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

Comparing Coro/Coro.pm (file contents):
Revision 1.105 by root, Fri Jan 5 16:55:01 2007 UTC vs.
Revision 1.152 by root, Sun Oct 7 13:53:37 2007 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 = '3.3';	62	our $VERSION = '4.1';
56		63
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
…		…
108		115
109	The current coroutine (the last coroutine switched to). The initial value	116	The current coroutine (the last coroutine switched to). The initial value
110	is C<$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		182
174	# static methods. not really.	183	# static methods. not really.
175		184
176	=back	185	=back
…		…
185		194
186	Create a new asynchronous coroutine and return it's coroutine object	195	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	196	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	197	terminated.
189		198
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	199	See the C<Coro::State::new> constructor for info about the coroutine
		200	environment in which coroutines run.
191		201
192	When the coroutine dies, the program will exit, just as in the main	202	Calling C<exit> in a coroutine will do the same as calling exit outside
193	program.	203	the coroutine. Likewise, when the coroutine dies, the program will exit,
		204	just as it would in the main program.
194		205
195	# create a new coroutine that just prints its arguments	206	# create a new coroutine that just prints its arguments
196	async {	207	async {
197	print "@_\n";	208	print "@_\n";
198	} 1,2,3,4;	209	} 1,2,3,4;
…		…
210	Similar to C<async>, but uses a coroutine pool, so you should not call	221	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	222	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 :).	223	that might have executed other code already (which can be good or bad :).
213		224
214	Also, the block is executed in an C<eval> context and a warning will be	225	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.	226	issued in case of an exception instead of terminating the program, as
		227	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		228	will not work in the expected way, unless you call terminate or cancel,
		229	which somehow defeats the purpose of pooling.
216		230
217	The priority will be reset to C<0> after each job, otherwise the coroutine	231	The priority will be reset to C<0> after each job, tracing will be
218	will be re-used "as-is".	232	disabled, the description will be reset and the default output filehandle
		233	gets restored, so you can change alkl these. Otherwise the coroutine will
		234	be re-used "as-is": most notably if you change other per-coroutine global
		235	stuff such as C<$/> you need to revert that change, which is most simply
		236	done by using local as in C< local $/ >.
219		237
220	The pool size is limited to 8 idle coroutines (this can be adjusted by	238	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	239	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
222	required.	240	required.
223		241
224	If you are concerned about pooled coroutines growing a lot because a	242	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 {	243	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.	244	{ terminate }> once per second or so to slowly replenish the pool. In
		245	addition to that, when the stacks used by a handler grows larger than 16kb
		246	(adjustable with $Coro::POOL_RSS) it will also exit.
227		247
228	=cut	248	=cut
229		249
230	our $POOL_SIZE = 8;	250	our $POOL_SIZE = 8;
		251	our $POOL_RSS = 16 * 1024;
231	our @pool;	252	our @async_pool;
232		253
233	sub pool_handler {	254	sub pool_handler {
		255	my $cb;
		256
234	while () {	257	while () {
235	my ($cb, @arg) = @{ delete $current->{_invoke} };
236
237	eval {	258	eval {
238	$cb->(@arg);	259	while () {
		260	_pool_1 $cb;
		261	&$cb;
		262	_pool_2 $cb;
		263	&schedule;
		264	}
239	};	265	};
		266
		267	last if $@ eq "\3async_pool terminate\2\n";
240	warn $@ if $@;	268	warn $@ if $@;
241		269	}
242	last if @pool >= $POOL_SIZE;	270	}
243	push @pool, $current;
244
245	$current->prio (0);
246	schedule;
247	}
248	}
249		271
250	sub async_pool(&@) {	272	sub async_pool(&@) {
251	# this is also inlined into the unlock_scheduler	273	# this is also inlined into the unlock_scheduler
252	my $coro = (pop @pool or new Coro \&pool_handler);	274	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
253		275
254	$coro->{_invoke} = [@_];	276	$coro->{_invoke} = [@_];
255	$coro->ready;	277	$coro->ready;
256		278
257	$coro	279	$coro
…		…
275	# wake up sleeping coroutine	297	# wake up sleeping coroutine
276	$current->ready;	298	$current->ready;
277	undef $current;	299	undef $current;
278	};	300	};
279		301
280	# call schedule until event occured.	302	# call schedule until event occurred.
281	# in case we are woken up for other reasons	303	# in case we are woken up for other reasons
282	# (current still defined), loop.	304	# (current still defined), loop.
283	Coro::schedule while $current;	305	Coro::schedule while $current;
284	}	306	}
285		307
…		…
287		309
288	"Cede" to other coroutines. This function puts the current coroutine into the	310	"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	311	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.	312	current "timeslice" to other coroutines of the same or higher priority.
291		313
		314	Returns true if at least one coroutine switch has happened.
		315
292	=item Coro::cede_notself	316	=item Coro::cede_notself
293		317
294	Works like cede, but is not exported by default and will cede to any	318	Works like cede, but is not exported by default and will cede to any
295	coroutine, regardless of priority, once.	319	coroutine, regardless of priority, once.
296		320
		321	Returns true if at least one coroutine switch has happened.
		322
297	=item terminate [arg...]	323	=item terminate [arg...]
298		324
299	Terminates the current coroutine with the given status values (see L<cancel>).	325	Terminates the current coroutine with the given status values (see L<cancel>).
		326
		327	=item killall
		328
		329	Kills/terminates/cancels all coroutines except the currently running
		330	one. This is useful after a fork, either in the child or the parent, as
		331	usually only one of them should inherit the running coroutines.
300		332
301	=cut	333	=cut
302		334
303	sub terminate {	335	sub terminate {
304	$current->cancel (@_);	336	$current->cancel (@_);
		337	}
		338
		339	sub killall {
		340	for (Coro::State::list) {
		341	$_->cancel
		342	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		343	}
305	}	344	}
306		345
307	=back	346	=back
308		347
309	# dynamic methods	348	# dynamic methods
…		…
319	Create a new coroutine and return it. When the sub returns the coroutine	358	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	359	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	360	called. To make the coroutine run you must first put it into the ready queue
322	by calling the ready method.	361	by calling the ready method.
323		362
324	Calling C<exit> in a coroutine will not work correctly, so do not do that.	363	See C<async> and C<Coro::State::new> for additional info about the
		364	coroutine environment.
325		365
326	=cut	366	=cut
327		367
328	sub _run_coro {	368	sub _run_coro {
329	terminate &{+shift};	369	terminate &{+shift};
…		…
353		393
354	=cut	394	=cut
355		395
356	sub cancel {	396	sub cancel {
357	my $self = shift;	397	my $self = shift;
358	$self->{status} = [@_];	398	$self->{_status} = [@_];
359		399
360	if ($current == $self) {	400	if ($current == $self) {
361	push @destroy, $self;	401	push @destroy, $self;
362	$manager->ready;	402	$manager->ready;
363	&schedule while 1;	403	&schedule while 1;
…		…
367	}	407	}
368		408
369	=item $coroutine->join	409	=item $coroutine->join
370		410
371	Wait until the coroutine terminates and return any values given to the	411	Wait until the coroutine terminates and return any values given to the
372	C<terminate> or C<cancel> functions. C<join> can be called multiple times	412	C<terminate> or C<cancel> functions. C<join> can be called concurrently
373	from multiple coroutine.	413	from multiple coroutines.
374		414
375	=cut	415	=cut
376		416
377	sub join {	417	sub join {
378	my $self = shift;	418	my $self = shift;
379		419
380	unless ($self->{status}) {	420	unless ($self->{_status}) {
381	my $current = $current;	421	my $current = $current;
382		422
383	push @{$self->{destroy_cb}}, sub {	423	push @{$self->{_on_destroy}}, sub {
384	$current->ready;	424	$current->ready;
385	undef $current;	425	undef $current;
386	};	426	};
387		427
388	&schedule while $current;	428	&schedule while $current;
389	}	429	}
390		430
391	wantarray ? @{$self->{status}} : $self->{status}[0];	431	wantarray ? @{$self->{_status}} : $self->{_status}[0];
392	}	432	}
393		433
394	=item $coroutine->on_destroy (\&cb)	434	=item $coroutine->on_destroy (\&cb)
395		435
396	Registers a callback that is called when this coroutine gets destroyed,	436	Registers a callback that is called when this coroutine gets destroyed,
…		…
400	=cut	440	=cut
401		441
402	sub on_destroy {	442	sub on_destroy {
403	my ($self, $cb) = @_;	443	my ($self, $cb) = @_;
404		444
405	push @{ $self->{destroy_cb} }, $cb;	445	push @{ $self->{_on_destroy} }, $cb;
406	}	446	}
407		447
408	=item $oldprio = $coroutine->prio ($newprio)	448	=item $oldprio = $coroutine->prio ($newprio)
409		449
410	Sets (or gets, if the argument is missing) the priority of the	450	Sets (or gets, if the argument is missing) the priority of the
…		…
435	=item $olddesc = $coroutine->desc ($newdesc)	475	=item $olddesc = $coroutine->desc ($newdesc)
436		476
437	Sets (or gets in case the argument is missing) the description for this	477	Sets (or gets in case the argument is missing) the description for this
438	coroutine. This is just a free-form string you can associate with a coroutine.	478	coroutine. This is just a free-form string you can associate with a coroutine.
439		479
		480	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
		481	can modify this member directly if you wish.
		482
		483	=item $coroutine->throw ([$scalar])
		484
		485	If C<$throw> is specified and defined, it will be thrown as an exception
		486	inside the coroutine at the next convinient point in time (usually after
		487	it gains control at the next schedule/transfer/cede). Otherwise clears the
		488	exception object.
		489
		490	The exception object will be thrown "as is" with the specified scalar in
		491	C<$@>, i.e. if it is a string, no line number or newline will be appended
		492	(unlike with C<die>).
		493
		494	This can be used as a softer means than C<cancel> to ask a coroutine to
		495	end itself, although there is no guarentee that the exception will lead to
		496	termination, and if the exception isn't caught it might well end the whole
		497	program.
		498
440	=cut	499	=cut
441		500
442	sub desc {	501	sub desc {
443	my $old = $_[0]{desc};	502	my $old = $_[0]{desc};
444	$_[0]{desc} = $_[1] if @_ > 1;	503	$_[0]{desc} = $_[1] if @_ > 1;
…		…
452	=over 4	511	=over 4
453		512
454	=item Coro::nready	513	=item Coro::nready
455		514
456	Returns the number of coroutines that are currently in the ready state,	515	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	516	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,	517	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	518	and C<schedule> would cause a deadlock unless there is an idle handler
460	that wakes up some coroutines.	519	that wakes up some coroutines.
461		520
462	=item my $guard = Coro::guard { ... }	521	=item my $guard = Coro::guard { ... }
463		522
464	This creates and returns a guard object. Nothing happens until the objetc	523	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	524	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	525	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	526	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,	527	guard block will be executed. The guard object supports only one method,
469	C<< ->cancel >>, which will keep the codeblock from being executed.	528	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
498	This utility function takes a BLOCK or code reference and "unblocks" it,	557	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	558	returning the new coderef. This means that the new coderef will return
500	immediately without blocking, returning nothing, while the original code	559	immediately without blocking, returning nothing, while the original code
501	ref will be called (with parameters) from within its own coroutine.	560	ref will be called (with parameters) from within its own coroutine.
502		561
503	The reason this fucntion exists is that many event libraries (such as the	562	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	563	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,	564	of thread-safety). This means you must not block within event callbacks,
506	otherwise you might suffer from crashes or worse.	565	otherwise you might suffer from crashes or worse.
507		566
508	This function allows your callbacks to block by executing them in another	567	This function allows your callbacks to block by executing them in another
…		…
519		578
520	# we create a special coro because we want to cede,	579	# we create a special coro because we want to cede,
521	# to reduce pressure on the coro pool (because most callbacks	580	# to reduce pressure on the coro pool (because most callbacks
522	# return immediately and can be reused) and because we cannot cede	581	# return immediately and can be reused) and because we cannot cede
523	# inside an event callback.	582	# inside an event callback.
524	our $unblock_scheduler = async {	583	our $unblock_scheduler = new Coro sub {
525	while () {	584	while () {
526	while (my $cb = pop @unblock_queue) {	585	while (my $cb = pop @unblock_queue) {
527	# this is an inlined copy of async_pool	586	# this is an inlined copy of async_pool
528	my $coro = (pop @pool or new Coro \&pool_handler);	587	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
529		588
530	$coro->{_invoke} = $cb;	589	$coro->{_invoke} = $cb;
531	$coro->ready;	590	$coro->ready;
532	cede; # for short-lived callbacks, this reduces pressure on the coro pool	591	cede; # for short-lived callbacks, this reduces pressure on the coro pool
533	}	592	}
534	schedule; # sleep well	593	schedule; # sleep well
535	}	594	}
536	};	595	};
		596	$unblock_scheduler->desc ("[unblock_sub scheduler]");
537		597
538	sub unblock_sub(&) {	598	sub unblock_sub(&) {
539	my $cb = shift;	599	my $cb = shift;
540		600
541	sub {	601	sub {
…		…
554		614
555	- you must make very sure that no coro is still active on global	615	- you must make very sure that no coro is still active on global
556	destruction. very bad things might happen otherwise (usually segfaults).	616	destruction. very bad things might happen otherwise (usually segfaults).
557		617
558	- this module is not thread-safe. You should only ever use this module	618	- 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	619	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	620	to allow per-thread schedulers, but Coro::State does not yet allow
561	this).	621	this).
562		622
563	=head1 SEE ALSO	623	=head1 SEE ALSO
564		624
		625	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		626
		627	Debugging: L<Coro::Debug>.
		628
565	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	629	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
566		630
567	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	631	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
568		632
569	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	633	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
570		634
		635	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		636
571	Embedding: L<Coro:MakeMaker>	637	Embedding: L<Coro:MakeMaker>.
572		638
573	=head1 AUTHOR	639	=head1 AUTHOR
574		640
575	Marc Lehmann <schmorp@schmorp.de>	641	Marc Lehmann <schmorp@schmorp.de>
576	http://home.schmorp.de/	642	http://home.schmorp.de/

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Comparing Coro/Coro.pm (file contents): Revision 1.105 by root, Fri Jan 5 16:55:01 2007 UTC vs. Revision 1.152 by root, Sun Oct 7 13:53:37 2007 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.105 by root, Fri Jan 5 16:55:01 2007 UTC vs.
Revision 1.152 by root, Sun Oct 7 13:53:37 2007 UTC