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

Comparing Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs.
Revision 1.179 by root, Sat Apr 19 19:06:02 2008 UTC

…		…
2		2
3	Coro - coroutine process abstraction	3	Coro - coroutine process abstraction
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 coroutine
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	my $lock = new Coro::Semaphore;
19	cede;	22	my $locked;
		23
		24	$lock->down;
		25	$locked = 1;
		26	$lock->up;
20		27
21	=head1 DESCRIPTION	28	=head1 DESCRIPTION
22		29
23	This module collection manages coroutines. Coroutines are similar	30	This module collection manages coroutines. Coroutines are similar
24	to threads but don't run in parallel at the same time even on SMP	31	to threads but don't run in parallel at the same time even on SMP
25	machines. The specific flavor of coroutine use din this module also	32	machines. The specific flavor of coroutine used in this module also
26	guarentees you that it will not switch between coroutines unless	33	guarantees you that it will not switch between coroutines unless
27	necessary, at easily-identified points in your program, so locking and	34	necessary, at easily-identified points in your program, so locking and
28	parallel access are rarely an issue, making coroutine programming much	35	parallel access are rarely an issue, making coroutine programming much
29	safer than threads programming.	36	safer than threads programming.
30		37
31	(Perl, however, does not natively support real threads but instead does a	38	(Perl, however, does not natively support real threads but instead does a
…		…
33	is a performance win on Windows machines, and a loss everywhere else).	40	is a performance win on Windows machines, and a loss everywhere else).
34		41
35	In this module, coroutines are defined as "callchain + lexical variables +	42	In this module, coroutines are defined as "callchain + lexical variables +
36	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,	43	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
37	its own set of lexicals and its own set of perls most important global	44	its own set of lexicals and its own set of perls most important global
38	variables.	45	variables (see L<Coro::State> for more configuration).
39		46
40	=cut	47	=cut
41		48
42	package Coro;	49	package Coro;
43		50
…		…
50		57
51	our $idle; # idle handler	58	our $idle; # idle handler
52	our $main; # main coroutine	59	our $main; # main coroutine
53	our $current; # current coroutine	60	our $current; # current coroutine
54		61
55	our $VERSION = '3.3';	62	our $VERSION = '4.51';
56		63
57	our @EXPORT = qw(async cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));	68	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62		69
63	{
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
97	=over 4	70	=over 4
98		71
99	=item $main	72	=item $main
100		73
101	This coroutine represents the main program.	74	This coroutine represents the main program.
…		…
108		81
109	The current coroutine (the last coroutine switched to). The initial value	82	The current coroutine (the last coroutine switched to). The initial value
110	is C<$main> (of course).	83	is C<$main> (of course).
111		84
112	This variable is B<strictly> I<read-only>. It is provided for performance	85	This variable is B<strictly> I<read-only>. It is provided for performance
113	reasons. If performance is not essentiel you are encouraged to use the	86	reasons. If performance is not essential you are encouraged to use the
114	C<Coro::current> function instead.	87	C<Coro::current> function instead.
115		88
116	=cut	89	=cut
117		90
		91	$main->{desc} = "[main::]";
		92
118	# maybe some other module used Coro::Specific before...	93	# maybe some other module used Coro::Specific before...
119	$main->{specific} = $current->{specific}	94	$main->{_specific} = $current->{_specific}
120	if $current;	95	if $current;
121		96
122	_set_current $main;	97	_set_current $main;
123		98
124	sub current() { $current }	99	sub current() { $current }
…		…
132	This hook is overwritten by modules such as C<Coro::Timer> and	107	This hook is overwritten by modules such as C<Coro::Timer> and
133	C<Coro::Event> to wait on an external event that hopefully wake up a	108	C<Coro::Event> to wait on an external event that hopefully wake up a
134	coroutine so the scheduler can run it.	109	coroutine so the scheduler can run it.
135		110
136	Please note that if your callback recursively invokes perl (e.g. for event	111	Please note that if your callback recursively invokes perl (e.g. for event
137	handlers), then it must be prepared to be called recursively.	112	handlers), then it must be prepared to be called recursively itself.
138		113
139	=cut	114	=cut
140		115
141	$idle = sub {	116	$idle = sub {
142	require Carp;	117	require Carp;
…		…
149	# free coroutine data and mark as destructed	124	# free coroutine data and mark as destructed
150	$self->_destroy	125	$self->_destroy
151	or return;	126	or return;
152		127
153	# call all destruction callbacks	128	# call all destruction callbacks
154	$_->(@{$self->{status}})	129	$_->(@{$self->{_status}})
155	for @{(delete $self->{destroy_cb}) \|\| []};	130	for @{(delete $self->{_on_destroy}) \|\| []};
156	}	131	}
157		132
158	# this coroutine is necessary because a coroutine	133	# this coroutine is necessary because a coroutine
159	# cannot destroy itself.	134	# cannot destroy itself.
160	my @destroy;	135	my @destroy;
…		…
166	while @destroy;	141	while @destroy;
167		142
168	&schedule;	143	&schedule;
169	}	144	}
170	};	145	};
171		146	$manager->desc ("[coro manager]");
172	$manager->prio (PRIO_MAX);	147	$manager->prio (PRIO_MAX);
173
174	# static methods. not really.
175		148
176	=back	149	=back
177		150
178	=head2 STATIC METHODS	151	=head2 STATIC METHODS
179		152
…		…
185		158
186	Create a new asynchronous coroutine and return it's coroutine object	159	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	160	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	161	terminated.
189		162
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	163	See the C<Coro::State::new> constructor for info about the coroutine
		164	environment in which coroutines run.
191		165
192	When the coroutine dies, the program will exit, just as in the main	166	Calling C<exit> in a coroutine will do the same as calling exit outside
193	program.	167	the coroutine. Likewise, when the coroutine dies, the program will exit,
		168	just as it would in the main program.
194		169
195	# create a new coroutine that just prints its arguments	170	# create a new coroutine that just prints its arguments
196	async {	171	async {
197	print "@_\n";	172	print "@_\n";
198	} 1,2,3,4;	173	} 1,2,3,4;
…		…
200	=cut	175	=cut
201		176
202	sub async(&@) {	177	sub async(&@) {
203	my $coro = new Coro @_;	178	my $coro = new Coro @_;
204	$coro->ready;	179	$coro->ready;
		180	$coro
		181	}
		182
		183	=item async_pool { ... } [@args...]
		184
		185	Similar to C<async>, but uses a coroutine pool, so you should not call
		186	terminate or join (although you are allowed to), and you get a coroutine
		187	that might have executed other code already (which can be good or bad :).
		188
		189	Also, the block is executed in an C<eval> context and a warning will be
		190	issued in case of an exception instead of terminating the program, as
		191	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		192	will not work in the expected way, unless you call terminate or cancel,
		193	which somehow defeats the purpose of pooling.
		194
		195	The priority will be reset to C<0> after each job, tracing will be
		196	disabled, the description will be reset and the default output filehandle
		197	gets restored, so you can change alkl these. Otherwise the coroutine will
		198	be re-used "as-is": most notably if you change other per-coroutine global
		199	stuff such as C<$/> you need to revert that change, which is most simply
		200	done by using local as in C< local $/ >.
		201
		202	The pool size is limited to 8 idle coroutines (this can be adjusted by
		203	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
		204	required.
		205
		206	If you are concerned about pooled coroutines growing a lot because a
		207	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
		208	{ terminate }> once per second or so to slowly replenish the pool. In
		209	addition to that, when the stacks used by a handler grows larger than 16kb
		210	(adjustable with $Coro::POOL_RSS) it will also exit.
		211
		212	=cut
		213
		214	our $POOL_SIZE = 8;
		215	our $POOL_RSS = 16 * 1024;
		216	our @async_pool;
		217
		218	sub pool_handler {
		219	my $cb;
		220
		221	while () {
		222	eval {
		223	while () {
		224	_pool_1 $cb;
		225	&$cb;
		226	_pool_2 $cb;
		227	&schedule;
		228	}
		229	};
		230
		231	last if $@ eq "\3async_pool terminate\2\n";
		232	warn $@ if $@;
		233	}
		234	}
		235
		236	sub async_pool(&@) {
		237	# this is also inlined into the unlock_scheduler
		238	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		239
		240	$coro->{_invoke} = [@_];
		241	$coro->ready;
		242
205	$coro	243	$coro
206	}	244	}
207		245
208	=item schedule	246	=item schedule
209		247
…		…
223	# wake up sleeping coroutine	261	# wake up sleeping coroutine
224	$current->ready;	262	$current->ready;
225	undef $current;	263	undef $current;
226	};	264	};
227		265
228	# call schedule until event occured.	266	# call schedule until event occurred.
229	# in case we are woken up for other reasons	267	# in case we are woken up for other reasons
230	# (current still defined), loop.	268	# (current still defined), loop.
231	Coro::schedule while $current;	269	Coro::schedule while $current;
232	}	270	}
233		271
…		…
244		282
245	=item terminate [arg...]	283	=item terminate [arg...]
246		284
247	Terminates the current coroutine with the given status values (see L<cancel>).	285	Terminates the current coroutine with the given status values (see L<cancel>).
248		286
		287	=item killall
		288
		289	Kills/terminates/cancels all coroutines except the currently running
		290	one. This is useful after a fork, either in the child or the parent, as
		291	usually only one of them should inherit the running coroutines.
		292
249	=cut	293	=cut
250		294
251	sub terminate {	295	sub terminate {
252	$current->cancel (@_);	296	$current->cancel (@_);
253	}	297	}
254		298
		299	sub killall {
		300	for (Coro::State::list) {
		301	$_->cancel
		302	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		303	}
		304	}
		305
255	=back	306	=back
256
257	# dynamic methods
258		307
259	=head2 COROUTINE METHODS	308	=head2 COROUTINE METHODS
260		309
261	These are the methods you can call on coroutine objects.	310	These are the methods you can call on coroutine objects.
262		311
…		…
267	Create a new coroutine and return it. When the sub returns the coroutine	316	Create a new coroutine and return it. When the sub returns the coroutine
268	automatically terminates as if C<terminate> with the returned values were	317	automatically terminates as if C<terminate> with the returned values were
269	called. To make the coroutine run you must first put it into the ready queue	318	called. To make the coroutine run you must first put it into the ready queue
270	by calling the ready method.	319	by calling the ready method.
271		320
272	Calling C<exit> in a coroutine will not work correctly, so do not do that.	321	See C<async> and C<Coro::State::new> for additional info about the
		322	coroutine environment.
273		323
274	=cut	324	=cut
275		325
276	sub _run_coro {	326	sub _run_coro {
277	terminate &{+shift};	327	terminate &{+shift};
…		…
301		351
302	=cut	352	=cut
303		353
304	sub cancel {	354	sub cancel {
305	my $self = shift;	355	my $self = shift;
306	$self->{status} = [@_];	356	$self->{_status} = [@_];
307		357
308	if ($current == $self) {	358	if ($current == $self) {
309	push @destroy, $self;	359	push @destroy, $self;
310	$manager->ready;	360	$manager->ready;
311	&schedule while 1;	361	&schedule while 1;
…		…
315	}	365	}
316		366
317	=item $coroutine->join	367	=item $coroutine->join
318		368
319	Wait until the coroutine terminates and return any values given to the	369	Wait until the coroutine terminates and return any values given to the
320	C<terminate> or C<cancel> functions. C<join> can be called multiple times	370	C<terminate> or C<cancel> functions. C<join> can be called concurrently
321	from multiple coroutine.	371	from multiple coroutines.
322		372
323	=cut	373	=cut
324		374
325	sub join {	375	sub join {
326	my $self = shift;	376	my $self = shift;
327		377
328	unless ($self->{status}) {	378	unless ($self->{_status}) {
329	my $current = $current;	379	my $current = $current;
330		380
331	push @{$self->{destroy_cb}}, sub {	381	push @{$self->{_on_destroy}}, sub {
332	$current->ready;	382	$current->ready;
333	undef $current;	383	undef $current;
334	};	384	};
335		385
336	&schedule while $current;	386	&schedule while $current;
337	}	387	}
338		388
339	wantarray ? @{$self->{status}} : $self->{status}[0];	389	wantarray ? @{$self->{_status}} : $self->{_status}[0];
340	}	390	}
341		391
342	=item $coroutine->on_destroy (\&cb)	392	=item $coroutine->on_destroy (\&cb)
343		393
344	Registers a callback that is called when this coroutine gets destroyed,	394	Registers a callback that is called when this coroutine gets destroyed,
…		…
348	=cut	398	=cut
349		399
350	sub on_destroy {	400	sub on_destroy {
351	my ($self, $cb) = @_;	401	my ($self, $cb) = @_;
352		402
353	push @{ $self->{destroy_cb} }, $cb;	403	push @{ $self->{_on_destroy} }, $cb;
354	}	404	}
355		405
356	=item $oldprio = $coroutine->prio ($newprio)	406	=item $oldprio = $coroutine->prio ($newprio)
357		407
358	Sets (or gets, if the argument is missing) the priority of the	408	Sets (or gets, if the argument is missing) the priority of the
…		…
383	=item $olddesc = $coroutine->desc ($newdesc)	433	=item $olddesc = $coroutine->desc ($newdesc)
384		434
385	Sets (or gets in case the argument is missing) the description for this	435	Sets (or gets in case the argument is missing) the description for this
386	coroutine. This is just a free-form string you can associate with a coroutine.	436	coroutine. This is just a free-form string you can associate with a coroutine.
387		437
		438	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
		439	can modify this member directly if you wish.
		440
		441	=item $coroutine->throw ([$scalar])
		442
		443	If C<$throw> is specified and defined, it will be thrown as an exception
		444	inside the coroutine at the next convinient point in time (usually after
		445	it gains control at the next schedule/transfer/cede). Otherwise clears the
		446	exception object.
		447
		448	The exception object will be thrown "as is" with the specified scalar in
		449	C<$@>, i.e. if it is a string, no line number or newline will be appended
		450	(unlike with C<die>).
		451
		452	This can be used as a softer means than C<cancel> to ask a coroutine to
		453	end itself, although there is no guarentee that the exception will lead to
		454	termination, and if the exception isn't caught it might well end the whole
		455	program.
		456
388	=cut	457	=cut
389		458
390	sub desc {	459	sub desc {
391	my $old = $_[0]{desc};	460	my $old = $_[0]{desc};
392	$_[0]{desc} = $_[1] if @_ > 1;	461	$_[0]{desc} = $_[1] if @_ > 1;
…		…
400	=over 4	469	=over 4
401		470
402	=item Coro::nready	471	=item Coro::nready
403		472
404	Returns the number of coroutines that are currently in the ready state,	473	Returns the number of coroutines that are currently in the ready state,
405	i.e. that can be swicthed to. The value C<0> means that the only runnable	474	i.e. that can be switched to. The value C<0> means that the only runnable
406	coroutine is the currently running one, so C<cede> would have no effect,	475	coroutine is the currently running one, so C<cede> would have no effect,
407	and C<schedule> would cause a deadlock unless there is an idle handler	476	and C<schedule> would cause a deadlock unless there is an idle handler
408	that wakes up some coroutines.	477	that wakes up some coroutines.
409		478
410	=item my $guard = Coro::guard { ... }	479	=item my $guard = Coro::guard { ... }
411		480
412	This creates and returns a guard object. Nothing happens until the objetc	481	This creates and returns a guard object. Nothing happens until the object
413	gets destroyed, in which case the codeblock given as argument will be	482	gets destroyed, in which case the codeblock given as argument will be
414	executed. This is useful to free locks or other resources in case of a	483	executed. This is useful to free locks or other resources in case of a
415	runtime error or when the coroutine gets canceled, as in both cases the	484	runtime error or when the coroutine gets canceled, as in both cases the
416	guard block will be executed. The guard object supports only one method,	485	guard block will be executed. The guard object supports only one method,
417	C<< ->cancel >>, which will keep the codeblock from being executed.	486	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
446	This utility function takes a BLOCK or code reference and "unblocks" it,	515	This utility function takes a BLOCK or code reference and "unblocks" it,
447	returning the new coderef. This means that the new coderef will return	516	returning the new coderef. This means that the new coderef will return
448	immediately without blocking, returning nothing, while the original code	517	immediately without blocking, returning nothing, while the original code
449	ref will be called (with parameters) from within its own coroutine.	518	ref will be called (with parameters) from within its own coroutine.
450		519
451	The reason this fucntion exists is that many event libraries (such as the	520	The reason this function exists is that many event libraries (such as the
452	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	521	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
453	of thread-safety). This means you must not block within event callbacks,	522	of thread-safety). This means you must not block within event callbacks,
454	otherwise you might suffer from crashes or worse.	523	otherwise you might suffer from crashes or worse.
455		524
456	This function allows your callbacks to block by executing them in another	525	This function allows your callbacks to block by executing them in another
…		…
461	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when	530	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
462	creating event callbacks that want to block.	531	creating event callbacks that want to block.
463		532
464	=cut	533	=cut
465		534
466	our @unblock_pool;
467	our @unblock_queue;	535	our @unblock_queue;
468	our $UNBLOCK_POOL_SIZE = 2;
469		536
470	sub unblock_handler_ {	537	# we create a special coro because we want to cede,
471	while () {	538	# to reduce pressure on the coro pool (because most callbacks
472	my ($cb, @arg) = @{ delete $Coro::current->{arg} };	539	# return immediately and can be reused) and because we cannot cede
473	$cb->(@arg);	540	# inside an event callback.
474
475	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
476	push @unblock_pool, $Coro::current;
477	schedule;
478	}
479	}
480
481	our $unblock_scheduler = async {	541	our $unblock_scheduler = new Coro sub {
482	while () {	542	while () {
483	while (my $cb = pop @unblock_queue) {	543	while (my $cb = pop @unblock_queue) {
484	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);	544	# this is an inlined copy of async_pool
485	$handler->{arg} = $cb;	545	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		546
		547	$coro->{_invoke} = $cb;
486	$handler->ready;	548	$coro->ready;
487	cede;	549	cede; # for short-lived callbacks, this reduces pressure on the coro pool
488	}	550	}
489		551	schedule; # sleep well
490	schedule;
491	}	552	}
492	};	553	};
		554	$unblock_scheduler->desc ("[unblock_sub scheduler]");
493		555
494	sub unblock_sub(&) {	556	sub unblock_sub(&) {
495	my $cb = shift;	557	my $cb = shift;
496		558
497	sub {	559	sub {
498	push @unblock_queue, [$cb, @_];	560	unshift @unblock_queue, [$cb, @_];
499	$unblock_scheduler->ready;	561	$unblock_scheduler->ready;
500	}	562	}
501	}	563	}
502		564
503	=back	565	=back
…		…
510		572
511	- you must make very sure that no coro is still active on global	573	- you must make very sure that no coro is still active on global
512	destruction. very bad things might happen otherwise (usually segfaults).	574	destruction. very bad things might happen otherwise (usually segfaults).
513		575
514	- this module is not thread-safe. You should only ever use this module	576	- this module is not thread-safe. You should only ever use this module
515	from the same thread (this requirement might be losened in the future	577	from the same thread (this requirement might be loosened in the future
516	to allow per-thread schedulers, but Coro::State does not yet allow	578	to allow per-thread schedulers, but Coro::State does not yet allow
517	this).	579	this).
518		580
519	=head1 SEE ALSO	581	=head1 SEE ALSO
520		582
		583	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		584
		585	Debugging: L<Coro::Debug>.
		586
521	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	587	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
522		588
523	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	589	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
524		590
525	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	591	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
526		592
		593	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		594
527	Embedding: L<Coro:MakeMaker>	595	Embedding: L<Coro::MakeMaker>.
528		596
529	=head1 AUTHOR	597	=head1 AUTHOR
530		598
531	Marc Lehmann <schmorp@schmorp.de>	599	Marc Lehmann <schmorp@schmorp.de>
532	http://home.schmorp.de/	600	http://home.schmorp.de/

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Comparing Coro/Coro.pm (file contents): Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs. Revision 1.179 by root, Sat Apr 19 19:06:02 2008 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs.
Revision 1.179 by root, Sat Apr 19 19:06:02 2008 UTC