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

Comparing Coro/Coro.pm (file contents):
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 UTC vs.
Revision 1.92 by root, Fri Dec 1 03:47:55 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 = 0.8;	46	our $VERSION = '3.0';
44		47
45	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
46	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
47	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48	);	51	);
49	@EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
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) {	110	if ($current) {
…		…
104		115
105	sub current() { $current }	116	sub current() { $current }
106		117
107	=item $idle	118	=item $idle
108		119
109	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
110	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits, because the program has no other way to continue.
111		123
112	=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 wake up a
		126	coroutine so the scheduler can run it.
113		127
114	# should be done using priorities :(	128	Please note that if your callback recursively invokes perl (e.g. for event
115	$idle = new Coro sub {	129	handlers), then it must be prepared to be called recursively.
		130
		131	=cut
		132
		133	$idle = sub {
116	print STDERR "FATAL: deadlock detected\n";	134	print STDERR "FATAL: deadlock detected\n";
117	exit(51);	135	exit (51);
118	};	136	};
119		137
120	# this coroutine is necessary because a coroutine	138	# this coroutine is necessary because a coroutine
121	# cannot destroy itself.	139	# cannot destroy itself.
122	my @destroy;	140	my @destroy;
123	my $manager;
124	$manager = new Coro sub {	141	my $manager; $manager = new Coro sub {
125	while() {	142	while () {
126	# by overwriting the state object with the manager we destroy it	143	# by overwriting the state object with the manager we destroy it
127	# while still being able to schedule this coroutine (in case it has	144	# while still being able to schedule this coroutine (in case it has
128	# been readied multiple times. this is harmless since the manager	145	# been readied multiple times. this is harmless since the manager
129	# can be called as many times as neccessary and will always	146	# can be called as many times as neccessary and will always
130	# remove itself from the runqueue	147	# remove itself from the runqueue
131	while (@destroy) {	148	while (@destroy) {
132	my $coro = pop @destroy;	149	my $coro = pop @destroy;
133	$coro->{status} \|\|= [];	150	$coro->{status} \|\|= [];
134	$_->ready for @{delete $coro->{join} \|\| []};	151	$_->ready for @{delete $coro->{join} \|\| []};
135	$coro->{_coro_state} = $manager->{_coro_state};	152
		153	# the next line destroys the coro state, but keeps the
		154	# coroutine itself intact (we basically make it a zombie
		155	# coroutine that always runs the manager thread, so it's possible
		156	# to transfer() to this coroutine).
		157	$coro->_clone_state_from ($manager);
136	}	158	}
137	&schedule;	159	&schedule;
138	}	160	}
139	};	161	};
140		162
…		…
142		164
143	=back	165	=back
144		166
145	=head2 STATIC METHODS	167	=head2 STATIC METHODS
146		168
147	Static methods are actually functions that operate on the current process only.	169	Static methods are actually functions that operate on the current coroutine only.
148		170
149	=over 4	171	=over 4
150		172
151	=item async { ... } [@args...]	173	=item async { ... } [@args...]
152		174
153	Create a new asynchronous process and return it's process object	175	Create a new asynchronous coroutine and return it's coroutine object
154	(usually unused). When the sub returns the new process is automatically	176	(usually unused). When the sub returns the new coroutine is automatically
155	terminated.	177	terminated.
		178
		179	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		180
		181	When the coroutine dies, the program will exit, just as in the main
		182	program.
156		183
157	# create a new coroutine that just prints its arguments	184	# create a new coroutine that just prints its arguments
158	async {	185	async {
159	print "@_\n";	186	print "@_\n";
160	} 1,2,3,4;	187	} 1,2,3,4;
161		188
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	189	=cut
166		190
167	sub async(&@) {	191	sub async(&@) {
168	my $pid = new Coro @_;	192	my $pid = new Coro @_;
169	$manager->ready; # this ensures that the stack is cloned from the manager
170	$pid->ready;	193	$pid->ready;
171	$pid;	194	$pid
172	}	195	}
173		196
174	=item schedule	197	=item schedule
175		198
176	Calls the scheduler. Please note that the current process will not be put	199	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	200	into the ready queue, so calling this function usually means you will
178	never be called again.	201	never be called again unless something else (e.g. an event handler) calls
		202	ready.
179		203
180	=cut	204	The canonical way to wait on external events is this:
		205
		206	{
		207	# remember current coroutine
		208	my $current = $Coro::current;
		209
		210	# register a hypothetical event handler
		211	on_event_invoke sub {
		212	# wake up sleeping coroutine
		213	$current->ready;
		214	undef $current;
		215	};
		216
		217	# call schedule until event occured.
