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

Comparing Coro/Coro.pm (file contents):
Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs.
Revision 1.141 by root, Tue Oct 2 10:38:17 2007 UTC

…		…
20		20
21	=head1 DESCRIPTION	21	=head1 DESCRIPTION
22		22
23	This module collection manages coroutines. Coroutines are similar	23	This module collection manages coroutines. Coroutines are similar
24	to threads but don't run in parallel at the same time even on SMP	24	to threads but don't run in parallel at the same time even on SMP
25	machines. The specific flavor of coroutine use din this module also	25	machines. The specific flavor of coroutine used in this module also
26	guarentees you that it will not switch between coroutines unless	26	guarantees you that it will not switch between coroutines unless
27	necessary, at easily-identified points in your program, so locking and	27	necessary, at easily-identified points in your program, so locking and
28	parallel access are rarely an issue, making coroutine programming much	28	parallel access are rarely an issue, making coroutine programming much
29	safer than threads programming.	29	safer than threads programming.
30		30
31	(Perl, however, does not natively support real threads but instead does a	31	(Perl, however, does not natively support real threads but instead does a
…		…
50		50
51	our $idle; # idle handler	51	our $idle; # idle handler
52	our $main; # main coroutine	52	our $main; # main coroutine
53	our $current; # current coroutine	53	our $current; # current coroutine
54		54
55	our $VERSION = '3.3';	55	our $VERSION = '3.8';
56		56
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	58	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	60	);
…		…
108		108
109	The current coroutine (the last coroutine switched to). The initial value	109	The current coroutine (the last coroutine switched to). The initial value
110	is C<$main> (of course).	110	is C<$main> (of course).
111		111
112	This variable is B<strictly> I<read-only>. It is provided for performance	112	This variable is B<strictly> I<read-only>. It is provided for performance
113	reasons. If performance is not essentiel you are encouraged to use the	113	reasons. If performance is not essential you are encouraged to use the
114	C<Coro::current> function instead.	114	C<Coro::current> function instead.
115		115
116	=cut	116	=cut
		117
		118	$main->{desc} = "[main::]";
117		119
118	# maybe some other module used Coro::Specific before...	120	# maybe some other module used Coro::Specific before...
119	$main->{specific} = $current->{specific}	121	$main->{specific} = $current->{specific}
120	if $current;	122	if $current;
121		123
…		…
166	while @destroy;	168	while @destroy;
167		169
168	&schedule;	170	&schedule;
169	}	171	}
170	};	172	};
171		173	$manager->desc ("[coro manager]");
172	$manager->prio (PRIO_MAX);	174	$manager->prio (PRIO_MAX);
173		175
174	# static methods. not really.	176	# static methods. not really.
175		177
176	=back	178	=back
…		…
185		187
186	Create a new asynchronous coroutine and return it's coroutine object	188	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	189	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	190	terminated.
189		191
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	192	Calling C<exit> in a coroutine will do the same as calling exit outside
191		193	the coroutine. Likewise, when the coroutine dies, the program will exit,
192	When the coroutine dies, the program will exit, just as in the main	194	just as it would in the main program.
193	program.
194		195
195	# create a new coroutine that just prints its arguments	196	# create a new coroutine that just prints its arguments
196	async {	197	async {
197	print "@_\n";	198	print "@_\n";
198	} 1,2,3,4;	199	} 1,2,3,4;
…		…
210	Similar to C<async>, but uses a coroutine pool, so you should not call	211	Similar to C<async>, but uses a coroutine pool, so you should not call
211	terminate or join (although you are allowed to), and you get a coroutine	212	terminate or join (although you are allowed to), and you get a coroutine
212	that might have executed other code already (which can be good or bad :).	213	that might have executed other code already (which can be good or bad :).
213		214
214	Also, the block is executed in an C<eval> context and a warning will be	215	Also, the block is executed in an C<eval> context and a warning will be
215	issued in case of an exception instead of terminating the program, as C<async> does.	216	issued in case of an exception instead of terminating the program, as
		217	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		218	will not work in the expected way, unless you call terminate or cancel,
		219	which somehow defeats the purpose of pooling.
216		220
217	The priority will be reset to C<0> after each job, otherwise the coroutine	221	The priority will be reset to C<0> after each job, otherwise the coroutine
218	will be re-used "as-is".	222	will be re-used "as-is".
219		223
220	The pool size is limited to 8 idle coroutines (this can be adjusted by	224	The pool size is limited to 8 idle coroutines (this can be adjusted by
221	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as	225	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
222	required.	226	required.
223		227
224	If you are concerned about pooled coroutines growing a lot because a	228	If you are concerned about pooled coroutines growing a lot because a
225	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool {	229	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
226	terminate }> once per second or so to slowly replenish the pool.	230	{ terminate }> once per second or so to slowly replenish the pool. In
		231	addition to that, when the stacks used by a handler grows larger than 16kb
		232	(adjustable with $Coro::POOL_RSS) it will also exit.
227		233
228	=cut	234	=cut
229		235
230	our $POOL_SIZE = 8;	236	our $POOL_SIZE = 8;
		237	our $POOL_RSS = 16 * 1024;
231	our @pool;	238	our @async_pool;
232		239
233	sub pool_handler {	240	sub pool_handler {
		241	my $cb;
		242
234	while () {	243	while () {
235	my ($cb, @arg) = @{ delete $current->{_invoke} };
236
237	eval {	244	eval {
238	$cb->(@arg);	245	while () {
		246	_pool_1 $cb;
		247	&$cb;
		248	_pool_2 $cb;
		249	&schedule;
		250	}
239	};	251	};
		252
		253	last if $@ eq "\3terminate\2\n";
240	warn $@ if $@;	254	warn $@ if $@;
241
242	last if @pool >= $POOL_SIZE;
243	push @pool, $current;
244
245	$current->prio (0);
246	schedule;
247	}	255	}
248	}	256	}
249		257
250	sub async_pool(&@) {	258	sub async_pool(&@) {
251	# this is also inlined into the unlock_scheduler	259	# this is also inlined into the unlock_scheduler
252	my $coro = (pop @pool or new Coro \&pool_handler);	260	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
253		261
254	$coro->{_invoke} = [@_];	262	$coro->{_invoke} = [@_];
255	$coro->ready;	263	$coro->ready;
256		264
257	$coro	265	$coro
…		…
275	# wake up sleeping coroutine	283	# wake up sleeping coroutine
276	$current->ready;	284	$current->ready;
277	undef $current;	285	undef $current;
278	};	286	};
279		287
280	# call schedule until event occured.	288	# call schedule until event occurred.
281	# in case we are woken up for other reasons	289	# in case we are woken up for other reasons
282	# (current still defined), loop.	290	# (current still defined), loop.
283	Coro::schedule while $current;	291	Coro::schedule while $current;
284	}	292	}
285		293
…		…
287		295
288	"Cede" to other coroutines. This function puts the current coroutine into the	296	"Cede" to other coroutines. This function puts the current coroutine into the
289	ready queue and calls C<schedule>, which has the effect of giving up the	297	ready queue and calls C<schedule>, which has the effect of giving up the
290	current "timeslice" to other coroutines of the same or higher priority.	298	current "timeslice" to other coroutines of the same or higher priority.
291		299
		300	Returns true if at least one coroutine switch has happened.
		301
292	=item Coro::cede_notself	302	=item Coro::cede_notself
293		303
294	Works like cede, but is not exported by default and will cede to any	304	Works like cede, but is not exported by default and will cede to any
295	coroutine, regardless of priority, once.	305	coroutine, regardless of priority, once.
296		306
		307	Returns true if at least one coroutine switch has happened.
		308
297	=item terminate [arg...]	309	=item terminate [arg...]
298		310
299	Terminates the current coroutine with the given status values (see L<cancel>).	311	Terminates the current coroutine with the given status values (see L<cancel>).
		312
		313	=item killall
		314
		315	Kills/terminates/cancels all coroutines except the currently running
		316	one. This is useful after a fork, either in the child or the parent, as
		317	usually only one of them should inherit the running coroutines.
300		318
301	=cut	319	=cut
302		320
303	sub terminate {	321	sub terminate {
304	$current->cancel (@_);	322	$current->cancel (@_);
		323	}
		324
		325	sub killall {
		326	for (Coro::State::list) {
		327	$_->cancel
		328	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		329	}
305	}	330	}
306		331
307	=back	332	=back
308		333
309	# dynamic methods	334	# dynamic methods
…		…
319	Create a new coroutine and return it. When the sub returns the coroutine	344	Create a new coroutine and return it. When the sub returns the coroutine
320	automatically terminates as if C<terminate> with the returned values were	345	automatically terminates as if C<terminate> with the returned values were
321	called. To make the coroutine run you must first put it into the ready queue	346	called. To make the coroutine run you must first put it into the ready queue
322	by calling the ready method.	347	by calling the ready method.
323		348
324	Calling C<exit> in a coroutine will not work correctly, so do not do that.	349	See C<async> for additional discussion.
325		350
326	=cut	351	=cut
327		352
328	sub _run_coro {	353	sub _run_coro {
329	terminate &{+shift};	354	terminate &{+shift};
…		…
452	=over 4	477	=over 4
453		478
454	=item Coro::nready	479	=item Coro::nready
455		480
456	Returns the number of coroutines that are currently in the ready state,	481	Returns the number of coroutines that are currently in the ready state,
457	i.e. that can be swicthed to. The value C<0> means that the only runnable	482	i.e. that can be switched to. The value C<0> means that the only runnable
458	coroutine is the currently running one, so C<cede> would have no effect,	483	coroutine is the currently running one, so C<cede> would have no effect,
459	and C<schedule> would cause a deadlock unless there is an idle handler	484	and C<schedule> would cause a deadlock unless there is an idle handler
460	that wakes up some coroutines.	485	that wakes up some coroutines.
461		486
462	=item my $guard = Coro::guard { ... }	487	=item my $guard = Coro::guard { ... }
463		488
464	This creates and returns a guard object. Nothing happens until the objetc	489	This creates and returns a guard object. Nothing happens until the object
465	gets destroyed, in which case the codeblock given as argument will be	490	gets destroyed, in which case the codeblock given as argument will be
466	executed. This is useful to free locks or other resources in case of a	491	executed. This is useful to free locks or other resources in case of a
467	runtime error or when the coroutine gets canceled, as in both cases the	492	runtime error or when the coroutine gets canceled, as in both cases the
468	guard block will be executed. The guard object supports only one method,	493	guard block will be executed. The guard object supports only one method,
469	C<< ->cancel >>, which will keep the codeblock from being executed.	494	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
498	This utility function takes a BLOCK or code reference and "unblocks" it,	523	This utility function takes a BLOCK or code reference and "unblocks" it,
499	returning the new coderef. This means that the new coderef will return	524	returning the new coderef. This means that the new coderef will return
500	immediately without blocking, returning nothing, while the original code	525	immediately without blocking, returning nothing, while the original code
501	ref will be called (with parameters) from within its own coroutine.	526	ref will be called (with parameters) from within its own coroutine.
502		527
503	The reason this fucntion exists is that many event libraries (such as the	528	The reason this function exists is that many event libraries (such as the
504	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	529	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
505	of thread-safety). This means you must not block within event callbacks,	530	of thread-safety). This means you must not block within event callbacks,
506	otherwise you might suffer from crashes or worse.	531	otherwise you might suffer from crashes or worse.
507		532
508	This function allows your callbacks to block by executing them in another	533	This function allows your callbacks to block by executing them in another
…		…
519		544
520	# we create a special coro because we want to cede,	545	# we create a special coro because we want to cede,
521	# to reduce pressure on the coro pool (because most callbacks	546	# to reduce pressure on the coro pool (because most callbacks
522	# return immediately and can be reused) and because we cannot cede	547	# return immediately and can be reused) and because we cannot cede
523	# inside an event callback.	548	# inside an event callback.
524	our $unblock_scheduler = async {	549	our $unblock_scheduler = new Coro sub {
525	while () {	550	while () {
526	while (my $cb = pop @unblock_queue) {	551	while (my $cb = pop @unblock_queue) {
527	# this is an inlined copy of async_pool	552	# this is an inlined copy of async_pool
528	my $coro = (pop @pool or new Coro \&pool_handler);	553	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
529		554
530	$coro->{_invoke} = $cb;	555	$coro->{_invoke} = $cb;
531	$coro->ready;	556	$coro->ready;
532	cede; # for short-lived callbacks, this reduces pressure on the coro pool	557	cede; # for short-lived callbacks, this reduces pressure on the coro pool
533	}	558	}
534	schedule; # sleep well	559	schedule; # sleep well
535	}	560	}
536	};	561	};
		562	$unblock_scheduler->desc ("[unblock_sub scheduler]");
537		563
538	sub unblock_sub(&) {	564	sub unblock_sub(&) {
539	my $cb = shift;	565	my $cb = shift;
540		566
541	sub {	567	sub {
…		…
554		580
555	- you must make very sure that no coro is still active on global	581	- you must make very sure that no coro is still active on global
556	destruction. very bad things might happen otherwise (usually segfaults).	582	destruction. very bad things might happen otherwise (usually segfaults).
557		583
558	- this module is not thread-safe. You should only ever use this module	584	- this module is not thread-safe. You should only ever use this module
559	from the same thread (this requirement might be losened in the future	585	from the same thread (this requirement might be loosened in the future
560	to allow per-thread schedulers, but Coro::State does not yet allow	586	to allow per-thread schedulers, but Coro::State does not yet allow
561	this).	587	this).
562		588
563	=head1 SEE ALSO	589	=head1 SEE ALSO
564		590

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Comparing Coro/Coro.pm (file contents): Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs. Revision 1.141 by root, Tue Oct 2 10:38:17 2007 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs.
Revision 1.141 by root, Tue Oct 2 10:38:17 2007 UTC