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

Comparing Coro/Coro.pm (file contents):
Revision 1.56 by pcg, Sat Nov 15 03:53:10 2003 UTC vs.
Revision 1.97 by root, Mon Dec 4 13:47:56 2006 UTC

…		…
8		8
9	async {	9	async {
10	# some asynchronous thread of execution	10	# some asynchronous thread of execution
11	};	11	};
12		12
13	# alternatively create an async process like this:	13	# alternatively create an async coroutine like this:
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
…		…
30		30
31	=cut	31	=cut
32		32
33	package Coro;	33	package Coro;
34		34
35	BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }	35	use strict;
		36	no warnings "uninitialized";
36		37
37	use Coro::State;	38	use Coro::State;
38		39
39	use vars qw($idle $main $current);	40	use base qw(Coro::State Exporter);
40		41
41	use base Exporter;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
43	$VERSION = "0.9";	46	our $VERSION = '3.01';
44		47
45	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
46	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
47	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48	);	51	);
49	@EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
50		53
51	{	54	{
52	my @async;	55	my @async;
53	my $init;	56	my $init;
54		57
55	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
56	sub import {	59	sub import {
		60	no strict 'refs';
		61
57	Coro->export_to_level(1, @_);	62	Coro->export_to_level (1, @_);
		63
58	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
59	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
60	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
61	my @attrs;	67	my @attrs;
62	for (@_) {	68	for (@_) {
…		…
89		95
90	$main = new Coro;	96	$main = new Coro;
91		97
92	=item $current (or as function: current)	98	=item $current (or as function: current)
93		99
94	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
95		106
96	=cut	107	=cut
97		108
98	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
99	if ($current) {
100	$main->{specific} = $current->{specific};	110	$main->{specific} = $current->{specific}
101	}	111	if $current;
102		112
103	$current = $main;	113	_set_current $main;
104		114
105	sub current() { $current }	115	sub current() { $current }
106		116
107	=item $idle	117	=item $idle
108		118
109	The coroutine to switch to when no other coroutine is running. The default	119	A callback that is called whenever the scheduler finds no ready coroutines
110	implementation prints "FATAL: deadlock detected" and exits.	120	to run. The default implementation prints "FATAL: deadlock detected" and
		121	exits, because the program has no other way to continue.
111		122
112	=cut	123	This hook is overwritten by modules such as C<Coro::Timer> and
		124	C<Coro::Event> to wait on an external event that hopefully wake up a
		125	coroutine so the scheduler can run it.
113		126
114	# should be done using priorities :(	127	Please note that if your callback recursively invokes perl (e.g. for event
115	$idle = new Coro sub {	128	handlers), then it must be prepared to be called recursively.
116	print STDERR "FATAL: deadlock detected\n";	129
117	exit(51);	130	=cut
		131
		132	$idle = sub {
		133	require Carp;
		134	Carp::croak ("FATAL: deadlock detected");
118	};	135	};
119		136
120	# this coroutine is necessary because a coroutine	137	# this coroutine is necessary because a coroutine
121	# cannot destroy itself.	138	# cannot destroy itself.
122	my @destroy;	139	my @destroy;
123	my $manager;
124	$manager = new Coro sub {	140	my $manager; $manager = new Coro sub {
125	while() {	141	while () {
126	# by overwriting the state object with the manager we destroy it	142	# by overwriting the state object with the manager we destroy it
127	# while still being able to schedule this coroutine (in case it has	143	# while still being able to schedule this coroutine (in case it has
128	# been readied multiple times. this is harmless since the manager	144	# been readied multiple times. this is harmless since the manager
129	# can be called as many times as neccessary and will always	145	# can be called as many times as neccessary and will always
130	# remove itself from the runqueue	146	# remove itself from the runqueue
131	while (@destroy) {	147	while (@destroy) {
132	my $coro = pop @destroy;	148	my $coro = pop @destroy;
133	$coro->{status} \|\|= [];	149	$coro->{status} \|\|= [];
134	$_->ready for @{delete $coro->{join} \|\| []};	150	$_->ready for @{delete $coro->{join} \|\| []};
135	$coro->{_coro_state} = $manager->{_coro_state};	151
		152	# the next line destroys the coro state, but keeps the
		153	# coroutine itself intact (we basically make it a zombie
		154	# coroutine that always runs the manager thread, so it's possible
		155	# to transfer() to this coroutine).
		156	$coro->_clone_state_from ($manager);
136	}	157	}
137	&schedule;	158	&schedule;
138	}	159	}
139	};	160	};
140		161
…		…
142		163
143	=back	164	=back
144		165
145	=head2 STATIC METHODS	166	=head2 STATIC METHODS
146		167
147	Static methods are actually functions that operate on the current process only.	168	Static methods are actually functions that operate on the current coroutine only.
148		169
149	=over 4	170	=over 4
150		171
151	=item async { ... } [@args...]	172	=item async { ... } [@args...]
152		173
153	Create a new asynchronous process and return it's process object	174	Create a new asynchronous coroutine and return it's coroutine object
154	(usually unused). When the sub returns the new process is automatically	175	(usually unused). When the sub returns the new coroutine is automatically
155	terminated.	176	terminated.
		177
		178	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		179
		180	When the coroutine dies, the program will exit, just as in the main
		181	program.
156		182
157	# create a new coroutine that just prints its arguments	183	# create a new coroutine that just prints its arguments
158	async {	184	async {
159	print "@_\n";	185	print "@_\n";
160	} 1,2,3,4;	186	} 1,2,3,4;
161		187
162	The coderef you submit MUST NOT be a closure that refers to variables
163	in an outer scope. This does NOT work. Pass arguments into it instead.
164
165	=cut	188	=cut
166		189
167	sub async(&@) {	190	sub async(&@) {
168	my $pid = new Coro @_;	191	my $pid = new Coro @_;
169	$manager->ready; # this ensures that the stack is cloned from the manager
170	$pid->ready;	192	$pid->ready;
171	$pid;	193	$pid
172	}	194	}
173		195
174	=item schedule	196	=item schedule
175		197
176	Calls the scheduler. Please note that the current process will not be put	198	Calls the scheduler. Please note that the current coroutine will not be put
177	into the ready queue, so calling this function usually means you will	199	into the ready queue, so calling this function usually means you will
178	never be called again.	200	never be called again unless something else (e.g. an event handler) calls
		201	ready.
179		202
180	=cut	203	The canonical way to wait on external events is this:
		204
		205	{
		206	# remember current coroutine
		207	my $current = $Coro::current;
		208
		209	# register a hypothetical event handler
		210	on_event_invoke sub {
		211	# wake up sleeping coroutine
		212	$current->ready;
		213	undef $current;
		214	};
		215
		216	# call schedule until event occured.
		217	# in case we are woken up for other reasons
		218	# (current still defined), loop.
		219	Coro::schedule while $current;
		220	}
181		221
182	=item cede	222	=item cede
183		223
184	"Cede" to other processes. This function puts the current process into the	224	"Cede" to other coroutines. This function puts the current coroutine into the
185	ready queue and calls C<schedule>, which has the effect of giving up the	225	ready queue and calls C<schedule>, which has the effect of giving up the
186	current "timeslice" to other coroutines of the same or higher priority.	226	current "timeslice" to other coroutines of the same or higher priority.
187		227
188	=cut
189
190	=item terminate [arg...]	228	=item terminate [arg...]
191		229
192	Terminates the current process.	230	Terminates the current coroutine with the given status values (see L<cancel>).
193
194	Future versions of this function will allow result arguments.
195		231
196	=cut	232	=cut
197		233
198	sub terminate {	234	sub terminate {
199	$current->{status} = [@_];
200	$current->cancel;	235	$current->cancel (@_);
201	&schedule;
202	die; # NORETURN
203	}	236	}
204		237
205	=back	238	=back
206		239
207	# dynamic methods	240	# dynamic methods
208		241
209	=head2 PROCESS METHODS	242	=head2 COROUTINE METHODS
210		243
211	These are the methods you can call on process objects.	244	These are the methods you can call on coroutine objects.
212		245
213	=over 4	246	=over 4
214		247
215	=item new Coro \&sub [, @args...]	248	=item new Coro \&sub [, @args...]
216		249
217	Create a new process and return it. When the sub returns the process	250	Create a new coroutine and return it. When the sub returns the coroutine
218	automatically terminates as if C<terminate> with the returned values were	251	automatically terminates as if C<terminate> with the returned values were
219	called. To make the process run you must first put it into the ready queue	252	called. To make the coroutine run you must first put it into the ready queue
220	by calling the ready method.	253	by calling the ready method.
221		254
222	=cut	255	Calling C<exit> in a coroutine will not work correctly, so do not do that.
223		256
		257	=cut
		258
224	sub _newcoro {	259	sub _run_coro {
225	terminate &{+shift};	260	terminate &{+shift};
226	}	261	}
227		262
228	sub new {	263	sub new {
229	my $class = shift;	264	my $class = shift;
230	bless {
231	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
232	}, $class;
233	}
234		265
235	=item $process->ready	266	$class->SUPER::new (\&_run_coro, @_)
		267	}
236		268
237	Put the given process into the ready queue.	269	=item $success = $coroutine->ready
238		270
239	=cut	271	Put the given coroutine into the ready queue (according to it's priority)
		272	and return true. If the coroutine is already in the ready queue, do nothing
		273	and return false.
240		274
241	=item $process->cancel	275	=item $is_ready = $coroutine->is_ready
242		276
243	Like C<terminate>, but terminates the specified process instead.	277	Return wether the coroutine is currently the ready queue or not,
		278
		279	=item $coroutine->cancel (arg...)
		280
		281	Terminates the given coroutine and makes it return the given arguments as
		282	status (default: the empty list).
244		283
245	=cut	284	=cut
246		285
247	sub cancel {	286	sub cancel {
		287	my $self = shift;
		288	$self->{status} = [@_];
248	push @destroy, $_[0];	289	push @destroy, $self;
249	$manager->ready;	290	$manager->ready;
250	&schedule if $current == $_[0];	291	&schedule if $current == $self;
251	}	292	}
252		293
253	=item $process->join	294	=item $coroutine->join
254		295
255	Wait until the coroutine terminates and return any values given to the	296	Wait until the coroutine terminates and return any values given to the
256	C<terminate> function. C<join> can be called multiple times from multiple	297	C<terminate> or C<cancel> functions. C<join> can be called multiple times
257	processes.	298	from multiple coroutine.
258		299
259	=cut	300	=cut
260		301
261	sub join {	302	sub join {
262	my $self = shift;	303	my $self = shift;
…		…
265	&schedule;	306	&schedule;
266	}	307	}
267	wantarray ? @{$self->{status}} : $self->{status}[0];	308	wantarray ? @{$self->{status}} : $self->{status}[0];
268	}	309	}
269		310
270	=item $oldprio = $process->prio($newprio)	311	=item $oldprio = $coroutine->prio ($newprio)
271		312
272	Sets (or gets, if the argument is missing) the priority of the	313	Sets (or gets, if the argument is missing) the priority of the
273	process. Higher priority processes get run before lower priority	314	coroutine. Higher priority coroutines get run before lower priority
274	processes. Priorities are small signed integers (currently -4 .. +3),	315	coroutines. Priorities are small signed integers (currently -4 .. +3),
275	that you can refer to using PRIO_xxx constants (use the import tag :prio	316	that you can refer to using PRIO_xxx constants (use the import tag :prio
276	to get then):	317	to get then):
277		318
278	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	319	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279	3 > 1 > 0 > -1 > -3 > -4	320	3 > 1 > 0 > -1 > -3 > -4
…		…
282	current->prio(PRIO_HIGH);	323	current->prio(PRIO_HIGH);
283		324
284	The idle coroutine ($Coro::idle) always has a lower priority than any	325	The idle coroutine ($Coro::idle) always has a lower priority than any
285	existing coroutine.	326	existing coroutine.
286		327
287	Changing the priority of the current process will take effect immediately,	328	Changing the priority of the current coroutine will take effect immediately,
288	but changing the priority of processes in the ready queue (but not	329	but changing the priority of coroutines in the ready queue (but not
289	running) will only take effect after the next schedule (of that	330	running) will only take effect after the next schedule (of that
290	process). This is a bug that will be fixed in some future version.	331	coroutine). This is a bug that will be fixed in some future version.
291		332
292	=cut
293
294	sub prio {
295	my $old = $_[0]{prio};
296	$_[0]{prio} = $_[1] if @_ > 1;
297	$old;
298	}
299
300	=item $newprio = $process->nice($change)	333	=item $newprio = $coroutine->nice ($change)
301		334
302	Similar to C<prio>, but subtract the given value from the priority (i.e.	335	Similar to C<prio>, but subtract the given value from the priority (i.e.
303	higher values mean lower priority, just as in unix).	336	higher values mean lower priority, just as in unix).
304		337
305	=cut
306
307	sub nice {
308	$_[0]{prio} -= $_[1];
309	}
310
311	=item $olddesc = $process->desc($newdesc)	338	=item $olddesc = $coroutine->desc ($newdesc)
312		339
313	Sets (or gets in case the argument is missing) the description for this	340	Sets (or gets in case the argument is missing) the description for this
314	process. This is just a free-form string you can associate with a process.	341	coroutine. This is just a free-form string you can associate with a coroutine.
315		342
316	=cut	343	=cut
317		344
318	sub desc {	345	sub desc {
319	my $old = $_[0]{desc};	346	my $old = $_[0]{desc};
…		…
321	$old;	348	$old;
322	}	349	}
323		350
324	=back	351	=back
325		352
		353	=head2 GLOBAL FUNCTIONS
		354
		355	=over 4
		356
		357	=item Coro::nready
		358
		359	Returns the number of coroutines that are currently in the ready state,
		360	i.e. that can be swicthed to. The value C<0> means that the only runnable
		361	coroutine is the currently running one, so C<cede> would have no effect,
		362	and C<schedule> would cause a deadlock unless there is an idle handler
		363	that wakes up some coroutines.
		364
		365	=item unblock_sub { ... }
		366
		367	This utility function takes a BLOCK or code reference and "unblocks" it,
		368	returning the new coderef. This means that the new coderef will return
		369	immediately without blocking, returning nothing, while the original code
		370	ref will be called (with parameters) from within its own coroutine.
		371
		372	The reason this fucntion exists is that many event libraries (such as the
		373	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		374	of thread-safety). This means you must not block within event callbacks,
		375	otherwise you might suffer from crashes or worse.
		376
		377	This function allows your callbacks to block by executing them in another
		378	coroutine where it is safe to block. One example where blocking is handy
		379	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		380	disk.
		381
		382	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		383	creating event callbacks that want to block.
		384
		385	=cut
		386
		387	our @unblock_pool;
		388	our @unblock_queue;
		389	our $UNBLOCK_POOL_SIZE = 2;
		390
		391	sub unblock_handler_ {
		392	while () {
		393	my ($cb, @arg) = @{ delete $Coro::current->{arg} };
		394	$cb->(@arg);
		395
		396	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
		397	push @unblock_pool, $Coro::current;
		398	schedule;
		399	}
		400	}
		401
		402	our $unblock_scheduler = async {
		403	while () {
		404	while (my $cb = pop @unblock_queue) {
		405	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);
		406	$handler->{arg} = $cb;
		407	$handler->ready;
		408	cede;
		409	}
		410
		411	schedule;
		412	}
		413	};
		414
		415	sub unblock_sub(&) {
		416	my $cb = shift;
		417
		418	sub {
		419	push @unblock_queue, [$cb, @_];
		420	$unblock_scheduler->ready;
		421	}
		422	}
		423
		424	=back
		425
326	=cut	426	=cut
327		427
328	1;	428	1;
329		429
330	=head1 BUGS/LIMITATIONS	430	=head1 BUGS/LIMITATIONS
…		…
337	to allow per-thread schedulers, but Coro::State does not yet allow	437	to allow per-thread schedulers, but Coro::State does not yet allow
338	this).	438	this).
339		439
340	=head1 SEE ALSO	440	=head1 SEE ALSO
341		441
342	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	442	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
343	L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,	443
344	L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.	444	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		445
		446	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		447
		448	Embedding: L<Coro:MakeMaker>
345		449
346	=head1 AUTHOR	450	=head1 AUTHOR
347		451
348	Marc Lehmann <pcg@goof.com>	452	Marc Lehmann <schmorp@schmorp.de>
349	http://www.goof.com/pcg/marc/	453	http://home.schmorp.de/
350		454
351	=cut	455	=cut
352		456

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Comparing Coro/Coro.pm (file contents): Revision 1.56 by pcg, Sat Nov 15 03:53:10 2003 UTC vs. Revision 1.97 by root, Mon Dec 4 13:47:56 2006 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.56 by pcg, Sat Nov 15 03:53:10 2003 UTC vs.
Revision 1.97 by root, Mon Dec 4 13:47:56 2006 UTC