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

Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC

…		…
14		14
15	sub some_func : Coro {	15	sub some_func : Coro {
16	# some more async code	16	# some more async code
17	}	17	}
18		18
19	yield;	19	cede;
20		20
21	=head1 DESCRIPTION	21	=head1 DESCRIPTION
22		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
23	=cut	31	=cut
24		32
25	package Coro;	33	package Coro;
26		34
		35	use strict;
		36	no warnings "uninitialized";
		37
27	use Coro::State;	38	use Coro::State;
28		39
29	use base Exporter;	40	use base qw(Coro::State Exporter);
30		41
		42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
		45
31	$VERSION = 0.03;	46	our $VERSION = '3.0';
32		47
33	@EXPORT = qw(async yield schedule);	48	our @EXPORT = qw(async cede schedule terminate current);
34	@EXPORT_OK = qw($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}};
35		53
36	{	54	{
37	use subs 'async';
38
39	my @async;	55	my @async;
		56	my $init;
40		57
41	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
42	sub import {	59	sub import {
		60	no strict 'refs';
		61
43	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
44	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
45	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
46	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
47	my @attrs;	67	my @attrs;
48	for (@_) {	68	for (@_) {
49	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
50	push @async, $ref;	70	push @async, $ref;
		71	unless ($init++) {
		72	eval q{
		73	sub INIT {
		74	&async(pop @async) while @async;
		75	}
		76	};
		77	}
51	} else {	78	} else {
52	push @attrs, @_;	79	push @attrs, $_;
53	}	80	}
54	}	81	}
55	return $old ? $old->($package, $name, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
56	};	83	};
57	}	84	}
58		85
59	sub INIT {
60	async pop @async while @async;
61	}
62	}	86	}
63		87
64	my $idle = new Coro sub {	88	=over 4
65	&yield while 1;
66	};
67		89
68	=item $main	90	=item $main
69		91
70	This coroutine represents the main program.	92	This coroutine represents the main program.
71		93
72	=cut	94	=cut
73		95
74	$main = new Coro;	96	$main = new Coro;
75		97
76	=item $current	98	=item $current (or as function: current)
77		99
78	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
79		106
80	=cut	107	=cut
81		108
82	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
83	if ($current) {	110	if ($current) {
84	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
85	}	112	}
86		113
87	$current = $main;	114	$current = $main;
88		115
89	# we really need priorities...	116	sub current() { $current }
90	my @ready = (); # the ready queue. hehe, rather broken ;)	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);
		133	};
		134
		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} \|\| []};
		149
		150	# the next line destroys the coro state, but keeps the
		151	# process itself intact (we basically make it a zombie
		152	# process that always runs the manager thread, so it's possible
		153	# to transfer() to this process).
		154	$coro->_clone_state_from ($manager);
		155	}
		156	&schedule;
		157	}
		158	};
91		159
92	# static methods. not really.	160	# static methods. not really.
93		161
		162	=back
		163
94	=head2 STATIC METHODS	164	=head2 STATIC METHODS
95		165
96	Static methods are actually functions that operate on the current process only.	166	Static methods are actually functions that operate on the current process only.
97		167
98	=over 4	168	=over 4
99		169
100	=item async { ... };	170	=item async { ... } [@args...]
101		171
102	Create a new asynchronous process and return it's process object	172	Create a new asynchronous process and return it's process object
103	(usually unused). When the sub returns the new process is automatically	173	(usually unused). When the sub returns the new process is automatically
104	terminated.	174	terminated.
105		175
106	=cut	176	Calling C<exit> in a coroutine will not work correctly, so do not do that.
107		177
		178	When the coroutine dies, the program will exit, just as in the main
		179	program.
		180
		181	# create a new coroutine that just prints its arguments
		182	async {
		183	print "@_\n";
		184	} 1,2,3,4;
		185
		186	=cut
		187
108	sub async(&) {	188	sub async(&@) {
109	(new Coro $_[0])->ready;	189	my $pid = new Coro @_;
		190	$pid->ready;
		191	$pid
110	}	192	}
111		193
112	=item schedule	194	=item schedule
113		195
114	Calls the scheduler. Please note that the current process will not be put	196	Calls the scheduler. Please note that the current process will not be put
115	into the ready queue, so calling this function usually means you will	197	into the ready queue, so calling this function usually means you will
116	never be called again.	198	never be called again.
117		199
118	=cut	200	=cut
119		201
120	my $prev;
121
122	sub schedule {
123	($prev, $current) = ($current, shift @ready);
124	Coro::State::transfer($prev, $current);
125	}
126
127	=item yield	202	=item cede
128		203
129	Yield to other processes. This function puts the current process into the	204	"Cede" to other processes. This function puts the current process into the
130	ready queue and calls C<schedule>.	205	ready queue and calls C<schedule>, which has the effect of giving up the
		206	current "timeslice" to other coroutines of the same or higher priority.
131		207
132	=cut	208	=cut
133		209
134	sub yield {
135	$current->ready;
136	&schedule;
137	}
138
139	=item terminate	210	=item terminate [arg...]
