[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 1.12 by root, Sun Jul 15 15:58:16 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	$VERSION = 0.05;
		32
		33	@EXPORT = qw(async yield schedule);
		34	@EXPORT_OK = qw($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	my $pid = new Coro $_[0];
		119	$pid->ready;
		120	$pid;
46	}	121	}
47		122
48	=item $coro = new [$coderef [, @args]]	123	=item schedule
49		124
50	Create a new coroutine and return it. The first C<transfer> call to this	125	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	126	into the ready queue, so calling this function usually means you will
52	returns it will be executed again.	127	never be called again.
53		128
54	If the coderef is omitted this function will create a new "empty"	129	=cut
55	coroutine, i.e. a coroutine that cannot be transfered to but can be used	130
56	to save the current coroutine in.	131	my $prev;
		132
		133	sub schedule {
		134	local @_;
		135	# should be done using priorities :(
		136	($prev, $current) = ($current, shift @ready \|\| $idle);
		137	Coro::State::transfer($prev, $current);
		138	}
		139
		140	=item yield
		141
		142	Yield to other processes. This function puts the current process into the
		143	ready queue and calls C<schedule>.
		144
		145	=cut
		146
		147	sub yield {
		148	$current->ready;
		149	&schedule;
		150	}
		151
		152	=item terminate
		153
		154	Terminates the current process.
		155
		156	=cut
		157
		158	sub terminate {
		159	&schedule;
		160	}
		161
		162	=back
		163
		164	# dynamic methods
		165
		166	=head2 PROCESS METHODS
		167
		168	These are the methods you can call on process objects.
		169
		170	=over 4
		171
		172	=item new Coro \⊂
		173
		174	Create a new process and return it. When the sub returns the process
		175	automatically terminates. To start the process you must first put it into
		176	the ready queue by calling the ready method.
57		177
58	=cut	178	=cut
59		179
60	sub new {	180	sub new {
		181	my $class = shift;
61	my $class = $_[0];	182	my $proc = $_[0];
62	my $proc = $_[1] \|\| sub { die "tried to transfer to an empty coroutine" };	183	bless {
63	bless _newprocess {	184	_coro_state => new Coro::State ($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;	185	}, $class;
73	}	186	}
74		187
75	=item $prev->transfer($next)	188	=item $process->ready
76		189
77	Save the state of the current subroutine in $prev and switch to the	190	Put the current process into the ready queue.
78	coroutine saved in $next.
79		191
80	=cut	192	=cut
81		193
82	# I call the _transfer function from a perl function	194	sub ready {
83	# because that way perl saves all important things on	195	push @ready, $_[0];
84	# the stack.
85	sub transfer {
86	_transfer($_[0], $_[1]);
87	}	196	}
88		197
89	=item $error, $error_msg, $error_coro	198	=back
90		199
91	This coroutine will be called on fatal errors. C<$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	200	=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		201
105	1;	202	1;
106		203
107	=back
108
109	=head1 BUGS
110
111	This module has not yet been extensively tested.
112
113	=head1 SEE ALSO	204	=head1 SEE ALSO
114		205
115	L<Coro::Process>, L<Coro::Signal>.	206	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		207	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
116		208
117	=head1 AUTHOR	209	=head1 AUTHOR
118		210
119	Marc Lehmann <pcg@goof.com>	211	Marc Lehmann <pcg@goof.com>
120	http://www.goof.com/pcg/marc/	212	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 1.12 by root, Sun Jul 15 15:58:16 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 1.12 by root, Sun Jul 15 15:58:16 2001 UTC