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

Comparing Coro/Coro.pm (file contents):
Revision 1.6 by root, Tue Jul 10 21:19:47 2001 UTC vs.
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - create and manage simple 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	$new = new Coro sub {	9	async {
10	print "in coroutine, switching back\n";	10	# some asynchronous thread of execution
11	$new->transfer($main);
12	print "in coroutine again, switching back\n";
13	$new->transfer($main);
14	};	11	};
15		12
16	$main = new Coro;	13	# alternatively create an async process like this:
17		14
18	print "in main, switching to coroutine\n";	15	sub some_func : Coro {
19	$main->transfer($new);	16	# some more async code
20	print "back in main, switch to coroutine again\n";	17	}
21	$main->transfer($new);	18
22	print "back in main\n";	19	yield;
23		20
24	=head1 DESCRIPTION	21	=head1 DESCRIPTION
25		22
26	This module implements coroutines. Coroutines, similar to continuations,	23	=cut
27	allow you to run more than one "thread of execution" in parallel. Unlike
28	threads this, only voluntary switching is used so locking problems are
29	greatly reduced.
30		24
31	Although this is the "main" module of the Coro family it provides only	25	package Coro;
32	low-level functionality. See L<Coro::Process> and related modules for a	26
33	more useful process abstraction including scheduling.	27	use Coro::State;
		28
		29	use base Exporter;
		30
		31	$VERSION = 0.04;
		32
		33	@EXPORT = qw(async yield schedule);
		34	@EXPORT_OK = qw($current);
		35
		36	{
		37	use subs 'async';
		38
		39	my @async;
		40
		41	# this way of handling attributes simply is NOT scalable ;()
		42	sub import {
		43	Coro->export_to_level(1, @_);
		44	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
		45	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
		46	my ($package, $ref) = (shift, shift);
		47	my @attrs;
		48	for (@_) {
		49	if ($_ eq "Coro") {
		50	push @async, $ref;
		51	} else {
		52	push @attrs, @_;
		53	}
		54	}
		55	return $old ? $old->($package, $name, @attrs) : @attrs;
		56	};
		57	}
		58
		59	sub INIT {
		60	async pop @async while @async;
		61	}
		62	}
		63
		64	=item $main
		65
		66	This coroutine represents the main program.
		67
		68	=cut
		69
		70	our $main = new Coro;
		71
		72	=item $current
		73
		74	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
		75
		76	=cut
		77
		78	# maybe some other module used Coro::Specific before...
		79	if ($current) {
		80	$main->{specific} = $current->{specific};
		81	}
		82
		83	our $current = $main;
		84
		85	=item $idle
		86
		87	The coroutine to switch to when no other coroutine is running. The default
		88	implementation prints "FATAL: deadlock detected" and exits.
		89
		90	=cut
		91
		92	# should be done using priorities :(
		93	our $idle = new Coro sub {
		94	print STDERR "FATAL: deadlock detected\n";
		95	exit(51);
		96	};
		97
		98	# we really need priorities...
		99	my @ready = (); # the ready queue. hehe, rather broken ;)
		100
		101	# static methods. not really.
		102
		103	=head2 STATIC METHODS
		104
		105	Static methods are actually functions that operate on the current process only.
34		106
35	=over 4	107	=over 4
36		108
37	=cut	109	=item async { ... };
38		110
39	package Coro;	111	Create a new asynchronous process and return it's process object
		112	(usually unused). When the sub returns the new process is automatically
		113	terminated.
40		114
41	BEGIN {	115	=cut
42	$VERSION = 0.03;
43		116
44	require XSLoader;	117	sub async(&) {
45	XSLoader::load Coro, $VERSION;	118	(new Coro $_[0])->ready;
46	}	119	}
47		120
48	=item $coro = new [$coderef [, @args]]	121	=item schedule
49		122
50	Create a new coroutine and return it. The first C<transfer> call to this	123	Calls the scheduler. Please note that the current process will not be put
51	coroutine will start execution at the given coderef. If, the subroutine	124	into the ready queue, so calling this function usually means you will
52	returns it will be executed again.	125	never be called again.
53		126
54	If the coderef is omitted this function will create a new "empty"	127	=cut
55	coroutine, i.e. a coroutine that cannot be transfered to but can be used	128
56	to save the current coroutine in.	129	my $prev;
		130
		131	sub schedule {
		132	# should be done using priorities :(
		133	($prev, $current) = ($current, shift @ready \|\| $idle);
		134	Coro::State::transfer($prev, $current);
		135	}
		136
		137	=item yield
		138
		139	Yield to other processes. This function puts the current process into the
		140	ready queue and calls C<schedule>.
		141
		142	=cut
		143
		144	sub yield {
		145	$current->ready;
		146	&schedule;
		147	}
		148
		149	=item terminate
		150
		151	Terminates the current process.
		152
		153	=cut
		154
		155	sub terminate {
		156	&schedule;
		157	}
		158
		159	=back
		160
		161	# dynamic methods
		162
		163	=head2 PROCESS METHODS
		164
		165	These are the methods you can call on process objects.
		166
		167	=over 4
		168
		169	=item new Coro \⊂
		170
		171	Create a new process and return it. When the sub returns the process
		172	automatically terminates. To start the process you must first put it into
		173	the ready queue by calling the ready method.
57		174
58	=cut	175	=cut
59		176
60	sub new {	177	sub new {
		178	my $class = shift;
61	my $class = $_[0];	179	my $proc = $_[0];
62	my $proc = $_[1] \|\| sub { die "tried to transfer to an empty coroutine" };	180	bless {
63	bless _newprocess {	181	_coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
64	do {
65	eval { &$proc };
66	if ($@) {
67	$error_msg = $@;
68	$error_coro = _newprocess { };
69	&transfer($error_coro, $error);
70	}
71	} while (1);
72	}, $class;	182	}, $class;
73	}	183	}
74		184
75	=item $prev->transfer($next)	185	=item $process->ready
76		186
77	Save the state of the current subroutine in $prev and switch to the	187	Put the current process into the ready queue.
78	coroutine saved in $next.
79		188
80	=cut	189	=cut
81		190
82	# I call the _transfer function from a perl function	191	sub ready {
83	# because that way perl saves all important things on	192	push @ready, $_[0];
84	# the stack.
85	sub transfer {
86	_transfer($_[0], $_[1]);
87	}	193	}
88		194
89	=item $error, $error_msg, $error_coro	195	=back
90		196
91	This coroutine will be called on fatal errors. C<$error_msg> and
92	C<$error_coro> return the error message and the error-causing coroutine
93	(NOT an object) respectively. This API might change.
94
95	=cut	197	=cut
96
97	$error_msg =
98	$error_coro = undef;
99
100	$error = _newprocess {
101	print STDERR "FATAL: $error_msg\nprogram aborted\n";
102	exit 50;
103	};
104		198
105	1;	199	1;
106		200
107	=back
108
109	=head1 BUGS
110
111	This module has not yet been extensively tested.
112
113	=head1 SEE ALSO	201	=head1 SEE ALSO
114		202
115	L<Coro::Process>, L<Coro::Signal>.	203	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		204	L<Coro::Signal>, L<Coro::State>.
116		205
117	=head1 AUTHOR	206	=head1 AUTHOR
118		207
119	Marc Lehmann <pcg@goof.com>	208	Marc Lehmann <pcg@goof.com>
120	http://www.goof.com/pcg/marc/	209	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.6 by root, Tue Jul 10 21:19:47 2001 UTC vs. Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.6 by root, Tue Jul 10 21:19:47 2001 UTC vs.
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC