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

Comparing Coro/Coro.pm (file contents):
Revision 1.5 by root, Tue Jul 10 01:43:21 2001 UTC vs.
Revision 1.11 by root, Sun Jul 15 03:24:18 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	$VERSION = 0.04;
		32
		33	@EXPORT = qw(async yield schedule);
		34	@EXPORT_OK = qw($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.
32		106
33	=over 4	107	=over 4
34		108
35	=cut	109	=item async { ... };
36		110
37	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.
38		114
39	BEGIN {
40	$VERSION = 0.03;
41
42	require XSLoader;
43	XSLoader::load Coro, $VERSION;
44	}
45
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	115	=cut
55		116
56	$main = $current = _newprocess {	117	sub async(&) {
57	# never being called	118	my $pid = new Coro $_[0];
58	};	119	$pid->ready;
		120	$pid;
		121	}
59		122
60	=item $error, $error_msg, $error_coro	123	=item schedule
61		124
62	This coroutine will be called on fatal errors. C<$error_msg> and	125	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,	126	into the ready queue, so calling this function usually means you will
64	respectively.	127	never be called again.
65		128
66	=cut	129	=cut
67		130
68	$error_msg =	131	my $prev;
69	$error_coro = undef;
70		132
71	$error = _newprocess {	133	sub schedule {
72	print STDERR "FATAL: $error_msg\nprogram aborted\n";	134	# should be done using priorities :(
73	exit 250;	135	($prev, $current) = ($current, shift @ready \|\| $idle);
74	};	136	Coro::State::transfer($prev, $current);
		137	}
75		138
76	=item $coro = new $coderef [, @args]	139	=item yield
77		140
78	Create a new coroutine and return it. The first C<resume> call to this	141	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	142	ready queue and calls C<schedule>.
80	should return a coroutine to switch to. If, after returning, the coroutine	143
81	is C<resume>d again it starts execution again at the givne coderef.	144	=cut
		145
		146	sub yield {
		147	$current->ready;
		148	&schedule;
		149	}
		150
		151	=item terminate
		152
		153	Terminates the current process.
		154
		155	=cut
		156
		157	sub terminate {
		158	&schedule;
		159	}
		160
		161	=back
		162
		163	# dynamic methods
		164
		165	=head2 PROCESS METHODS
		166
		167	These are the methods you can call on process objects.
		168
		169	=over 4
		170
		171	=item new Coro \⊂
		172
		173	Create a new process and return it. When the sub returns the process
		174	automatically terminates. To start the process you must first put it into
		175	the ready queue by calling the ready method.
82		176
83	=cut	177	=cut
84		178
85	sub new {	179	sub new {
86	my $class = $_[0];	180	my $class = shift;
87	my $proc = $_[1];	181	my $proc = $_[0];
88	bless _newprocess {	182	bless {
89	do {	183	_coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
90	eval { &$proc->resume };
91	if ($@) {
92	($error_msg, $error_coro) = ($@, $current);
93	$error->resume;
94	}
95	} while (1);
96	}, $class;	184	}, $class;
97	}	185	}
98		186
99	=item $coro->resume	187	=item $process->ready
100		188
101	Resume execution at the given coroutine.	189	Put the current process into the ready queue.
102		190
103	=cut	191	=cut
104		192
105	my $prev;	193	sub ready {
106		194	push @ready, $_[0];
107	# I call the _transfer function from a pelr function
108	# because that way perl saves all important things on
109	# the stack.
110	sub resume {
111	$prev = $current; $current = $_[0];
112	_transfer($prev, $current);
113	}	195	}
		196
		197	=back
		198
		199	=cut
114		200
115	1;	201	1;
116		202
117	=back
118
119	=head1 BUGS
120
121	This module has not yet been extensively tested.
122
123	=head1 SEE ALSO	203	=head1 SEE ALSO
124		204
125	L<Coro::Process>, L<Coro::Signal>.	205	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		206	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
126		207
127	=head1 AUTHOR	208	=head1 AUTHOR
128		209
129	Marc Lehmann <pcg@goof.com>	210	Marc Lehmann <pcg@goof.com>
130	http://www.goof.com/pcg/marc/	211	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.5 by root, Tue Jul 10 01:43:21 2001 UTC vs. Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.5 by root, Tue Jul 10 01:43:21 2001 UTC vs.
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC