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

Comparing Coro/Coro.pm (file contents):
Revision 1.115 by root, Wed Feb 28 11:43:03 2007 UTC vs.
Revision 1.178 by root, Thu Apr 17 22:33:10 2008 UTC

…		…
6		6
7	use Coro;	7	use Coro;
8		8
9	async {	9	async {
10	# some asynchronous thread of execution	10	# some asynchronous thread of execution
		11	print "2\n";
		12	cede; # yield back to main
		13	print "4\n";
11	};	14	};
		15	print "1\n";
		16	cede; # yield to coroutine
		17	print "3\n";
		18	cede; # and again
12		19
13	# alternatively create an async coroutine like this:	20	# use locking
		21	my $lock = new Coro::Semaphore;
		22	my $locked;
14		23
15	sub some_func : Coro {	24	$lock->down;
16	# some more async code	25	$locked = 1;
17	}	26	$lock->up;
18
19	cede;
20		27
21	=head1 DESCRIPTION	28	=head1 DESCRIPTION
22		29
23	This module collection manages coroutines. Coroutines are similar	30	This module collection manages coroutines. Coroutines are similar
24	to threads but don't run in parallel at the same time even on SMP	31	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	32	machines. The specific flavor of coroutine used in this module also
26	guarentees you that it will not switch between coroutines unless	33	guarantees you that it will not switch between coroutines unless
27	necessary, at easily-identified points in your program, so locking and	34	necessary, at easily-identified points in your program, so locking and
28	parallel access are rarely an issue, making coroutine programming much	35	parallel access are rarely an issue, making coroutine programming much
29	safer than threads programming.	36	safer than threads programming.
30		37
31	(Perl, however, does not natively support real threads but instead does a	38	(Perl, however, does not natively support real threads but instead does a
…		…
33	is a performance win on Windows machines, and a loss everywhere else).	40	is a performance win on Windows machines, and a loss everywhere else).
34		41
35	In this module, coroutines are defined as "callchain + lexical variables +	42	In this module, coroutines are defined as "callchain + lexical variables +
36	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,	43	@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
37	its own set of lexicals and its own set of perls most important global	44	its own set of lexicals and its own set of perls most important global
38	variables.	45	variables (see L<Coro::State> for more configuration).
39		46
40	=cut	47	=cut
41		48
42	package Coro;	49	package Coro;
43		50
…		…
50		57
51	our $idle; # idle handler	58	our $idle; # idle handler
52	our $main; # main coroutine	59	our $main; # main coroutine
53	our $current; # current coroutine	60	our $current; # current coroutine
54		61
55	our $VERSION = '3.501';	62	our $VERSION = '4.51';
56		63
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
…		…
108		115
109	The current coroutine (the last coroutine switched to). The initial value	116	The current coroutine (the last coroutine switched to). The initial value
110	is C<$main> (of course).	117	is C<$main> (of course).
111		118
112	This variable is B<strictly> I<read-only>. It is provided for performance	119	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	120	reasons. If performance is not essential you are encouraged to use the
114	C<Coro::current> function instead.	121	C<Coro::current> function instead.
115		122
116	=cut	123	=cut
117		124
		125	$main->{desc} = "[main::]";
		126
118	# maybe some other module used Coro::Specific before...	127	# maybe some other module used Coro::Specific before...
119	$main->{specific} = $current->{specific}	128	$main->{_specific} = $current->{_specific}
120	if $current;	129	if $current;
121		130
122	_set_current $main;	131	_set_current $main;
123		132
124	sub current() { $current }	133	sub current() { $current }
…		…
132	This hook is overwritten by modules such as C<Coro::Timer> and	141	This hook is overwritten by modules such as C<Coro::Timer> and
133	C<Coro::Event> to wait on an external event that hopefully wake up a	142	C<Coro::Event> to wait on an external event that hopefully wake up a
134	coroutine so the scheduler can run it.	143	coroutine so the scheduler can run it.
135		144
136	Please note that if your callback recursively invokes perl (e.g. for event	145	Please note that if your callback recursively invokes perl (e.g. for event
137	handlers), then it must be prepared to be called recursively.	146	handlers), then it must be prepared to be called recursively itself.
