[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 1.17 by root, Thu Jul 19 02:45:09 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	This module collection manages coroutines. Coroutines are similar to
25	allow you to run more than one "thread of execution" in parallel. Unlike	24	Threads but don't run in parallel.
26	threads this, only voluntary switching is used so locking problems are
27	greatly reduced.
28		25
29	Although this is the "main" module of the Coro family it provides only	26	This module is still experimental, see the BUGS section below.
30	low-level functionality. See L<Coro::Process> and related modules for a	27
31	more useful process abstraction including scheduling.	28	=cut
		29
		30	package Coro;
		31
		32	use Coro::State;
		33
		34	use base Exporter;
		35
		36	$VERSION = 0.08;
		37
		38	@EXPORT = qw(async yield schedule terminate);
		39	@EXPORT_OK = qw($current);
		40
		41	{
		42	use subs 'async';
		43
		44	my @async;
		45
		46	# this way of handling attributes simply is NOT scalable ;()
		47	sub import {
		48	Coro->export_to_level(1, @_);
		49	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
		50	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
		51	my ($package, $ref) = (shift, shift);
		52	my @attrs;
		53	for (@_) {
		54	if ($_ eq "Coro") {
		55	push @async, $ref;
		56	} else {
		57	push @attrs, $_;
		58	}
		59	}
		60	return $old ? $old->($package, $ref, @attrs) : @attrs;
		61	};
		62	}
		63
		64	sub INIT {
		65	async pop @async while @async;
		66	}
		67	}
		68
		69	=item $main
		70
		71	This coroutine represents the main program.
		72
		73	=cut
		74
		75	our $main = new Coro;
		76
		77	=item $current
		78
		79	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
		80
		81	=cut
		82
		83	# maybe some other module used Coro::Specific before...
		84	if ($current) {
		85	$main->{specific} = $current->{specific};
		86	}
		87
		88	our $current = $main;
		89
		90	=item $idle
		91
		92	The coroutine to switch to when no other coroutine is running. The default
		93	implementation prints "FATAL: deadlock detected" and exits.
		94
		95	=cut
		96
		97	# should be done using priorities :(
		98	our $idle = new Coro sub {
		99	print STDERR "FATAL: deadlock detected\n";
		100	exit(51);
		101	};
		102
		103	# we really need priorities...
		104	my @ready; # the ready queue. hehe, rather broken ;)
		105
		106	# static methods. not really.
		107
		108	=head2 STATIC METHODS
		109
		110	Static methods are actually functions that operate on the current process only.
32		111
33	=over 4	112	=over 4
34		113
35	=cut	114	=item async { ... } [@args...]
36		115
37	package Coro;	116	Create a new asynchronous process and return it's process object
		117	(usually unused). When the sub returns the new process is automatically
		118	terminated.
38		119
39	BEGIN {	120	# create a new coroutine that just prints its arguments
40	$VERSION = 0.03;	121	async {
		122	print "@_\n";
		123	} 1,2,3,4;
41		124
42	require XSLoader;	125	The coderef you submit MUST NOT be a closure that refers to variables
43	XSLoader::load Coro, $VERSION;	126	in an outer scope. This does NOT work. Pass arguments into it instead.
44	}
45		127
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	128	=cut
55		129
56	$main = $current = _newprocess {	130	sub async(&@) {
57	# never being called	131	my $pid = new Coro @_;
58	};	132	$pid->ready;
		133	$pid;
		134	}
59		135
60	=item $error, $error_msg, $error_coro	136	=item schedule
61		137
62	This coroutine will be called on fatal errors. C<$error_msg> and	138	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,	139	into the ready queue, so calling this function usually means you will
64	respectively.	140	never be called again.
65		141
66	=cut	142	=cut
67		143
68	$error_msg =	144	my $prev;
69	$error_coro = undef;
70		145
71	$error = _newprocess {	146	sub schedule {
72	print STDERR "FATAL: $error_msg\nprogram aborted\n";	147	# should be done using priorities :(
73	exit 250;	148	($prev, $current) = ($current, shift @ready \|\| $idle);
74	};	149	Coro::State::transfer($prev, $current);
		150	}
75		151
76	=item $coro = new $coderef [, @args]	152	=item yield
77		153
78	Create a new coroutine and return it. The first C<resume> call to this	154	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	155	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		156
83	=cut	157	=cut
		158
		159	sub yield {
		160	$current->ready;
		161	&schedule;
		162	}
		163
		164	=item terminate
		165
		166	Terminates the current process.
		167
		168	Future versions of this function will allow result arguments.
		169
		170	=cut
		171
		172	sub terminate {
		173	$current->{_results} = [@_];
		174	&schedule;
		175	}
		176
		177	=back
		178
		179	# dynamic methods
		180
		181	=head2 PROCESS METHODS
		182
		183	These are the methods you can call on process objects.
		184
		185	=over 4
		186
		187	=item new Coro \&sub [, @args...]
		188
		189	Create a new process and return it. When the sub returns the process
		190	automatically terminates. To start the process you must first put it into
		191	the ready queue by calling the ready method.
		192
		193	The coderef you submit MUST NOT be a closure that refers to variables
		194	in an outer scope. This does NOT work. Pass arguments into it instead.
		195
		196	=cut
		197
		198	sub _newcoro {
		199	terminate &{+shift};
		200	}
84		201
85	sub new {	202	sub new {
86	my $class = $_[0];	203	my $class = shift;
87	my $proc = $_[1];	204	bless {
88	bless _newprocess {	205	_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;	206	}, $class;
97	}	207	}
98		208
99	=item $coro->resume	209	=item $process->ready
100		210
101	Resume execution at the given coroutine.	211	Put the current process into the ready queue.
102		212
103	=cut	213	=cut
104		214
105	my $prev;	215	sub ready {
106		216	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	}	217	}
		218
		219	=back
		220
		221	=cut
114		222
115	1;	223	1;
116		224
117	=back	225	=head1 BUGS/LIMITATIONS
118		226
119	=head1 BUGS	227	- could be faster, especially when the core would introduce special
120		228	support for coroutines (like it does for threads).
121	This module has not yet been extensively tested.	229	- there is still a memleak on coroutine termination that I could not
		230	identify. Could be as small as a single SV.
		231	- this module is not well-tested.
		232	- if variables or arguments "disappear" (become undef) or become
		233	corrupted please contact the author so he cen iron out the
		234	remaining bugs.
		235	- this module is not thread-safe. You must only ever use this module from
		236	the same thread (this requirement might be loosened in the future to
		237	allow per-thread schedulers, but Coro::Satte does not yet allow this).
122		238
123	=head1 SEE ALSO	239	=head1 SEE ALSO
124		240
125	L<Coro::Process>, L<Coro::Signal>.	241	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		242	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
126		243
127	=head1 AUTHOR	244	=head1 AUTHOR
128		245
129	Marc Lehmann <pcg@goof.com>	246	Marc Lehmann <pcg@goof.com>
130	http://www.goof.com/pcg/marc/	247	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 1.17 by root, Thu Jul 19 02:45:09 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 1.17 by root, Thu Jul 19 02:45:09 2001 UTC