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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.148 by root, Sat May 31 00:40:16 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 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 });
22		31
23	=head1 INTRODUCTION/TUTORIAL	32	=head1 INTRODUCTION/TUTORIAL
24		33
25	This manpage is mainly a reference manual. If you are interested	34	This manpage is mainly a reference manual. If you are interested
26	in a tutorial or some gentle introduction, have a look at the	35	in a tutorial or some gentle introduction, have a look at the
33		42
34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
36		45
37	First and foremost, I<AnyEvent is not an event model> itself, it only	46	First and foremost, I<AnyEvent is not an event model> itself, it only
38	interfaces to whatever event model the main program happens to use in a	47	interfaces to whatever event model the main program happens to use, in a
39	pragmatic way. For event models and certain classes of immortals alike,	48	pragmatic way. For event models and certain classes of immortals alike,
40	the statement "there can only be one" is a bitter reality: In general,	49	the statement "there can only be one" is a bitter reality: In general,
41	only one event loop can be active at the same time in a process. AnyEvent	50	only one event loop can be active at the same time in a process. AnyEvent
42	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
43		53
44	The goal of AnyEvent is to offer module authors the ability to do event	54	The goal of AnyEvent is to offer module authors the ability to do event
45	programming (waiting for I/O or timer events) without subscribing to a	55	programming (waiting for I/O or timer events) without subscribing to a
46	religion, a way of living, and most importantly: without forcing your	56	religion, a way of living, and most importantly: without forcing your
47	module users into the same thing by forcing them to use the same event	57	module users into the same thing by forcing them to use the same event
48	model you use.	58	model you use.
49		59
50	For modules like POE or IO::Async (which is a total misnomer as it is	60	For modules like POE or IO::Async (which is a total misnomer as it is
51	actually doing all I/O I<synchronously>...), using them in your module is	61	actually doing all I/O I<synchronously>...), using them in your module is
52	like joining a cult: After you joined, you are dependent on them and you	62	like joining a cult: After you joined, you are dependent on them and you
53	cannot use anything else, as it is simply incompatible to everything that	63	cannot use anything else, as they are simply incompatible to everything
54	isn't itself. What's worse, all the potential users of your module are	64	that isn't them. What's worse, all the potential users of your
55	I<also> forced to use the same event loop you use.	65	module are I<also> forced to use the same event loop you use.
56		66
57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	68	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
59	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	69	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
60	your module uses one of those, every user of your module has to use it,	70	your module uses one of those, every user of your module has to use it,
61	too. But if your module uses AnyEvent, it works transparently with all	71	too. But if your module uses AnyEvent, it works transparently with all
62	event models it supports (including stuff like POE and IO::Async, as long	72	event models it supports (including stuff like IO::Async, as long as those
63	as those use one of the supported event loops. It is trivial to add new	73	use one of the supported event loops. It is trivial to add new event loops
64	event loops to AnyEvent, too, so it is future-proof).	74	to AnyEvent, too, so it is future-proof).
65		75
66	In addition to being free of having to use I<the one and only true event	76	In addition to being free of having to use I<the one and only true event
67	model>, AnyEvent also is free of bloat and policy: with POE or similar	77	model>, AnyEvent also is free of bloat and policy: with POE or similar
68	modules, you get an enormous amount of code and strict rules you have to	78	modules, you get an enormous amount of code and strict rules you have to
69	follow. AnyEvent, on the other hand, is lean and up to the point, by only	79	follow. AnyEvent, on the other hand, is lean and up to the point, by only
…		…
127	These watchers are normal Perl objects with normal Perl lifetime. After	137	These watchers are normal Perl objects with normal Perl lifetime. After
128	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
129	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
130	is in control).	140	is in control).
131		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
132	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
133	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
134	to it).	150	to it).
135		151
136	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.
…		…
138	Many watchers either are used with "recursion" (repeating timers for	154	Many watchers either are used with "recursion" (repeating timers for
139	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.
