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

Comparing Coro/Coro.pm (file contents):
Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 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 = 0.95;	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	=cut	189	=cut
163		190
164	sub async(&@) {	191	sub async(&@) {
165	my $pid = new Coro @_;	192	my $pid = new Coro @_;
166	$manager->ready; # this ensures that the stack is cloned from the manager
167	$pid->ready;	193	$pid->ready;
168	$pid;	194	$pid
169	}	195	}
170		196
171	=item schedule	197	=item schedule
172		198
173	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
174	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
175	never be called again.	201	never be called again unless something else (e.g. an event handler) calls
		202	ready.
176		203
177	=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	}
178		222
179	=item cede	223	=item cede
180		224
181	"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
182	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
183	current "timeslice" to other coroutines of the same or higher priority.	227	current "timeslice" to other coroutines of the same or higher priority.
184		228
185	=cut
186
187	=item terminate [arg...]	229	=item terminate [arg...]
188		230
189	Terminates the current process.	231	Terminates the current coroutine with the given status values (see L<cancel>).
190
191	Future versions of this function will allow result arguments.
192		232
193	=cut	233	=cut
194		234
195	sub terminate {	235	sub terminate {
196	$current->{status} = [@_];
197	$current->cancel;	236	$current->cancel (@_);
198	&schedule;
199	die; # NORETURN
200	}	237	}
201		238
202	=back	239	=back
203		240
204	# dynamic methods	241	# dynamic methods
205		242
206	=head2 PROCESS METHODS	243	=head2 COROUTINE METHODS
207		244
208	These are the methods you can call on process objects.	245	These are the methods you can call on coroutine objects.
209		246
210	=over 4	247	=over 4
211		248
212	=item new Coro \&sub [, @args...]	249	=item new Coro \&sub [, @args...]
213		250
214	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
215	automatically terminates as if C<terminate> with the returned values were	252	automatically terminates as if C<terminate> with the returned values were
216	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
217	by calling the ready method.	254	by calling the ready method.
218		255
219	=cut	256	Calling C<exit> in a coroutine will not work correctly, so do not do that.
220		257
		258	=cut
		259
221	sub _newcoro {	260	sub _new_coro {
222	terminate &{+shift};	261	terminate &{+shift};
223	}	262	}
224		263
225	sub new {	264	sub new {
226	my $class = shift;	265	my $class = shift;
227	bless {
228	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
229	}, $class;
230	}
231		266
232	=item $process->ready	267	$class->SUPER::new (\&_new_coro, @_)
		268	}
233		269
234	Put the given process into the ready queue.	270	=item $success = $coroutine->ready
235		271
236	=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.
237		275
238	=item $process->cancel	276	=item $is_ready = $coroutine->is_ready
239		277
240	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).
241		284
242	=cut	285	=cut
243		286
244	sub cancel {	287	sub cancel {
		288	my $self = shift;
		289	$self->{status} = [@_];
245	push @destroy, $_[0];	290	push @destroy, $self;
246	$manager->ready;	291	$manager->ready;
247	&schedule if $current == $_[0];	292	&schedule if $current == $self;
248	}	293	}
249		294
250	=item $process->join	295	=item $coroutine->join
251		296
252	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
253	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
254	processes.	299	from multiple coroutine.
255		300
256	=cut	301	=cut
257		302
258	sub join {	303	sub join {
259	my $self = shift;	304	my $self = shift;
…		…
262	&schedule;	307	&schedule;
263	}	308	}
264	wantarray ? @{$self->{status}} : $self->{status}[0];	309	wantarray ? @{$self->{status}} : $self->{status}[0];
265	}	310	}
266		311
267	=item $oldprio = $process->prio($newprio)	312	=item $oldprio = $coroutine->prio ($newprio)
268		313
269	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
270	process. Higher priority processes get run before lower priority	315	coroutine. Higher priority coroutines get run before lower priority
271	processes. Priorities are small signed integers (currently -4 .. +3),	316	coroutines. Priorities are small signed integers (currently -4 .. +3),
272	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
273	to get then):	318	to get then):
274		319
275	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
276	3 > 1 > 0 > -1 > -3 > -4	321	3 > 1 > 0 > -1 > -3 > -4
…		…
279	current->prio(PRIO_HIGH);	324	current->prio(PRIO_HIGH);
280		325
281	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
282	existing coroutine.	327	existing coroutine.
283		328
284	Changing the priority of the current process will take effect immediately,	329	Changing the priority of the current coroutine will take effect immediately,
285	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
286	running) will only take effect after the next schedule (of that	331	running) will only take effect after the next schedule (of that
287	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.
288		333
289	=cut
290
291	sub prio {
292	my $old = $_[0]{prio};
293	$_[0]{prio} = $_[1] if @_ > 1;
294	$old;
295	}
296
297	=item $newprio = $process->nice($change)	334	=item $newprio = $coroutine->nice ($change)
298		335
299	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.
300	higher values mean lower priority, just as in unix).	337	higher values mean lower priority, just as in unix).
301		338
302	=cut
303
304	sub nice {
305	$_[0]{prio} -= $_[1];
306	}
307
308	=item $olddesc = $process->desc($newdesc)	339	=item $olddesc = $coroutine->desc ($newdesc)
309		340
310	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
311	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.
312		343
313	=cut	344	=cut
314		345
315	sub desc {	346	sub desc {
316	my $old = $_[0]{desc};	347	my $old = $_[0]{desc};
…		…
318	$old;	349	$old;
319	}	350	}
320		351
321	=back	352	=back
322		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
323	=cut	419	=cut
324		420
325	1;	421	1;
326		422
327	=head1 BUGS/LIMITATIONS	423	=head1 BUGS/LIMITATIONS
…		…
334	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
335	this).	431	this).
336		432
337	=head1 SEE ALSO	433	=head1 SEE ALSO
338		434
339	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>.
340	L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,	436
341	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>
342		442
343	=head1 AUTHOR	443	=head1 AUTHOR
344		444
345	Marc Lehmann <pcg@goof.com>	445	Marc Lehmann <schmorp@schmorp.de>
346	http://www.goof.com/pcg/marc/	446	http://home.schmorp.de/
347		447
348	=cut	448	=cut
349		449

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Comparing Coro/Coro.pm (file contents): Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 UTC vs. Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 UTC vs.
Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC