w;	230	undef $w;
204		231
205	Example 2:
206
207	# fire an event after 0.5 seconds, then roughly every second	232	Example 2: fire an event after 0.5 seconds, then roughly every second.
208	my $w;
209		233
210	my $cb = sub {
211	# cancel the old timer while creating a new one
212	$w = AnyEvent->timer (after => 1, cb => $cb);	234	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		235	warn "timeout\n";
213	};	236	};
214
215	# start the "loop" by creating the first watcher
216	$w = AnyEvent->timer (after => 0.5, cb => $cb);
217		237
218	=head3 TIMING ISSUES	238	=head3 TIMING ISSUES
219		239
220	There are two ways to handle timers: based on real time (relative, "fire	240	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	241	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
299	=back	319	=back
300		320
301	=head2 SIGNAL WATCHERS	321	=head2 SIGNAL WATCHERS
302		322
303	You can watch for signals using a signal watcher, C<signal> is the signal	323	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	324	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
305	be invoked whenever a signal occurs.	325	callback to be invoked whenever a signal occurs.
306		326
307	Although the callback might get passed parameters, their value and	327	Although the callback might get passed parameters, their value and
308	presence is undefined and you cannot rely on them. Portable AnyEvent	328	presence is undefined and you cannot rely on them. Portable AnyEvent
309	callbacks cannot use arguments passed to signal watcher callbacks.	329	callbacks cannot use arguments passed to signal watcher callbacks.
310		330
…		…
326	=head2 CHILD PROCESS WATCHERS	346	=head2 CHILD PROCESS WATCHERS
327		347
328	You can also watch on a child process exit and catch its exit status.	348	You can also watch on a child process exit and catch its exit status.
329		349
330	The child process is specified by the C<pid> argument (if set to C<0>, it	350	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	351	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	352	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	353	any trace events (stopped/continued).
334	and exit status (as returned by waitpid), so unlike other watcher types,	354
335	you I<can> rely on child watcher callback arguments.	355	The callback will be called with the pid and exit status (as returned by
		356	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		357	callback arguments.
		358
		359	This watcher type works by installing a signal handler for C<SIGCHLD>,
		360	and since it cannot be shared, nothing else should use SIGCHLD or reap
		361	random child processes (waiting for specific child processes, e.g. inside
		362	C<system>, is just fine).
336		363
337	There is a slight catch to child watchers, however: you usually start them	364	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	365	I<after> the child process was created, and this means the process could
339	have exited already (and no SIGCHLD will be sent anymore).	366	have exited already (and no SIGCHLD will be sent anymore).
340		367
…		…
346	AnyEvent program, you I<have> to create at least one watcher before you	373	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>).	374	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
348		375
349	Example: fork a process and wait for it	376	Example: fork a process and wait for it
350		377
351	my $done = AnyEvent->condvar;	378	my $done = AnyEvent->condvar;
352		379
353	my $pid = fork or exit 5;	380	my $pid = fork or exit 5;
354		381
355	my $w = AnyEvent->child (	382	my $w = AnyEvent->child (
356	pid => $pid,	383	pid => $pid,
357	cb => sub {	384	cb => sub {
358	my ($pid, $status) = @_;	385	my ($pid, $status) = @_;
359	warn "pid $pid exited with status $status";	386	warn "pid $pid exited with status $status";
360	$done->send;	387	$done->send;
361	},	388	},
362	);	389	);
363		390
364	# do something else, then wait for process exit	391	# do something else, then wait for process exit
365	$done->recv;	392	$done->recv;
366		393
367	=head2 CONDITION VARIABLES	394	=head2 CONDITION VARIABLES
368		395
369	If you are familiar with some event loops you will know that all of them	396	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	397	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	403	The instrument to do that is called a "condition variable", so called
377	because they represent a condition that must become true.	404	because they represent a condition that must become true.
378		405
379	Condition variables can be created by calling the C<< AnyEvent->condvar	406	Condition variables can be created by calling the C<< AnyEvent->condvar
380	>> method, usually without arguments. The only argument pair allowed is	407	>> method, usually without arguments. The only argument pair allowed is
		408
381	C<cb>, which specifies a callback to be called when the condition variable	409	C<cb>, which specifies a callback to be called when the condition variable
382	becomes true.	410	becomes true, with the condition variable as the first argument (but not
		411	the results).
383		412
384	After creation, the condition variable is "false" until it becomes "true"	413	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	414	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<<	415	were a callback, read about the caveats in the description for the C<<
387	->send >> method).	416	->send >> method).
…		…
443		472
444	my $done = AnyEvent->condvar;	473	my $done = AnyEvent->condvar;
445	my $delay = AnyEvent->timer (after => 5, cb => $done);	474	my $delay = AnyEvent->timer (after => 5, cb => $done);
446	$done->recv;	475	$done->recv;
447		476
		477	Example: Imagine an API that returns a condvar and doesn't support
		478	callbacks. This is how you make a synchronous call, for example from
		479	the main program:
		480
		481	use AnyEvent::CouchDB;
		482
		483	...
		484
		485	my @info = $couchdb->info->recv;
		486
		487	And this is how you would just ste a callback to be called whenever the
		488	results are available:
		489
		490	$couchdb->info->cb (sub {
		491	my @info = $_[0]->recv;
		492	});
		493
448	=head3 METHODS FOR PRODUCERS	494	=head3 METHODS FOR PRODUCERS
449		495
450	These methods should only be used by the producing side, i.e. the	496	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	497	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	498	the producer side which creates the condvar in most cases, but it isn't
…		…
585	=item $bool = $cv->ready	631	=item $bool = $cv->ready
586		632
587	Returns true when the condition is "true", i.e. whether C<send> or	633	Returns true when the condition is "true", i.e. whether C<send> or
588	C<croak> have been called.	634	C<croak> have been called.
589		635
590	=item $cb = $cv->cb ([new callback])	636	=item $cb = $cv->cb ($cb->($cv))
591		637
592	This is a mutator function that returns the callback set and optionally	638	This is a mutator function that returns the callback set and optionally
593	replaces it before doing so.	639	replaces it before doing so.
594		640
595	The callback will be called when the condition becomes "true", i.e. when	641	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	642	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.	643	variable itself. Calling C<recv> inside the callback or at any later time
		644	is guaranteed not to block.
598		645
599	=back	646	=back
600		647
601	=head1 GLOBAL VARIABLES AND FUNCTIONS	648	=head1 GLOBAL VARIABLES AND FUNCTIONS
602		649
…		…
731	=item L<AnyEvent::Util>	778	=item L<AnyEvent::Util>
732		779
733	Contains various utility functions that replace often-used but blocking	780	Contains various utility functions that replace often-used but blocking
734	functions such as C<inet_aton> by event-/callback-based versions.	781	functions such as C<inet_aton> by event-/callback-based versions.
735		782
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>	783	=item L<AnyEvent::Socket>
741		784
742	Provides various utility functions for (internet protocol) sockets,	785	Provides various utility functions for (internet protocol) sockets,
743	addresses and name resolution. Also functions to create non-blocking tcp	786	addresses and name resolution. Also functions to create non-blocking tcp
744	connections or tcp servers, with IPv6 and SRV record support and more.	787	connections or tcp servers, with IPv6 and SRV record support and more.
745		788
		789	=item L<AnyEvent::Handle>
		790
		791	Provide read and write buffers, manages watchers for reads and writes,
		792	supports raw and formatted I/O, I/O queued and fully transparent and
		793	non-blocking SSL/TLS.
		794
746	=item L<AnyEvent::DNS>	795	=item L<AnyEvent::DNS>
747		796
748	Provides rich asynchronous DNS resolver capabilities.	797	Provides rich asynchronous DNS resolver capabilities.
749		798
		799	=item L<AnyEvent::HTTP>
		800
		801	A simple-to-use HTTP library that is capable of making a lot of concurrent
		802	HTTP requests.
		803
750	=item L<AnyEvent::HTTPD>	804	=item L<AnyEvent::HTTPD>
751		805
752	Provides a simple web application server framework.	806	Provides a simple web application server framework.
753		807
754	=item L<AnyEvent::FastPing>	808	=item L<AnyEvent::FastPing>
755		809
756	The fastest ping in the west.	810	The fastest ping in the west.
757		811
		812	=item L<AnyEvent::DBI>
		813
		814	Executes L<DBI> requests asynchronously in a proxy process.
		815
		816	=item L<AnyEvent::AIO>
		817
		818	Truly asynchronous I/O, should be in the toolbox of every event
		819	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		820	together.
		821
		822	=item L<AnyEvent::BDB>
		823
		824	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		825	L<BDB> and AnyEvent together.
		826
		827	=item L<AnyEvent::GPSD>
		828
		829	A non-blocking interface to gpsd, a daemon delivering GPS information.
		830
		831	=item L<AnyEvent::IGS>
		832
		833	A non-blocking interface to the Internet Go Server protocol (used by
		834	L<App::IGS>).
		835
758	=item L<Net::IRC3>	836	=item L<AnyEvent::IRC>
759		837
760	AnyEvent based IRC client module family.	838	AnyEvent based IRC client module family (replacing the older Net::IRC3).
761		839
762	=item L<Net::XMPP2>	840	=item L<Net::XMPP2>
763		841
764	AnyEvent based XMPP (Jabber protocol) module family.	842	AnyEvent based XMPP (Jabber protocol) module family.
765		843
…		…
774		852
775	=item L<Coro>	853	=item L<Coro>
776		854
777	Has special support for AnyEvent via L<Coro::AnyEvent>.	855	Has special support for AnyEvent via L<Coro::AnyEvent>.
778		856
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>	857	=item L<IO::Lambda>
791		858
792	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	859	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
793		860
794	=back	861	=back
…		…
796	=cut	863	=cut
797		864
798	package AnyEvent;	865	package AnyEvent;
799		866
800	no warnings;	867	no warnings;
801	use strict;	868	use strict qw(vars subs);
802		869
803	use Carp;	870	use Carp;
804		871
805	our $VERSION = '4.05';	872	our $VERSION = 4.341;
806	our $MODEL;	873	our $MODEL;
807		874
808	our $AUTOLOAD;	875	our $AUTOLOAD;
809	our @ISA;	876	our @ISA;
810		877
…		…
913	$MODEL	980	$MODEL
914	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	981	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
915	}	982	}
916	}	983	}
917		984
		985	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		986
918	unshift @ISA, $MODEL;	987	unshift @ISA, $MODEL;
919	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	988
		989	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
920		990
921	(shift @post_detect)->() while @post_detect;	991	(shift @post_detect)->() while @post_detect;
922	}	992	}
923		993
924	$MODEL	994	$MODEL
…		…
934		1004
935	my $class = shift;	1005	my $class = shift;
936	$class->$func (@_);	1006	$class->$func (@_);
937	}	1007	}
938		1008
		1009	# utility function to dup a filehandle. this is used by many backends
		1010	# to support binding more than one watcher per filehandle (they usually
		1011	# allow only one watcher per fd, so we dup it to get a different one).
		1012	sub _dupfh($$$$) {
		1013	my ($poll, $fh, $r, $w) = @_;
		1014
		1015	# cygwin requires the fh mode to be matching, unix doesn't
		1016	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1017	: $poll eq "w" ? ($w, ">")
		1018	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1019
		1020	open my $fh2, "$mode&" . fileno $fh
		1021	or die "cannot dup() filehandle: $!";
		1022
		1023	# we assume CLOEXEC is already set by perl in all important cases
		1024
		1025	($fh2, $rw)
		1026	}
		1027
939	package AnyEvent::Base;	1028	package AnyEvent::Base;
940		1029
941	# default implementation for now and time	1030	# default implementation for now and time
942		1031
943	use Time::HiRes ();	1032	BEGIN {
		1033	if (eval "use Time::HiRes (); time (); 1") {
		1034	*_time = \&Time::HiRes::time;
		1035	# if (eval "use POSIX (); (POSIX::times())...
		1036	} else {
		1037	*_time = sub { time }; # epic fail
		1038	}
		1039	}
944		1040
945	sub time { Time::HiRes::time }	1041	sub time { _time }
946	sub now { Time::HiRes::time }	1042	sub now { _time }
947		1043
948	# default implementation for ->condvar	1044	# default implementation for ->condvar
949		1045
950	sub condvar {	1046	sub condvar {
951	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1047	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
952	}	1048	}
953		1049
954	# default implementation for ->signal	1050	# default implementation for ->signal
955		1051
956	our %SIG_CB;	1052	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1053
		1054	sub _signal_exec {
		1055	while (%SIG_EV) {
		1056	sysread $SIGPIPE_R, my $dummy, 4;
		1057	for (keys %SIG_EV) {
		1058	delete $SIG_EV{$_};
		1059	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1060	}
		1061	}
		1062	}
957		1063
958	sub signal {	1064	sub signal {
959	my (undef, %arg) = @_;	1065	my (undef, %arg) = @_;
960		1066
		1067	unless ($SIGPIPE_R) {
		1068	if (AnyEvent::WIN32) {
		1069	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1070	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1071	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1072	} else {
		1073	pipe $SIGPIPE_R, $SIGPIPE_W;
		1074	require Fcntl;
		1075	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1076	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1077	}
		1078
		1079	$SIGPIPE_R
		1080	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1081
		1082	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1083	}
		1084
961	my $signal = uc $arg{signal}	1085	my $signal = uc $arg{signal}
962	or Carp::croak "required option 'signal' is missing";	1086	or Carp::croak "required option 'signal' is missing";
963		1087
964	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1088	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
965	$SIG{$signal} \|\|= sub {	1089	$SIG{$signal} \|\|= sub {
966	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1090	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1091	undef $SIG_EV{$signal};
967	};	1092	};
968		1093
969	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1094	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
970	}	1095	}
971		1096
972	sub AnyEvent::Base::Signal::DESTROY {	1097	sub AnyEvent::Base::Signal::DESTROY {
973	my ($signal, $cb) = @{$_[0]};	1098	my ($signal, $cb) = @{$_[0]};
974		1099
975	delete $SIG_CB{$signal}{$cb};	1100	delete $SIG_CB{$signal}{$cb};
976		1101
977	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1102	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
978	}	1103	}
979		1104
980	# default implementation for ->child	1105	# default implementation for ->child
981		1106
982	our %PID_CB;	1107	our %PID_CB;
…		…
1090		1215
1091	# undocumented/compatibility with pre-3.4	1216	# undocumented/compatibility with pre-3.4
1092	*broadcast = \&send;	1217	*broadcast = \&send;
1093	*wait = \&_wait;	1218	*wait = \&_wait;
1094		1219
		1220	=head1 ERROR AND EXCEPTION HANDLING
		1221
		1222	In general, AnyEvent does not do any error handling - it relies on the
		1223	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1224	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1225	checking of all AnyEvent methods, however, which is highly useful during
		1226	development.
		1227
		1228	As for exception handling (i.e. runtime errors and exceptions thrown while
		1229	executing a callback), this is not only highly event-loop specific, but
		1230	also not in any way wrapped by this module, as this is the job of the main
		1231	program.
		1232
		1233	The pure perl event loop simply re-throws the exception (usually
		1234	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1235	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1236	so on.
		1237
		1238	=head1 ENVIRONMENT VARIABLES
		1239
		1240	The following environment variables are used by this module or its
		1241	submodules:
		1242
		1243	=over 4
		1244
		1245	=item C<PERL_ANYEVENT_VERBOSE>
		1246
		1247	By default, AnyEvent will be completely silent except in fatal
		1248	conditions. You can set this environment variable to make AnyEvent more
		1249	talkative.
		1250
		1251	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1252	conditions, such as not being able to load the event model specified by
		1253	C<PERL_ANYEVENT_MODEL>.
		1254
		1255	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1256	model it chooses.
		1257
		1258	=item C<PERL_ANYEVENT_STRICT>
		1259
		1260	AnyEvent does not do much argument checking by default, as thorough
		1261	argument checking is very costly. Setting this variable to a true value
		1262	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1263	check the arguments passed to most method calls. If it finds any problems
		1264	it will croak.
		1265
		1266	In other words, enables "strict" mode.
		1267
		1268	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1269	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1270	developing programs can be very useful, however.
		1271
		1272	=item C<PERL_ANYEVENT_MODEL>
		1273
		1274	This can be used to specify the event model to be used by AnyEvent, before
		1275	auto detection and -probing kicks in. It must be a string consisting
		1276	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1277	and the resulting module name is loaded and if the load was successful,
		1278	used as event model. If it fails to load AnyEvent will proceed with
		1279	auto detection and -probing.
		1280
		1281	This functionality might change in future versions.
		1282
		1283	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1284	could start your program like this:
		1285
		1286	PERL_ANYEVENT_MODEL=Perl perl ...
		1287
		1288	=item C<PERL_ANYEVENT_PROTOCOLS>
		1289
		1290	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1291	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1292	of auto probing).
		1293
		1294	Must be set to a comma-separated list of protocols or address families,
		1295	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1296	used, and preference will be given to protocols mentioned earlier in the
		1297	list.
		1298
		1299	This variable can effectively be used for denial-of-service attacks
		1300	against local programs (e.g. when setuid), although the impact is likely
		1301	small, as the program has to handle conenction and other failures anyways.
		1302
		1303	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1304	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1305	- only support IPv4, never try to resolve or contact IPv6
		1306	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1307	IPv6, but prefer IPv6 over IPv4.
		1308
		1309	=item C<PERL_ANYEVENT_EDNS0>
		1310
		1311	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1312	for DNS. This extension is generally useful to reduce DNS traffic, but
		1313	some (broken) firewalls drop such DNS packets, which is why it is off by
		1314	default.
		1315
		1316	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1317	EDNS0 in its DNS requests.
		1318
		1319	=item C<PERL_ANYEVENT_MAX_FORKS>
		1320
		1321	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1322	will create in parallel.
		1323
		1324	=back
		1325
1095	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1326	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1096		1327
1097	This is an advanced topic that you do not normally need to use AnyEvent in	1328	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	1329	a module. This section is only of use to event loop authors who want to
1099	provide AnyEvent compatibility.	1330	provide AnyEvent compatibility.
…		…
1132		1363
1133	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1364	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1134	condition variables: code blocking while waiting for a condition will	1365	condition variables: code blocking while waiting for a condition will
1135	C<die>. This still works with most modules/usages, and blocking calls must	1366	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.	1367	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		1368
1211	=head1 EXAMPLE PROGRAM	1369	=head1 EXAMPLE PROGRAM
1212		1370
1213	The following program uses an I/O watcher to read data from STDIN, a timer	1371	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	1372	to display a message once per second, and a condition variable to quit the
…		…
1408	watcher.	1566	watcher.
1409		1567
1410	=head3 Results	1568	=head3 Results
1411		1569
1412	name watchers bytes create invoke destroy comment	1570	name watchers bytes create invoke destroy comment
1413	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1571	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	1572	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	1573	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	1574	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	1575	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	1576	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	1577	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	1578	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	1579	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	1580	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1423		1581
1424	=head3 Discussion	1582	=head3 Discussion
1425		1583
1426	The benchmark does I<not> measure scalability of the event loop very	1584	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)	1585	well. For example, a select-based event loop (such as the pure perl one)
…		…
1629	watchers, as the management overhead dominates.	1787	watchers, as the management overhead dominates.
1630		1788
1631	=back	1789	=back
1632		1790
1633		1791
		1792	=head1 SIGNALS
		1793
		1794	AnyEvent currently installs handlers for these signals:
		1795
		1796	=over 4
		1797
		1798	=item SIGCHLD
		1799
		1800	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1801	emulation for event loops that do not support them natively. Also, some
		1802	event loops install a similar handler.
		1803
		1804	=item SIGPIPE
		1805
		1806	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1807	when AnyEvent gets loaded.
		1808
		1809	The rationale for this is that AnyEvent users usually do not really depend
		1810	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1811	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1812	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1813	some random socket.
		1814
		1815	The rationale for installing a no-op handler as opposed to ignoring it is
		1816	that this way, the handler will be restored to defaults on exec.
		1817
		1818	Feel free to install your own handler, or reset it to defaults.
		1819
		1820	=back
		1821
		1822	=cut
		1823
		1824	$SIG{PIPE} = sub { }
		1825	unless defined $SIG{PIPE};
		1826
		1827
1634	=head1 FORK	1828	=head1 FORK
1635		1829
1636	Most event libraries are not fork-safe. The ones who are usually are	1830	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>	1831	because they rely on inefficient but fork-safe C<select> or C<poll>
1638	calls. Only L<EV> is fully fork-aware.	1832	calls. Only L<EV> is fully fork-aware.
…		…
1651	specified in the variable.	1845	specified in the variable.
1652		1846
1653	You can make AnyEvent completely ignore this variable by deleting it	1847	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:	1848	before the first watcher gets created, e.g. with a C<BEGIN> block:
1655		1849
1656	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1850	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1657		1851
1658	use AnyEvent;	1852	use AnyEvent;
1659		1853
1660	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1854	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	1855	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).	1856	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1857	$ENV{PERL_ANYEGENT_STRICT}.
		1858
		1859
		1860	=head1 BUGS
		1861
		1862	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1863	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1864	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1865	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1866	pronounced).
1663		1867
1664		1868
1665	=head1 SEE ALSO	1869	=head1 SEE ALSO
1666		1870
1667	Utility functions: L<AnyEvent::Util>.	1871	Utility functions: L<AnyEvent::Util>.
…		…
1684	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1888	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1685		1889
1686		1890
1687	=head1 AUTHOR	1891	=head1 AUTHOR
1688		1892
1689	Marc Lehmann <schmorp@schmorp.de>	1893	Marc Lehmann <schmorp@schmorp.de>
1690	http://home.schmorp.de/	1894	http://home.schmorp.de/
1691		1895
1692	=cut	1896	=cut
1693		1897
1694	1	1898	1
1695		1899

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs. Revision 1.197 by root, Thu Mar 26 15:51:44 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs.
Revision 1.197 by root, Thu Mar 26 15:51:44 2009 UTC