[ViewVC] Diff of: cvs/cvsroot/Coro/Coro.pm

Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.145 by root, Wed Oct 3 16:03:17 2007 UTC vs.
Revision 1.274 by root, Sat Dec 12 01:30:26 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - coroutine process abstraction	3	Coro - the only real threads in perl
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use Coro;	7	use Coro;
8		8
9	async {	9	async {
10	# some asynchronous thread of execution	10	# some asynchronous thread of execution
		11	print "2\n";
		12	cede; # yield back to main
		13	print "4\n";
11	};	14	};
12		15	print "1\n";
13	# alternatively create an async coroutine like this:	16	cede; # yield to coro
14		17	print "3\n";
15	sub some_func : Coro {	18	cede; # and again
16	# some more async code	19
17	}	20	# use locking
18		21	use Coro::Semaphore;
19	cede;	22	my $lock = new Coro::Semaphore;
		23	my $locked;
		24
		25	$lock->down;
		26	$locked = 1;
		27	$lock->up;
20		28
21	=head1 DESCRIPTION	29	=head1 DESCRIPTION
22		30
23	This module collection manages coroutines. Coroutines are similar	31	For a tutorial-style introduction, please read the L<Coro::Intro>
24	to threads but don't run in parallel at the same time even on SMP	32	manpage. This manpage mainly contains reference information.
25	machines. The specific flavor of coroutine used in this module also
26	guarantees you that it will not switch between coroutines unless
27	necessary, at easily-identified points in your program, so locking and
28	parallel access are rarely an issue, making coroutine programming much
29	safer than threads programming.
30		33
31	(Perl, however, does not natively support real threads but instead does a	34	This module collection manages continuations in general, most often in
32	very slow and memory-intensive emulation of processes using threads. This	35	the form of cooperative threads (also called coros, or simply "coro"
33	is a performance win on Windows machines, and a loss everywhere else).	36	in the documentation). They are similar to kernel threads but don't (in
		37	general) run in parallel at the same time even on SMP machines. The
		38	specific flavor of thread offered by this module also guarantees you that
		39	it will not switch between threads unless necessary, at easily-identified
		40	points in your program, so locking and parallel access are rarely an
		41	issue, making thread programming much safer and easier than using other
		42	thread models.
34		43
		44	Unlike the so-called "Perl threads" (which are not actually real threads
		45	but only the windows process emulation (see section of same name for more
		46	details) ported to unix, and as such act as processes), Coro provides
		47	a full shared address space, which makes communication between threads
		48	very easy. And Coro's threads are fast, too: disabling the Windows
		49	process emulation code in your perl and using Coro can easily result in
		50	a two to four times speed increase for your programs. A parallel matrix
		51	multiplication benchmark runs over 300 times faster on a single core than
		52	perl's pseudo-threads on a quad core using all four cores.
		53
		54	Coro achieves that by supporting multiple running interpreters that share
		55	data, which is especially useful to code pseudo-parallel processes and
		56	for event-based programming, such as multiple HTTP-GET requests running
		57	concurrently. See L<Coro::AnyEvent> to learn more on how to integrate Coro
		58	into an event-based environment.
		59
35	In this module, coroutines are defined as "callchain + lexical variables +	60	In this module, a thread is defined as "callchain + lexical variables +
36	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,	61	some package variables + C stack), that is, a thread has its own callchain,
37	its own set of lexicals and its own set of perls most important global	62	its own set of lexicals and its own set of perls most important global
38	variables.	63	variables (see L<Coro::State> for more configuration and background info).
		64
		65	See also the C<SEE ALSO> section at the end of this document - the Coro
		66	module family is quite large.
39		67
40	=cut	68	=cut
41		69
42	package Coro;	70	package Coro;
43		71
44	use strict;	72	use common::sense;
45	no warnings "uninitialized";	73
		74	use Carp ();
		75
		76	use Guard ();
46		77
47	use Coro::State;	78	use Coro::State;
48		79
49	use base qw(Coro::State Exporter);	80	use base qw(Coro::State Exporter);
50		81
51	our $idle; # idle handler	82	our $idle; # idle handler
52	our $main; # main coroutine	83	our $main; # main coro
53	our $current; # current coroutine	84	our $current; # current coro
54		85
55	our $VERSION = '4.0';	86	our $VERSION = 5.21;
56		87
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	88	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub rouse_cb rouse_wait);
58	our %EXPORT_TAGS = (	89	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	90	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	91	);
61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));	92	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62		93
63	{	94	=head1 GLOBAL VARIABLES
64	my @async;
65	my $init;
66
67	# this way of handling attributes simply is NOT scalable ;()
68	sub import {
69	no strict 'refs';
70
71	Coro->export_to_level (1, @_);
72
73	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
74	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
75	my ($package, $ref) = (shift, shift);
76	my @attrs;
77	for (@_) {
78	if ($_ eq "Coro") {
79	push @async, $ref;
80	unless ($init++) {
81	eval q{
82	sub INIT {
83	&async(pop @async) while @async;
84	}
85	};
86	}
87	} else {
88	push @attrs, $_;
89	}
90	}
91	return $old ? $old->($package, $ref, @attrs) : @attrs;
92	};
93	}
94
95	}
96		95
97	=over 4	96	=over 4
98		97
99	=item $main	98	=item $Coro::main
100		99
101	This coroutine represents the main program.	100	This variable stores the Coro object that represents the main
		101	program. While you cna C<ready> it and do most other things you can do to
		102	coro, it is mainly useful to compare again C<$Coro::current>, to see
		103	whether you are running in the main program or not.
102		104
103	=cut	105	=cut
104		106
105	$main = new Coro;	107	# $main is now being initialised by Coro::State
106		108
107	=item $current (or as function: current)	109	=item $Coro::current
108		110
109	The current coroutine (the last coroutine switched to). The initial value	111	The Coro object representing the current coro (the last
		112	coro that the Coro scheduler switched to). The initial value is
110	is C<$main> (of course).	113	C<$Coro::main> (of course).
111		114
112	This variable is B<strictly> I<read-only>. It is provided for performance	115	This variable is B<strictly> I<read-only>. You can take copies of the
113	reasons. If performance is not essential you are encouraged to use the	116	value stored in it and use it as any other Coro object, but you must
114	C<Coro::current> function instead.	117	not otherwise modify the variable itself.
115		118
116	=cut	119	=cut
117		120
118	$main->{desc} = "[main::]";
119
120	# maybe some other module used Coro::Specific before...
121	$main->{_specific} = $current->{_specific}
122	if $current;
123
124	_set_current $main;
125
126	sub current() { $current }	121	sub current() { $current } # [DEPRECATED]
127		122
128	=item $idle	123	=item $Coro::idle
129		124
130	A callback that is called whenever the scheduler finds no ready coroutines	125	This variable is mainly useful to integrate Coro into event loops. It is
		126	usually better to rely on L<Coro::AnyEvent> or L<Coro::EV>, as this is
		127	pretty low-level functionality.
		128
		129	This variable stores a Coro object that is put into the ready queue when
		130	there are no other ready threads (without invoking any ready hooks).
		131
131	to run. The default implementation prints "FATAL: deadlock detected" and	132	The default implementation dies with "FATAL: deadlock detected.", followed
132	exits, because the program has no other way to continue.	133	by a thread listing, because the program has no other way to continue.
133		134
134	This hook is overwritten by modules such as C<Coro::Timer> and	135	This hook is overwritten by modules such as C<Coro::EV> and
135	C<Coro::Event> to wait on an external event that hopefully wake up a	136	C<Coro::AnyEvent> to wait on an external event that hopefully wake up a
136	coroutine so the scheduler can run it.	137	coro so the scheduler can run it.
137		138
138	Please note that if your callback recursively invokes perl (e.g. for event	139	See L<Coro::EV> or L<Coro::AnyEvent> for examples of using this technique.
139	handlers), then it must be prepared to be called recursively.
140		140
141	=cut	141	=cut
142		142
143	$idle = sub {	143	$idle = new Coro sub {
144	require Carp;	144	require Coro::Debug;
145	Carp::croak ("FATAL: deadlock detected");	145	die "FATAL: deadlock detected.\n"
		146	. Coro::Debug::ps_listing ();
146	};	147	};
147		148
148	sub _cancel {
149	my ($self) = @_;
150
151	# free coroutine data and mark as destructed
152	$self->_destroy
153	or return;
154
155	# call all destruction callbacks
156	$_->(@{$self->{_status}})
157	for @{(delete $self->{_on_destroy}) \|\| []};
158	}
159
160	# this coroutine is necessary because a coroutine	149	# this coro is necessary because a coro
161	# cannot destroy itself.	150	# cannot destroy itself.
162	my @destroy;	151	our @destroy;
163	my $manager;	152	our $manager;
164		153
165	$manager = new Coro sub {	154	$manager = new Coro sub {
166	while () {	155	while () {
167	(shift @destroy)->_cancel	156	Coro::State::cancel shift @destroy
168	while @destroy;	157	while @destroy;
169		158
170	&schedule;	159	&schedule;
171	}	160	}
172	};	161	};
173	$manager->desc ("[coro manager]");	162	$manager->{desc} = "[coro manager]";
174	$manager->prio (PRIO_MAX);	163	$manager->prio (PRIO_MAX);
175		164
176	# static methods. not really.
177
178	=back	165	=back
179		166
180	=head2 STATIC METHODS	167	=head1 SIMPLE CORO CREATION
181
182	Static methods are actually functions that operate on the current coroutine only.
183		168
184	=over 4	169	=over 4
185		170
186	=item async { ... } [@args...]	171	=item async { ... } [@args...]
187		172
188	Create a new asynchronous coroutine and return it's coroutine object	173	Create a new coro and return its Coro object (usually
189	(usually unused). When the sub returns the new coroutine is automatically	174	unused). The coro will be put into the ready queue, so
		175	it will start running automatically on the next scheduler run.
		176
		177	The first argument is a codeblock/closure that should be executed in the
		178	coro. When it returns argument returns the coro is automatically
190	terminated.	179	terminated.
191		180
		181	The remaining arguments are passed as arguments to the closure.
		182
192	See the C<Coro::State::new> constructor for info about the coroutine	183	See the C<Coro::State::new> constructor for info about the coro
193	environment.	184	environment in which coro are executed.
194		185
195	Calling C<exit> in a coroutine will do the same as calling exit outside	186	Calling C<exit> in a coro will do the same as calling exit outside
196	the coroutine. Likewise, when the coroutine dies, the program will exit,	187	the coro. Likewise, when the coro dies, the program will exit,
197	just as it would in the main program.	188	just as it would in the main program.
198		189
		190	If you do not want that, you can provide a default C<die> handler, or
		191	simply avoid dieing (by use of C<eval>).
		192
199	# create a new coroutine that just prints its arguments	193	Example: Create a new coro that just prints its arguments.
		194
200	async {	195	async {
201	print "@_\n";	196	print "@_\n";
202	} 1,2,3,4;	197	} 1,2,3,4;
203		198
204	=cut
205
206	sub async(&@) {
207	my $coro = new Coro @_;
208	$coro->ready;
209	$coro
210	}
211
212	=item async_pool { ... } [@args...]	199	=item async_pool { ... } [@args...]
213		200
214	Similar to C<async>, but uses a coroutine pool, so you should not call	201	Similar to C<async>, but uses a coro pool, so you should not call
215	terminate or join (although you are allowed to), and you get a coroutine	202	terminate or join on it (although you are allowed to), and you get a
216	that might have executed other code already (which can be good or bad :).	203	coro that might have executed other code already (which can be good
		204	or bad :).
217		205
		206	On the plus side, this function is about twice as fast as creating (and
		207	destroying) a completely new coro, so if you need a lot of generic
		208	coros in quick successsion, use C<async_pool>, not C<async>.
		209
218	Also, the block is executed in an C<eval> context and a warning will be	210	The code block is executed in an C<eval> context and a warning will be
219	issued in case of an exception instead of terminating the program, as	211	issued in case of an exception instead of terminating the program, as
220	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>	212	C<async> does. As the coro is being reused, stuff like C<on_destroy>
221	will not work in the expected way, unless you call terminate or cancel,	213	will not work in the expected way, unless you call terminate or cancel,
222	which somehow defeats the purpose of pooling.	214	which somehow defeats the purpose of pooling (but is fine in the
		215	exceptional case).
223		216
224	The priority will be reset to C<0> after each job, otherwise the coroutine	217	The priority will be reset to C<0> after each run, tracing will be
225	will be re-used "as-is".	218	disabled, the description will be reset and the default output filehandle
		219	gets restored, so you can change all these. Otherwise the coro will
		220	be re-used "as-is": most notably if you change other per-coro global
		221	stuff such as C<$/> you I<must needs> revert that change, which is most
		222	simply done by using local as in: C<< local $/ >>.
226		223
227	The pool size is limited to 8 idle coroutines (this can be adjusted by	224	The idle pool size is limited to C<8> idle coros (this can be
228	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as	225	adjusted by changing $Coro::POOL_SIZE), but there can be as many non-idle
229	required.	226	coros as required.
230		227
231	If you are concerned about pooled coroutines growing a lot because a	228	If you are concerned about pooled coros growing a lot because a
232	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool	229	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
233	{ terminate }> once per second or so to slowly replenish the pool. In	230	{ terminate }> once per second or so to slowly replenish the pool. In
234	addition to that, when the stacks used by a handler grows larger than 16kb	231	addition to that, when the stacks used by a handler grows larger than 32kb
235	(adjustable with $Coro::POOL_RSS) it will also exit.	232	(adjustable via $Coro::POOL_RSS) it will also be destroyed.
236		233
237	=cut	234	=cut
238		235
239	our $POOL_SIZE = 8;	236	our $POOL_SIZE = 8;
240	our $POOL_RSS = 16 * 1024;	237	our $POOL_RSS = 32 * 1024;
241	our @async_pool;	238	our @async_pool;
242		239
243	sub pool_handler {	240	sub pool_handler {
244	my $cb;
245
246	while () {	241	while () {
247	eval {	242	eval {
248	while () {	243	&{&_pool_handler} while 1;
249	_pool_1 $cb;
250	&$cb;
251	_pool_2 $cb;
252	&schedule;
253	}
254	};	244	};
255		245
256	last if $@ eq "\3terminate\2\n";
257	warn $@ if $@;	246	warn $@ if $@;
258	}	247	}
259	}	248	}
260		249
261	sub async_pool(&@) {	250	=back
262	# this is also inlined into the unlock_scheduler
263	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
264		251
265	$coro->{_invoke} = [@_];	252	=head1 STATIC METHODS
266	$coro->ready;
267		253
268	$coro	254	Static methods are actually functions that implicitly operate on the
269	}	255	current coro.
		256
		257	=over 4
270		258
271	=item schedule	259	=item schedule
272		260
273	Calls the scheduler. Please note that the current coroutine will not be put	261	Calls the scheduler. The scheduler will find the next coro that is
		262	to be run from the ready queue and switches to it. The next coro
		263	to be run is simply the one with the highest priority that is longest
		264	in its ready queue. If there is no coro ready, it will call the
		265	C<$Coro::idle> hook.
		266
		267	Please note that the current coro will I<not> be put into the ready
274	into the ready queue, so calling this function usually means you will	268	queue, so calling this function usually means you will never be called
275	never be called again unless something else (e.g. an event handler) calls	269	again unless something else (e.g. an event handler) calls C<< ->ready >>,
276	ready.	270	thus waking you up.
277		271
278	The canonical way to wait on external events is this:	272	This makes C<schedule> I<the> generic method to use to block the current
		273	coro and wait for events: first you remember the current coro in
		274	a variable, then arrange for some callback of yours to call C<< ->ready
		275	>> on that once some event happens, and last you call C<schedule> to put
		276	yourself to sleep. Note that a lot of things can wake your coro up,
		277	so you need to check whether the event indeed happened, e.g. by storing the
		278	status in a variable.
279		279
280	{	280	See B<HOW TO WAIT FOR A CALLBACK>, below, for some ways to wait for callbacks.
281	# remember current coroutine
282	my $current = $Coro::current;
283		281
284	# register a hypothetical event handler	282	=item cede
285	on_event_invoke sub {	283
286	# wake up sleeping coroutine	284	"Cede" to other coros. This function puts the current coro into
287	$current->ready;	285	the ready queue and calls C<schedule>, which has the effect of giving
288	undef $current;	286	up the current "timeslice" to other coros of the same or higher
		287	priority. Once your coro gets its turn again it will automatically be
		288	resumed.
		289
		290	This function is often called C<yield> in other languages.
		291
		292	=item Coro::cede_notself
		293
		294	Works like cede, but is not exported by default and will cede to I<any>
		295	coro, regardless of priority. This is useful sometimes to ensure
		296	progress is made.
		297
		298	=item terminate [arg...]
		299
		300	Terminates the current coro with the given status values (see L<cancel>).
		301
		302	=item Coro::on_enter BLOCK, Coro::on_leave BLOCK
		303
		304	These function install enter and leave winders in the current scope. The
		305	enter block will be executed when on_enter is called and whenever the
		306	current coro is re-entered by the scheduler, while the leave block is
		307	executed whenever the current coro is blocked by the scheduler, and
		308	also when the containing scope is exited (by whatever means, be it exit,
		309	die, last etc.).
		310
		311	I<Neither invoking the scheduler, nor exceptions, are allowed within those
		312	BLOCKs>. That means: do not even think about calling C<die> without an
		313	eval, and do not even think of entering the scheduler in any way.
