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

Comparing Coro/Coro.pm (file contents):
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs.
Revision 1.83 by root, Fri Nov 24 15:34:33 2006 UTC

…		…
19	cede;	19	cede;
20		20
21	=head1 DESCRIPTION	21	=head1 DESCRIPTION
22		22
23	This module collection manages coroutines. Coroutines are similar to	23	This module collection manages coroutines. Coroutines are similar to
24	Threads but don't run in parallel.	24	threads but don't run in parallel.
25
26	This module is still experimental, see the BUGS section below.
27		25
28	In this module, coroutines are defined as "callchain + lexical variables	26	In this module, coroutines are defined as "callchain + lexical variables
29	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own	27	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30	callchain, it's own set of lexicals and it's own set of perl's most	28	callchain, it's own set of lexicals and it's own set of perl's most
31	important global variables.	29	important global variables.
32		30
33	=cut	31	=cut
34		32
35	package Coro;	33	package Coro;
36		34
		35	use strict;
		36	no warnings "uninitialized";
		37
37	use Coro::State;	38	use Coro::State;
38		39
39	use base Exporter;	40	use base qw(Coro::State Exporter);
40		41
41	$VERSION = 0.10;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
		46	our $VERSION = '2.5';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
44	@EXPORT_OK = qw($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}};
45		53
46	{	54	{
47	my @async;	55	my @async;
		56	my $init;
48		57
49	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
50	sub import {	59	sub import {
		60	no strict 'refs';
		61
51	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
52	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
53	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
54	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
55	my @attrs;	67	my @attrs;
56	for (@_) {	68	for (@_) {
57	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
58	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	}
59	} else {	78	} else {
60	push @attrs, $_;	79	push @attrs, $_;
61	}	80	}
62	}	81	}
63	return $old ? $old->($package, $ref, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
64	};	83	};
65	}	84	}
66		85
67	sub INIT {
68	&async(pop @async) while @async;
69	}
70	}	86	}
		87
		88	=over 4
71		89
72	=item $main	90	=item $main
73		91
74	This coroutine represents the main program.	92	This coroutine represents the main program.
75		93
76	=cut	94	=cut
77		95
78	our $main = new Coro;	96	$main = new Coro;
79		97
80	=item $current (or as function: current)	98	=item $current (or as function: current)
81		99
82	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
83		106
84	=cut	107	=cut
85		108
86	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
87	if ($current) {	110	if ($current) {
88	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
89	}	112	}
90		113
91	our $current = $main;	114	$current = $main;
92		115
93	sub current() { $current }	116	sub current() { $current }
94		117
95	=item $idle	118	=item $idle
96		119
97	The coroutine to switch to when no other coroutine is running. The default	120	A callback that is called whenever the scheduler finds no ready coroutines
98	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
99		123
100	=cut	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.
101		127
102	# should be done using priorities :(	128	=cut
103	our $idle = new Coro sub {	129
		130	$idle = sub {
104	print STDERR "FATAL: deadlock detected\n";	131	print STDERR "FATAL: deadlock detected\n";
105	exit(51);	132	exit (51);
106	};	133	};
107		134
108	# we really need priorities...	135	# this coroutine is necessary because a coroutine
109	my @ready; # the ready queue. hehe, rather broken ;)	136	# cannot destroy itself.
		137	my @destroy;
		138	my $manager;
		139	$manager = new Coro sub {
		140	while () {
		141	# by overwriting the state object with the manager we destroy it
		142	# while still being able to schedule this coroutine (in case it has
		143	# been readied multiple times. this is harmless since the manager
		144	# can be called as many times as neccessary and will always
		145	# remove itself from the runqueue
		146	while (@destroy) {
		147	my $coro = pop @destroy;
		148	$coro->{status} \|\|= [];
		149	$_->ready for @{delete $coro->{join} \|\| []};
		150
		151	# the next line destroys the coro state, but keeps the
		152	# process itself intact (we basically make it a zombie
		153	# process that always runs the manager thread, so it's possible
		154	# to transfer() to this process).
		155	$coro->_clone_state_from ($manager);
		156	}
		157	&schedule;
		158	}
		159	};
110		160
111	# static methods. not really.	161	# static methods. not really.
		162
		163	=back
112		164
113	=head2 STATIC METHODS	165	=head2 STATIC METHODS
114		166
115	Static methods are actually functions that operate on the current process only.	167	Static methods are actually functions that operate on the current process only.
116		168
…		…
119	=item async { ... } [@args...]	171	=item async { ... } [@args...]
120		172
121	Create a new asynchronous process and return it's process object	173	Create a new asynchronous process and return it's process object
122	(usually unused). When the sub returns the new process is automatically	174	(usually unused). When the sub returns the new process is automatically
123	terminated.	175	terminated.
		176
		177	When the coroutine dies, the program will exit, just as in the main
		178	program.
124		179
125	# create a new coroutine that just prints its arguments	180	# create a new coroutine that just prints its arguments
126	async {	181	async {
127	print "@_\n";	182	print "@_\n";
128	} 1,2,3,4;	183	} 1,2,3,4;
129		184
130	The coderef you submit MUST NOT be a closure that refers to variables
131	in an outer scope. This does NOT work. Pass arguments into it instead.
132
133	=cut	185	=cut
134		186
135	sub async(&@) {	187	sub async(&@) {
136	my $pid = new Coro @_;	188	my $pid = new Coro @_;
		189	$manager->ready; # this ensures that the stack is cloned from the manager
137	$pid->ready;	190	$pid->ready;
138	$pid;	191	$pid;
139	}	192	}
140		193
141	=item schedule	194	=item schedule
…		…
144	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
145	never be called again.	198	never be called again.
146		199
147	=cut	200	=cut
148		201
149	my $prev;
150
151	sub schedule {
152	# should be done using priorities :(
153	($prev, $current) = ($current, shift @ready \|\| $idle);
154	Coro::State::transfer($prev, $current);
155	}
156
157	=item cede	202	=item cede
158		203
159	"Cede" to other processes. This function puts the current process into the	204	"Cede" to other processes. This function puts the current process into the
160	ready queue and calls C<schedule>, which has the effect of giving up the	205	ready queue and calls C<schedule>, which has the effect of giving up the
161	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
162		207
163	=cut	208	=cut
164		209
165	sub cede {
166	$current->ready;
167	&schedule;
168	}
169
170	=item terminate	210	=item terminate [arg...]
171		211
172	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
173		213
174	Future versions of this function will allow result arguments.
175
176	=cut	214	=cut
177		215
178	# this coroutine is necessary because a coroutine	216	sub terminate {
179	# cannot destroy itself.	217	$current->cancel (@_);
180	my @destroy;	218	}
181	my $terminate = new Coro sub {	219
182	while() {	220	=back
183	delete ((pop @destroy)->{_coro_state}) while @destroy;	221
		222	# dynamic methods
		223
		224	=head2 PROCESS METHODS
		225
		226	These are the methods you can call on process objects.
		227
		228	=over 4
		229
		230	=item new Coro \&sub [, @args...]
		231
		232	Create a new process and return it. When the sub returns the process
		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
		235	by calling the ready method.
		236
		237	=cut
		238
		239	sub _newcoro {
		240	terminate &{+shift};
		241	}
		242
		243	sub new {
		244	my $class = shift;
		245
		246	$class->SUPER::new (\&_newcoro, @_)
		247	}
		248
		249	=item $process->ready
		250
		251	Put the given process into the ready queue.
		252
		253	=cut
		254
		255	=item $process->cancel (arg...)
		256
		257	Terminates the given process and makes it return the given arguments as
		258	status (default: the empty list).
		259
		260	=cut
		261
		262	sub cancel {
		263	my $self = shift;
		264	$self->{status} = [@_];
		265	push @destroy, $self;
		266	$manager->ready;
		267	&schedule if $current == $self;
		268	}
		269
		270	=item $process->join
		271
		272	Wait until the coroutine terminates and return any values given to the
		273	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		274	from multiple processes.
		275
		276	=cut
		277
		278	sub join {
		279	my $self = shift;
		280	unless ($self->{status}) {
		281	push @{$self->{join}}, $current;
184	&schedule;	282	&schedule;
185	}	283	}
186	};	284	wantarray ? @{$self->{status}} : $self->{status}[0];
		285	}
187		286
188	sub terminate {	287	=item $oldprio = $process->prio ($newprio)
189	push @destroy, $current;	288
190	$terminate->ready;	289	Sets (or gets, if the argument is missing) the priority of the
191	&schedule;	290	process. Higher priority processes get run before lower priority
192	# NORETURN	291	processes. Priorities are small signed integers (currently -4 .. +3),
		292	that you can refer to using PRIO_xxx constants (use the import tag :prio
		293	to get then):
		294
		295	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		296	3 > 1 > 0 > -1 > -3 > -4
		297
		298	# set priority to HIGH
		299	current->prio(PRIO_HIGH);
		300
		301	The idle coroutine ($Coro::idle) always has a lower priority than any
		302	existing coroutine.
		303
		304	Changing the priority of the current process will take effect immediately,
		305	but changing the priority of processes in the ready queue (but not
		306	running) will only take effect after the next schedule (of that
		307	process). This is a bug that will be fixed in some future version.
		308
		309	=item $newprio = $process->nice ($change)
		310
		311	Similar to C<prio>, but subtract the given value from the priority (i.e.
		312	higher values mean lower priority, just as in unix).
		313
		314	=item $olddesc = $process->desc ($newdesc)
		315
		316	Sets (or gets in case the argument is missing) the description for this
		317	process. This is just a free-form string you can associate with a process.
		318
		319	=cut
		320
		321	sub desc {
		322	my $old = $_[0]{desc};
		323	$_[0]{desc} = $_[1] if @_ > 1;
		324	$old;
193	}	325	}
194		326
195	=back	327	=back
196		328
197	# dynamic methods
198
199	=head2 PROCESS METHODS
200
201	These are the methods you can call on process objects.
202
203	=over 4
204
205	=item new Coro \&sub [, @args...]
206
207	Create a new process and return it. When the sub returns the process
208	automatically terminates. To start the process you must first put it into
209	the ready queue by calling the ready method.
210
211	The coderef you submit MUST NOT be a closure that refers to variables
212	in an outer scope. This does NOT work. Pass arguments into it instead.
213
214	=cut
215
216	sub _newcoro {
217	terminate &{+shift};
218	}
219
220	sub new {
221	my $class = shift;
222	bless {
223	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
224	}, $class;
225	}
226
227	=item $process->ready
228
229	Put the current process into the ready queue.
230
231	=cut
232
233	sub ready {
234	push @ready, $_[0];
235	}
236
237	=back
238
239	=cut	329	=cut
240		330
241	1;	331	1;
242		332
243	=head1 BUGS/LIMITATIONS	333	=head1 BUGS/LIMITATIONS
244		334
245	- could be faster, especially when the core would introduce special	335	- you must make very sure that no coro is still active on global
246	support for coroutines (like it does for threads).	336	destruction. very bad things might happen otherwise (usually segfaults).
247	- there is still a memleak on coroutine termination that I could not	337
248	identify. Could be as small as a single SV.
249	- this module is not well-tested.
250	- if variables or arguments "disappear" (become undef) or become
251	corrupted please contact the author so he cen iron out the
252	remaining bugs.
253	- this module is not thread-safe. You must only ever use this module from	338	- this module is not thread-safe. You should only ever use this module
254	the same thread (this requirement might be loosened in the future to	339	from the same thread (this requirement might be losened in the future
255	allow per-thread schedulers, but Coro::State does not yet allow this).	340	to allow per-thread schedulers, but Coro::State does not yet allow
		341	this).
256		342
257	=head1 SEE ALSO	343	=head1 SEE ALSO
258		344
259	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	345	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
260	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	346
		347	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		348
		349	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		350
		351	Embedding: L<Coro:MakeMaker>
261		352
262	=head1 AUTHOR	353	=head1 AUTHOR
263		354
264	Marc Lehmann <pcg@goof.com>	355	Marc Lehmann <schmorp@schmorp.de>
265	http://www.goof.com/pcg/marc/	356	http://home.schmorp.de/
266		357
267	=cut	358	=cut
268		359

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Comparing Coro/Coro.pm (file contents): Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs. Revision 1.83 by root, Fri Nov 24 15:34:33 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs.
Revision 1.83 by root, Fri Nov 24 15:34:33 2006 UTC