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

Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.88 by root, Sun Nov 26 02:54:55 2006 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - create an 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	async {
		10	# some asynchronous thread of execution
		11	};
		12
		13	# alternatively create an async process like this:
		14
		15	sub some_func : Coro {
		16	# some more async code
		17	}
		18
		19	cede;
		20
9	=head1 DESCRIPTION	21	=head1 DESCRIPTION
10		22
		23	This module collection manages coroutines. Coroutines are similar to
		24	threads but don't run in parallel.
		25
		26	In this module, coroutines are defined as "callchain + lexical variables
		27	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
		28	callchain, it's own set of lexicals and it's own set of perl's most
		29	important global variables.
		30
		31	=cut
		32
		33	package Coro;
		34
		35	use strict;
		36	no warnings "uninitialized";
		37
		38	use Coro::State;
		39
		40	use base qw(Coro::State Exporter);
		41
		42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
		45
		46	our $VERSION = '3.0';
		47
		48	our @EXPORT = qw(async cede schedule terminate current);
		49	our %EXPORT_TAGS = (
		50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
		51	);
		52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
		53
		54	{
		55	my @async;
		56	my $init;
		57
		58	# this way of handling attributes simply is NOT scalable ;()
		59	sub import {
		60	no strict 'refs';
		61
		62	Coro->export_to_level(1, @_);
		63
		64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
		65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
		66	my ($package, $ref) = (shift, shift);
		67	my @attrs;
		68	for (@_) {
		69	if ($_ eq "Coro") {
		70	push @async, $ref;
		71	unless ($init++) {
		72	eval q{
		73	sub INIT {
		74	&async(pop @async) while @async;
		75	}
		76	};
		77	}
		78	} else {
		79	push @attrs, $_;
		80	}
		81	}
		82	return $old ? $old->($package, $ref, @attrs) : @attrs;
		83	};
		84	}
		85
		86	}
		87
11	=over 4	88	=over 4
12		89
13	=cut
14
15	package Coro;
16
17	BEGIN {
18	$VERSION = 0.01;
19
20	require XSLoader;
21	XSLoader::load Coro, $VERSION;
22	}
23
24	=item $main	90	=item $main
25		91
26	This coroutine represents the main program.	92	This coroutine represents the main program.
27		93
28	=item $current	94	=cut
29		95
		96	$main = new Coro;
		97
		98	=item $current (or as function: current)
		99
30	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
31		102
32	=cut	103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
33		106
34	$main = $current = _newprocess {	107	=cut
35	# never being called	108
		109	# maybe some other module used Coro::Specific before...
		110	if ($current) {
		111	$main->{specific} = $current->{specific};
		112	}
		113
		114	$current = $main;
		115
		116	sub current() { $current }
		117
		118	=item $idle
		119
		120	A callback that is called whenever the scheduler finds no ready coroutines
		121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
		123
		124	This hook is overwritten by modules such as C<Coro::Timer> and
		125	C<Coro::Event> to wait on an external event that hopefully wakes up some
		126	coroutine.
		127
		128	=cut
		129
		130	$idle = sub {
		131	print STDERR "FATAL: deadlock detected\n";
		132	exit (51);
36	};	133	};
37		134
38	=item $error, $error_msg, $error_coro	135	# this coroutine is necessary because a coroutine
		136	# cannot destroy itself.
		137	my @destroy;
		138	my $manager; $manager = new Coro sub {
		139	while () {
		140	# by overwriting the state object with the manager we destroy it
		141	# while still being able to schedule this coroutine (in case it has
		142	# been readied multiple times. this is harmless since the manager
		143	# can be called as many times as neccessary and will always
		144	# remove itself from the runqueue
		145	while (@destroy) {
		146	my $coro = pop @destroy;
		147	$coro->{status} \|\|= [];
		148	$_->ready for @{delete $coro->{join} \|\| []};
39		149
40	This coroutine will be called on fatal errors. C<$error_msg> and	150	# the next line destroys the coro state, but keeps the
41	C<$error_coro> return the error message and the error-causing coroutine,	151	# process itself intact (we basically make it a zombie
42	respectively.	152	# process that always runs the manager thread, so it's possible
43		153	# to transfer() to this process).
44	=cut	154	$coro->_clone_state_from ($manager);
45		155	}
46	$error_msg =	156	&schedule;
47	$error_coro = undef;	157	}
48
49	$error = _newprocess {
50	print STDERR "FATAL: $error_msg, program aborted\n";
51	exit 250;
52	};	158	};
53		159
54	=item $coro = new $coderef [, @args]	160	# static methods. not really.
55		161
56	Create a new coroutine and return it. The first C<resume> call to this	162	=back
57	coroutine will start execution at the given coderef. If it returns it
58	should return a coroutine to switch to. If, after returning, the coroutine
59	is C<resume>d again it starts execution again at the givne coderef.
60		163
		164	=head2 STATIC METHODS
		165
		166	Static methods are actually functions that operate on the current process only.
		167
		168	=over 4
		169
		170	=item async { ... } [@args...]
		171
		172	Create a new asynchronous process and return it's process object
		173	(usually unused). When the sub returns the new process is automatically
		174	terminated.
		175
		176	When the coroutine dies, the program will exit, just as in the main
		177	program.
		178
		179	# create a new coroutine that just prints its arguments
		180	async {
		181	print "@_\n";
		182	} 1,2,3,4;
		183
61	=cut	184	=cut
		185
		186	sub async(&@) {
		187	my $pid = new Coro @_;
		188	$pid->ready;
		189	$pid
		190	}
		191
		192	=item schedule
		193
		194	Calls the scheduler. Please note that the current process will not be put
		195	into the ready queue, so calling this function usually means you will
		196	never be called again.
		197
		198	=cut
		199
		200	=item cede
		201
		202	"Cede" to other processes. This function puts the current process into the
		203	ready queue and calls C<schedule>, which has the effect of giving up the
		204	current "timeslice" to other coroutines of the same or higher priority.
		205
		206	=cut
		207
		208	=item terminate [arg...]
		209
		210	Terminates the current process with the given status values (see L<cancel>).
		211
		212	=cut
		213
		214	sub terminate {
		215	$current->cancel (@_);
		216	}
		217
		218	=back
		219
		220	# dynamic methods
		221
		222	=head2 PROCESS METHODS
		223
		224	These are the methods you can call on process objects.
		225
		226	=over 4
		227
		228	=item new Coro \&sub [, @args...]
		229
		230	Create a new process and return it. When the sub returns the process
		231	automatically terminates as if C<terminate> with the returned values were
		232	called. To make the process run you must first put it into the ready queue
		233	by calling the ready method.
		234
		235	=cut
		236
		237	sub _new_coro {
		238	terminate &{+shift};
		239	}
62		240
63	sub new {	241	sub new {
64	my $class = $_[0];	242	my $class = shift;
65	my $proc = $_[1];
66	bless _newprocess {
67	do {
68	eval { &$proc->resume };
69	if ($@) {
70	($error_msg, $error_coro) = ($@, $current);
71	$error->resume;
72	}
73	} while ();
74	}, $class;
75	}
76		243
77	=item $coro->resume	244	$class->SUPER::new (\&_new_coro, @_)
78
79	Resume execution at the given coroutine.
80
81	=cut
82
83	my $prev;
84
85	sub resume {
86	$prev = $current; $current = $_[0];
87	_transfer($prev, $current);
88	}	245	}
		246
		247	=item $process->ready
		248
		249	Put the given process into the ready queue.
		250
		251	=cut
		252
		253	=item $process->cancel (arg...)
		254
		255	Terminates the given process and makes it return the given arguments as
		256	status (default: the empty list).
		257
		258	=cut
		259
		260	sub cancel {
		261	my $self = shift;
		262	$self->{status} = [@_];
		263	push @destroy, $self;
		264	$manager->ready;
		265	&schedule if $current == $self;
		266	}
		267
		268	=item $process->join
		269
		270	Wait until the coroutine terminates and return any values given to the
		271	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		272	from multiple processes.
		273
		274	=cut
		275
		276	sub join {
		277	my $self = shift;
		278	unless ($self->{status}) {
		279	push @{$self->{join}}, $current;
		280	&schedule;
		281	}
		282	wantarray ? @{$self->{status}} : $self->{status}[0];
		283	}
		284
		285	=item $oldprio = $process->prio ($newprio)
		286
		287	Sets (or gets, if the argument is missing) the priority of the
		288	process. Higher priority processes get run before lower priority
		289	processes. Priorities are small signed integers (currently -4 .. +3),
		290	that you can refer to using PRIO_xxx constants (use the import tag :prio
		291	to get then):
		292
		293	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		294	3 > 1 > 0 > -1 > -3 > -4
		295
		296	# set priority to HIGH
		297	current->prio(PRIO_HIGH);
		298
		299	The idle coroutine ($Coro::idle) always has a lower priority than any
		300	existing coroutine.
		301
		302	Changing the priority of the current process will take effect immediately,
		303	but changing the priority of processes in the ready queue (but not
		304	running) will only take effect after the next schedule (of that
		305	process). This is a bug that will be fixed in some future version.
		306
		307	=item $newprio = $process->nice ($change)
		308
		309	Similar to C<prio>, but subtract the given value from the priority (i.e.
		310	higher values mean lower priority, just as in unix).
		311
		312	=item $olddesc = $process->desc ($newdesc)
		313
		314	Sets (or gets in case the argument is missing) the description for this
		315	process. This is just a free-form string you can associate with a process.
		316
		317	=cut
		318
		319	sub desc {
		320	my $old = $_[0]{desc};
		321	$_[0]{desc} = $_[1] if @_ > 1;
		322	$old;
		323	}
		324
		325	=back
		326
		327	=cut
89		328
90	1;	329	1;
91		330
92	=back	331	=head1 BUGS/LIMITATIONS
93		332
94	=head1 BUGS	333	- you must make very sure that no coro is still active on global
		334	destruction. very bad things might happen otherwise (usually segfaults).
95		335
96	This module has not yet been extensively tested.	336	- this module is not thread-safe. You should only ever use this module
		337	from the same thread (this requirement might be losened in the future
		338	to allow per-thread schedulers, but Coro::State does not yet allow
		339	this).
		340
		341	=head1 SEE ALSO
		342
		343	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
		344
		345	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		346
		347	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		348
		349	Embedding: L<Coro:MakeMaker>
97		350
98	=head1 AUTHOR	351	=head1 AUTHOR
99		352
100	Marc Lehmann <pcg@goof.com>	353	Marc Lehmann <schmorp@schmorp.de>
101	http://www.goof.com/pcg/marc/	354	http://home.schmorp.de/
102		355
103	=cut	356	=cut
104		357

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Comparing Coro/Coro.pm (file contents): Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs. Revision 1.88 by root, Sun Nov 26 02:54:55 2006 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.88 by root, Sun Nov 26 02:54:55 2006 UTC