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

Comparing Coro/Coro.pm (file contents):
Revision 1.3 by root, Tue Jul 3 04:02:31 2001 UTC vs.
Revision 1.19 by root, Sat Jul 21 03:44:06 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	$VERSION = 0.09;
		37
		38	@EXPORT = qw(async yield schedule terminate current);
		39	@EXPORT_OK = qw($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 $current (or as function: current)
		78
		79	The current coroutine (the last coroutine switched to). The initial value is C<$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	sub current() { $current }
		91
		92	=item $idle
		93
		94	The coroutine to switch to when no other coroutine is running. The default
		95	implementation prints "FATAL: deadlock detected" and exits.
		96
		97	=cut
		98
		99	# should be done using priorities :(
		100	our $idle = new Coro sub {
		101	print STDERR "FATAL: deadlock detected\n";
		102	exit(51);
		103	};
		104
		105	# we really need priorities...
		106	my @ready; # the ready queue. hehe, rather broken ;)
		107
		108	# static methods. not really.
		109
		110	=head2 STATIC METHODS
		111
		112	Static methods are actually functions that operate on the current process only.
32		113
33	=over 4	114	=over 4
34		115
35	=cut	116	=item async { ... } [@args...]
36		117
37	package Coro;	118	Create a new asynchronous process and return it's process object
		119	(usually unused). When the sub returns the new process is automatically
		120	terminated.
38		121
39	BEGIN {	122	# create a new coroutine that just prints its arguments
40	$VERSION = 0.01;	123	async {
		124	print "@_\n";
		125	} 1,2,3,4;
41		126
42	require XSLoader;	127	The coderef you submit MUST NOT be a closure that refers to variables
43	XSLoader::load Coro, $VERSION;	128	in an outer scope. This does NOT work. Pass arguments into it instead.
44	}
45		129
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	130	=cut
55		131
56	$main = $current = _newprocess {	132	sub async(&@) {
57	# never being called	133	my $pid = new Coro @_;
58	};	134	$pid->ready;
		135	$pid;
		136	}
59		137
60	=item $error, $error_msg, $error_coro	138	=item schedule
61		139
62	This coroutine will be called on fatal errors. C<$error_msg> and	140	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,	141	into the ready queue, so calling this function usually means you will
64	respectively.	142	never be called again.
65		143
66	=cut	144	=cut
67		145
68	$error_msg =	146	my $prev;
69	$error_coro = undef;
70		147
71	$error = _newprocess {	148	sub schedule {
72	print STDERR "FATAL: $error_msg\nprogram aborted\n";	149	# should be done using priorities :(
73	exit 250;	150	($prev, $current) = ($current, shift @ready \|\| $idle);
74	};	151	Coro::State::transfer($prev, $current);
		152	}
75		153
76	=item $coro = new $coderef [, @args]	154	=item yield
77		155
78	Create a new coroutine and return it. The first C<resume> call to this	156	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	157	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		158
83	=cut	159	=cut
		160
		161	sub yield {
		162	$current->ready;
		163	&schedule;
		164	}
		165
		166	=item terminate
		167
		168	Terminates the current process.
		169
		170	Future versions of this function will allow result arguments.
		171
		172	=cut
		173
		174	sub terminate {
		175	$current->{_results} = [@_];
		176	&schedule;
		177	}
		178
		179	=back
		180
		181	# dynamic methods
		182
		183	=head2 PROCESS METHODS
		184
		185	These are the methods you can call on process objects.
		186
		187	=over 4
		188
		189	=item new Coro \&sub [, @args...]
		190
		191	Create a new process and return it. When the sub returns the process
		192	automatically terminates. To start the process you must first put it into
		193	the ready queue by calling the ready method.
		194
		195	The coderef you submit MUST NOT be a closure that refers to variables
		196	in an outer scope. This does NOT work. Pass arguments into it instead.
		197
		198	=cut
		199
		200	sub _newcoro {
		201	terminate &{+shift};
		202	}
84		203
85	sub new {	204	sub new {
86	my $class = $_[0];	205	my $class = shift;
87	my $proc = $_[1];	206	bless {
88	bless _newprocess {	207	_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 ();
96	}, $class;	208	}, $class;
97	}	209	}
98		210
99	=item $coro->resume	211	=item $process->ready
100		212
101	Resume execution at the given coroutine.	213	Put the current process into the ready queue.
102		214
103	=cut	215	=cut
104		216
105	my $prev;	217	sub ready {
106		218	push @ready, $_[0];
107	sub resume {
108	$prev = $current; $current = $_[0];
109	_transfer($prev, $current);
110	}	219	}
		220
		221	=back
		222
		223	=cut
111		224
112	1;	225	1;
113		226
114	=back	227	=head1 BUGS/LIMITATIONS
115		228
116	=head1 BUGS	229	- could be faster, especially when the core would introduce special
117		230	support for coroutines (like it does for threads).
118	This module has not yet been extensively tested.	231	- there is still a memleak on coroutine termination that I could not
		232	identify. Could be as small as a single SV.
		233	- this module is not well-tested.
		234	- if variables or arguments "disappear" (become undef) or become
		235	corrupted please contact the author so he cen iron out the
		236	remaining bugs.
		237	- this module is not thread-safe. You must only ever use this module from
		238	the same thread (this requirement might be loosened in the future to
		239	allow per-thread schedulers, but Coro::Satte does not yet allow this).
119		240
120	=head1 SEE ALSO	241	=head1 SEE ALSO
121		242
122	L<Coro::Process>, L<Coro::Signal>.	243	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		244	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
123		245
124	=head1 AUTHOR	246	=head1 AUTHOR
125		247
126	Marc Lehmann <pcg@goof.com>	248	Marc Lehmann <pcg@goof.com>
127	http://www.goof.com/pcg/marc/	249	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.3 by root, Tue Jul 3 04:02:31 2001 UTC vs. Revision 1.19 by root, Sat Jul 21 03:44:06 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.3 by root, Tue Jul 3 04:02:31 2001 UTC vs.
Revision 1.19 by root, Sat Jul 21 03:44:06 2001 UTC