140		211
141	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
142		213
143	=cut	214	=cut
144		215
145	sub terminate {	216	sub terminate {
146	&schedule;	217	$current->cancel (@_);
147	}	218	}
148		219
149	=back	220	=back
150		221
151	# dynamic methods	222	# dynamic methods
…		…
154		225
155	These are the methods you can call on process objects.	226	These are the methods you can call on process objects.
156		227
157	=over 4	228	=over 4
158		229
159	=item new Coro \⊂	230	=item new Coro \&sub [, @args...]
160		231
161	Create a new process and return it. When the sub returns the process	232	Create a new process and return it. When the sub returns the process
162	automatically terminates. To start the process you must first put it into	233	automatically terminates as if C<terminate> with the returned values were
		234	called. To make the process run you must first put it into the ready queue
163	the ready queue by calling the ready method.	235	by calling the ready method.
164		236
		237	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		238
165	=cut	239	=cut
		240
		241	sub _new_coro {
		242	terminate &{+shift};
		243	}
166		244
167	sub new {	245	sub new {
168	my $class = shift;	246	my $class = shift;
169	my $proc = $_[0];
170	bless {
171	_coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc),
172	}, $class;
173	}
174		247
		248	$class->SUPER::new (\&_new_coro, @_)
		249	}
		250
175	=item $process->ready	251	=item $success = $process->ready
176		252
177	Put the current process into the ready queue.	253	Put the given process into the ready queue (according to it's priority)
		254	and return true. If the process is already in the ready queue, do nothing
		255	and return false.
178		256
179	=cut	257	=item $is_ready = $process->is_ready
180		258
181	sub ready {	259	Return wether the process is currently the ready queue or not,
182	push @ready, $_[0];	260
		261	=item $process->cancel (arg...)
		262
		263	Terminates the given process and makes it return the given arguments as
		264	status (default: the empty list).
		265
		266	=cut
		267
		268	sub cancel {
		269	my $self = shift;
		270	$self->{status} = [@_];
		271	push @destroy, $self;
		272	$manager->ready;
		273	&schedule if $current == $self;
		274	}
		275
		276	=item $process->join
		277
		278	Wait until the coroutine terminates and return any values given to the
		279	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		280	from multiple processes.
		281
		282	=cut
		283
		284	sub join {
		285	my $self = shift;
		286	unless ($self->{status}) {
		287	push @{$self->{join}}, $current;
		288	&schedule;
		289	}
		290	wantarray ? @{$self->{status}} : $self->{status}[0];
		291	}
		292
		293	=item $oldprio = $process->prio ($newprio)
		294
		295	Sets (or gets, if the argument is missing) the priority of the
		296	process. Higher priority processes get run before lower priority
		297	processes. Priorities are small signed integers (currently -4 .. +3),
		298	that you can refer to using PRIO_xxx constants (use the import tag :prio
		299	to get then):
		300
		301	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		302	3 > 1 > 0 > -1 > -3 > -4
		303
		304	# set priority to HIGH
		305	current->prio(PRIO_HIGH);
		306
		307	The idle coroutine ($Coro::idle) always has a lower priority than any
		308	existing coroutine.
		309
		310	Changing the priority of the current process will take effect immediately,
		311	but changing the priority of processes in the ready queue (but not
		312	running) will only take effect after the next schedule (of that
		313	process). This is a bug that will be fixed in some future version.
		314
		315	=item $newprio = $process->nice ($change)
		316
		317	Similar to C<prio>, but subtract the given value from the priority (i.e.
		318	higher values mean lower priority, just as in unix).
		319
		320	=item $olddesc = $process->desc ($newdesc)
		321
		322	Sets (or gets in case the argument is missing) the description for this
		323	process. This is just a free-form string you can associate with a process.
		324
		325	=cut
		326
		327	sub desc {
		328	my $old = $_[0]{desc};
		329	$_[0]{desc} = $_[1] if @_ > 1;
		330	$old;
183	}	331	}
184		332
185	=back	333	=back
186		334
187	=cut	335	=cut
188		336
189	1;	337	1;
190		338
		339	=head1 BUGS/LIMITATIONS
		340
		341	- you must make very sure that no coro is still active on global
		342	destruction. very bad things might happen otherwise (usually segfaults).
		343
		344	- this module is not thread-safe. You should only ever use this module
		345	from the same thread (this requirement might be losened in the future
		346	to allow per-thread schedulers, but Coro::State does not yet allow
		347	this).
		348
		349	=head1 SEE ALSO
		350
		351	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
		352
		353	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		354
		355	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		356
		357	Embedding: L<Coro:MakeMaker>
		358
191	=head1 AUTHOR	359	=head1 AUTHOR
192		360
193	Marc Lehmann <pcg@goof.com>	361	Marc Lehmann <schmorp@schmorp.de>
194	http://www.goof.com/pcg/marc/	362	http://home.schmorp.de/
195		363
196	=cut	364	=cut
197		365

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Comparing Coro/Coro.pm (file contents): Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs. Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.8 by root, Sat Jul 14 22:14:21 2001 UTC vs.
Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC