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

Comparing Coro/Coro.pm (file contents):
Revision 1.53 by root, Tue May 27 01:15:26 2003 UTC vs.
Revision 1.93 by root, Fri Dec 1 19:41:06 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	use strict;
35	no warnings qw(uninitialized);	36	no warnings "uninitialized";
36		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 = 0.7;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
		46	our $VERSION = '3.0';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
44	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
45	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46	);	51	);
47	@EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
48		53
49	{	54	{
50	my @async;	55	my @async;
51	my $init;	56	my $init;
52		57
53	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
54	sub import {	59	sub import {
		60	no strict 'refs';
		61
55	Coro->export_to_level(1, @_);	62	Coro->export_to_level (1, @_);
		63
56	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
57	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
58	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
59	my @attrs;	67	my @attrs;
60	for (@_) {	68	for (@_) {
…		…
83		91
84	This coroutine represents the main program.	92	This coroutine represents the main program.
85		93
86	=cut	94	=cut
87		95
88	our $main = new Coro;	96	$main = new Coro;
89		97
90	=item $current (or as function: current)	98	=item $current (or as function: current)
91		99
92	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
93		106
94	=cut	107	=cut
95		108
96	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
97	if ($current) {
98	$main->{specific} = $current->{specific};	110	$main->{specific} = $current->{specific}
99	}	111	if $current;
100		112
101	our $current = $main;	113	_set_current $main;
102		114
103	sub current() { $current }	115	sub current() { $current }
104		116
105	=item $idle	117	=item $idle
106		118
107	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
108	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.
109		122
110	=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.
111		126
112	# should be done using priorities :(	127	Please note that if your callback recursively invokes perl (e.g. for event
113	our $idle = new Coro sub {	128	handlers), then it must be prepared to be called recursively.
		129
		130	=cut
		131
		132	$idle = sub {
114	print STDERR "FATAL: deadlock detected\n";	133	print STDERR "FATAL: deadlock detected\n";
115	exit(51);	134	exit (51);
116	};	135	};
117		136
118	# this coroutine is necessary because a coroutine	137	# this coroutine is necessary because a coroutine
119	# cannot destroy itself.	138	# cannot destroy itself.
120	my @destroy;	139	my @destroy;
121	my $manager;
122	$manager = new Coro sub {	140	my $manager; $manager = new Coro sub {
123	while() {	141	while () {
124	# by overwriting the state object with the manager we destroy it	142	# by overwriting the state object with the manager we destroy it
125	# 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
126	# been readied multiple times. this is harmless since the manager	144	# been readied multiple times. this is harmless since the manager
127	# can be called as many times as neccessary and will always	145	# can be called as many times as neccessary and will always
128	# remove itself from the runqueue	146	# remove itself from the runqueue
129	while (@destroy) {	147	while (@destroy) {
130	my $coro = pop @destroy;	148	my $coro = pop @destroy;
131	$coro->{status} \|\|= [];	149	$coro->{status} \|\|= [];
132	$_->ready for @{delete $coro->{join} \|\| []};	150	$_->ready for @{delete $coro->{join} \|\| []};
133	$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);
134	}	157	}
135	&schedule;	158	&schedule;
136	}	159	}
137	};	160	};
138		161
…		…
140		163
141	=back	164	=back
142		165
143	=head2 STATIC METHODS	166	=head2 STATIC METHODS
144		167
145	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.
146		169
147	=over 4	170	=over 4
148		171
149	=item async { ... } [@args...]	172	=item async { ... } [@args...]
150		173
151	Create a new asynchronous process and return it's process object	174	Create a new asynchronous coroutine and return it's coroutine object
152	(usually unused). When the sub returns the new process is automatically	175	(usually unused). When the sub returns the new coroutine is automatically
153	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.
154		182
155	# create a new coroutine that just prints its arguments	183	# create a new coroutine that just prints its arguments
156	async {	184	async {
157	print "@_\n";	185	print "@_\n";
158	} 1,2,3,4;	186	} 1,2,3,4;
159		187
160	The coderef you submit MUST NOT be a closure that refers to variables
161	in an outer scope. This does NOT work. Pass arguments into it instead.
162
163	=cut	188	=cut
164		189
165	sub async(&@) {	190	sub async(&@) {
166	my $pid = new Coro @_;	191	my $pid = new Coro @_;
167	$manager->ready; # this ensures that the stack is cloned from the manager
168	$pid->ready;	192	$pid->ready;
169	$pid;	193	$pid
170	}	194	}
171		195
172	=item schedule	196	=item schedule
173		197
174	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
175	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
176	never be called again.	200	never be called again unless something else (e.g. an event handler) calls
		201	ready.
177		202
178	=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	}
179		221
180	=item cede	222	=item cede
181		223
182	"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
183	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
184	current "timeslice" to other coroutines of the same or higher priority.	226	current "timeslice" to other coroutines of the same or higher priority.
185		227
186	=cut
187
188	=item terminate [arg...]	228	=item terminate [arg...]
189		229
190	Terminates the current process.	230	Terminates the current coroutine with the given status values (see L<cancel>).
191
192	Future versions of this function will allow result arguments.
193		231
194	=cut	232	=cut
195		233
196	sub terminate {	234	sub terminate {
197	$current->{status} = [@_];
198	$current->cancel;	235	$current->cancel (@_);
199	&schedule;
200	die; # NORETURN
201	}	236	}
202		237
203	=back	238	=back
204		239
205	# dynamic methods	240	# dynamic methods
206		241
207	=head2 PROCESS METHODS	242	=head2 COROUTINE METHODS
208		243
209	These are the methods you can call on process objects.	244	These are the methods you can call on coroutine objects.
210		245
211	=over 4	246	=over 4
212		247
213	=item new Coro \&sub [, @args...]	248	=item new Coro \&sub [, @args...]
214		249
215	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
216	automatically terminates as if C<terminate> with the returned values were	251	automatically terminates as if C<terminate> with the returned values were
217	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
218	by calling the ready method.	253	by calling the ready method.
219		254
220	=cut	255	Calling C<exit> in a coroutine will not work correctly, so do not do that.
221		256
		257	=cut
		258
222	sub _newcoro {	259	sub _new_coro {
223	terminate &{+shift};	260	terminate &{+shift};
224	}	261	}
225		262
226	sub new {	263	sub new {
227	my $class = shift;	264	my $class = shift;
228	bless {
229	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
230	}, $class;
231	}
232		265
233	=item $process->ready	266	$class->SUPER::new (\&_new_coro, @_)
		267	}
234		268
235	Put the given process into the ready queue.	269	=item $success = $coroutine->ready
236		270
237	=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.
238		274
239	=item $process->cancel	275	=item $is_ready = $coroutine->is_ready
240		276
241	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).
242		283
243	=cut	284	=cut
244		285
245	sub cancel {	286	sub cancel {
		287	my $self = shift;
		288	$self->{status} = [@_];
246	push @destroy, $_[0];	289	push @destroy, $self;
247	$manager->ready;	290	$manager->ready;
248	&schedule if $current == $_[0];	291	&schedule if $current == $self;
249	}	292	}
250		293
251	=item $process->join	294	=item $coroutine->join
252		295
253	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
254	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
255	processes.	298	from multiple coroutine.
256		299
257	=cut	300	=cut
258		301
259	sub join {	302	sub join {
260	my $self = shift;	303	my $self = shift;
…		…
263	&schedule;	306	&schedule;
264	}	307	}
265	wantarray ? @{$self->{status}} : $self->{status}[0];	308	wantarray ? @{$self->{status}} : $self->{status}[0];
266	}	309	}
267		310
268	=item $oldprio = $process->prio($newprio)	311	=item $oldprio = $coroutine->prio ($newprio)
269		312
270	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
271	process. Higher priority processes get run before lower priority	314	coroutine. Higher priority coroutines get run before lower priority
272	processes. Priorities are small signed integers (currently -4 .. +3),	315	coroutines. Priorities are small signed integers (currently -4 .. +3),
273	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
274	to get then):	317	to get then):
275		318
276	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
277	3 > 1 > 0 > -1 > -3 > -4	320	3 > 1 > 0 > -1 > -3 > -4
…		…
280	current->prio(PRIO_HIGH);	323	current->prio(PRIO_HIGH);
281		324
282	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
283	existing coroutine.	326	existing coroutine.
284		327
285	Changing the priority of the current process will take effect immediately,	328	Changing the priority of the current coroutine will take effect immediately,
286	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
287	running) will only take effect after the next schedule (of that	330	running) will only take effect after the next schedule (of that
288	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.
289		332
290	=cut
291
292	sub prio {
293	my $old = $_[0]{prio};
294	$_[0]{prio} = $_[1] if @_ > 1;
295	$old;
296	}
297
298	=item $newprio = $process->nice($change)	333	=item $newprio = $coroutine->nice ($change)
299		334
300	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.
301	higher values mean lower priority, just as in unix).	336	higher values mean lower priority, just as in unix).
302		337
303	=cut
304
305	sub nice {
306	$_[0]{prio} -= $_[1];
307	}
308
309	=item $olddesc = $process->desc($newdesc)	338	=item $olddesc = $coroutine->desc ($newdesc)
310		339
311	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
312	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.
313		342
314	=cut	343	=cut
315		344
316	sub desc {	345	sub desc {
317	my $old = $_[0]{desc};	346	my $old = $_[0]{desc};
…		…
319	$old;	348	$old;
320	}	349	}
321		350
322	=back	351	=back
323		352
		353	=head2 UTILITY FUNCTIONS
		354
		355	=over 4
		356
		357	=item unblock_sub { ... }
		358
		359	This utility function takes a BLOCK or code reference and "unblocks" it,
		360	returning the new coderef. This means that the new coderef will return
		361	immediately without blocking, returning nothing, while the original code
		362	ref will be called (with parameters) from within its own coroutine.
		363
		364	The reason this fucntion exists is that many event libraries (such as the
		365	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		366	of thread-safety). This means you must not block within event callbacks,
		367	otherwise you might suffer from crashes or worse.
		368
		369	This function allows your callbacks to block by executing them in another
		370	coroutine where it is safe to block. One example where blocking is handy
		371	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		372	disk.
		373
		374	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		375	creating event callbacks that want to block.
		376
		377	=cut
		378
		379	our @unblock_pool;
		380	our @unblock_queue;
		381	our $UNBLOCK_POOL_SIZE = 2;
		382
		383	sub unblock_handler_ {
		384	while () {
		385	my ($cb, @arg) = @{ delete $Coro::current->{arg} };
		386	$cb->(@arg);
		387
		388	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
		389	push @unblock_pool, $Coro::current;
		390	schedule;
		391	}
		392	}
		393
		394	our $unblock_scheduler = async {
		395	while () {
		396	while (my $cb = pop @unblock_queue) {
		397	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);
		398	$handler->{arg} = $cb;
		399	$handler->ready;
		400	cede;
		401	}
		402
		403	schedule;
		404	}
		405	};
		406
		407	sub unblock_sub(&) {
		408	my $cb = shift;
		409
		410	sub {
		411	push @unblock_queue, [$cb, @_];
		412	$unblock_scheduler->ready;
		413	}
		414	}
		415
		416	=back
		417
324	=cut	418	=cut
325		419
326	1;	420	1;
327		421
328	=head1 BUGS/LIMITATIONS	422	=head1 BUGS/LIMITATIONS
…		…
335	to allow per-thread schedulers, but Coro::State does not yet allow	429	to allow per-thread schedulers, but Coro::State does not yet allow
336	this).	430	this).
337		431
338	=head1 SEE ALSO	432	=head1 SEE ALSO
339		433
340	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	434	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
341	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	435
342	L<Coro::Handle>, L<Coro::Socket>.	436	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		437
		438	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		439
		440	Embedding: L<Coro:MakeMaker>
343		441
344	=head1 AUTHOR	442	=head1 AUTHOR
345		443
346	Marc Lehmann <pcg@goof.com>	444	Marc Lehmann <schmorp@schmorp.de>
347	http://www.goof.com/pcg/marc/	445	http://home.schmorp.de/
348		446
349	=cut	447	=cut
350		448

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Comparing Coro/Coro.pm (file contents): Revision 1.53 by root, Tue May 27 01:15:26 2003 UTC vs. Revision 1.93 by root, Fri Dec 1 19:41:06 2006 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.53 by root, Tue May 27 01:15:26 2003 UTC vs.
Revision 1.93 by root, Fri Dec 1 19:41:06 2006 UTC