140		156
141	An any way to achieve that is this pattern:	157	An any way to achieve that is this pattern:
142		158
143	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	159	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
144	# you can use $w here, for example to undef it	160	# you can use $w here, for example to undef it
145	undef $w;	161	undef $w;
146	});	162	});
147		163
148	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,
149	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
150	declared.	166	declared.
151		167
152	=head2 I/O WATCHERS	168	=head2 I/O WATCHERS
153		169
154	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
155	with the following mandatory key-value pairs as arguments:	171	with the following mandatory key-value pairs as arguments:
156		172
157	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
158	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
159	which creates a watcher waiting for "r"eadable or "w"ritable events,	181	watcher waiting for "r"eadable or "w"ritable events, respectively.
		182
160	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.
161	becomes ready.
162		184
163	Although the callback might get passed parameters, their value and	185	Although the callback might get passed parameters, their value and
164	presence is undefined and you cannot rely on them. Portable AnyEvent	186	presence is undefined and you cannot rely on them. Portable AnyEvent
165	callbacks cannot use arguments passed to I/O watcher callbacks.	187	callbacks cannot use arguments passed to I/O watcher callbacks.
166		188
…		…
170		192
171	Some event loops issue spurious readyness notifications, so you should	193	Some event loops issue spurious readyness notifications, so you should
172	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
173	handles.	195	handles.
174		196
175	Example:
176
177	# 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
178	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	200	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
179	chomp (my $input = <STDIN>);	201	chomp (my $input = <STDIN>);
180	warn "read: $input\n";	202	warn "read: $input\n";
181	undef $w;	203	undef $w;
182	});	204	});
…		…
192		214
193	Although the callback might get passed parameters, their value and	215	Although the callback might get passed parameters, their value and
194	presence is undefined and you cannot rely on them. Portable AnyEvent	216	presence is undefined and you cannot rely on them. Portable AnyEvent
195	callbacks cannot use arguments passed to time watcher callbacks.	217	callbacks cannot use arguments passed to time watcher callbacks.
196		218
197	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
198	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
199	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.
200		224
201	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.
202		228
203	# fire an event after 7.7 seconds	229	Example: fire an event after 7.7 seconds.
		230
204	my $w = AnyEvent->timer (after => 7.7, cb => sub {	231	my $w = AnyEvent->timer (after => 7.7, cb => sub {
205	warn "timeout\n";	232	warn "timeout\n";
206	});	233	});
207		234
208	# to cancel the timer:	235	# to cancel the timer:
209	undef $w;	236	undef $w;
210		237
211	Example 2:
212
213	# 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.
214	my $w;
215		239
216	my $cb = sub {
217	# cancel the old timer while creating a new one
218	$w = AnyEvent->timer (after => 1, cb => $cb);	240	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		241	warn "timeout\n";
219	};	242	};
220
221	# start the "loop" by creating the first watcher
222	$w = AnyEvent->timer (after => 0.5, cb => $cb);
223		243
224	=head3 TIMING ISSUES	244	=head3 TIMING ISSUES
225		245
226	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
227	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
…		…
305	=back	325	=back
306		326
307	=head2 SIGNAL WATCHERS	327	=head2 SIGNAL WATCHERS
308		328
309	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
310	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
311	be invoked whenever a signal occurs.	331	callback to be invoked whenever a signal occurs.
312		332
313	Although the callback might get passed parameters, their value and	333	Although the callback might get passed parameters, their value and
314	presence is undefined and you cannot rely on them. Portable AnyEvent	334	presence is undefined and you cannot rely on them. Portable AnyEvent
315	callbacks cannot use arguments passed to signal watcher callbacks.	335	callbacks cannot use arguments passed to signal watcher callbacks.
316		336
…		…
332	=head2 CHILD PROCESS WATCHERS	352	=head2 CHILD PROCESS WATCHERS
333		353
334	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.
335		355
336	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
337	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
338	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
339	signal handler for C<SIGCHLD>. The callback will be called with the pid	359	any trace events (stopped/continued).
340	and exit status (as returned by waitpid), so unlike other watcher types,	360
341	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).
342		369
343	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
344	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
345	have exited already (and no SIGCHLD will be sent anymore).	372	have exited already (and no SIGCHLD will be sent anymore).
346		373
…		…
352	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
353	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	380	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
354		381
355	Example: fork a process and wait for it	382	Example: fork a process and wait for it
356		383
357	my $done = AnyEvent->condvar;	384	my $done = AnyEvent->condvar;
358		385
359	my $pid = fork or exit 5;	386	my $pid = fork or exit 5;
360		387
361	my $w = AnyEvent->child (	388	my $w = AnyEvent->child (
362	pid => $pid,	389	pid => $pid,
363	cb => sub {	390	cb => sub {
364	my ($pid, $status) = @_;	391	my ($pid, $status) = @_;
365	warn "pid $pid exited with status $status";	392	warn "pid $pid exited with status $status";
366	$done->send;	393	$done->send;
367	},	394	},
368	);	395	);
369		396
370	# do something else, then wait for process exit	397	# do something else, then wait for process exit
371	$done->recv;	398	$done->recv;
372		399
373	=head2 CONDITION VARIABLES	400	=head2 CONDITION VARIABLES
374		401
375	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
376	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
…		…
382	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
383	because they represent a condition that must become true.	410	because they represent a condition that must become true.
384		411
385	Condition variables can be created by calling the C<< AnyEvent->condvar	412	Condition variables can be created by calling the C<< AnyEvent->condvar
386	>> method, usually without arguments. The only argument pair allowed is	413	>> method, usually without arguments. The only argument pair allowed is
		414
387	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
388	becomes true.	416	becomes true, with the condition variable as the first argument (but not
		417	the results).
389		418
390	After creation, the condition variable is "false" until it becomes "true"	419	After creation, the condition variable is "false" until it becomes "true"
391	by calling the C<send> method (or calling the condition variable as if it	420	by calling the C<send> method (or calling the condition variable as if it
392	were a callback, read about the caveats in the description for the C<<	421	were a callback, read about the caveats in the description for the C<<
393	->send >> method).	422	->send >> method).
…		…
449		478
450	my $done = AnyEvent->condvar;	479	my $done = AnyEvent->condvar;
451	my $delay = AnyEvent->timer (after => 5, cb => $done);	480	my $delay = AnyEvent->timer (after => 5, cb => $done);
452	$done->recv;	481	$done->recv;
453		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
454	=head3 METHODS FOR PRODUCERS	500	=head3 METHODS FOR PRODUCERS
455		501
456	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
457	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
458	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
…		…
591	=item $bool = $cv->ready	637	=item $bool = $cv->ready
592		638
593	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
594	C<croak> have been called.	640	C<croak> have been called.
595		641
596	=item $cb = $cv->cb ([new callback])	642	=item $cb = $cv->cb ($cb->($cv))
597		643
598	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
599	replaces it before doing so.	645	replaces it before doing so.
600		646
601	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
602	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
603	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.
604		651
605	=back	652	=back
606		653
607	=head1 GLOBAL VARIABLES AND FUNCTIONS	654	=head1 GLOBAL VARIABLES AND FUNCTIONS
608		655
…		…
737	=item L<AnyEvent::Util>	784	=item L<AnyEvent::Util>
738		785
739	Contains various utility functions that replace often-used but blocking	786	Contains various utility functions that replace often-used but blocking
740	functions such as C<inet_aton> by event-/callback-based versions.	787	functions such as C<inet_aton> by event-/callback-based versions.
741		788
742	=item L<AnyEvent::Handle>
743
744	Provide read and write buffers and manages watchers for reads and writes.
745
746	=item L<AnyEvent::Socket>	789	=item L<AnyEvent::Socket>
747		790
748	Provides various utility functions for (internet protocol) sockets,	791	Provides various utility functions for (internet protocol) sockets,
749	addresses and name resolution. Also functions to create non-blocking tcp	792	addresses and name resolution. Also functions to create non-blocking tcp
750	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.
751		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
752	=item L<AnyEvent::DNS>	801	=item L<AnyEvent::DNS>
753		802
754	Provides rich asynchronous DNS resolver capabilities.	803	Provides rich asynchronous DNS resolver capabilities.
755		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
756	=item L<AnyEvent::HTTPD>	810	=item L<AnyEvent::HTTPD>
757		811
758	Provides a simple web application server framework.	812	Provides a simple web application server framework.
759		813
760	=item L<AnyEvent::FastPing>	814	=item L<AnyEvent::FastPing>
761		815
762	The fastest ping in the west.	816	The fastest ping in the west.
763		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
764	=item L<Net::IRC3>	842	=item L<AnyEvent::IRC>
765		843
766	AnyEvent based IRC client module family.	844	AnyEvent based IRC client module family (replacing the older Net::IRC3).
767		845
768	=item L<Net::XMPP2>	846	=item L<Net::XMPP2>
769		847
770	AnyEvent based XMPP (Jabber protocol) module family.	848	AnyEvent based XMPP (Jabber protocol) module family.
771		849
…		…
780		858
781	=item L<Coro>	859	=item L<Coro>
782		860
783	Has special support for AnyEvent via L<Coro::AnyEvent>.	861	Has special support for AnyEvent via L<Coro::AnyEvent>.
784		862
785	=item L<AnyEvent::AIO>, L<IO::AIO>
786
787	Truly asynchronous I/O, should be in the toolbox of every event
788	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
789	together.
790
791	=item L<AnyEvent::BDB>, L<BDB>
792
793	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
794	IO::AIO and AnyEvent together.
795
796	=item L<IO::Lambda>	863	=item L<IO::Lambda>
797		864
798	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.
799		866
800	=back	867	=back
…		…
802	=cut	869	=cut
803		870
804	package AnyEvent;	871	package AnyEvent;
805		872
806	no warnings;	873	no warnings;
807	use strict;	874	use strict qw(vars subs);
808		875
809	use Carp;	876	use Carp;
810		877
811	our $VERSION = 4.11;	878	our $VERSION = 4.35;
812	our $MODEL;	879	our $MODEL;
813		880
814	our $AUTOLOAD;	881	our $AUTOLOAD;
815	our @ISA;	882	our @ISA;
816		883
…		…
919	$MODEL	986	$MODEL
920	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	987	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
921	}	988	}
922	}	989	}
923		990
		991	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		992
924	unshift @ISA, $MODEL;	993	unshift @ISA, $MODEL;
925	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	994
		995	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
926		996
927	(shift @post_detect)->() while @post_detect;	997	(shift @post_detect)->() while @post_detect;
928	}	998	}
929		999
930	$MODEL	1000	$MODEL
…		…
940		1010
941	my $class = shift;	1011	my $class = shift;
942	$class->$func (@_);	1012	$class->$func (@_);
943	}	1013	}
944		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
945	package AnyEvent::Base;	1034	package AnyEvent::Base;
946		1035
947	# default implementation for now and time	1036	# default implementation for now and time
948		1037
949	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	}
950		1046
951	sub time { Time::HiRes::time }	1047	sub time { _time }
952	sub now { Time::HiRes::time }	1048	sub now { _time }
953		1049
954	# default implementation for ->condvar	1050	# default implementation for ->condvar
955		1051
956	sub condvar {	1052	sub condvar {
957	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1053	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
958	}	1054	}
959		1055
960	# default implementation for ->signal	1056	# default implementation for ->signal
961		1057
962	our %SIG_CB;	1058	our ($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	}
963		1070
964	sub signal {	1071	sub signal {
965	my (undef, %arg) = @_;	1072	my (undef, %arg) = @_;
966		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	# not strictly required, as $^F is normally 2, but let's make sure...
		1093	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1094	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1095
		1096	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1097	}
		1098
967	my $signal = uc $arg{signal}	1099	my $signal = uc $arg{signal}
968	or Carp::croak "required option 'signal' is missing";	1100	or Carp::croak "required option 'signal' is missing";
969		1101
970	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1102	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
971	$SIG{$signal} \|\|= sub {	1103	$SIG{$signal} \|\|= sub {
972	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1104	local $!;
		1105	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1106	undef $SIG_EV{$signal};
973	};	1107	};
974		1108
975	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1109	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
976	}	1110	}
977		1111
978	sub AnyEvent::Base::Signal::DESTROY {	1112	sub AnyEvent::Base::Signal::DESTROY {
979	my ($signal, $cb) = @{$_[0]};	1113	my ($signal, $cb) = @{$_[0]};
980		1114
981	delete $SIG_CB{$signal}{$cb};	1115	delete $SIG_CB{$signal}{$cb};
982		1116
983	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1117	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
984	}	1118	}
985		1119
986	# default implementation for ->child	1120	# default implementation for ->child
987		1121
988	our %PID_CB;	1122	our %PID_CB;
…		…
1096		1230
1097	# undocumented/compatibility with pre-3.4	1231	# undocumented/compatibility with pre-3.4
1098	*broadcast = \&send;	1232	*broadcast = \&send;
1099	*wait = \&_wait;	1233	*wait = \&_wait;
1100		1234
		1235	=head1 ERROR AND EXCEPTION HANDLING
		1236
		1237	In general, AnyEvent does not do any error handling - it relies on the
		1238	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1239	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1240	checking of all AnyEvent methods, however, which is highly useful during
		1241	development.
		1242
		1243	As for exception handling (i.e. runtime errors and exceptions thrown while
		1244	executing a callback), this is not only highly event-loop specific, but
		1245	also not in any way wrapped by this module, as this is the job of the main
		1246	program.
		1247
		1248	The pure perl event loop simply re-throws the exception (usually
		1249	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1250	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1251	so on.
		1252
		1253	=head1 ENVIRONMENT VARIABLES
		1254
		1255	The following environment variables are used by this module or its
		1256	submodules:
		1257
		1258	=over 4
		1259
		1260	=item C<PERL_ANYEVENT_VERBOSE>
		1261
		1262	By default, AnyEvent will be completely silent except in fatal
		1263	conditions. You can set this environment variable to make AnyEvent more
		1264	talkative.
		1265
		1266	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1267	conditions, such as not being able to load the event model specified by
		1268	C<PERL_ANYEVENT_MODEL>.
		1269
		1270	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1271	model it chooses.
		1272
		1273	=item C<PERL_ANYEVENT_STRICT>
		1274
		1275	AnyEvent does not do much argument checking by default, as thorough
		1276	argument checking is very costly. Setting this variable to a true value
		1277	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1278	check the arguments passed to most method calls. If it finds any problems
		1279	it will croak.
		1280
		1281	In other words, enables "strict" mode.
		1282
		1283	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1284	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1285	developing programs can be very useful, however.
		1286
		1287	=item C<PERL_ANYEVENT_MODEL>
		1288
		1289	This can be used to specify the event model to be used by AnyEvent, before
		1290	auto detection and -probing kicks in. It must be a string consisting
		1291	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1292	and the resulting module name is loaded and if the load was successful,
		1293	used as event model. If it fails to load AnyEvent will proceed with
		1294	auto detection and -probing.
		1295
		1296	This functionality might change in future versions.
		1297
		1298	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1299	could start your program like this:
		1300
		1301	PERL_ANYEVENT_MODEL=Perl perl ...
		1302
		1303	=item C<PERL_ANYEVENT_PROTOCOLS>
		1304
		1305	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1306	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1307	of auto probing).
		1308
		1309	Must be set to a comma-separated list of protocols or address families,
		1310	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1311	used, and preference will be given to protocols mentioned earlier in the
		1312	list.
		1313
		1314	This variable can effectively be used for denial-of-service attacks
		1315	against local programs (e.g. when setuid), although the impact is likely
		1316	small, as the program has to handle conenction and other failures anyways.
		1317
		1318	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1319	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1320	- only support IPv4, never try to resolve or contact IPv6
		1321	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1322	IPv6, but prefer IPv6 over IPv4.
		1323
		1324	=item C<PERL_ANYEVENT_EDNS0>
		1325
		1326	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1327	for DNS. This extension is generally useful to reduce DNS traffic, but
		1328	some (broken) firewalls drop such DNS packets, which is why it is off by
		1329	default.
		1330
		1331	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1332	EDNS0 in its DNS requests.
		1333
		1334	=item C<PERL_ANYEVENT_MAX_FORKS>
		1335
		1336	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1337	will create in parallel.
		1338
		1339	=back
		1340
1101	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1341	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1102		1342
1103	This is an advanced topic that you do not normally need to use AnyEvent in	1343	This is an advanced topic that you do not normally need to use AnyEvent in
1104	a module. This section is only of use to event loop authors who want to	1344	a module. This section is only of use to event loop authors who want to
1105	provide AnyEvent compatibility.	1345	provide AnyEvent compatibility.
…		…
1138		1378
1139	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1379	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1140	condition variables: code blocking while waiting for a condition will	1380	condition variables: code blocking while waiting for a condition will
1141	C<die>. This still works with most modules/usages, and blocking calls must	1381	C<die>. This still works with most modules/usages, and blocking calls must
1142	not be done in an interactive application, so it makes sense.	1382	not be done in an interactive application, so it makes sense.
1143
1144	=head1 ENVIRONMENT VARIABLES
1145
1146	The following environment variables are used by this module:
1147
1148	=over 4
1149
1150	=item C<PERL_ANYEVENT_VERBOSE>
1151
1152	By default, AnyEvent will be completely silent except in fatal
1153	conditions. You can set this environment variable to make AnyEvent more
1154	talkative.
1155
1156	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1157	conditions, such as not being able to load the event model specified by
1158	C<PERL_ANYEVENT_MODEL>.
1159
1160	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1161	model it chooses.
1162
1163	=item C<PERL_ANYEVENT_MODEL>
1164
1165	This can be used to specify the event model to be used by AnyEvent, before
1166	auto detection and -probing kicks in. It must be a string consisting
1167	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1168	and the resulting module name is loaded and if the load was successful,
1169	used as event model. If it fails to load AnyEvent will proceed with
1170	auto detection and -probing.
1171
1172	This functionality might change in future versions.
1173
1174	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1175	could start your program like this:
1176
1177	PERL_ANYEVENT_MODEL=Perl perl ...
1178
1179	=item C<PERL_ANYEVENT_PROTOCOLS>
1180
1181	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1182	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1183	of auto probing).
1184
1185	Must be set to a comma-separated list of protocols or address families,
1186	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1187	used, and preference will be given to protocols mentioned earlier in the
1188	list.
1189
1190	This variable can effectively be used for denial-of-service attacks
1191	against local programs (e.g. when setuid), although the impact is likely
1192	small, as the program has to handle connection errors already-
1193
1194	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1195	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1196	- only support IPv4, never try to resolve or contact IPv6
1197	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1198	IPv6, but prefer IPv6 over IPv4.
1199
1200	=item C<PERL_ANYEVENT_EDNS0>
1201
1202	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1203	for DNS. This extension is generally useful to reduce DNS traffic, but
1204	some (broken) firewalls drop such DNS packets, which is why it is off by
1205	default.
1206
1207	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1208	EDNS0 in its DNS requests.
1209
1210	=item C<PERL_ANYEVENT_MAX_FORKS>
1211
1212	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1213	will create in parallel.
1214
1215	=back
1216		1383
1217	=head1 EXAMPLE PROGRAM	1384	=head1 EXAMPLE PROGRAM
1218		1385
1219	The following program uses an I/O watcher to read data from STDIN, a timer	1386	The following program uses an I/O watcher to read data from STDIN, a timer
1220	to display a message once per second, and a condition variable to quit the	1387	to display a message once per second, and a condition variable to quit the
…		…
1414	watcher.	1581	watcher.
1415		1582
1416	=head3 Results	1583	=head3 Results
1417		1584
1418	name watchers bytes create invoke destroy comment	1585	name watchers bytes create invoke destroy comment
1419	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1586	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1420	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1587	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1421	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1588	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1422	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1589	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1423	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1590	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1424	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1591	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1425	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1592	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1426	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1593	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1427	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1594	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1428	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1595	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1429		1596
1430	=head3 Discussion	1597	=head3 Discussion
1431		1598
1432	The benchmark does I<not> measure scalability of the event loop very	1599	The benchmark does I<not> measure scalability of the event loop very
1433	well. For example, a select-based event loop (such as the pure perl one)	1600	well. For example, a select-based event loop (such as the pure perl one)
…		…
1635	watchers, as the management overhead dominates.	1802	watchers, as the management overhead dominates.
1636		1803
1637	=back	1804	=back
1638		1805
1639		1806
		1807	=head1 SIGNALS
		1808
		1809	AnyEvent currently installs handlers for these signals:
		1810
		1811	=over 4
		1812
		1813	=item SIGCHLD
		1814
		1815	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1816	emulation for event loops that do not support them natively. Also, some
		1817	event loops install a similar handler.
		1818
		1819	=item SIGPIPE
		1820
		1821	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1822	when AnyEvent gets loaded.
		1823
		1824	The rationale for this is that AnyEvent users usually do not really depend
		1825	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1826	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1827	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1828	some random socket.
		1829
		1830	The rationale for installing a no-op handler as opposed to ignoring it is
		1831	that this way, the handler will be restored to defaults on exec.
		1832
		1833	Feel free to install your own handler, or reset it to defaults.
		1834
		1835	=back
		1836
		1837	=cut
		1838
		1839	$SIG{PIPE} = sub { }
		1840	unless defined $SIG{PIPE};
		1841
		1842
1640	=head1 FORK	1843	=head1 FORK
1641		1844
1642	Most event libraries are not fork-safe. The ones who are usually are	1845	Most event libraries are not fork-safe. The ones who are usually are
1643	because they rely on inefficient but fork-safe C<select> or C<poll>	1846	because they rely on inefficient but fork-safe C<select> or C<poll>
1644	calls. Only L<EV> is fully fork-aware.	1847	calls. Only L<EV> is fully fork-aware.
…		…
1657	specified in the variable.	1860	specified in the variable.
1658		1861
1659	You can make AnyEvent completely ignore this variable by deleting it	1862	You can make AnyEvent completely ignore this variable by deleting it
1660	before the first watcher gets created, e.g. with a C<BEGIN> block:	1863	before the first watcher gets created, e.g. with a C<BEGIN> block:
1661		1864
1662	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1865	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1663		1866
1664	use AnyEvent;	1867	use AnyEvent;
1665		1868
1666	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1869	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1667	be used to probe what backend is used and gain other information (which is	1870	be used to probe what backend is used and gain other information (which is
1668	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1871	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1872	$ENV{PERL_ANYEGENT_STRICT}.
		1873
		1874
		1875	=head1 BUGS
		1876
		1877	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1878	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1879	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1880	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1881	pronounced).
1669		1882
1670		1883
1671	=head1 SEE ALSO	1884	=head1 SEE ALSO
1672		1885
1673	Utility functions: L<AnyEvent::Util>.	1886	Utility functions: L<AnyEvent::Util>.
…		…
1690	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1903	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1691		1904
1692		1905
1693	=head1 AUTHOR	1906	=head1 AUTHOR
1694		1907
1695	Marc Lehmann <schmorp@schmorp.de>	1908	Marc Lehmann <schmorp@schmorp.de>
1696	http://home.schmorp.de/	1909	http://home.schmorp.de/
1697		1910
1698	=cut	1911	=cut
1699		1912
1700	1	1913	1
1701		1914

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.148 by root, Sat May 31 00:40:16 2008 UTC vs. Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.148 by root, Sat May 31 00:40:16 2008 UTC vs.
Revision 1.202 by root, Wed Apr 1 15:29:00 2009 UTC