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

Comparing Coro/Coro.pm (file contents):
Revision 1.26 by root, Fri Jul 27 02:51:33 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 = 0.12;	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;
48	my $init;	56	my $init;
49		57
50	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
51	sub import {	59	sub import {
		60	no strict 'refs';
		61
52	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
53	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
54	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
55	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
56	my @attrs;	67	my @attrs;
57	for (@_) {	68	for (@_) {
…		…
72	};	83	};
73	}	84	}
74		85
75	}	86	}
76		87
		88	=over 4
		89
77	=item $main	90	=item $main
78		91
79	This coroutine represents the main program.	92	This coroutine represents the main program.
80		93
81	=cut	94	=cut
82		95
83	our $main = new Coro;	96	$main = new Coro;
84		97
85	=item $current (or as function: current)	98	=item $current (or as function: current)
86		99
87	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
88		106
89	=cut	107	=cut
90		108
91	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
92	if ($current) {	110	if ($current) {
93	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
94	}	112	}
95		113
96	our $current = $main;	114	$current = $main;
97		115
98	sub current() { $current }	116	sub current() { $current }
99		117
100	=item $idle	118	=item $idle
101		119
102	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
103	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
104		123
105	=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.
106		127
107	# should be done using priorities :(	128	=cut
108	our $idle = new Coro sub {	129
		130	$idle = sub {
109	print STDERR "FATAL: deadlock detected\n";	131	print STDERR "FATAL: deadlock detected\n";
110	exit(51);	132	exit (51);
111	};	133	};
112		134
113	# this coroutine is necessary because a coroutine	135	# this coroutine is necessary because a coroutine
114	# cannot destroy itself.	136	# cannot destroy itself.
115	my @destroy;	137	my @destroy;
		138	my $manager;
116	my $manager = new Coro sub {	139	$manager = new Coro sub {
117	while() {	140	while () {
118	delete ((pop @destroy)->{_coro_state}) while @destroy;	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	}
119	&schedule;	157	&schedule;
120	}	158	}
121	};	159	};
122		160
123	# we really need priorities...
124	my @ready; # the ready queue. hehe, rather broken ;)
125
126	# static methods. not really.	161	# static methods. not really.
		162
		163	=back
127		164
128	=head2 STATIC METHODS	165	=head2 STATIC METHODS
129		166
130	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.
131		168
…		…
134	=item async { ... } [@args...]	171	=item async { ... } [@args...]
135		172
136	Create a new asynchronous process and return it's process object	173	Create a new asynchronous process and return it's process object
137	(usually unused). When the sub returns the new process is automatically	174	(usually unused). When the sub returns the new process is automatically
138	terminated.	175	terminated.
		176
		177	When the coroutine dies, the program will exit, just as in the main
		178	program.
139		179
140	# create a new coroutine that just prints its arguments	180	# create a new coroutine that just prints its arguments
141	async {	181	async {
142	print "@_\n";	182	print "@_\n";
143	} 1,2,3,4;	183	} 1,2,3,4;
144
145	The coderef you submit MUST NOT be a closure that refers to variables
146	in an outer scope. This does NOT work. Pass arguments into it instead.
147		184
148	=cut	185	=cut
149		186
150	sub async(&@) {	187	sub async(&@) {
151	my $pid = new Coro @_;	188	my $pid = new Coro @_;
…		…
160	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
161	never be called again.	198	never be called again.
162		199
163	=cut	200	=cut
164		201
165	my $prev;
166
167	sub schedule {
168	# should be done using priorities :(
169	($prev, $current) = ($current, shift @ready \|\| $idle);
170	Coro::State::transfer($prev, $current);
171	}
172
173	=item cede	202	=item cede
174		203
175	"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
176	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
177	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
178		207
179	=cut	208	=cut
180		209
181	sub cede {
182	$current->ready;
183	&schedule;
184	}
185
186	=item terminate	210	=item terminate [arg...]
187		211
188	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
189
190	Future versions of this function will allow result arguments.
191		213
192	=cut	214	=cut
193		215
194	sub terminate {	216	sub terminate {
195	push @destroy, $current;	217	$current->cancel (@_);
196	$manager->ready;
197	&schedule;
198	# NORETURN
199	}	218	}
200		219
201	=back	220	=back
202		221
203	# dynamic methods	222	# dynamic methods
…		…
209	=over 4	228	=over 4
210		229
211	=item new Coro \&sub [, @args...]	230	=item new Coro \&sub [, @args...]
212		231
213	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
214	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
215	the ready queue by calling the ready method.	235	by calling the ready method.
216
217	The coderef you submit MUST NOT be a closure that refers to variables
218	in an outer scope. This does NOT work. Pass arguments into it instead.
219		236
220	=cut	237	=cut
221		238
222	sub _newcoro {	239	sub _newcoro {
223	terminate &{+shift};	240	terminate &{+shift};
224	}	241	}
225		242
226	sub new {	243	sub new {
227	my $class = shift;	244	my $class = shift;
228	bless {	245
229	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),	246	$class->SUPER::new (\&_newcoro, @_)
230	}, $class;
231	}	247	}
232		248
233	=item $process->ready	249	=item $process->ready
234		250
235	Put the current process into the ready queue.	251	Put the given process into the ready queue.
236		252
237	=cut	253	=cut
238		254
239	sub ready {	255	=item $process->cancel (arg...)
240	push @ready, $_[0];	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}}, $current;
		282	&schedule;
		283	}
		284	wantarray ? @{$self->{status}} : $self->{status}[0];
		285	}
		286
		287	=item $oldprio = $process->prio ($newprio)
		288
		289	Sets (or gets, if the argument is missing) the priority of the
		290	process. Higher priority processes get run before lower priority
		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;
241	}	325	}
242		326
243	=back	327	=back
244		328
245	=cut	329	=cut
246		330
247	1;	331	1;
248		332
249	=head1 BUGS/LIMITATIONS	333	=head1 BUGS/LIMITATIONS
250		334
251	- could be faster, especially when the core would introduce special	335	- you must make very sure that no coro is still active on global
252	support for coroutines (like it does for threads).	336	destruction. very bad things might happen otherwise (usually segfaults).
253	- there is still a memleak on coroutine termination that I could not	337
254	identify. Could be as small as a single SV.
255	- this module is not well-tested.
256	- if variables or arguments "disappear" (become undef) or become
257	corrupted please contact the author so he cen iron out the
258	remaining bugs.
259	- 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
260	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
261	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).
262		342
263	=head1 SEE ALSO	343	=head1 SEE ALSO
264		344
265	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>.
266	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	346
267	L<Coro::Handle>, L<Coro::Socket>.	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>
268		352
269	=head1 AUTHOR	353	=head1 AUTHOR
270		354
271	Marc Lehmann <pcg@goof.com>	355	Marc Lehmann <schmorp@schmorp.de>
272	http://www.goof.com/pcg/marc/	356	http://home.schmorp.de/
273		357
274	=cut	358	=cut
275		359

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Comparing Coro/Coro.pm (file contents): Revision 1.26 by root, Fri Jul 27 02:51:33 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 1.26 by root, Fri Jul 27 02:51:33 2001 UTC vs.
Revision 1.83 by root, Fri Nov 24 15:34:33 2006 UTC