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

Comparing Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs.
Revision 1.139 by root, Thu Sep 27 15:52:30 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 $VERSION = '3.8';
56		56
57	our @EXPORT = qw(async cede schedule terminate current unblock_sub);	57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	58	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	60	);
61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));	61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62		62
…		…
108		108
109	The current coroutine (the last coroutine switched to). The initial value	109	The current coroutine (the last coroutine switched to). The initial value
110	is C<$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
…		…
153	# call all destruction callbacks	155	# call all destruction callbacks
154	$_->(@{$self->{status}})	156	$_->(@{$self->{status}})
155	for @{(delete $self->{destroy_cb}) \|\| []};	157	for @{(delete $self->{destroy_cb}) \|\| []};
156	}	158	}
157		159
		160	sub _do_trace_sub {
		161	&{$current->{_trace_sub_cb}}
		162	}
		163
		164	sub _do_trace_line {
		165	&{$current->{_trace_line_cb}}
		166	}
		167
158	# this coroutine is necessary because a coroutine	168	# this coroutine is necessary because a coroutine
159	# cannot destroy itself.	169	# cannot destroy itself.
160	my @destroy;	170	my @destroy;
161	my $manager;	171	my $manager;
162		172
…		…
166	while @destroy;	176	while @destroy;
167		177
168	&schedule;	178	&schedule;
169	}	179	}
170	};	180	};
171		181	$manager->desc ("[coro manager]");
172	$manager->prio (PRIO_MAX);	182	$manager->prio (PRIO_MAX);
173		183
174	# static methods. not really.	184	# static methods. not really.
175		185
176	=back	186	=back
…		…
185		195
186	Create a new asynchronous coroutine and return it's coroutine object	196	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	197	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	198	terminated.
189		199
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	200	Calling C<exit> in a coroutine will do the same as calling exit outside
191		201	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	202	just as it would in the main program.
193	program.
194		203
195	# create a new coroutine that just prints its arguments	204	# create a new coroutine that just prints its arguments
196	async {	205	async {
197	print "@_\n";	206	print "@_\n";
198	} 1,2,3,4;	207	} 1,2,3,4;
…		…
200	=cut	209	=cut
201		210
202	sub async(&@) {	211	sub async(&@) {
203	my $coro = new Coro @_;	212	my $coro = new Coro @_;
204	$coro->ready;	213	$coro->ready;
		214	$coro
		215	}
		216
		217	=item async_pool { ... } [@args...]
		218
		219	Similar to C<async>, but uses a coroutine pool, so you should not call
		220	terminate or join (although you are allowed to), and you get a coroutine
		221	that might have executed other code already (which can be good or bad :).
		222
		223	Also, the block is executed in an C<eval> context and a warning will be
		224	issued in case of an exception instead of terminating the program, as
		225	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		226	will not work in the expected way, unless you call terminate or cancel,
		227	which somehow defeats the purpose of pooling.
		228
		229	The priority will be reset to C<0> after each job, otherwise the coroutine
		230	will be re-used "as-is".
		231
		232	The pool size is limited to 8 idle coroutines (this can be adjusted by
		233	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
		234	required.
		235
		236	If you are concerned about pooled coroutines growing a lot because a
		237	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
		238	{ terminate }> once per second or so to slowly replenish the pool. In
		239	addition to that, when the stacks used by a handler grows larger than 16kb
		240	(adjustable with $Coro::POOL_RSS) it will also exit.
		241
		242	=cut
		243
		244	our $POOL_SIZE = 8;
		245	our $POOL_RSS = 16 * 1024;
		246	our @async_pool;
		247
		248	sub pool_handler {
		249	my $cb;
		250
		251	while () {
		252	eval {
		253	while () {
		254	_pool_1 $cb;
		255	&$cb;
		256	_pool_2 $cb;
		257	&schedule;
		258	}
		259	};
		260
		261	last if $@ eq "\3terminate\2\n";
		262	warn $@ if $@;
		263	}
		264	}
		265
		266	sub async_pool(&@) {
		267	# this is also inlined into the unlock_scheduler
		268	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		269
		270	$coro->{_invoke} = [@_];
		271	$coro->ready;
		272
205	$coro	273	$coro
206	}	274	}
207		275
208	=item schedule	276	=item schedule
209		277
…		…
223	# wake up sleeping coroutine	291	# wake up sleeping coroutine
224	$current->ready;	292	$current->ready;
225	undef $current;	293	undef $current;
226	};	294	};
227		295
228	# call schedule until event occured.	296	# call schedule until event occurred.
229	# in case we are woken up for other reasons	297	# in case we are woken up for other reasons
230	# (current still defined), loop.	298	# (current still defined), loop.
231	Coro::schedule while $current;	299	Coro::schedule while $current;
232	}	300	}
233		301
…		…
235		303
236	"Cede" to other coroutines. This function puts the current coroutine into the	304	"Cede" to other coroutines. This function puts the current coroutine into the
237	ready queue and calls C<schedule>, which has the effect of giving up the	305	ready queue and calls C<schedule>, which has the effect of giving up the
238	current "timeslice" to other coroutines of the same or higher priority.	306	current "timeslice" to other coroutines of the same or higher priority.
239		307
		308	Returns true if at least one coroutine switch has happened.
		309
240	=item Coro::cede_notself	310	=item Coro::cede_notself
241		311
242	Works like cede, but is not exported by default and will cede to any	312	Works like cede, but is not exported by default and will cede to any
243	coroutine, regardless of priority, once.	313	coroutine, regardless of priority, once.
		314
		315	Returns true if at least one coroutine switch has happened.
244		316
245	=item terminate [arg...]	317	=item terminate [arg...]
246		318
247	Terminates the current coroutine with the given status values (see L<cancel>).	319	Terminates the current coroutine with the given status values (see L<cancel>).
248		320
…		…
267	Create a new coroutine and return it. When the sub returns the coroutine	339	Create a new coroutine and return it. When the sub returns the coroutine
268	automatically terminates as if C<terminate> with the returned values were	340	automatically terminates as if C<terminate> with the returned values were
269	called. To make the coroutine run you must first put it into the ready queue	341	called. To make the coroutine run you must first put it into the ready queue
270	by calling the ready method.	342	by calling the ready method.
271		343
272	Calling C<exit> in a coroutine will not work correctly, so do not do that.	344	See C<async> for additional discussion.
273		345
274	=cut	346	=cut
275		347
276	sub _run_coro {	348	sub _run_coro {
277	terminate &{+shift};	349	terminate &{+shift};
…		…
400	=over 4	472	=over 4
401		473
402	=item Coro::nready	474	=item Coro::nready
403		475
404	Returns the number of coroutines that are currently in the ready state,	476	Returns the number of coroutines that are currently in the ready state,
405	i.e. that can be swicthed to. The value C<0> means that the only runnable	477	i.e. that can be switched to. The value C<0> means that the only runnable
406	coroutine is the currently running one, so C<cede> would have no effect,	478	coroutine is the currently running one, so C<cede> would have no effect,
407	and C<schedule> would cause a deadlock unless there is an idle handler	479	and C<schedule> would cause a deadlock unless there is an idle handler
408	that wakes up some coroutines.	480	that wakes up some coroutines.
409		481
410	=item my $guard = Coro::guard { ... }	482	=item my $guard = Coro::guard { ... }
411		483
412	This creates and returns a guard object. Nothing happens until the objetc	484	This creates and returns a guard object. Nothing happens until the object
413	gets destroyed, in which case the codeblock given as argument will be	485	gets destroyed, in which case the codeblock given as argument will be
414	executed. This is useful to free locks or other resources in case of a	486	executed. This is useful to free locks or other resources in case of a
415	runtime error or when the coroutine gets canceled, as in both cases the	487	runtime error or when the coroutine gets canceled, as in both cases the
416	guard block will be executed. The guard object supports only one method,	488	guard block will be executed. The guard object supports only one method,
417	C<< ->cancel >>, which will keep the codeblock from being executed.	489	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
446	This utility function takes a BLOCK or code reference and "unblocks" it,	518	This utility function takes a BLOCK or code reference and "unblocks" it,
447	returning the new coderef. This means that the new coderef will return	519	returning the new coderef. This means that the new coderef will return
448	immediately without blocking, returning nothing, while the original code	520	immediately without blocking, returning nothing, while the original code
449	ref will be called (with parameters) from within its own coroutine.	521	ref will be called (with parameters) from within its own coroutine.
450		522
451	The reason this fucntion exists is that many event libraries (such as the	523	The reason this function exists is that many event libraries (such as the
452	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	524	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
453	of thread-safety). This means you must not block within event callbacks,	525	of thread-safety). This means you must not block within event callbacks,
454	otherwise you might suffer from crashes or worse.	526	otherwise you might suffer from crashes or worse.
455		527
456	This function allows your callbacks to block by executing them in another	528	This function allows your callbacks to block by executing them in another
…		…
461	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when	533	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
462	creating event callbacks that want to block.	534	creating event callbacks that want to block.
463		535
464	=cut	536	=cut
465		537
466	our @unblock_pool;
467	our @unblock_queue;	538	our @unblock_queue;
468	our $UNBLOCK_POOL_SIZE = 2;
469		539
470	sub unblock_handler_ {	540	# we create a special coro because we want to cede,
471	while () {	541	# to reduce pressure on the coro pool (because most callbacks
472	my ($cb, @arg) = @{ delete $Coro::current->{arg} };	542	# return immediately and can be reused) and because we cannot cede
473	$cb->(@arg);	543	# inside an event callback.
474
475	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
476	push @unblock_pool, $Coro::current;
477	schedule;
478	}
479	}
480
481	our $unblock_scheduler = async {	544	our $unblock_scheduler = new Coro sub {
482	while () {	545	while () {
483	while (my $cb = pop @unblock_queue) {	546	while (my $cb = pop @unblock_queue) {
484	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);	547	# this is an inlined copy of async_pool
485	$handler->{arg} = $cb;	548	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		549
		550	$coro->{_invoke} = $cb;
486	$handler->ready;	551	$coro->ready;
487	cede;	552	cede; # for short-lived callbacks, this reduces pressure on the coro pool
488	}	553	}
489		554	schedule; # sleep well
490	schedule;
491	}	555	}
492	};	556	};
		557	$unblock_scheduler->desc ("[unblock_sub scheduler]");
493		558
494	sub unblock_sub(&) {	559	sub unblock_sub(&) {
495	my $cb = shift;	560	my $cb = shift;
496		561
497	sub {	562	sub {
498	push @unblock_queue, [$cb, @_];	563	unshift @unblock_queue, [$cb, @_];
499	$unblock_scheduler->ready;	564	$unblock_scheduler->ready;
500	}	565	}
501	}	566	}
502		567
503	=back	568	=back
…		…
510		575
511	- you must make very sure that no coro is still active on global	576	- you must make very sure that no coro is still active on global
512	destruction. very bad things might happen otherwise (usually segfaults).	577	destruction. very bad things might happen otherwise (usually segfaults).
513		578
514	- this module is not thread-safe. You should only ever use this module	579	- this module is not thread-safe. You should only ever use this module
515	from the same thread (this requirement might be losened in the future	580	from the same thread (this requirement might be loosened in the future
516	to allow per-thread schedulers, but Coro::State does not yet allow	581	to allow per-thread schedulers, but Coro::State does not yet allow
517	this).	582	this).
518		583
519	=head1 SEE ALSO	584	=head1 SEE ALSO
520		585

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Comparing Coro/Coro.pm (file contents): Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs. Revision 1.139 by root, Thu Sep 27 15:52:30 2007 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs.
Revision 1.139 by root, Thu Sep 27 15:52:30 2007 UTC