		218	# in case we are woken up for other reasons
		219	# (current still defined), loop.
		220	Coro::schedule while $current;
		221	}
181		222
182	=item cede	223	=item cede
183		224
184	"Cede" to other processes. This function puts the current process into the	225	"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	226	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.	227	current "timeslice" to other coroutines of the same or higher priority.
187		228
188	=cut
189
190	=item terminate [arg...]	229	=item terminate [arg...]
191		230
192	Terminates the current process.	231	Terminates the current coroutine with the given status values (see L<cancel>).
193
194	Future versions of this function will allow result arguments.
195		232
196	=cut	233	=cut
197		234
198	sub terminate {	235	sub terminate {
199	$current->{status} = [@_];
200	$current->cancel;	236	$current->cancel (@_);
201	&schedule;
202	die; # NORETURN
203	}	237	}
204		238
205	=back	239	=back
206		240
207	# dynamic methods	241	# dynamic methods
208		242
209	=head2 PROCESS METHODS	243	=head2 COROUTINE METHODS
210		244
211	These are the methods you can call on process objects.	245	These are the methods you can call on coroutine objects.
212		246
213	=over 4	247	=over 4
214		248
215	=item new Coro \&sub [, @args...]	249	=item new Coro \&sub [, @args...]
216		250
217	Create a new process and return it. When the sub returns the process	251	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	252	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	253	called. To make the coroutine run you must first put it into the ready queue
220	by calling the ready method.	254	by calling the ready method.
221		255
222	=cut	256	Calling C<exit> in a coroutine will not work correctly, so do not do that.
223		257
		258	=cut
		259
224	sub _newcoro {	260	sub _new_coro {
225	terminate &{+shift};	261	terminate &{+shift};
226	}	262	}
227		263
228	sub new {	264	sub new {
229	my $class = shift;	265	my $class = shift;
230	bless {
231	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
232	}, $class;
233	}
234		266
235	=item $process->ready	267	$class->SUPER::new (\&_new_coro, @_)
		268	}
236		269
237	Put the given process into the ready queue.	270	=item $success = $coroutine->ready
238		271
239	=cut	272	Put the given coroutine into the ready queue (according to it's priority)
		273	and return true. If the coroutine is already in the ready queue, do nothing
		274	and return false.
240		275
241	=item $process->cancel	276	=item $is_ready = $coroutine->is_ready
242		277
243	Like C<terminate>, but terminates the specified process instead.	278	Return wether the coroutine is currently the ready queue or not,
		279
		280	=item $coroutine->cancel (arg...)
		281
		282	Terminates the given coroutine and makes it return the given arguments as
		283	status (default: the empty list).
244		284
245	=cut	285	=cut
246		286
247	sub cancel {	287	sub cancel {
		288	my $self = shift;
		289	$self->{status} = [@_];
248	push @destroy, $_[0];	290	push @destroy, $self;
249	$manager->ready;	291	$manager->ready;
250	&schedule if $current == $_[0];	292	&schedule if $current == $self;
251	}	293	}
252		294
253	=item $process->join	295	=item $coroutine->join
254		296
255	Wait until the coroutine terminates and return any values given to the	297	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	298	C<terminate> or C<cancel> functions. C<join> can be called multiple times
257	processes.	299	from multiple coroutine.
258		300
259	=cut	301	=cut
260		302
261	sub join {	303	sub join {
262	my $self = shift;	304	my $self = shift;
…		…
265	&schedule;	307	&schedule;
266	}	308	}
267	wantarray ? @{$self->{status}} : $self->{status}[0];	309	wantarray ? @{$self->{status}} : $self->{status}[0];
268	}	310	}
269		311
270	=item $oldprio = $process->prio($newprio)	312	=item $oldprio = $coroutine->prio ($newprio)
271		313
272	Sets (or gets, if the argument is missing) the priority of the	314	Sets (or gets, if the argument is missing) the priority of the
273	process. Higher priority processes get run before lower priority	315	coroutine. Higher priority coroutines get run before lower priority
274	processes. Priorities are small signed integers (currently -4 .. +3),	316	coroutines. Priorities are small signed integers (currently -4 .. +3),
275	that you can refer to using PRIO_xxx constants (use the import tag :prio	317	that you can refer to using PRIO_xxx constants (use the import tag :prio
276	to get then):	318	to get then):
277		319
278	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	320	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279	3 > 1 > 0 > -1 > -3 > -4	321	3 > 1 > 0 > -1 > -3 > -4
…		…
282	current->prio(PRIO_HIGH);	324	current->prio(PRIO_HIGH);
283		325
284	The idle coroutine ($Coro::idle) always has a lower priority than any	326	The idle coroutine ($Coro::idle) always has a lower priority than any
285	existing coroutine.	327	existing coroutine.