138		147
139	=cut	148	=cut
140		149
141	$idle = sub {	150	$idle = sub {
142	require Carp;	151	require Carp;
…		…
149	# free coroutine data and mark as destructed	158	# free coroutine data and mark as destructed
150	$self->_destroy	159	$self->_destroy
151	or return;	160	or return;
152		161
153	# call all destruction callbacks	162	# call all destruction callbacks
154	$_->(@{$self->{status}})	163	$_->(@{$self->{_status}})
155	for @{(delete $self->{destroy_cb}) \|\| []};	164	for @{(delete $self->{_on_destroy}) \|\| []};
156	}	165	}
157		166
158	# this coroutine is necessary because a coroutine	167	# this coroutine is necessary because a coroutine
159	# cannot destroy itself.	168	# cannot destroy itself.
160	my @destroy;	169	my @destroy;
…		…
166	while @destroy;	175	while @destroy;
167		176
168	&schedule;	177	&schedule;
169	}	178	}
170	};	179	};
171		180	$manager->desc ("[coro manager]");
172	$manager->prio (PRIO_MAX);	181	$manager->prio (PRIO_MAX);
173
174	# static methods. not really.
175		182
176	=back	183	=back
177		184
178	=head2 STATIC METHODS	185	=head2 STATIC METHODS
179		186
…		…
185		192
186	Create a new asynchronous coroutine and return it's coroutine object	193	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	194	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	195	terminated.
189		196
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	197	See the C<Coro::State::new> constructor for info about the coroutine
		198	environment in which coroutines run.
191		199
192	When the coroutine dies, the program will exit, just as in the main	200	Calling C<exit> in a coroutine will do the same as calling exit outside
193	program.	201	the coroutine. Likewise, when the coroutine dies, the program will exit,
		202	just as it would in the main 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;
…		…
215	issued in case of an exception instead of terminating the program, as	224	issued in case of an exception instead of terminating the program, as
216	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>	225	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
217	will not work in the expected way, unless you call terminate or cancel,	226	will not work in the expected way, unless you call terminate or cancel,
218	which somehow defeats the purpose of pooling.	227	which somehow defeats the purpose of pooling.
219		228
220	The priority will be reset to C<0> after each job, otherwise the coroutine	229	The priority will be reset to C<0> after each job, tracing will be
221	will be re-used "as-is".	230	disabled, the description will be reset and the default output filehandle
		231	gets restored, so you can change alkl these. Otherwise the coroutine will
		232	be re-used "as-is": most notably if you change other per-coroutine global
		233	stuff such as C<$/> you need to revert that change, which is most simply
		234	done by using local as in C< local $/ >.
222		235
223	The pool size is limited to 8 idle coroutines (this can be adjusted by	236	The pool size is limited to 8 idle coroutines (this can be adjusted by
224	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as	237	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
225	required.	238	required.
226		239
227	If you are concerned about pooled coroutines growing a lot because a	240	If you are concerned about pooled coroutines growing a lot because a
228	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool {	241	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
229	terminate }> once per second or so to slowly replenish the pool.	242	{ terminate }> once per second or so to slowly replenish the pool. In
		243	addition to that, when the stacks used by a handler grows larger than 16kb
		244	(adjustable with $Coro::POOL_RSS) it will also exit.
230		245
231	=cut	246	=cut
232		247
233	our $POOL_SIZE = 8;	248	our $POOL_SIZE = 8;
		249	our $POOL_RSS = 16 * 1024;
234	our @pool;	250	our @async_pool;
235		251
236	sub pool_handler {	252	sub pool_handler {
		253	my $cb;
		254
237	while () {	255	while () {
238	eval {	256	eval {
239	my ($cb, @arg) = @{ delete $current->{_invoke} or return };	257	while () {
240	$cb->(@arg);	258	_pool_1 $cb;
		259	&$cb;
		260	_pool_2 $cb;
		261	&schedule;
		262	}
241	};	263	};
		264
		265	last if $@ eq "\3async_pool terminate\2\n";
242	warn $@ if $@;	266	warn $@ if $@;
243
244	last if @pool >= $POOL_SIZE;
245	push @pool, $current;
246
247	$current->prio (0);
248	schedule;
249	}	267	}
250	}	268	}
251		269
252	sub async_pool(&@) {	270	sub async_pool(&@) {
253	# this is also inlined into the unlock_scheduler	271	# this is also inlined into the unlock_scheduler
254	my $coro = (pop @pool or new Coro \&pool_handler);	272	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
255		273
256	$coro->{_invoke} = [@_];	274	$coro->{_invoke} = [@_];
257	$coro->ready;	275	$coro->ready;
258		276
259	$coro	277	$coro
…		…
277	# wake up sleeping coroutine	295	# wake up sleeping coroutine
278	$current->ready;	296	$current->ready;
279	undef $current;	297	undef $current;
280	};	298	};
281		299
282	# call schedule until event occured.	300	# call schedule until event occurred.