		314
		315	Since both BLOCKs are tied to the current scope, they will automatically
		316	be removed when the current scope exits.
		317
		318	These functions implement the same concept as C<dynamic-wind> in scheme
		319	does, and are useful when you want to localise some resource to a specific
		320	coro.
		321
		322	They slow down thread switching considerably for coros that use them
		323	(about 40% for a BLOCK with a single assignment, so thread switching is
		324	still reasonably fast if the handlers are fast).
		325
		326	These functions are best understood by an example: The following function
		327	will change the current timezone to "Antarctica/South_Pole", which
		328	requires a call to C<tzset>, but by using C<on_enter> and C<on_leave>,
		329	which remember/change the current timezone and restore the previous
		330	value, respectively, the timezone is only changed for the coro that
		331	installed those handlers.
		332
		333	use POSIX qw(tzset);
		334
		335	async {
		336	my $old_tz; # store outside TZ value here
		337
		338	Coro::on_enter {
		339	$old_tz = $ENV{TZ}; # remember the old value
		340
		341	$ENV{TZ} = "Antarctica/South_Pole";
		342	tzset; # enable new value
289	};	343	};
290		344
291	# call schedule until event occurred.	345	Coro::on_leave {
292	# in case we are woken up for other reasons	346	$ENV{TZ} = $old_tz;
293	# (current still defined), loop.	347	tzset; # restore old value
294	Coro::schedule while $current;	348	};
		349
		350	# at this place, the timezone is Antarctica/South_Pole,
		351	# without disturbing the TZ of any other coro.
295	}	352	};
296		353
297	=item cede	354	This can be used to localise about any resource (locale, uid, current
		355	working directory etc.) to a block, despite the existance of other
		356	coros.
298		357
299	"Cede" to other coroutines. This function puts the current coroutine into the	358	Another interesting example implements time-sliced multitasking using
300	ready queue and calls C<schedule>, which has the effect of giving up the	359	interval timers (this could obviously be optimised, but does the job):
301	current "timeslice" to other coroutines of the same or higher priority.
302		360
303	Returns true if at least one coroutine switch has happened.	361	# "timeslice" the given block
		362	sub timeslice(&) {
		363	use Time::HiRes ();
304		364
305	=item Coro::cede_notself	365	Coro::on_enter {
		366	# on entering the thread, we set an VTALRM handler to cede
		367	$SIG{VTALRM} = sub { cede };
		368	# and then start the interval timer
		369	Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01;
		370	};
		371	Coro::on_leave {
		372	# on leaving the thread, we stop the interval timer again
		373	Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0;
		374	};
306		375
307	Works like cede, but is not exported by default and will cede to any	376	&{+shift};
308	coroutine, regardless of priority, once.	377	}
309		378
310	Returns true if at least one coroutine switch has happened.	379	# use like this:
		380	timeslice {
		381	# The following is an endless loop that would normally
		382	# monopolise the process. Since it runs in a timesliced
		383	# environment, it will regularly cede to other threads.
		384	while () { }
		385	};
311		386
312	=item terminate [arg...]
313
314	Terminates the current coroutine with the given status values (see L<cancel>).
315		387
316	=item killall	388	=item killall
317		389
318	Kills/terminates/cancels all coroutines except the currently running	390	Kills/terminates/cancels all coros except the currently running one.
319	one. This is useful after a fork, either in the child or the parent, as
320	usually only one of them should inherit the running coroutines.
321		391
322	=cut	392	Note that while this will try to free some of the main interpreter
		393	resources if the calling coro isn't the main coro, but one
		394	cannot free all of them, so if a coro that is not the main coro
		395	calls this function, there will be some one-time resource leak.
323		396
324	sub terminate {	397	=cut
325	$current->cancel (@_);
326	}
327		398
328	sub killall {	399	sub killall {
329	for (Coro::State::list) {	400	for (Coro::State::list) {
330	$_->cancel	401	$_->cancel
331	if $_ != $current && UNIVERSAL::isa $_, "Coro";	402	if $_ != $current && UNIVERSAL::isa $_, "Coro";
332	}	403	}
333	}	404	}
334		405
335	=back	406	=back
336		407
337	# dynamic methods
338
339	=head2 COROUTINE METHODS	408	=head1 CORO OBJECT METHODS
340		409
341	These are the methods you can call on coroutine objects.	410	These are the methods you can call on coro objects (or to create
		411	them).
342		412
343	=over 4	413	=over 4
344		414
345	=item new Coro \&sub [, @args...]	415	=item new Coro \&sub [, @args...]
346		416
347	Create a new coroutine and return it. When the sub returns the coroutine	417	Create a new coro and return it. When the sub returns, the coro
348	automatically terminates as if C<terminate> with the returned values were	418	automatically terminates as if C<terminate> with the returned values were
349	called. To make the coroutine run you must first put it into the ready queue	419	called. To make the coro run you must first put it into the ready
350	by calling the ready method.	420	queue by calling the ready method.
351		421
352	See C<async> and C<Coro::State::new> for additional info about the	422	See C<async> and C<Coro::State::new> for additional info about the
353	coroutine environment.	423	coro environment.
354		424
355	=cut	425	=cut
356		426
357	sub _run_coro {	427	sub _coro_run {
358	terminate &{+shift};	428	terminate &{+shift};
359	}	429	}
360		430
361	sub new {
362	my $class = shift;
363
364	$class->SUPER::new (\&_run_coro, @_)
365	}
366
367	=item $success = $coroutine->ready	431	=item $success = $coro->ready
368		432
369	Put the given coroutine into the ready queue (according to it's priority)	433	Put the given coro into the end of its ready queue (there is one
370	and return true. If the coroutine is already in the ready queue, do nothing	434	queue for each priority) and return true. If the coro is already in
371	and return false.	435	the ready queue, do nothing and return false.
372		436
		437	This ensures that the scheduler will resume this coro automatically
		438	once all the coro of higher priority and all coro of the same
		439	priority that were put into the ready queue earlier have been resumed.