286		328
287	Changing the priority of the current process will take effect immediately,	329	Changing the priority of the current coroutine will take effect immediately,
288	but changing the priority of processes in the ready queue (but not	330	but changing the priority of coroutines in the ready queue (but not
289	running) will only take effect after the next schedule (of that	331	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.	332	coroutine). This is a bug that will be fixed in some future version.
291		333
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)	334	=item $newprio = $coroutine->nice ($change)
301		335
302	Similar to C<prio>, but subtract the given value from the priority (i.e.	336	Similar to C<prio>, but subtract the given value from the priority (i.e.
303	higher values mean lower priority, just as in unix).	337	higher values mean lower priority, just as in unix).
304		338
305	=cut
306
307	sub nice {
308	$_[0]{prio} -= $_[1];
309	}
310
311	=item $olddesc = $process->desc($newdesc)	339	=item $olddesc = $coroutine->desc ($newdesc)
312		340
313	Sets (or gets in case the argument is missing) the description for this	341	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.	342	coroutine. This is just a free-form string you can associate with a coroutine.
315		343
316	=cut	344	=cut
317		345
318	sub desc {	346	sub desc {
319	my $old = $_[0]{desc};	347	my $old = $_[0]{desc};
…		…
321	$old;	349	$old;
322	}	350	}
323		351
324	=back	352	=back
325		353
		354	=head2 UTILITY FUNCTIONS
		355
		356	=over 4
		357
		358	=item unblock_sub { ... }
		359
		360	This utility function takes a BLOCK or code reference and "unblocks" it,
		361	returning the new coderef. This means that the new coderef will return
		362	immediately without blocking, returning nothing, while the original code
		363	ref will be called (with parameters) from within its own coroutine.
		364
		365	The reason this fucntion exists is that many event libraries (such as the
		366	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		367	of thread-safety). This means you must not block within event callbacks,
		368	otherwise you might suffer from crashes or worse.
		369
		370	This function allows your callbacks to block by executing them in another
		371	coroutine where it is safe to block. One example where blocking is handy
		372	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		373	disk.
		374
		375	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		376	creating event callbacks that want to block.
		377
		378	=cut
		379
		380	our @unblock_pool;
		381	our @unblock_queue;
		382	our $UNBLOCK_POOL_SIZE = 2;
		383
		384	sub unblock_handler_ {
		385	while () {
		386	my ($cb, @arg) = @{ delete $Coro::current->{arg} };
		387	$cb->(@arg);
		388
		389	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
		390	push @unblock_pool, $Coro::current;
		391	schedule;
		392	}
		393	}
		394
		395	our $unblock_scheduler = async {
		396	while () {
		397	while (my $cb = pop @unblock_queue) {
		398	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);
		399	$handler->{arg} = $cb;
		400	$handler->ready;
		401	cede;
		402	}
		403
		404	schedule;
		405	}
		406	};
		407
		408	sub unblock_sub(&) {
		409	my $cb = shift;
		410
		411	sub {
		412	push @unblock_queue, [$cb, @_];
		413	$unblock_scheduler->ready;
		414	}
		415	}
		416
		417	=back
		418
326	=cut	419	=cut
327		420
328	1;	421	1;
329		422
330	=head1 BUGS/LIMITATIONS	423	=head1 BUGS/LIMITATIONS
…		…
337	to allow per-thread schedulers, but Coro::State does not yet allow	430	to allow per-thread schedulers, but Coro::State does not yet allow
338	this).	431	this).
339		432
340	=head1 SEE ALSO	433	=head1 SEE ALSO
341		434
342	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	435	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>,	436
344	L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.	437	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		438
		439	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		440
		441	Embedding: L<Coro:MakeMaker>
345		442
346	=head1 AUTHOR	443	=head1 AUTHOR
347		444
348	Marc Lehmann <pcg@goof.com>	445	Marc Lehmann <schmorp@schmorp.de>
349	http://www.goof.com/pcg/marc/	446	http://home.schmorp.de/
350		447
351	=cut	448	=cut
352		449

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Comparing Coro/Coro.pm (file contents): Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 UTC vs. Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 UTC vs.
Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC