[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 1.200 by root, Wed Apr 1 14:02:27 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> is the Perl I<file handle> (I<not> file descriptor) to watch
		174	for events (AnyEvent might or might not keep a reference to this file
		175	handle). Note that only file handles pointing to things for which
		176	non-blocking operation makes sense are allowed. This includes sockets,
		177	most character devices, pipes, fifos and so on, but not for example files
		178	or block devices.
		179
152	for events. C<poll> must be a string that is either C<r> or C<w>,	180	C<poll> must be a string that is either C<r> or C<w>, which creates a
153	which creates a watcher waiting for "r"eadable or "w"ritable events,	181	watcher waiting for "r"eadable or "w"ritable events, respectively.
		182
154	respectively. C<cb> is the callback to invoke each time the file handle	183	C<cb> is the callback to invoke each time the file handle becomes ready.
155	becomes ready.
156		184
157	Although the callback might get passed parameters, their value and	185	Although the callback might get passed parameters, their value and
158	presence is undefined and you cannot rely on them. Portable AnyEvent	186	presence is undefined and you cannot rely on them. Portable AnyEvent
159	callbacks cannot use arguments passed to I/O watcher callbacks.	187	callbacks cannot use arguments passed to I/O watcher callbacks.
160		188
…		…
164		192
165	Some event loops issue spurious readyness notifications, so you should	193	Some event loops issue spurious readyness notifications, so you should
166	always use non-blocking calls when reading/writing from/to your file	194	always use non-blocking calls when reading/writing from/to your file
167	handles.	195	handles.
168		196
169	Example:
170
171	# wait for readability of STDIN, then read a line and disable the watcher	197	Example: wait for readability of STDIN, then read a line and disable the
		198	watcher.
		199
172	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	200	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173	chomp (my $input = <STDIN>);	201	chomp (my $input = <STDIN>);
174	warn "read: $input\n";	202	warn "read: $input\n";
175	undef $w;	203	undef $w;
176	});	204	});
…		…
186		214
187	Although the callback might get passed parameters, their value and	215	Although the callback might get passed parameters, their value and
188	presence is undefined and you cannot rely on them. Portable AnyEvent	216	presence is undefined and you cannot rely on them. Portable AnyEvent
189	callbacks cannot use arguments passed to time watcher callbacks.	217	callbacks cannot use arguments passed to time watcher callbacks.
190		218
191	The timer callback will be invoked at most once: if you want a repeating	219	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	220	parameter, C<interval>, as a strictly positive number (> 0), then the
193	and Glib).	221	callback will be invoked regularly at that interval (in fractional
		222	seconds) after the first invocation. If C<interval> is specified with a
		223	false value, then it is treated as if it were missing.
194		224
195	Example:	225	The callback will be rescheduled before invoking the callback, but no
		226	attempt is done to avoid timer drift in most backends, so the interval is
		227	only approximate.
196		228
197	# fire an event after 7.7 seconds	229	Example: fire an event after 7.7 seconds.
		230
198	my $w = AnyEvent->timer (after => 7.7, cb => sub {	231	my $w = AnyEvent->timer (after => 7.7, cb => sub {
199	warn "timeout\n";	232	warn "timeout\n";
200	});	233	});
201		234
202	# to cancel the timer:	235	# to cancel the timer:
203	undef $w;	236	undef $w;
204		237
205	Example 2:
206
207	# fire an event after 0.5 seconds, then roughly every second	238	Example 2: fire an event after 0.5 seconds, then roughly every second.
208	my $w;
209		239
210	my $cb = sub {
211	# cancel the old timer while creating a new one
212	$w = AnyEvent->timer (after => 1, cb => $cb);	240	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		241	warn "timeout\n";
213	};	242	};
214
215	# start the "loop" by creating the first watcher
216	$w = AnyEvent->timer (after => 0.5, cb => $cb);
217		243
218	=head3 TIMING ISSUES	244	=head3 TIMING ISSUES
219		245
220	There are two ways to handle timers: based on real time (relative, "fire	246	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	247	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
299	=back	325	=back
300		326
301	=head2 SIGNAL WATCHERS	327	=head2 SIGNAL WATCHERS
302		328
303	You can watch for signals using a signal watcher, C<signal> is the signal	329	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	330	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
305	be invoked whenever a signal occurs.	331	callback to be invoked whenever a signal occurs.
306		332
307	Although the callback might get passed parameters, their value and	333	Although the callback might get passed parameters, their value and
308	presence is undefined and you cannot rely on them. Portable AnyEvent	334	presence is undefined and you cannot rely on them. Portable AnyEvent
309	callbacks cannot use arguments passed to signal watcher callbacks.	335	callbacks cannot use arguments passed to signal watcher callbacks.
310		336
…		…
326	=head2 CHILD PROCESS WATCHERS	352	=head2 CHILD PROCESS WATCHERS
327		353
328	You can also watch on a child process exit and catch its exit status.	354	You can also watch on a child process exit and catch its exit status.
329		355
330	The child process is specified by the C<pid> argument (if set to C<0>, it	356	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	357	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	358	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	359	any trace events (stopped/continued).
334	and exit status (as returned by waitpid), so unlike other watcher types,	360
335	you I<can> rely on child watcher callback arguments.	361	The callback will be called with the pid and exit status (as returned by
		362	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		363	callback arguments.
		364
		365	This watcher type works by installing a signal handler for C<SIGCHLD>,
		366	and since it cannot be shared, nothing else should use SIGCHLD or reap
		367	random child processes (waiting for specific child processes, e.g. inside
		368	C<system>, is just fine).
336		369
337	There is a slight catch to child watchers, however: you usually start them	370	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	371	I<after> the child process was created, and this means the process could
339	have exited already (and no SIGCHLD will be sent anymore).	372	have exited already (and no SIGCHLD will be sent anymore).
340		373
…		…
346	AnyEvent program, you I<have> to create at least one watcher before you	379	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>).	380	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
348		381
349	Example: fork a process and wait for it	382	Example: fork a process and wait for it
350		383
351	my $done = AnyEvent->condvar;	384	my $done = AnyEvent->condvar;
352		385
353	my $pid = fork or exit 5;	386	my $pid = fork or exit 5;
354		387
355	my $w = AnyEvent->child (	388	my $w = AnyEvent->child (
356	pid => $pid,	389	pid => $pid,
357	cb => sub {	390	cb => sub {
358	my ($pid, $status) = @_;	391	my ($pid, $status) = @_;
359	warn "pid $pid exited with status $status";	392	warn "pid $pid exited with status $status";
360	$done->send;	393	$done->send;
361	},	394	},
362	);	395	);
363		396
364	# do something else, then wait for process exit	397	# do something else, then wait for process exit
365	$done->recv;	398	$done->recv;
366		399
367	=head2 CONDITION VARIABLES	400	=head2 CONDITION VARIABLES
368		401
369	If you are familiar with some event loops you will know that all of them	402	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	403	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	409	The instrument to do that is called a "condition variable", so called
377	because they represent a condition that must become true.	410	because they represent a condition that must become true.
378		411
379	Condition variables can be created by calling the C<< AnyEvent->condvar	412	Condition variables can be created by calling the C<< AnyEvent->condvar
380	>> method, usually without arguments. The only argument pair allowed is	413	>> method, usually without arguments. The only argument pair allowed is
		414
381	C<cb>, which specifies a callback to be called when the condition variable	415	C<cb>, which specifies a callback to be called when the condition variable
382	becomes true.	416	becomes true, with the condition variable as the first argument (but not
		417	the results).
383		418
384	After creation, the condition variable is "false" until it becomes "true"	419	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	420	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<<	421	were a callback, read about the caveats in the description for the C<<
387	->send >> method).	422	->send >> method).
…		…
443		478
444	my $done = AnyEvent->condvar;	479	my $done = AnyEvent->condvar;
445	my $delay = AnyEvent->timer (after => 5, cb => $done);	480	my $delay = AnyEvent->timer (after => 5, cb => $done);
446	$done->recv;	481	$done->recv;
447		482
		483	Example: Imagine an API that returns a condvar and doesn't support
		484	callbacks. This is how you make a synchronous call, for example from
		485	the main program:
		486
		487	use AnyEvent::CouchDB;
		488
		489	...
		490
		491	my @info = $couchdb->info->recv;
		492
		493	And this is how you would just ste a callback to be called whenever the
		494	results are available:
		495
		496	$couchdb->info->cb (sub {
		497	my @info = $_[0]->recv;
		498	});
		499
448	=head3 METHODS FOR PRODUCERS	500	=head3 METHODS FOR PRODUCERS
449		501
450	These methods should only be used by the producing side, i.e. the	502	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	503	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	504	the producer side which creates the condvar in most cases, but it isn't
…		…
585	=item $bool = $cv->ready	637	=item $bool = $cv->ready
586		638
587	Returns true when the condition is "true", i.e. whether C<send> or	639	Returns true when the condition is "true", i.e. whether C<send> or
588	C<croak> have been called.	640	C<croak> have been called.
589		641
590	=item $cb = $cv->cb ([new callback])	642	=item $cb = $cv->cb ($cb->($cv))
591		643
592	This is a mutator function that returns the callback set and optionally	644	This is a mutator function that returns the callback set and optionally
593	replaces it before doing so.	645	replaces it before doing so.
594		646
595	The callback will be called when the condition becomes "true", i.e. when	647	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	648	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.	649	variable itself. Calling C<recv> inside the callback or at any later time
		650	is guaranteed not to block.
598		651
599	=back	652	=back
600		653
601	=head1 GLOBAL VARIABLES AND FUNCTIONS	654	=head1 GLOBAL VARIABLES AND FUNCTIONS
602		655
…		…
731	=item L<AnyEvent::Util>	784	=item L<AnyEvent::Util>
732		785
733	Contains various utility functions that replace often-used but blocking	786	Contains various utility functions that replace often-used but blocking
734	functions such as C<inet_aton> by event-/callback-based versions.	787	functions such as C<inet_aton> by event-/callback-based versions.
735		788
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>	789	=item L<AnyEvent::Socket>
741		790
742	Provides various utility functions for (internet protocol) sockets,	791	Provides various utility functions for (internet protocol) sockets,
743	addresses and name resolution. Also functions to create non-blocking tcp	792	addresses and name resolution. Also functions to create non-blocking tcp
744	connections or tcp servers, with IPv6 and SRV record support and more.	793	connections or tcp servers, with IPv6 and SRV record support and more.
745		794
		795	=item L<AnyEvent::Handle>
		796
		797	Provide read and write buffers, manages watchers for reads and writes,
		798	supports raw and formatted I/O, I/O queued and fully transparent and
		799	non-blocking SSL/TLS.
		800
746	=item L<AnyEvent::DNS>	801	=item L<AnyEvent::DNS>
747		802
748	Provides rich asynchronous DNS resolver capabilities.	803	Provides rich asynchronous DNS resolver capabilities.
749		804
		805	=item L<AnyEvent::HTTP>
		806
		807	A simple-to-use HTTP library that is capable of making a lot of concurrent
		808	HTTP requests.
		809
750	=item L<AnyEvent::HTTPD>	810	=item L<AnyEvent::HTTPD>
751		811
752	Provides a simple web application server framework.	812	Provides a simple web application server framework.
753		813
754	=item L<AnyEvent::FastPing>	814	=item L<AnyEvent::FastPing>
755		815
756	The fastest ping in the west.	816	The fastest ping in the west.
757		817
		818	=item L<AnyEvent::DBI>
		819
		820	Executes L<DBI> requests asynchronously in a proxy process.
		821
		822	=item L<AnyEvent::AIO>
		823
		824	Truly asynchronous I/O, should be in the toolbox of every event
		825	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		826	together.
		827
		828	=item L<AnyEvent::BDB>
		829
		830	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		831	L<BDB> and AnyEvent together.
		832
		833	=item L<AnyEvent::GPSD>
		834
		835	A non-blocking interface to gpsd, a daemon delivering GPS information.
		836
		837	=item L<AnyEvent::IGS>
		838
		839	A non-blocking interface to the Internet Go Server protocol (used by
		840	L<App::IGS>).
		841
758	=item L<Net::IRC3>	842	=item L<AnyEvent::IRC>
759		843
760	AnyEvent based IRC client module family.	844	AnyEvent based IRC client module family (replacing the older Net::IRC3).
761		845
762	=item L<Net::XMPP2>	846	=item L<Net::XMPP2>
763		847
764	AnyEvent based XMPP (Jabber protocol) module family.	848	AnyEvent based XMPP (Jabber protocol) module family.
765		849
…		…
774		858
775	=item L<Coro>	859	=item L<Coro>
776		860
777	Has special support for AnyEvent via L<Coro::AnyEvent>.	861	Has special support for AnyEvent via L<Coro::AnyEvent>.
778		862
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>	863	=item L<IO::Lambda>
791		864
792	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	865	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
793		866
794	=back	867	=back
…		…
796	=cut	869	=cut
797		870
798	package AnyEvent;	871	package AnyEvent;
799		872
800	no warnings;	873	no warnings;
801	use strict;	874	use strict qw(vars subs);
802		875
803	use Carp;	876	use Carp;
804		877
805	our $VERSION = '4.05';	878	our $VERSION = 4.35;
806	our $MODEL;	879	our $MODEL;
807		880
808	our $AUTOLOAD;	881	our $AUTOLOAD;
809	our @ISA;	882	our @ISA;
810		883
…		…
913	$MODEL	986	$MODEL
914	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	987	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
915	}	988	}
916	}	989	}
917		990
		991	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		992
918	unshift @ISA, $MODEL;	993	unshift @ISA, $MODEL;
919	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	994
		995	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
920		996
921	(shift @post_detect)->() while @post_detect;	997	(shift @post_detect)->() while @post_detect;
922	}	998	}
923		999
924	$MODEL	1000	$MODEL
…		…
934		1010
935	my $class = shift;	1011	my $class = shift;
936	$class->$func (@_);	1012	$class->$func (@_);
937	}	1013	}
938		1014
		1015	# utility function to dup a filehandle. this is used by many backends
		1016	# to support binding more than one watcher per filehandle (they usually
		1017	# allow only one watcher per fd, so we dup it to get a different one).
		1018	sub _dupfh($$$$) {
		1019	my ($poll, $fh, $r, $w) = @_;
		1020
		1021	# cygwin requires the fh mode to be matching, unix doesn't
		1022	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1023	: $poll eq "w" ? ($w, ">")
		1024	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1025
		1026	open my $fh2, "$mode&" . fileno $fh
		1027	or die "cannot dup() filehandle: $!";
		1028
		1029	# we assume CLOEXEC is already set by perl in all important cases
		1030
		1031	($fh2, $rw)
		1032	}
		1033
939	package AnyEvent::Base;	1034	package AnyEvent::Base;
940		1035
941	# default implementation for now and time	1036	# default implementation for now and time
942		1037
943	use Time::HiRes ();	1038	BEGIN {
		1039	if (eval "use Time::HiRes (); time (); 1") {
		1040	*_time = \&Time::HiRes::time;
		1041	# if (eval "use POSIX (); (POSIX::times())...
		1042	} else {
		1043	*_time = sub { time }; # epic fail
		1044	}
		1045	}
944		1046
945	sub time { Time::HiRes::time }	1047	sub time { _time }
946	sub now { Time::HiRes::time }	1048	sub now { _time }
947		1049
948	# default implementation for ->condvar	1050	# default implementation for ->condvar
949		1051
950	sub condvar {	1052	sub condvar {
951	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1053	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
952	}	1054	}
953		1055
954	# default implementation for ->signal	1056	# default implementation for ->signal
955		1057
956	our %SIG_CB;	1058	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1059
		1060	sub _signal_exec {
		1061	sysread $SIGPIPE_R, my $dummy, 4;
		1062
		1063	while (%SIG_EV) {
		1064	for (keys %SIG_EV) {
		1065	delete $SIG_EV{$_};
		1066	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1067	}
		1068	}
		1069	}
957		1070
958	sub signal {	1071	sub signal {
959	my (undef, %arg) = @_;	1072	my (undef, %arg) = @_;
960		1073
		1074	unless ($SIGPIPE_R) {
		1075	require Fcntl;
		1076
		1077	if (AnyEvent::WIN32) {
		1078	require AnyEvent::Util;
		1079
		1080	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1081	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1082	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1083	} else {
		1084	pipe $SIGPIPE_R, $SIGPIPE_W;
		1085	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1086	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1087	}
		1088
		1089	$SIGPIPE_R
		1090	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1091
		1092	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1093	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1094
		1095	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1096	}
		1097
961	my $signal = uc $arg{signal}	1098	my $signal = uc $arg{signal}
962	or Carp::croak "required option 'signal' is missing";	1099	or Carp::croak "required option 'signal' is missing";
963		1100
964	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1101	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
965	$SIG{$signal} \|\|= sub {	1102	$SIG{$signal} \|\|= sub {
966	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1103	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1104	undef $SIG_EV{$signal};
967	};	1105	};
968		1106
969	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1107	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
970	}	1108	}
971		1109
972	sub AnyEvent::Base::Signal::DESTROY {	1110	sub AnyEvent::Base::Signal::DESTROY {
973	my ($signal, $cb) = @{$_[0]};	1111	my ($signal, $cb) = @{$_[0]};
974		1112
975	delete $SIG_CB{$signal}{$cb};	1113	delete $SIG_CB{$signal}{$cb};
976		1114
977	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1115	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
978	}	1116	}
979		1117
980	# default implementation for ->child	1118	# default implementation for ->child
981		1119
982	our %PID_CB;	1120	our %PID_CB;
…		…
1090		1228
1091	# undocumented/compatibility with pre-3.4	1229	# undocumented/compatibility with pre-3.4
1092	*broadcast = \&send;	1230	*broadcast = \&send;
1093	*wait = \&_wait;	1231	*wait = \&_wait;
1094		1232
		1233	=head1 ERROR AND EXCEPTION HANDLING
		1234
		1235	In general, AnyEvent does not do any error handling - it relies on the
		1236	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1237	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1238	checking of all AnyEvent methods, however, which is highly useful during
		1239	development.
		1240
		1241	As for exception handling (i.e. runtime errors and exceptions thrown while
		1242	executing a callback), this is not only highly event-loop specific, but
		1243	also not in any way wrapped by this module, as this is the job of the main
		1244	program.
		1245
		1246	The pure perl event loop simply re-throws the exception (usually
		1247	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1248	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1249	so on.
		1250
		1251	=head1 ENVIRONMENT VARIABLES
		1252
		1253	The following environment variables are used by this module or its
		1254	submodules:
		1255
		1256	=over 4
		1257
		1258	=item C<PERL_ANYEVENT_VERBOSE>
		1259
		1260	By default, AnyEvent will be completely silent except in fatal
		1261	conditions. You can set this environment variable to make AnyEvent more
		1262	talkative.
		1263
		1264	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1265	conditions, such as not being able to load the event model specified by
		1266	C<PERL_ANYEVENT_MODEL>.
		1267
		1268	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1269	model it chooses.
		1270
		1271	=item C<PERL_ANYEVENT_STRICT>
		1272
		1273	AnyEvent does not do much argument checking by default, as thorough
		1274	argument checking is very costly. Setting this variable to a true value
		1275	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1276	check the arguments passed to most method calls. If it finds any problems
		1277	it will croak.
		1278
		1279	In other words, enables "strict" mode.
		1280
		1281	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1282	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1283	developing programs can be very useful, however.
		1284
		1285	=item C<PERL_ANYEVENT_MODEL>
		1286
		1287	This can be used to specify the event model to be used by AnyEvent, before
		1288	auto detection and -probing kicks in. It must be a string consisting
		1289	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1290	and the resulting module name is loaded and if the load was successful,
		1291	used as event model. If it fails to load AnyEvent will proceed with
		1292	auto detection and -probing.
		1293
		1294	This functionality might change in future versions.
		1295
		1296	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1297	could start your program like this:
		1298
		1299	PERL_ANYEVENT_MODEL=Perl perl ...
		1300
		1301	=item C<PERL_ANYEVENT_PROTOCOLS>
		1302
		1303	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1304	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1305	of auto probing).
		1306
		1307	Must be set to a comma-separated list of protocols or address families,
		1308	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1309	used, and preference will be given to protocols mentioned earlier in the
		1310	list.
		1311
		1312	This variable can effectively be used for denial-of-service attacks
		1313	against local programs (e.g. when setuid), although the impact is likely
		1314	small, as the program has to handle conenction and other failures anyways.
		1315
		1316	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1317	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1318	- only support IPv4, never try to resolve or contact IPv6
		1319	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1320	IPv6, but prefer IPv6 over IPv4.
		1321
		1322	=item C<PERL_ANYEVENT_EDNS0>
		1323
		1324	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1325	for DNS. This extension is generally useful to reduce DNS traffic, but
		1326	some (broken) firewalls drop such DNS packets, which is why it is off by
		1327	default.
		1328
		1329	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1330	EDNS0 in its DNS requests.
		1331
		1332	=item C<PERL_ANYEVENT_MAX_FORKS>
		1333
		1334	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1335	will create in parallel.
		1336
		1337	=back
		1338
1095	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1339	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1096		1340
1097	This is an advanced topic that you do not normally need to use AnyEvent in	1341	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	1342	a module. This section is only of use to event loop authors who want to
1099	provide AnyEvent compatibility.	1343	provide AnyEvent compatibility.
…		…
1132		1376
1133	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1377	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1134	condition variables: code blocking while waiting for a condition will	1378	condition variables: code blocking while waiting for a condition will
1135	C<die>. This still works with most modules/usages, and blocking calls must	1379	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.	1380	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		1381
1211	=head1 EXAMPLE PROGRAM	1382	=head1 EXAMPLE PROGRAM
1212		1383
1213	The following program uses an I/O watcher to read data from STDIN, a timer	1384	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	1385	to display a message once per second, and a condition variable to quit the
…		…
1408	watcher.	1579	watcher.
1409		1580
1410	=head3 Results	1581	=head3 Results
1411		1582
1412	name watchers bytes create invoke destroy comment	1583	name watchers bytes create invoke destroy comment
1413	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1584	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	1585	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	1586	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	1587	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	1588	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	1589	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	1590	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	1591	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	1592	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	1593	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1423		1594
1424	=head3 Discussion	1595	=head3 Discussion
1425		1596
1426	The benchmark does I<not> measure scalability of the event loop very	1597	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)	1598	well. For example, a select-based event loop (such as the pure perl one)
…		…
1629	watchers, as the management overhead dominates.	1800	watchers, as the management overhead dominates.
1630		1801
1631	=back	1802	=back
1632		1803
1633		1804
		1805	=head1 SIGNALS
		1806
		1807	AnyEvent currently installs handlers for these signals:
		1808
		1809	=over 4
		1810
		1811	=item SIGCHLD
		1812
		1813	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1814	emulation for event loops that do not support them natively. Also, some
		1815	event loops install a similar handler.
		1816
		1817	=item SIGPIPE
		1818
		1819	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1820	when AnyEvent gets loaded.
		1821
		1822	The rationale for this is that AnyEvent users usually do not really depend
		1823	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1824	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1825	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1826	some random socket.
		1827
		1828	The rationale for installing a no-op handler as opposed to ignoring it is
		1829	that this way, the handler will be restored to defaults on exec.
		1830
		1831	Feel free to install your own handler, or reset it to defaults.
		1832
		1833	=back
		1834
		1835	=cut
		1836
		1837	$SIG{PIPE} = sub { }
		1838	unless defined $SIG{PIPE};
		1839
		1840
1634	=head1 FORK	1841	=head1 FORK
1635		1842
1636	Most event libraries are not fork-safe. The ones who are usually are	1843	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>	1844	because they rely on inefficient but fork-safe C<select> or C<poll>
1638	calls. Only L<EV> is fully fork-aware.	1845	calls. Only L<EV> is fully fork-aware.
…		…
1651	specified in the variable.	1858	specified in the variable.
1652		1859
1653	You can make AnyEvent completely ignore this variable by deleting it	1860	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:	1861	before the first watcher gets created, e.g. with a C<BEGIN> block:
1655		1862
1656	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1863	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1657		1864
1658	use AnyEvent;	1865	use AnyEvent;
1659		1866
1660	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1867	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	1868	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).	1869	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1870	$ENV{PERL_ANYEGENT_STRICT}.
		1871
		1872
		1873	=head1 BUGS
		1874
		1875	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1876	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1877	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1878	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1879	pronounced).
1663		1880
1664		1881
1665	=head1 SEE ALSO	1882	=head1 SEE ALSO
1666		1883
1667	Utility functions: L<AnyEvent::Util>.	1884	Utility functions: L<AnyEvent::Util>.
…		…
1684	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1901	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1685		1902
1686		1903
1687	=head1 AUTHOR	1904	=head1 AUTHOR
1688		1905
1689	Marc Lehmann <schmorp@schmorp.de>	1906	Marc Lehmann <schmorp@schmorp.de>
1690	http://home.schmorp.de/	1907	http://home.schmorp.de/
1691		1908
1692	=cut	1909	=cut
1693		1910
1694	1	1911	1
1695		1912

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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 1.200 by root, Wed Apr 1 14:02:27 2009 UTC

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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 1.200 by root, Wed Apr 1 14:02:27 2009 UTC