		440
		441	=item $coro->suspend
		442
		443	Suspends the specified coro. A suspended coro works just like any other
		444	coro, except that the scheduler will not select a suspended coro for
		445	execution.
		446
		447	Suspending a coro can be useful when you want to keep the coro from
		448	running, but you don't want to destroy it, or when you want to temporarily
		449	freeze a coro (e.g. for debugging) to resume it later.
		450
		451	A scenario for the former would be to suspend all (other) coros after a
		452	fork and keep them alive, so their destructors aren't called, but new
		453	coros can be created.
		454
		455	=item $coro->resume
		456
		457	If the specified coro was suspended, it will be resumed. Note that when
		458	the coro was in the ready queue when it was suspended, it might have been
		459	unreadied by the scheduler, so an activation might have been lost.
		460
		461	To avoid this, it is best to put a suspended coro into the ready queue
		462	unconditionally, as every synchronisation mechanism must protect itself
		463	against spurious wakeups, and the one in the Coro family certainly do
		464	that.
		465
373	=item $is_ready = $coroutine->is_ready	466	=item $is_ready = $coro->is_ready
374		467
375	Return wether the coroutine is currently the ready queue or not,	468	Returns true iff the Coro object is in the ready queue. Unless the Coro
		469	object gets destroyed, it will eventually be scheduled by the scheduler.
376		470
		471	=item $is_running = $coro->is_running
		472
		473	Returns true iff the Coro object is currently running. Only one Coro object
		474	can ever be in the running state (but it currently is possible to have
		475	multiple running Coro::States).
		476
		477	=item $is_suspended = $coro->is_suspended
		478
		479	Returns true iff this Coro object has been suspended. Suspended Coros will
		480	not ever be scheduled.
		481
377	=item $coroutine->cancel (arg...)	482	=item $coro->cancel (arg...)
378		483
379	Terminates the given coroutine and makes it return the given arguments as	484	Terminates the given Coro and makes it return the given arguments as
380	status (default: the empty list). Never returns if the coroutine is the	485	status (default: the empty list). Never returns if the Coro is the
381	current coroutine.	486	current Coro.
382		487
383	=cut	488	=cut
384		489
385	sub cancel {	490	sub cancel {
386	my $self = shift;	491	my $self = shift;
387	$self->{_status} = [@_];
388		492
389	if ($current == $self) {	493	if ($current == $self) {
390	push @destroy, $self;	494	terminate @_;
391	$manager->ready;
392	&schedule while 1;
393	} else {	495	} else {
394	$self->_cancel;	496	$self->{_status} = [@_];
		497	Coro::State::cancel $self;
395	}	498	}
396	}	499	}
397		500
		501	=item $coro->schedule_to
		502
		503	Puts the current coro to sleep (like C<Coro::schedule>), but instead
		504	of continuing with the next coro from the ready queue, always switch to
		505	the given coro object (regardless of priority etc.). The readyness
		506	state of that coro isn't changed.
		507
		508	This is an advanced method for special cases - I'd love to hear about any
		509	uses for this one.
		510
		511	=item $coro->cede_to
		512
		513	Like C<schedule_to>, but puts the current coro into the ready
		514	queue. This has the effect of temporarily switching to the given
		515	coro, and continuing some time later.
		516
		517	This is an advanced method for special cases - I'd love to hear about any
		518	uses for this one.
		519
		520	=item $coro->throw ([$scalar])
		521
		522	If C<$throw> is specified and defined, it will be thrown as an exception
		523	inside the coro at the next convenient point in time. Otherwise
		524	clears the exception object.
		525
		526	Coro will check for the exception each time a schedule-like-function
		527	returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down
		528	>>, C<< Coro::Handle->readable >> and so on. Most of these functions
		529	detect this case and return early in case an exception is pending.
		530
		531	The exception object will be thrown "as is" with the specified scalar in
		532	C<$@>, i.e. if it is a string, no line number or newline will be appended
		533	(unlike with C<die>).
		534
		535	This can be used as a softer means than C<cancel> to ask a coro to
		536	end itself, although there is no guarantee that the exception will lead to
		537	termination, and if the exception isn't caught it might well end the whole
		538	program.
		539
		540	You might also think of C<throw> as being the moral equivalent of
		541	C<kill>ing a coro with a signal (in this case, a scalar).
		542
398	=item $coroutine->join	543	=item $coro->join
399		544
400	Wait until the coroutine terminates and return any values given to the	545	Wait until the coro terminates and return any values given to the
401	C<terminate> or C<cancel> functions. C<join> can be called concurrently	546	C<terminate> or C<cancel> functions. C<join> can be called concurrently
402	from multiple coroutines.	547	from multiple coro, and all will be resumed and given the status
		548	return once the C<$coro> terminates.
403		549
404	=cut	550	=cut
405		551
406	sub join {	552	sub join {
407	my $self = shift;	553	my $self = shift;
418	}	564	}
419		565
420	wantarray ? @{$self->{_status}} : $self->{_status}[0];	566	wantarray ? @{$self->{_status}} : $self->{_status}[0];
421	}	567	}
422		568
423	=item $coroutine->on_destroy (\&cb)	569	=item $coro->on_destroy (\&cb)
424		570
425	Registers a callback that is called when this coroutine gets destroyed,	571	Registers a callback that is called when this coro gets destroyed,
426	but before it is joined. The callback gets passed the terminate arguments,	572	but before it is joined. The callback gets passed the terminate arguments,
427	if any.	573	if any, and I<must not> die, under any circumstances.
428		574
429	=cut	575	=cut
430		576
431	sub on_destroy {	577	sub on_destroy {
432	my ($self, $cb) = @_;	578	my ($self, $cb) = @_;
433		579
434	push @{ $self->{_on_destroy} }, $cb;	580	push @{ $self->{_on_destroy} }, $cb;
435	}	581	}
436		582
437	=item $oldprio = $coroutine->prio ($newprio)	583	=item $oldprio = $coro->prio ($newprio)
438		584
439	Sets (or gets, if the argument is missing) the priority of the	585	Sets (or gets, if the argument is missing) the priority of the
440	coroutine. Higher priority coroutines get run before lower priority	586	coro. Higher priority coro get run before lower priority
441	coroutines. Priorities are small signed integers (currently -4 .. +3),	587	coro. Priorities are small signed integers (currently -4 .. +3),
442	that you can refer to using PRIO_xxx constants (use the import tag :prio	588	that you can refer to using PRIO_xxx constants (use the import tag :prio
443	to get then):	589	to get then):
444		590
445	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	591	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
446	3 > 1 > 0 > -1 > -3 > -4	592	3 > 1 > 0 > -1 > -3 > -4
447		593
448	# set priority to HIGH	594	# set priority to HIGH
449	current->prio(PRIO_HIGH);	595	current->prio (PRIO_HIGH);
450		596
451	The idle coroutine ($Coro::idle) always has a lower priority than any	597	The idle coro ($Coro::idle) always has a lower priority than any
452	existing coroutine.	598	existing coro.
453		599
454	Changing the priority of the current coroutine will take effect immediately,	600	Changing the priority of the current coro will take effect immediately,
455	but changing the priority of coroutines in the ready queue (but not	601	but changing the priority of coro in the ready queue (but not
456	running) will only take effect after the next schedule (of that	602	running) will only take effect after the next schedule (of that
457	coroutine). This is a bug that will be fixed in some future version.	603	coro). This is a bug that will be fixed in some future version.
458		604
459	=item $newprio = $coroutine->nice ($change)	605	=item $newprio = $coro->nice ($change)
460		606
461	Similar to C<prio>, but subtract the given value from the priority (i.e.	607	Similar to C<prio>, but subtract the given value from the priority (i.e.
462	higher values mean lower priority, just as in unix).	608	higher values mean lower priority, just as in unix).
463		609
464	=item $olddesc = $coroutine->desc ($newdesc)	610	=item $olddesc = $coro->desc ($newdesc)
465		611
466	Sets (or gets in case the argument is missing) the description for this	612	Sets (or gets in case the argument is missing) the description for this
467	coroutine. This is just a free-form string you can associate with a coroutine.	613	coro. This is just a free-form string you can associate with a
		614	coro.
468		615
469	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You	616	This method simply sets the C<< $coro->{desc} >> member to the given
470	can modify this member directly if you wish.	617	string. You can modify this member directly if you wish.
471		618
472	=cut	619	=cut
473		620
474	sub desc {	621	sub desc {
475	my $old = $_[0]{desc};	622	my $old = $_[0]{desc};
476	$_[0]{desc} = $_[1] if @_ > 1;	623	$_[0]{desc} = $_[1] if @_ > 1;
477	$old;	624	$old;
478	}	625	}
479		626
		627	sub transfer {
		628	require Carp;
		629	Carp::croak ("You must not call ->transfer on Coro objects. Use Coro::State objects or the ->schedule_to method. Caught");
		630	}
		631
480	=back	632	=back
481		633
482	=head2 GLOBAL FUNCTIONS	634	=head1 GLOBAL FUNCTIONS
483		635
484	=over 4	636	=over 4
485		637
486	=item Coro::nready	638	=item Coro::nready
487		639
488	Returns the number of coroutines that are currently in the ready state,	640	Returns the number of coro that are currently in the ready state,
489	i.e. that can be switched to. The value C<0> means that the only runnable	641	i.e. that can be switched to by calling C<schedule> directory or
		642	indirectly. The value C<0> means that the only runnable coro is the
490	coroutine is the currently running one, so C<cede> would have no effect,	643	currently running one, so C<cede> would have no effect, and C<schedule>
491	and C<schedule> would cause a deadlock unless there is an idle handler	644	would cause a deadlock unless there is an idle handler that wakes up some
492	that wakes up some coroutines.	645	coro.
493		646
494	=item my $guard = Coro::guard { ... }	647	=item my $guard = Coro::guard { ... }
495		648
496	This creates and returns a guard object. Nothing happens until the object	649	This function still exists, but is deprecated. Please use the
497	gets destroyed, in which case the codeblock given as argument will be	650	C<Guard::guard> function instead.
498	executed. This is useful to free locks or other resources in case of a
499	runtime error or when the coroutine gets canceled, as in both cases the
500	guard block will be executed. The guard object supports only one method,
501	C<< ->cancel >>, which will keep the codeblock from being executed.
502		651
503	Example: set some flag and clear it again when the coroutine gets canceled
504	or the function returns:
505
506	sub do_something {
507	my $guard = Coro::guard { $busy = 0 };
508	$busy = 1;
509
510	# do something that requires $busy to be true
511	}
512
513	=cut	652	=cut
514		653
515	sub guard(&) {	654	BEGIN { *guard = \&Guard::guard }
516	bless \(my $cb = $_[0]), "Coro::guard"
517	}
518
519	sub Coro::guard::cancel {
520	${$_[0]} = sub { };
521	}
522
523	sub Coro::guard::DESTROY {
524	${$_[0]}->();
525	}
526
527		655
528	=item unblock_sub { ... }	656	=item unblock_sub { ... }
529		657
530	This utility function takes a BLOCK or code reference and "unblocks" it,	658	This utility function takes a BLOCK or code reference and "unblocks" it,
531	returning the new coderef. This means that the new coderef will return	659	returning a new coderef. Unblocking means that calling the new coderef
532	immediately without blocking, returning nothing, while the original code	660	will return immediately without blocking, returning nothing, while the
533	ref will be called (with parameters) from within its own coroutine.	661	original code ref will be called (with parameters) from within another
		662	coro.
534		663
535	The reason this function exists is that many event libraries (such as the	664	The reason this function exists is that many event libraries (such as the
536	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	665	venerable L<Event\|Event> module) are not thread-safe (a weaker form
537	of thread-safety). This means you must not block within event callbacks,	666	of reentrancy). This means you must not block within event callbacks,
538	otherwise you might suffer from crashes or worse.	667	otherwise you might suffer from crashes or worse. The only event library
		668	currently known that is safe to use without C<unblock_sub> is L<EV>.
		669
		670	Coro will try to catch you when you block in the event loop
		671	("FATAL:$Coro::IDLE blocked itself"), but this is just best effort and
		672	only works when you do not run your own event loop.
539		673
540	This function allows your callbacks to block by executing them in another	674	This function allows your callbacks to block by executing them in another
541	coroutine where it is safe to block. One example where blocking is handy	675	coro where it is safe to block. One example where blocking is handy
542	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to	676	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
543	disk.	677	disk, for example.
544		678
545	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when	679	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
546	creating event callbacks that want to block.	680	creating event callbacks that want to block.
		681
		682	If your handler does not plan to block (e.g. simply sends a message to
		683	another coro, or puts some other coro into the ready queue), there is
		684	no reason to use C<unblock_sub>.
		685
		686	Note that you also need to use C<unblock_sub> for any other callbacks that
		687	are indirectly executed by any C-based event loop. For example, when you
		688	use a module that uses L<AnyEvent> (and you use L<Coro::AnyEvent>) and it
		689	provides callbacks that are the result of some event callback, then you
		690	must not block either, or use C<unblock_sub>.
547		691
548	=cut	692	=cut
549		693
550	our @unblock_queue;	694	our @unblock_queue;
551		695
…		…
554	# return immediately and can be reused) and because we cannot cede	698	# return immediately and can be reused) and because we cannot cede
555	# inside an event callback.	699	# inside an event callback.
556	our $unblock_scheduler = new Coro sub {	700	our $unblock_scheduler = new Coro sub {
557	while () {	701	while () {
558	while (my $cb = pop @unblock_queue) {	702	while (my $cb = pop @unblock_queue) {
559	# this is an inlined copy of async_pool	703	&async_pool (@$cb);
560	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
561		704
562	$coro->{_invoke} = $cb;
563	$coro->ready;
564	cede; # for short-lived callbacks, this reduces pressure on the coro pool	705	# for short-lived callbacks, this reduces pressure on the coro pool
		706	# as the chance is very high that the async_poll coro will be back
		707	# in the idle state when cede returns
		708	cede;
565	}	709	}
566	schedule; # sleep well	710	schedule; # sleep well
567	}	711	}
568	};	712	};
569	$unblock_scheduler->desc ("[unblock_sub scheduler]");	713	$unblock_scheduler->{desc} = "[unblock_sub scheduler]";
570		714
571	sub unblock_sub(&) {	715	sub unblock_sub(&) {
572	my $cb = shift;	716	my $cb = shift;
573		717
574	sub {	718	sub {
575	unshift @unblock_queue, [$cb, @_];	719	unshift @unblock_queue, [$cb, @_];
576	$unblock_scheduler->ready;	720	$unblock_scheduler->ready;
577	}	721	}
578	}	722	}
579		723
		724	=item $cb = rouse_cb
		725
		726	Create and return a "rouse callback". That's a code reference that,
		727	when called, will remember a copy of its arguments and notify the owner
		728	coro of the callback.
		729
		730	See the next function.
		731
		732	=item @args = rouse_wait [$cb]
		733
		734	Wait for the specified rouse callback (or the last one that was created in
		735	this coro).
		736
		737	As soon as the callback is invoked (or when the callback was invoked
		738	before C<rouse_wait>), it will return the arguments originally passed to
		739	the rouse callback. In scalar context, that means you get the I<last>
		740	argument, just as if C<rouse_wait> had a C<return ($a1, $a2, $a3...)>
		741	statement at the end.
		742
		743	See the section B<HOW TO WAIT FOR A CALLBACK> for an actual usage example.
		744
580	=back	745	=back
581		746
582	=cut	747	=cut
583		748
584	1;	749	1;
585		750
		751	=head1 HOW TO WAIT FOR A CALLBACK
		752
		753	It is very common for a coro to wait for some callback to be
		754	called. This occurs naturally when you use coro in an otherwise
		755	event-based program, or when you use event-based libraries.
		756
		757	These typically register a callback for some event, and call that callback
		758	when the event occured. In a coro, however, you typically want to
		759	just wait for the event, simplyifying things.
		760
		761	For example C<< AnyEvent->child >> registers a callback to be called when
		762	a specific child has exited:
		763
		764	my $child_watcher = AnyEvent->child (pid => $pid, cb => sub { ... });
		765
		766	But from within a coro, you often just want to write this:
		767
		768	my $status = wait_for_child $pid;
		769
		770	Coro offers two functions specifically designed to make this easy,
		771	C<Coro::rouse_cb> and C<Coro::rouse_wait>.
		772
		773	The first function, C<rouse_cb>, generates and returns a callback that,
		774	when invoked, will save its arguments and notify the coro that
		775	created the callback.
		776
		777	The second function, C<rouse_wait>, waits for the callback to be called
		778	(by calling C<schedule> to go to sleep) and returns the arguments
		779	originally passed to the callback.
		780
		781	Using these functions, it becomes easy to write the C<wait_for_child>
		782	function mentioned above:
		783
		784	sub wait_for_child($) {
		785	my ($pid) = @_;
		786
		787	my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb);
		788
		789	my ($rpid, $rstatus) = Coro::rouse_wait;
		790	$rstatus
		791	}
		792
		793	In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough,
		794	you can roll your own, using C<schedule>:
		795
		796	sub wait_for_child($) {
		797	my ($pid) = @_;
		798
		799	# store the current coro in $current,
		800	# and provide result variables for the closure passed to ->child
		801	my $current = $Coro::current;
		802	my ($done, $rstatus);
		803
		804	# pass a closure to ->child
		805	my $watcher = AnyEvent->child (pid => $pid, cb => sub {
		806	$rstatus = $_[1]; # remember rstatus
		807	$done = 1; # mark $rstatus as valud
		808	});
		809
		810	# wait until the closure has been called
		811	schedule while !$done;
		812
		813	$rstatus
		814	}
		815
		816
586	=head1 BUGS/LIMITATIONS	817	=head1 BUGS/LIMITATIONS
587		818
588	- you must make very sure that no coro is still active on global	819	=over 4
589	destruction. very bad things might happen otherwise (usually segfaults).