283	# in case we are woken up for other reasons	301	# in case we are woken up for other reasons
284	# (current still defined), loop.	302	# (current still defined), loop.
285	Coro::schedule while $current;	303	Coro::schedule while $current;
286	}	304	}
287		305
…		…
289		307
290	"Cede" to other coroutines. This function puts the current coroutine into the	308	"Cede" to other coroutines. This function puts the current coroutine into the
291	ready queue and calls C<schedule>, which has the effect of giving up the	309	ready queue and calls C<schedule>, which has the effect of giving up the
292	current "timeslice" to other coroutines of the same or higher priority.	310	current "timeslice" to other coroutines of the same or higher priority.
293		311
294	Returns true if at least one coroutine switch has happened.
295
296	=item Coro::cede_notself	312	=item Coro::cede_notself
297		313
298	Works like cede, but is not exported by default and will cede to any	314	Works like cede, but is not exported by default and will cede to any
299	coroutine, regardless of priority, once.	315	coroutine, regardless of priority, once.
300		316
301	Returns true if at least one coroutine switch has happened.
302
303	=item terminate [arg...]	317	=item terminate [arg...]
304		318
305	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>).
		320
		321	=item killall
		322
		323	Kills/terminates/cancels all coroutines except the currently running
		324	one. This is useful after a fork, either in the child or the parent, as
		325	usually only one of them should inherit the running coroutines.
306		326
307	=cut	327	=cut
308		328
309	sub terminate {	329	sub terminate {
310	$current->cancel (@_);	330	$current->cancel (@_);
311	}	331	}
312		332
		333	sub killall {
		334	for (Coro::State::list) {
		335	$_->cancel
		336	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		337	}
		338	}
		339
313	=back	340	=back
314
315	# dynamic methods
316		341
317	=head2 COROUTINE METHODS	342	=head2 COROUTINE METHODS
318		343
319	These are the methods you can call on coroutine objects.	344	These are the methods you can call on coroutine objects.
320		345
…		…
325	Create a new coroutine and return it. When the sub returns the coroutine	350	Create a new coroutine and return it. When the sub returns the coroutine
326	automatically terminates as if C<terminate> with the returned values were	351	automatically terminates as if C<terminate> with the returned values were
327	called. To make the coroutine run you must first put it into the ready queue	352	called. To make the coroutine run you must first put it into the ready queue
328	by calling the ready method.	353	by calling the ready method.
329		354
330	Calling C<exit> in a coroutine will not work correctly, so do not do that.	355	See C<async> and C<Coro::State::new> for additional info about the
		356	coroutine environment.
331		357
332	=cut	358	=cut
333		359
334	sub _run_coro {	360	sub _run_coro {
335	terminate &{+shift};	361	terminate &{+shift};
…		…
359		385
360	=cut	386	=cut
361		387
362	sub cancel {	388	sub cancel {
363	my $self = shift;	389	my $self = shift;
364	$self->{status} = [@_];	390	$self->{_status} = [@_];
365		391
366	if ($current == $self) {	392	if ($current == $self) {
367	push @destroy, $self;	393	push @destroy, $self;
368	$manager->ready;	394	$manager->ready;
369	&schedule while 1;	395	&schedule while 1;
…		…
373	}	399	}
374		400
375	=item $coroutine->join	401	=item $coroutine->join
376		402
377	Wait until the coroutine terminates and return any values given to the	403	Wait until the coroutine terminates and return any values given to the
378	C<terminate> or C<cancel> functions. C<join> can be called multiple times	404	C<terminate> or C<cancel> functions. C<join> can be called concurrently
379	from multiple coroutine.	405	from multiple coroutines.
380		406
381	=cut	407	=cut
382		408
383	sub join {	409	sub join {
384	my $self = shift;	410	my $self = shift;
385		411
386	unless ($self->{status}) {	412	unless ($self->{_status}) {
387	my $current = $current;	413	my $current = $current;
388		414
389	push @{$self->{destroy_cb}}, sub {	415	push @{$self->{_on_destroy}}, sub {
390	$current->ready;	416	$current->ready;
391	undef $current;	417	undef $current;
392	};	418	};
393		419
394	&schedule while $current;	420	&schedule while $current;
395	}	421	}
396		422
397	wantarray ? @{$self->{status}} : $self->{status}[0];	423	wantarray ? @{$self->{_status}} : $self->{_status}[0];
398	}	424	}
399		425
400	=item $coroutine->on_destroy (\&cb)	426	=item $coroutine->on_destroy (\&cb)
401		427
402	Registers a callback that is called when this coroutine gets destroyed,	428	Registers a callback that is called when this coroutine gets destroyed,
…		…
406	=cut	432	=cut
407		433
408	sub on_destroy {	434	sub on_destroy {
409	my ($self, $cb) = @_;	435	my ($self, $cb) = @_;
410		436
411	push @{ $self->{destroy_cb} }, $cb;	437	push @{ $self->{_on_destroy} }, $cb;
412	}	438	}
413		439
414	=item $oldprio = $coroutine->prio ($newprio)	440	=item $oldprio = $coroutine->prio ($newprio)
415		441
416	Sets (or gets, if the argument is missing) the priority of the	442	Sets (or gets, if the argument is missing) the priority of the
…		…
441	=item $olddesc = $coroutine->desc ($newdesc)	467	=item $olddesc = $coroutine->desc ($newdesc)
442		468
443	Sets (or gets in case the argument is missing) the description for this	469	Sets (or gets in case the argument is missing) the description for this
444	coroutine. This is just a free-form string you can associate with a coroutine.	470	coroutine. This is just a free-form string you can associate with a coroutine.
445		471
		472	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
		473	can modify this member directly if you wish.
		474
		475	=item $coroutine->throw ([$scalar])
		476
		477	If C<$throw> is specified and defined, it will be thrown as an exception
		478	inside the coroutine at the next convinient point in time (usually after
		479	it gains control at the next schedule/transfer/cede). Otherwise clears the
		480	exception object.
		481
		482	The exception object will be thrown "as is" with the specified scalar in
		483	C<$@>, i.e. if it is a string, no line number or newline will be appended
		484	(unlike with C<die>).
		485
		486	This can be used as a softer means than C<cancel> to ask a coroutine to
		487	end itself, although there is no guarentee that the exception will lead to
		488	termination, and if the exception isn't caught it might well end the whole
		489	program.
		490
446	=cut	491	=cut
447		492
448	sub desc {	493	sub desc {
449	my $old = $_[0]{desc};	494	my $old = $_[0]{desc};
450	$_[0]{desc} = $_[1] if @_ > 1;	495	$_[0]{desc} = $_[1] if @_ > 1;
…		…
458	=over 4	503	=over 4
459		504
460	=item Coro::nready	505	=item Coro::nready
461		506
462	Returns the number of coroutines that are currently in the ready state,	507	Returns the number of coroutines that are currently in the ready state,
463	i.e. that can be swicthed to. The value C<0> means that the only runnable	508	i.e. that can be switched to. The value C<0> means that the only runnable
464	coroutine is the currently running one, so C<cede> would have no effect,	509	coroutine is the currently running one, so C<cede> would have no effect,
465	and C<schedule> would cause a deadlock unless there is an idle handler	510	and C<schedule> would cause a deadlock unless there is an idle handler
466	that wakes up some coroutines.	511	that wakes up some coroutines.
467		512
468	=item my $guard = Coro::guard { ... }	513	=item my $guard = Coro::guard { ... }
469		514
470	This creates and returns a guard object. Nothing happens until the objetc	515	This creates and returns a guard object. Nothing happens until the object
471	gets destroyed, in which case the codeblock given as argument will be	516	gets destroyed, in which case the codeblock given as argument will be
472	executed. This is useful to free locks or other resources in case of a	517	executed. This is useful to free locks or other resources in case of a
473	runtime error or when the coroutine gets canceled, as in both cases the	518	runtime error or when the coroutine gets canceled, as in both cases the
474	guard block will be executed. The guard object supports only one method,	519	guard block will be executed. The guard object supports only one method,
475	C<< ->cancel >>, which will keep the codeblock from being executed.	520	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
504	This utility function takes a BLOCK or code reference and "unblocks" it,	549	This utility function takes a BLOCK or code reference and "unblocks" it,
505	returning the new coderef. This means that the new coderef will return	550	returning the new coderef. This means that the new coderef will return
506	immediately without blocking, returning nothing, while the original code	551	immediately without blocking, returning nothing, while the original code
507	ref will be called (with parameters) from within its own coroutine.	552	ref will be called (with parameters) from within its own coroutine.
508		553
509	The reason this fucntion exists is that many event libraries (such as the	554	The reason this function exists is that many event libraries (such as the
510	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	555	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
511	of thread-safety). This means you must not block within event callbacks,	556	of thread-safety). This means you must not block within event callbacks,
512	otherwise you might suffer from crashes or worse.	557	otherwise you might suffer from crashes or worse.
513		558
514	This function allows your callbacks to block by executing them in another	559	This function allows your callbacks to block by executing them in another
…		…
525		570
526	# we create a special coro because we want to cede,	571	# we create a special coro because we want to cede,
527	# to reduce pressure on the coro pool (because most callbacks	572	# to reduce pressure on the coro pool (because most callbacks
528	# return immediately and can be reused) and because we cannot cede	573	# return immediately and can be reused) and because we cannot cede
529	# inside an event callback.	574	# inside an event callback.
530	our $unblock_scheduler = async {	575	our $unblock_scheduler = new Coro sub {
531	while () {	576	while () {
532	while (my $cb = pop @unblock_queue) {	577	while (my $cb = pop @unblock_queue) {
533	# this is an inlined copy of async_pool	578	# this is an inlined copy of async_pool
534	my $coro = (pop @pool or new Coro \&pool_handler);	579	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
535		580
536	$coro->{_invoke} = $cb;	581	$coro->{_invoke} = $cb;
537	$coro->ready;	582	$coro->ready;
538	cede; # for short-lived callbacks, this reduces pressure on the coro pool	583	cede; # for short-lived callbacks, this reduces pressure on the coro pool
539	}	584	}
540	schedule; # sleep well	585	schedule; # sleep well
541	}	586	}
542	};	587	};
		588	$unblock_scheduler->desc ("[unblock_sub scheduler]");
543		589
544	sub unblock_sub(&) {	590	sub unblock_sub(&) {
545	my $cb = shift;	591	my $cb = shift;
546		592
547	sub {	593	sub {
…		…
560		606
561	- you must make very sure that no coro is still active on global	607	- you must make very sure that no coro is still active on global
562	destruction. very bad things might happen otherwise (usually segfaults).	608	destruction. very bad things might happen otherwise (usually segfaults).
563		609
564	- this module is not thread-safe. You should only ever use this module	610	- this module is not thread-safe. You should only ever use this module
565	from the same thread (this requirement might be losened in the future	611	from the same thread (this requirement might be loosened in the future
566	to allow per-thread schedulers, but Coro::State does not yet allow	612	to allow per-thread schedulers, but Coro::State does not yet allow
567	this).	613	this).
568		614
569	=head1 SEE ALSO	615	=head1 SEE ALSO
570		616
		617	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		618
		619	Debugging: L<Coro::Debug>.
		620
571	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	621	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
572		622
573	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	623	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
574		624
575	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	625	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
576		626
		627	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		628
577	Embedding: L<Coro:MakeMaker>	629	Embedding: L<Coro::MakeMaker>.
578		630
579	=head1 AUTHOR	631	=head1 AUTHOR
580		632
581	Marc Lehmann <schmorp@schmorp.de>	633	Marc Lehmann <schmorp@schmorp.de>
582	http://home.schmorp.de/	634	http://home.schmorp.de/

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Comparing Coro/Coro.pm (file contents): Revision 1.115 by root, Wed Feb 28 11:43:03 2007 UTC vs. Revision 1.178 by root, Thu Apr 17 22:33:10 2008 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.115 by root, Wed Feb 28 11:43:03 2007 UTC vs.
Revision 1.178 by root, Thu Apr 17 22:33:10 2008 UTC