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

Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.26 by root, Fri Jul 27 02:51:33 2001 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - create an manage coroutines	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 {
		10	# some asynchronous thread of execution
		11	};
		12
		13	# alternatively create an async process like this:
		14
		15	sub some_func : Coro {
		16	# some more async code
		17	}
		18
		19	cede;
		20
9	=head1 DESCRIPTION	21	=head1 DESCRIPTION
10		22
		23	This module collection manages coroutines. Coroutines are similar to
		24	Threads but don't run in parallel.
		25
		26	This module is still experimental, see the BUGS section below.
		27
		28	In this module, coroutines are defined as "callchain + lexical variables
		29	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
		30	callchain, it's own set of lexicals and it's own set of perl's most
		31	important global variables.
		32
		33	=cut
		34
		35	package Coro;
		36
		37	use Coro::State;
		38
		39	use base Exporter;
		40
		41	$VERSION = 0.12;
		42
		43	@EXPORT = qw(async cede schedule terminate current);
		44	@EXPORT_OK = qw($current);
		45
		46	{
		47	my @async;
		48	my $init;
		49
		50	# this way of handling attributes simply is NOT scalable ;()
		51	sub import {
		52	Coro->export_to_level(1, @_);
		53	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
		54	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
		55	my ($package, $ref) = (shift, shift);
		56	my @attrs;
		57	for (@_) {
		58	if ($_ eq "Coro") {
		59	push @async, $ref;
		60	unless ($init++) {
		61	eval q{
		62	sub INIT {
		63	&async(pop @async) while @async;
		64	}
		65	};
		66	}
		67	} else {
		68	push @attrs, $_;
		69	}
		70	}
		71	return $old ? $old->($package, $ref, @attrs) : @attrs;
		72	};
		73	}
		74
		75	}
		76
		77	=item $main
		78
		79	This coroutine represents the main program.
		80
		81	=cut
		82
		83	our $main = new Coro;
		84
		85	=item $current (or as function: current)
		86
		87	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
		88
		89	=cut
		90
		91	# maybe some other module used Coro::Specific before...
		92	if ($current) {
		93	$main->{specific} = $current->{specific};
		94	}
		95
		96	our $current = $main;
		97
		98	sub current() { $current }
		99
		100	=item $idle
		101
		102	The coroutine to switch to when no other coroutine is running. The default
		103	implementation prints "FATAL: deadlock detected" and exits.
		104
		105	=cut
		106
		107	# should be done using priorities :(
		108	our $idle = new Coro sub {
		109	print STDERR "FATAL: deadlock detected\n";
		110	exit(51);
		111	};
		112
		113	# this coroutine is necessary because a coroutine
		114	# cannot destroy itself.
		115	my @destroy;
		116	my $manager = new Coro sub {
		117	while() {
		118	delete ((pop @destroy)->{_coro_state}) while @destroy;
		119	&schedule;
		120	}
		121	};
		122
		123	# we really need priorities...
		124	my @ready; # the ready queue. hehe, rather broken ;)
		125
		126	# static methods. not really.
		127
		128	=head2 STATIC METHODS
		129
		130	Static methods are actually functions that operate on the current process only.
		131
11	=over 4	132	=over 4
12		133
13	=cut	134	=item async { ... } [@args...]
14		135
15	package Coro;	136	Create a new asynchronous process and return it's process object
		137	(usually unused). When the sub returns the new process is automatically
		138	terminated.
16		139
17	BEGIN {	140	# create a new coroutine that just prints its arguments
18	$VERSION = 0.01;	141	async {
		142	print "@_\n";
		143	} 1,2,3,4;
19		144
20	require XSLoader;	145	The coderef you submit MUST NOT be a closure that refers to variables
21	XSLoader::load Coro, $VERSION;	146	in an outer scope. This does NOT work. Pass arguments into it instead.
22	}
23		147
24	=item $main
25
26	This coroutine represents the main program.
27
28	=item $current
29
30	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
31
32	=cut	148	=cut
33		149
34	$main = $current = _newprocess {	150	sub async(&@) {
35	# never being called	151	my $pid = new Coro @_;
36	};	152	$manager->ready; # this ensures that the stack is cloned from the manager
		153	$pid->ready;
		154	$pid;
		155	}
37		156
38	=item $error, $error_msg, $error_coro	157	=item schedule
39		158
40	This coroutine will be called on fatal errors. C<$error_msg> and	159	Calls the scheduler. Please note that the current process will not be put
41	C<$error_coro> return the error message and the error-causing coroutine,	160	into the ready queue, so calling this function usually means you will
42	respectively.	161	never be called again.
43		162
44	=cut	163	=cut
45		164
46	$error_msg =	165	my $prev;
47	$error_coro = undef;
48		166
49	$error = _newprocess {	167	sub schedule {
50	print STDERR "FATAL: $error_msg, program aborted\n";	168	# should be done using priorities :(
51	exit 250;	169	($prev, $current) = ($current, shift @ready \|\| $idle);
52	};	170	Coro::State::transfer($prev, $current);
		171	}
53		172
54	=item $coro = new $coderef [, @args]	173	=item cede
55		174
56	Create a new coroutine and return it. The first C<resume> call to this	175	"Cede" to other processes. This function puts the current process into the
57	coroutine will start execution at the given coderef. If it returns it	176	ready queue and calls C<schedule>, which has the effect of giving up the
58	should return a coroutine to switch to. If, after returning, the coroutine	177	current "timeslice" to other coroutines of the same or higher priority.
59	is C<resume>d again it starts execution again at the givne coderef.
60		178
61	=cut	179	=cut
		180
		181	sub cede {
		182	$current->ready;
		183	&schedule;
		184	}
		185
		186	=item terminate
		187
		188	Terminates the current process.
		189
		190	Future versions of this function will allow result arguments.
		191
		192	=cut
		193
		194	sub terminate {
		195	push @destroy, $current;
		196	$manager->ready;
		197	&schedule;
		198	# NORETURN
		199	}
		200
		201	=back
		202
		203	# dynamic methods
		204
		205	=head2 PROCESS METHODS
		206
		207	These are the methods you can call on process objects.
		208
		209	=over 4
		210
		211	=item new Coro \&sub [, @args...]
		212
		213	Create a new process and return it. When the sub returns the process
		214	automatically terminates. To start the process you must first put it into
		215	the ready queue by calling the ready method.
		216
		217	The coderef you submit MUST NOT be a closure that refers to variables
		218	in an outer scope. This does NOT work. Pass arguments into it instead.
		219
		220	=cut
		221
		222	sub _newcoro {
		223	terminate &{+shift};
		224	}
62		225
63	sub new {	226	sub new {
64	my $class = $_[0];	227	my $class = shift;
65	my $proc = $_[1];	228	bless {
66	bless _newprocess {	229	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
67	do {
68	eval { &$proc->resume };
69	if ($@) {
70	($error_msg, $error_coro) = ($@, $current);
71	$error->resume;
72	}
73	} while ();
74	}, $class;	230	}, $class;
75	}	231	}
76		232
77	=item $coro->resume	233	=item $process->ready
78		234
79	Resume execution at the given coroutine.	235	Put the current process into the ready queue.
80		236
81	=cut	237	=cut
82		238
83	my $prev;	239	sub ready {
84		240	push @ready, $_[0];
85	sub resume {
86	$prev = $current; $current = $_[0];
87	_transfer($prev, $current);
88	}	241	}
		242
		243	=back
		244
		245	=cut
89		246
90	1;	247	1;
91		248
92	=back	249	=head1 BUGS/LIMITATIONS
93		250
94	=head1 BUGS	251	- could be faster, especially when the core would introduce special
		252	support for coroutines (like it does for threads).
		253	- there is still a memleak on coroutine termination that I could not
		254	identify. Could be as small as a single SV.
		255	- this module is not well-tested.
		256	- if variables or arguments "disappear" (become undef) or become
		257	corrupted please contact the author so he cen iron out the
		258	remaining bugs.
		259	- this module is not thread-safe. You must only ever use this module from
		260	the same thread (this requirement might be loosened in the future to
		261	allow per-thread schedulers, but Coro::State does not yet allow this).
95		262
96	This module has not yet been extensively tested.	263	=head1 SEE ALSO
		264
		265	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		266	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
		267	L<Coro::Handle>, L<Coro::Socket>.
97		268
98	=head1 AUTHOR	269	=head1 AUTHOR
99		270
100	Marc Lehmann <pcg@goof.com>	271	Marc Lehmann <pcg@goof.com>
101	http://www.goof.com/pcg/marc/	272	http://www.goof.com/pcg/marc/

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing Coro/Coro.pm (file contents): Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs. Revision 1.26 by root, Fri Jul 27 02:51:33 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.26 by root, Fri Jul 27 02:51:33 2001 UTC