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

Comparing Coro/Coro.pm (file contents):
Revision 1.20 by root, Sat Jul 21 18:21:45 2001 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 process 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	yield;	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 to	30	This module collection manages coroutines. Coroutines are similar
24	Threads but don't run in parallel.	31	to threads but don't run in parallel at the same time even on SMP
		32	machines. The specific flavor of coroutine used in this module also
		33	guarantees you that it will not switch between coroutines unless
		34	necessary, at easily-identified points in your program, so locking and
		35	parallel access are rarely an issue, making coroutine programming much
		36	safer than threads programming.
25		37
26	This module is still experimental, see the BUGS section below.	38	(Perl, however, does not natively support real threads but instead does a
		39	very slow and memory-intensive emulation of processes using threads. This
		40	is a performance win on Windows machines, and a loss everywhere else).
27		41
28	In this module, coroutines are defined as "callchain + lexical variables	42	In this module, coroutines are defined as "callchain + lexical variables +
29	+ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's	43	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
30	own set of lexicals and it's own set of perl's most important global	44	its own set of lexicals and its own set of perls most important global
31	variables.	45	variables (see L<Coro::State> for more configuration).
32		46
33	=cut	47	=cut
34		48
35	package Coro;	49	package Coro;
36		50
		51	use strict;
		52	no warnings "uninitialized";
		53
37	use Coro::State;	54	use Coro::State;
38		55
39	use base Exporter;	56	use base qw(Coro::State Exporter);
40		57
41	$VERSION = 0.10;	58	our $idle; # idle handler
		59	our $main; # main coroutine
		60	our $current; # current coroutine
42		61
		62	our $VERSION = '4.51';
		63
43	@EXPORT = qw(async yield schedule terminate current);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
44	@EXPORT_OK = qw($current);	65	our %EXPORT_TAGS = (
		66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
		67	);
		68	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
45		69
46	{	70	=over 4
47	my @async;
48
49	# this way of handling attributes simply is NOT scalable ;()
50	sub import {
51	Coro->export_to_level(1, @_);
52	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
53	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
54	my ($package, $ref) = (shift, shift);
55	my @attrs;
56	for (@_) {
57	if ($_ eq "Coro") {
58	push @async, $ref;
59	} else {
60	push @attrs, $_;
61	}
62	}
63	return $old ? $old->($package, $ref, @attrs) : @attrs;
64	};
65	}
66
67	sub INIT {
68	&async(pop @async) while @async;
69	}
70	}
71		71
72	=item $main	72	=item $main
73		73
74	This coroutine represents the main program.	74	This coroutine represents the main program.
75		75
76	=cut	76	=cut
77		77
78	our $main = new Coro;	78	$main = new Coro;
79		79
80	=item $current (or as function: current)	80	=item $current (or as function: current)
81		81
82	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	82	The current coroutine (the last coroutine switched to). The initial value
		83	is C<$main> (of course).
83		84
		85	This variable is B<strictly> I<read-only>. It is provided for performance
		86	reasons. If performance is not essential you are encouraged to use the
		87	C<Coro::current> function instead.
		88
84	=cut	89	=cut
		90
		91	$main->{desc} = "[main::]";
85		92
86	# maybe some other module used Coro::Specific before...	93	# maybe some other module used Coro::Specific before...
87	if ($current) {
88	$main->{specific} = $current->{specific};	94	$main->{_specific} = $current->{_specific}
89	}	95	if $current;
90		96
91	our $current = $main;	97	_set_current $main;
92		98
93	sub current() { $current }	99	sub current() { $current }
94		100
95	=item $idle	101	=item $idle
96		102
97	The coroutine to switch to when no other coroutine is running. The default	103	A callback that is called whenever the scheduler finds no ready coroutines
98	implementation prints "FATAL: deadlock detected" and exits.	104	to run. The default implementation prints "FATAL: deadlock detected" and
		105	exits, because the program has no other way to continue.
99		106
100	=cut	107	This hook is overwritten by modules such as C<Coro::Timer> and
		108	C<Coro::Event> to wait on an external event that hopefully wake up a
		109	coroutine so the scheduler can run it.
101		110
102	# should be done using priorities :(	111	Please note that if your callback recursively invokes perl (e.g. for event
103	our $idle = new Coro sub {	112	handlers), then it must be prepared to be called recursively itself.
104	print STDERR "FATAL: deadlock detected\n";	113
105	exit(51);	114	=cut
		115
		116	$idle = sub {
		117	require Carp;
		118	Carp::croak ("FATAL: deadlock detected");
106	};	119	};
107		120
108	# we really need priorities...	121	sub _cancel {
109	my @ready; # the ready queue. hehe, rather broken ;)	122	my ($self) = @_;
110		123
111	# static methods. not really.	124	# free coroutine data and mark as destructed
		125	$self->_destroy
		126	or return;
		127
		128	# call all destruction callbacks
		129	$_->(@{$self->{_status}})
		130	for @{(delete $self->{_on_destroy}) \|\| []};
		131	}
		132
		133	# this coroutine is necessary because a coroutine
		134	# cannot destroy itself.
		135	my @destroy;
		136	my $manager;
		137
		138	$manager = new Coro sub {
		139	while () {
		140	(shift @destroy)->_cancel
		141	while @destroy;
		142
		143	&schedule;
		144	}
		145	};
		146	$manager->desc ("[coro manager]");
		147	$manager->prio (PRIO_MAX);
		148
		149	=back
112		150
113	=head2 STATIC METHODS	151	=head2 STATIC METHODS
114		152
115	Static methods are actually functions that operate on the current process only.	153	Static methods are actually functions that operate on the current coroutine only.
116		154
117	=over 4	155	=over 4
118		156
119	=item async { ... } [@args...]	157	=item async { ... } [@args...]
120		158
121	Create a new asynchronous process and return it's process object	159	Create a new asynchronous coroutine and return it's coroutine object
122	(usually unused). When the sub returns the new process is automatically	160	(usually unused). When the sub returns the new coroutine is automatically
123	terminated.	161	terminated.
		162
		163	See the C<Coro::State::new> constructor for info about the coroutine
		164	environment in which coroutines run.
		165
		166	Calling C<exit> in a coroutine will do the same as calling exit outside
		167	the coroutine. Likewise, when the coroutine dies, the program will exit,
		168	just as it would in the main program.
124		169
125	# create a new coroutine that just prints its arguments	170	# create a new coroutine that just prints its arguments
126	async {	171	async {
127	print "@_\n";	172	print "@_\n";
128	} 1,2,3,4;	173	} 1,2,3,4;
129		174
130	The coderef you submit MUST NOT be a closure that refers to variables
131	in an outer scope. This does NOT work. Pass arguments into it instead.
132
133	=cut	175	=cut
134		176
135	sub async(&@) {	177	sub async(&@) {
136	my $pid = new Coro @_;	178	my $coro = new Coro @_;
137	$pid->ready;	179	$coro->ready;
138	$pid;	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
		243	$coro
139	}	244	}
140		245
141	=item schedule	246	=item schedule
142		247
143	Calls the scheduler. Please note that the current process will not be put	248	Calls the scheduler. Please note that the current coroutine will not be put
144	into the ready queue, so calling this function usually means you will	249	into the ready queue, so calling this function usually means you will
145	never be called again.	250	never be called again unless something else (e.g. an event handler) calls
		251	ready.
146		252
147	=cut	253	The canonical way to wait on external events is this:
148		254
149	my $prev;	255	{
		256	# remember current coroutine
		257	my $current = $Coro::current;
150		258
151	sub schedule {	259	# register a hypothetical event handler
152	# should be done using priorities :(	260	on_event_invoke sub {
153	($prev, $current) = ($current, shift @ready \|\| $idle);	261	# wake up sleeping coroutine
154	Coro::State::transfer($prev, $current);
155	}
156
157	=item yield
158
159	Yield to other processes. This function puts the current process into the
160	ready queue and calls C<schedule>.
161
162	=cut
163
164	sub yield {
165	$current->ready;	262	$current->ready;
166	&schedule;	263	undef $current;
167	}	264	};
168		265
		266	# call schedule until event occurred.
		267	# in case we are woken up for other reasons
		268	# (current still defined), loop.
		269	Coro::schedule while $current;
		270	}
		271
		272	=item cede
		273
		274	"Cede" to other coroutines. This function puts the current coroutine into the
		275	ready queue and calls C<schedule>, which has the effect of giving up the
		276	current "timeslice" to other coroutines of the same or higher priority.
		277
		278	=item Coro::cede_notself
		279
		280	Works like cede, but is not exported by default and will cede to any
		281	coroutine, regardless of priority, once.
		282
169	=item terminate	283	=item terminate [arg...]
170		284
171	Terminates the current process.	285	Terminates the current coroutine with the given status values (see L<cancel>).
172		286
173	Future versions of this function will allow result arguments.	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.
174		292
175	=cut	293	=cut
176		294
177	sub terminate {	295	sub terminate {
178	$current->{_results} = [@_];	296	$current->cancel (@_);
179	&schedule;	297	}
		298
		299	sub killall {
		300	for (Coro::State::list) {
		301	$_->cancel
		302	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		303	}
180	}	304	}
181		305
182	=back	306	=back
183		307
184	# dynamic methods
185
186	=head2 PROCESS METHODS	308	=head2 COROUTINE METHODS
187		309
188	These are the methods you can call on process objects.	310	These are the methods you can call on coroutine objects.
189		311
190	=over 4	312	=over 4
191		313
192	=item new Coro \&sub [, @args...]	314	=item new Coro \&sub [, @args...]
193		315
194	Create a new process and return it. When the sub returns the process	316	Create a new coroutine and return it. When the sub returns the coroutine
195	automatically terminates. To start the process you must first put it into	317	automatically terminates as if C<terminate> with the returned values were
		318	called. To make the coroutine run you must first put it into the ready queue
196	the ready queue by calling the ready method.	319	by calling the ready method.
197		320
198	The coderef you submit MUST NOT be a closure that refers to variables	321	See C<async> and C<Coro::State::new> for additional info about the
199	in an outer scope. This does NOT work. Pass arguments into it instead.	322	coroutine environment.
200		323
201	=cut	324	=cut
202		325
203	sub _newcoro {	326	sub _run_coro {
204	terminate &{+shift};	327	terminate &{+shift};
205	}	328	}
206		329
207	sub new {	330	sub new {
208	my $class = shift;	331	my $class = shift;
209	bless {
210	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
211	}, $class;
212	}
213		332
214	=item $process->ready	333	$class->SUPER::new (\&_run_coro, @_)
		334	}
215		335
216	Put the current process into the ready queue.	336	=item $success = $coroutine->ready
217		337
218	=cut	338	Put the given coroutine into the ready queue (according to it's priority)
		339	and return true. If the coroutine is already in the ready queue, do nothing
		340	and return false.
219		341
220	sub ready {	342	=item $is_ready = $coroutine->is_ready
221	push @ready, $_[0];	343
		344	Return wether the coroutine is currently the ready queue or not,
		345
		346	=item $coroutine->cancel (arg...)
		347
		348	Terminates the given coroutine and makes it return the given arguments as
		349	status (default: the empty list). Never returns if the coroutine is the
		350	current coroutine.
		351
		352	=cut
		353
		354	sub cancel {
		355	my $self = shift;
		356	$self->{_status} = [@_];
		357
		358	if ($current == $self) {
		359	push @destroy, $self;
		360	$manager->ready;
		361	&schedule while 1;
		362	} else {
		363	$self->_cancel;
		364	}
		365	}
		366
		367	=item $coroutine->join
		368
		369	Wait until the coroutine terminates and return any values given to the
		370	C<terminate> or C<cancel> functions. C<join> can be called concurrently
		371	from multiple coroutines.
		372
		373	=cut
		374
		375	sub join {
		376	my $self = shift;
		377
		378	unless ($self->{_status}) {
		379	my $current = $current;
		380
		381	push @{$self->{_on_destroy}}, sub {
		382	$current->ready;
		383	undef $current;
		384	};
		385
		386	&schedule while $current;
		387	}
		388
		389	wantarray ? @{$self->{_status}} : $self->{_status}[0];
		390	}
		391
		392	=item $coroutine->on_destroy (\&cb)
		393
		394	Registers a callback that is called when this coroutine gets destroyed,
		395	but before it is joined. The callback gets passed the terminate arguments,
		396	if any.
		397
		398	=cut
		399
		400	sub on_destroy {
		401	my ($self, $cb) = @_;
		402
		403	push @{ $self->{_on_destroy} }, $cb;
		404	}
		405
		406	=item $oldprio = $coroutine->prio ($newprio)
		407
		408	Sets (or gets, if the argument is missing) the priority of the
		409	coroutine. Higher priority coroutines get run before lower priority
		410	coroutines. Priorities are small signed integers (currently -4 .. +3),
		411	that you can refer to using PRIO_xxx constants (use the import tag :prio
		412	to get then):
		413
		414	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		415	3 > 1 > 0 > -1 > -3 > -4
		416
		417	# set priority to HIGH
		418	current->prio(PRIO_HIGH);
		419
		420	The idle coroutine ($Coro::idle) always has a lower priority than any
		421	existing coroutine.
		422
		423	Changing the priority of the current coroutine will take effect immediately,
		424	but changing the priority of coroutines in the ready queue (but not
		425	running) will only take effect after the next schedule (of that
		426	coroutine). This is a bug that will be fixed in some future version.
		427
		428	=item $newprio = $coroutine->nice ($change)
		429
		430	Similar to C<prio>, but subtract the given value from the priority (i.e.
		431	higher values mean lower priority, just as in unix).
		432
		433	=item $olddesc = $coroutine->desc ($newdesc)
		434
		435	Sets (or gets in case the argument is missing) the description for this
		436	coroutine. This is just a free-form string you can associate with a coroutine.
		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
		457	=cut
		458
		459	sub desc {
		460	my $old = $_[0]{desc};
		461	$_[0]{desc} = $_[1] if @_ > 1;
		462	$old;
222	}	463	}
223		464
224	=back	465	=back
225		466
		467	=head2 GLOBAL FUNCTIONS
		468
		469	=over 4
		470
		471	=item Coro::nready
		472
		473	Returns the number of coroutines that are currently in the ready state,
		474	i.e. that can be switched to. The value C<0> means that the only runnable
		475	coroutine is the currently running one, so C<cede> would have no effect,
		476	and C<schedule> would cause a deadlock unless there is an idle handler
		477	that wakes up some coroutines.
		478
		479	=item my $guard = Coro::guard { ... }
		480
		481	This creates and returns a guard object. Nothing happens until the object
		482	gets destroyed, in which case the codeblock given as argument will be
		483	executed. This is useful to free locks or other resources in case of a
		484	runtime error or when the coroutine gets canceled, as in both cases the
		485	guard block will be executed. The guard object supports only one method,
		486	C<< ->cancel >>, which will keep the codeblock from being executed.
		487
		488	Example: set some flag and clear it again when the coroutine gets canceled
		489	or the function returns:
		490
		491	sub do_something {
		492	my $guard = Coro::guard { $busy = 0 };
		493	$busy = 1;
		494
		495	# do something that requires $busy to be true
		496	}
		497
		498	=cut
		499
		500	sub guard(&) {
		501	bless \(my $cb = $_[0]), "Coro::guard"
		502	}
		503
		504	sub Coro::guard::cancel {
		505	${$_[0]} = sub { };
		506	}
		507
		508	sub Coro::guard::DESTROY {
		509	${$_[0]}->();
		510	}
		511
		512
		513	=item unblock_sub { ... }
		514
		515	This utility function takes a BLOCK or code reference and "unblocks" it,
		516	returning the new coderef. This means that the new coderef will return
		517	immediately without blocking, returning nothing, while the original code
		518	ref will be called (with parameters) from within its own coroutine.
		519
		520	The reason this function exists is that many event libraries (such as the
		521	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		522	of thread-safety). This means you must not block within event callbacks,
		523	otherwise you might suffer from crashes or worse.
		524
		525	This function allows your callbacks to block by executing them in another
		526	coroutine where it is safe to block. One example where blocking is handy
		527	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		528	disk.
		529
		530	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		531	creating event callbacks that want to block.
		532
		533	=cut
		534
		535	our @unblock_queue;
		536
		537	# we create a special coro because we want to cede,
		538	# to reduce pressure on the coro pool (because most callbacks
		539	# return immediately and can be reused) and because we cannot cede
		540	# inside an event callback.
		541	our $unblock_scheduler = new Coro sub {
		542	while () {
		543	while (my $cb = pop @unblock_queue) {
		544	# this is an inlined copy of async_pool
		545	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		546
		547	$coro->{_invoke} = $cb;
		548	$coro->ready;
		549	cede; # for short-lived callbacks, this reduces pressure on the coro pool
		550	}
		551	schedule; # sleep well
		552	}
		553	};
		554	$unblock_scheduler->desc ("[unblock_sub scheduler]");
		555
		556	sub unblock_sub(&) {
		557	my $cb = shift;
		558
		559	sub {
		560	unshift @unblock_queue, [$cb, @_];
		561	$unblock_scheduler->ready;
		562	}
		563	}
		564
		565	=back
		566
226	=cut	567	=cut
227		568
228	1;	569	1;
229		570
230	=head1 BUGS/LIMITATIONS	571	=head1 BUGS/LIMITATIONS
231		572
232	- could be faster, especially when the core would introduce special	573	- you must make very sure that no coro is still active on global
233	support for coroutines (like it does for threads).	574	destruction. very bad things might happen otherwise (usually segfaults).
234	- there is still a memleak on coroutine termination that I could not	575
235	identify. Could be as small as a single SV.
236	- this module is not well-tested.
237	- if variables or arguments "disappear" (become undef) or become
238	corrupted please contact the author so he cen iron out the
239	remaining bugs.
240	- this module is not thread-safe. You must only ever use this module from	576	- this module is not thread-safe. You should only ever use this module
241	the same thread (this requirement might be loosened in the future to	577	from the same thread (this requirement might be loosened in the future
242	allow per-thread schedulers, but Coro::State does not yet allow this).	578	to allow per-thread schedulers, but Coro::State does not yet allow
		579	this).
243		580
244	=head1 SEE ALSO	581	=head1 SEE ALSO
245		582
246	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	583	Lower level Configuration, Coroutine Environment: L<Coro::State>.
247	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	584
		585	Debugging: L<Coro::Debug>.
		586
		587	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
		588
		589	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		590
		591	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
		592
		593	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		594
		595	Embedding: L<Coro::MakeMaker>.
248		596
249	=head1 AUTHOR	597	=head1 AUTHOR
250		598
251	Marc Lehmann <pcg@goof.com>	599	Marc Lehmann <schmorp@schmorp.de>
252	http://www.goof.com/pcg/marc/	600	http://home.schmorp.de/
253		601
254	=cut	602	=cut
255		603

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Comparing Coro/Coro.pm (file contents): Revision 1.20 by root, Sat Jul 21 18:21:45 2001 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 1.20 by root, Sat Jul 21 18:21:45 2001 UTC vs.
Revision 1.179 by root, Sat Apr 19 19:06:02 2008 UTC