590		820
		821	=item fork with pthread backend
		822
		823	When Coro is compiled using the pthread backend (which isn't recommended
		824	but required on many BSDs as their libcs are completely broken), then
		825	coro will not survive a fork. There is no known workaround except to
		826	fix your libc and use a saner backend.
		827
		828	=item perl process emulation ("threads")
		829
591	- this module is not thread-safe. You should only ever use this module	830	This module is not perl-pseudo-thread-safe. You should only ever use this
592	from the same thread (this requirement might be loosened in the future	831	module from the first thread (this requirement might be removed in the
593	to allow per-thread schedulers, but Coro::State does not yet allow	832	future to allow per-thread schedulers, but Coro::State does not yet allow
594	this).	833	this). I recommend disabling thread support and using processes, as having
		834	the windows process emulation enabled under unix roughly halves perl
		835	performance, even when not used.
		836
		837	=item coro switching is not signal safe
		838
		839	You must not switch to another coro from within a signal handler (only
		840	relevant with %SIG - most event libraries provide safe signals), I<unless>
		841	you are sure you are not interrupting a Coro function.
		842
		843	That means you I<MUST NOT> call any function that might "block" the
		844	current coro - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or
		845	anything that calls those. Everything else, including calling C<ready>,
		846	works.
		847
		848	=back
		849
		850
		851	=head1 WINDOWS PROCESS EMULATION
		852
		853	A great many people seem to be confused about ithreads (for example, Chip
		854	Salzenberg called me unintelligent, incapable, stupid and gullible,
		855	while in the same mail making rather confused statements about perl
		856	ithreads (for example, that memory or files would be shared), showing his
		857	lack of understanding of this area - if it is hard to understand for Chip,
		858	it is probably not obvious to everybody).
		859
		860	What follows is an ultra-condensed version of my talk about threads in
		861	scripting languages given onthe perl workshop 2009:
		862
		863	The so-called "ithreads" were originally implemented for two reasons:
		864	first, to (badly) emulate unix processes on native win32 perls, and
		865	secondly, to replace the older, real thread model ("5.005-threads").
		866
		867	It does that by using threads instead of OS processes. The difference
		868	between processes and threads is that threads share memory (and other
		869	state, such as files) between threads within a single process, while
		870	processes do not share anything (at least not semantically). That
		871	means that modifications done by one thread are seen by others, while
		872	modifications by one process are not seen by other processes.
		873
		874	The "ithreads" work exactly like that: when creating a new ithreads
		875	process, all state is copied (memory is copied physically, files and code
		876	is copied logically). Afterwards, it isolates all modifications. On UNIX,
		877	the same behaviour can be achieved by using operating system processes,
		878	except that UNIX typically uses hardware built into the system to do this
		879	efficiently, while the windows process emulation emulates this hardware in
		880	software (rather efficiently, but of course it is still much slower than
		881	dedicated hardware).
		882
		883	As mentioned before, loading code, modifying code, modifying data
		884	structures and so on is only visible in the ithreads process doing the
		885	modification, not in other ithread processes within the same OS process.
		886
		887	This is why "ithreads" do not implement threads for perl at all, only
		888	processes. What makes it so bad is that on non-windows platforms, you can
		889	actually take advantage of custom hardware for this purpose (as evidenced
		890	by the forks module, which gives you the (i-) threads API, just much
		891	faster).
		892
		893	Sharing data is in the i-threads model is done by transfering data
		894	structures between threads using copying semantics, which is very slow -
		895	shared data simply does not exist. Benchmarks using i-threads which are
		896	communication-intensive show extremely bad behaviour with i-threads (in
		897	fact, so bad that Coro, which cannot take direct advantage of multiple
		898	CPUs, is often orders of magnitude faster because it shares data using
		899	real threads, refer to my talk for details).
		900
		901	As summary, i-threads use threads to implement processes, while
		902	the compatible forks module uses processes to emulate, uhm,
		903	processes. I-threads slow down every perl program when enabled, and
		904	outside of windows, serve no (or little) practical purpose, but
		905	disadvantages every single-threaded Perl program.
		906
		907	This is the reason that I try to avoid the name "ithreads", as it is
		908	misleading as it implies that it implements some kind of thread model for
		909	perl, and prefer the name "windows process emulation", which describes the
		910	actual use and behaviour of it much better.
595		911
596	=head1 SEE ALSO	912	=head1 SEE ALSO
597		913
		914	Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
		915
		916	Debugging: L<Coro::Debug>.
		917
598	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	918	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
599		919
600	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	920	Locking and IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>,
		921	L<Coro::SemaphoreSet>, L<Coro::RWLock>.
601		922
602	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	923	I/O and Timers: L<Coro::Timer>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::AIO>.
603		924
604	Embedding: L<Coro:MakeMaker>	925	Compatibility with other modules: L<Coro::LWP> (but see also L<AnyEvent::HTTP> for
		926	a better-working alternative), L<Coro::BDB>, L<Coro::Storable>,
		927	L<Coro::Select>.
		928
		929	XS API: L<Coro::MakeMaker>.
		930
		931	Low level Configuration, Thread Environment, Continuations: L<Coro::State>.
605		932
606	=head1 AUTHOR	933	=head1 AUTHOR
607		934
608	Marc Lehmann <schmorp@schmorp.de>	935	Marc Lehmann <schmorp@schmorp.de>
609	http://home.schmorp.de/	936	http://home.schmorp.de/

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Revision 1.274 by root, Sat Dec 12 01:30:26 2009 UTC