[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 1.152 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 $VERSION = '4.1';
56		63
57	our @EXPORT = qw(async cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));	68	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62		69
…		…
108		115
109	The current coroutine (the last coroutine switched to). The initial value	116	The current coroutine (the last coroutine switched to). The initial value
110	is C<$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;
…		…
200	=cut	211	=cut
201		212
202	sub async(&@) {	213	sub async(&@) {
203	my $coro = new Coro @_;	214	my $coro = new Coro @_;
204	$coro->ready;	215	$coro->ready;
		216	$coro
		217	}
		218
		219	=item async_pool { ... } [@args...]
		220
		221	Similar to C<async>, but uses a coroutine pool, so you should not call
		222	terminate or join (although you are allowed to), and you get a coroutine
		223	that might have executed other code already (which can be good or bad :).
		224
		225	Also, the block is executed in an C<eval> context and a warning will be
		226	issued in case of an exception instead of terminating the program, as
		227	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		228	will not work in the expected way, unless you call terminate or cancel,
		229	which somehow defeats the purpose of pooling.
		230
		231	The priority will be reset to C<0> after each job, tracing will be
		232	disabled, the description will be reset and the default output filehandle
		233	gets restored, so you can change alkl these. Otherwise the coroutine will
		234	be re-used "as-is": most notably if you change other per-coroutine global
		235	stuff such as C<$/> you need to revert that change, which is most simply
		236	done by using local as in C< local $/ >.
		237
		238	The pool size is limited to 8 idle coroutines (this can be adjusted by
		239	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
		240	required.
		241
		242	If you are concerned about pooled coroutines growing a lot because a
		243	single C<async_pool> used a lot of stackspace you can e.g. C<async_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.
		247
		248	=cut
		249
		250	our $POOL_SIZE = 8;
		251	our $POOL_RSS = 16 * 1024;
		252	our @async_pool;
		253
		254	sub pool_handler {
		255	my $cb;
		256
		257	while () {
		258	eval {
		259	while () {
		260	_pool_1 $cb;
		261	&$cb;
		262	_pool_2 $cb;
		263	&schedule;
		264	}
		265	};
		266
		267	last if $@ eq "\3async_pool terminate\2\n";
		268	warn $@ if $@;
		269	}
		270	}
		271
		272	sub async_pool(&@) {
		273	# this is also inlined into the unlock_scheduler
		274	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		275
		276	$coro->{_invoke} = [@_];
		277	$coro->ready;
		278
205	$coro	279	$coro
206	}	280	}
207		281
208	=item schedule	282	=item schedule
209		283
…		…
223	# wake up sleeping coroutine	297	# wake up sleeping coroutine
224	$current->ready;	298	$current->ready;
225	undef $current;	299	undef $current;
226	};	300	};
227		301
228	# call schedule until event occured.	302	# call schedule until event occurred.
229	# in case we are woken up for other reasons	303	# in case we are woken up for other reasons
230	# (current still defined), loop.	304	# (current still defined), loop.
231	Coro::schedule while $current;	305	Coro::schedule while $current;
232	}	306	}
233		307
…		…
235		309
236	"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
237	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
238	current "timeslice" to other coroutines of the same or higher priority.	312	current "timeslice" to other coroutines of the same or higher priority.
239		313
		314	Returns true if at least one coroutine switch has happened.
		315
240	=item Coro::cede_notself	316	=item Coro::cede_notself
241		317
242	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
243	coroutine, regardless of priority, once.	319	coroutine, regardless of priority, once.
244		320
		321	Returns true if at least one coroutine switch has happened.
		322
245	=item terminate [arg...]	323	=item terminate [arg...]
246		324
247	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.
248		332
249	=cut	333	=cut
250		334
251	sub terminate {	335	sub terminate {
252	$current->cancel (@_);	336	$current->cancel (@_);
		337	}
		338
		339	sub killall {
		340	for (Coro::State::list) {
		341	$_->cancel
		342	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		343	}
253	}	344	}
254		345
255	=back	346	=back
256		347
257	# dynamic methods	348	# dynamic methods
…		…
267	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
268	automatically terminates as if C<terminate> with the returned values were	359	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	360	called. To make the coroutine run you must first put it into the ready queue
270	by calling the ready method.	361	by calling the ready method.
271		362
272	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.
273		365
274	=cut	366	=cut
275		367
276	sub _run_coro {	368	sub _run_coro {
277	terminate &{+shift};	369	terminate &{+shift};
…		…
301		393
302	=cut	394	=cut
303		395
304	sub cancel {	396	sub cancel {
305	my $self = shift;	397	my $self = shift;
306	$self->{status} = [@_];	398	$self->{_status} = [@_];
307		399
308	if ($current == $self) {	400	if ($current == $self) {
309	push @destroy, $self;	401	push @destroy, $self;
310	$manager->ready;	402	$manager->ready;
311	&schedule while 1;	403	&schedule while 1;
…		…
315	}	407	}
316		408
317	=item $coroutine->join	409	=item $coroutine->join
318		410
319	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
320	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
321	from multiple coroutine.	413	from multiple coroutines.
322		414
323	=cut	415	=cut
324		416
325	sub join {	417	sub join {
326	my $self = shift;	418	my $self = shift;
327		419
328	unless ($self->{status}) {	420	unless ($self->{_status}) {
329	my $current = $current;	421	my $current = $current;
330		422
331	push @{$self->{destroy_cb}}, sub {	423	push @{$self->{_on_destroy}}, sub {
332	$current->ready;	424	$current->ready;
333	undef $current;	425	undef $current;
334	};	426	};
335		427
336	&schedule while $current;	428	&schedule while $current;
337	}	429	}
338		430
339	wantarray ? @{$self->{status}} : $self->{status}[0];	431	wantarray ? @{$self->{_status}} : $self->{_status}[0];
340	}	432	}
341		433
342	=item $coroutine->on_destroy (\&cb)	434	=item $coroutine->on_destroy (\&cb)
343		435
344	Registers a callback that is called when this coroutine gets destroyed,	436	Registers a callback that is called when this coroutine gets destroyed,
…		…
348	=cut	440	=cut
349		441
350	sub on_destroy {	442	sub on_destroy {
351	my ($self, $cb) = @_;	443	my ($self, $cb) = @_;
352		444
353	push @{ $self->{destroy_cb} }, $cb;	445	push @{ $self->{_on_destroy} }, $cb;
354	}	446	}
355		447
356	=item $oldprio = $coroutine->prio ($newprio)	448	=item $oldprio = $coroutine->prio ($newprio)
357		449
358	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
…		…
383	=item $olddesc = $coroutine->desc ($newdesc)	475	=item $olddesc = $coroutine->desc ($newdesc)
384		476
385	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
386	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.
387		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
388	=cut	499	=cut
389		500
390	sub desc {	501	sub desc {
391	my $old = $_[0]{desc};	502	my $old = $_[0]{desc};
392	$_[0]{desc} = $_[1] if @_ > 1;	503	$_[0]{desc} = $_[1] if @_ > 1;
…		…
400	=over 4	511	=over 4
401		512
402	=item Coro::nready	513	=item Coro::nready
403		514
404	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,
405	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
406	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,
407	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
408	that wakes up some coroutines.	519	that wakes up some coroutines.
409		520
410	=item my $guard = Coro::guard { ... }	521	=item my $guard = Coro::guard { ... }
411		522
412	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
413	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
414	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
415	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
416	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,
417	C<< ->cancel >>, which will keep the codeblock from being executed.	528	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
446	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,
447	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
448	immediately without blocking, returning nothing, while the original code	559	immediately without blocking, returning nothing, while the original code
449	ref will be called (with parameters) from within its own coroutine.	560	ref will be called (with parameters) from within its own coroutine.
450		561
451	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
452	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
453	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,
454	otherwise you might suffer from crashes or worse.	565	otherwise you might suffer from crashes or worse.
455		566
456	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
…		…
461	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when	572	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
462	creating event callbacks that want to block.	573	creating event callbacks that want to block.
463		574
464	=cut	575	=cut
465		576
466	our @unblock_pool;
467	our @unblock_queue;	577	our @unblock_queue;
468	our $UNBLOCK_POOL_SIZE = 2;
469		578
470	sub unblock_handler_ {	579	# we create a special coro because we want to cede,
471	while () {	580	# to reduce pressure on the coro pool (because most callbacks
472	my ($cb, @arg) = @{ delete $Coro::current->{arg} };	581	# return immediately and can be reused) and because we cannot cede
473	$cb->(@arg);	582	# 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 {	583	our $unblock_scheduler = new Coro sub {
482	while () {	584	while () {
483	while (my $cb = pop @unblock_queue) {	585	while (my $cb = pop @unblock_queue) {
484	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);	586	# this is an inlined copy of async_pool
485	$handler->{arg} = $cb;	587	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		588
		589	$coro->{_invoke} = $cb;
486	$handler->ready;	590	$coro->ready;
487	cede;	591	cede; # for short-lived callbacks, this reduces pressure on the coro pool
488	}	592	}
489		593	schedule; # sleep well
490	schedule;
491	}	594	}
492	};	595	};
		596	$unblock_scheduler->desc ("[unblock_sub scheduler]");
493		597
494	sub unblock_sub(&) {	598	sub unblock_sub(&) {
495	my $cb = shift;	599	my $cb = shift;
496		600
497	sub {	601	sub {
498	push @unblock_queue, [$cb, @_];	602	unshift @unblock_queue, [$cb, @_];
499	$unblock_scheduler->ready;	603	$unblock_scheduler->ready;
500	}	604	}
501	}	605	}
502		606
503	=back	607	=back
…		…
510		614
511	- 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
512	destruction. very bad things might happen otherwise (usually segfaults).	616	destruction. very bad things might happen otherwise (usually segfaults).
513		617
514	- 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
515	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
516	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
517	this).	621	this).
518		622
519	=head1 SEE ALSO	623	=head1 SEE ALSO
520		624
		625	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		626
		627	Debugging: L<Coro::Debug>.
		628
521	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	629	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
522		630
523	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>.
524		632
525	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>.
526		634
		635	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		636
527	Embedding: L<Coro:MakeMaker>	637	Embedding: L<Coro:MakeMaker>.
528		638
529	=head1 AUTHOR	639	=head1 AUTHOR
530		640
531	Marc Lehmann <schmorp@schmorp.de>	641	Marc Lehmann <schmorp@schmorp.de>
532	http://home.schmorp.de/	642	http://home.schmorp.de/

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing Coro/Coro.pm (file contents): Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs. Revision 1.152 by root, Sun Oct 7 13:53:37 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 1.152 by root, Sun Oct 7 13:53:37 2007 UTC