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

Comparing Coro/Coro.pm (file contents):
Revision 1.4 by root, Tue Jul 3 05:05:45 2001 UTC vs.
Revision 1.13 by root, Tue Jul 17 00:24:14 2001 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - create and 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	$new = new Coro sub {	9	async {
10	print "in coroutine, switching back\n";	10	# some asynchronous thread of execution
11	$Coro::main->resume;
12	print "in coroutine again, switching back\n";
13	$Coro::main->resume;
14	};	11	};
15		12
16	print "in main, switching to coroutine\n";	13	# alternatively create an async process like this:
17	$new->resume;	14
18	print "back in main, switch to coroutine again\n";	15	sub some_func : Coro {
19	$new->resume;	16	# some more async code
20	print "back in main\n";	17	}
		18
		19	yield;
21		20
22	=head1 DESCRIPTION	21	=head1 DESCRIPTION
23		22
24	This module implements coroutines. Coroutines, similar to continuations,	23	=cut
25	allow you to run more than one "thread of execution" in parallel. Unlike
26	threads this, only voluntary switching is used so locking problems are
27	greatly reduced.
28		24
29	Although this is the "main" module of the Coro family it provides only	25	package Coro;
30	low-level functionality. See L<Coro::Process> and related modules for a	26
31	more useful process abstraction including scheduling.	27	use Coro::State;
		28
		29	use base Exporter;
		30
		31	$VERSION = 0.05;
		32
		33	@EXPORT = qw(async yield schedule terminate);
		34	@EXPORT_OK = qw($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; #d#
		100	our @ready = (); # the ready queue. hehe, rather broken ;)
		101
		102	# static methods. not really.
		103
		104	=head2 STATIC METHODS
		105
		106	Static methods are actually functions that operate on the current process only.
32		107
33	=over 4	108	=over 4
34		109
35	=cut	110	=item async { ... } [@args...]
36		111
37	package Coro;	112	Create a new asynchronous process and return it's process object
		113	(usually unused). When the sub returns the new process is automatically
		114	terminated.
38		115
39	BEGIN {	116	# create a new coroutine that just prints its arguments
40	$VERSION = 0.01;	117	async {
		118	print "@_\n";
		119	} 1,2,3,4;
41		120
42	require XSLoader;	121	The coderef you submit MUST NOT be a closure that refers to variables
43	XSLoader::load Coro, $VERSION;	122	in an outer scope. This does NOT work. Pass arguments into it instead.
44	}
45		123
46	=item $main
47
48	This coroutine represents the main program.
49
50	=item $current
51
52	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
53
54	=cut	124	=cut
55		125
56	$main = $current = _newprocess {	126	sub async(&@) {
57	# never being called	127	my $pid = new Coro @_;
58	};	128	$pid->ready;
		129	$pid;
		130	}
59		131
60	=item $error, $error_msg, $error_coro	132	=item schedule
61		133
62	This coroutine will be called on fatal errors. C<$error_msg> and	134	Calls the scheduler. Please note that the current process will not be put
63	C<$error_coro> return the error message and the error-causing coroutine,	135	into the ready queue, so calling this function usually means you will
64	respectively.	136	never be called again.
65		137
66	=cut	138	=cut
67		139
68	$error_msg =	140	my $prev;
69	$error_coro = undef;
70		141
71	$error = _newprocess {	142	sub schedule {
72	print STDERR "FATAL: $error_msg\nprogram aborted\n";	143	# should be done using priorities :(
73	exit 250;	144	($prev, $current) = ($current, shift @ready \|\| $idle);
74	};	145	Coro::State::transfer($prev, $current);
		146	}
75		147
76	=item $coro = new $coderef [, @args]	148	=item yield
77		149
78	Create a new coroutine and return it. The first C<resume> call to this	150	Yield to other processes. This function puts the current process into the
79	coroutine will start execution at the given coderef. If it returns it	151	ready queue and calls C<schedule>.
80	should return a coroutine to switch to. If, after returning, the coroutine
81	is C<resume>d again it starts execution again at the givne coderef.
82		152
83	=cut	153	=cut
		154
		155	sub yield {
		156	$current->ready;
		157	&schedule;
		158	}
		159
		160	=item terminate
		161
		162	Terminates the current process.
		163
		164	Future versions of this function will allow result arguments.
		165
		166	=cut
		167
		168	sub terminate {
		169	$current->{_results} = [@_];
		170	&schedule;
		171	}
		172
		173	=back
		174
		175	# dynamic methods
		176
		177	=head2 PROCESS METHODS
		178
		179	These are the methods you can call on process objects.
		180
		181	=over 4
		182
		183	=item new Coro \&sub [, @args...]
		184
		185	Create a new process and return it. When the sub returns the process
		186	automatically terminates. To start the process you must first put it into
		187	the ready queue by calling the ready method.
		188
		189	The coderef you submit MUST NOT be a closure that refers to variables
		190	in an outer scope. This does NOT work. Pass arguments into it instead.
		191
		192	=cut
		193
		194	sub _newcoro {
		195	terminate &{+shift};
		196	}
84		197
85	sub new {	198	sub new {
86	my $class = $_[0];	199	my $class = shift;
87	my $proc = $_[1];	200	bless {
88	bless _newprocess {	201	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
89	do {
90	eval { &$proc->resume };
91	if ($@) {
92	($error_msg, $error_coro) = ($@, $current);
93	$error->resume;
94	}
95	} while (1);
96	}, $class;	202	}, $class;
97	}	203	}
98		204
99	=item $coro->resume	205	=item $process->ready
100		206
101	Resume execution at the given coroutine.	207	Put the current process into the ready queue.
102		208
103	=cut	209	=cut
104		210
105	my $prev;	211	sub ready {
106		212	push @ready, $_[0];
107	sub resume {
108	$prev = $current; $current = $_[0];
109	_transfer($prev, $current);
110	}	213	}
		214
		215	=back
		216
		217	=cut
111		218
112	1;	219	1;
113		220
114	=back
115
116	=head1 BUGS
117
118	This module has not yet been extensively tested.
119
120	=head1 SEE ALSO	221	=head1 SEE ALSO
121		222
122	L<Coro::Process>, L<Coro::Signal>.	223	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		224	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
123		225
124	=head1 AUTHOR	226	=head1 AUTHOR
125		227
126	Marc Lehmann <pcg@goof.com>	228	Marc Lehmann <pcg@goof.com>
127	http://www.goof.com/pcg/marc/	229	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.4 by root, Tue Jul 3 05:05:45 2001 UTC vs. Revision 1.13 by root, Tue Jul 17 00:24:14 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.4 by root, Tue Jul 3 05:05:45 2001 UTC vs.
Revision 1.13 by root, Tue Jul 17 00:24:14 2001 UTC