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

Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 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 = '3.3';	62	our $VERSION = '4.51';
56		63
57	our @EXPORT = qw(async cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
61	our @EXPORT_OK = (@{$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
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;
…		…
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	$coro
		215	}
		216
		217	=item async_pool { ... } [@args...]
		218
		219	Similar to C<async>, but uses a coroutine pool, so you should not call
		220	terminate or join (although you are allowed to), and you get a coroutine
		221	that might have executed other code already (which can be good or bad :).
		222
		223	Also, the block is executed in an C<eval> context and a warning will be
		224	issued in case of an exception instead of terminating the program, as
		225	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		226	will not work in the expected way, unless you call terminate or cancel,
		227	which somehow defeats the purpose of pooling.
		228
		229	The priority will be reset to C<0> after each job, tracing will be
		230	disabled, the description will be reset and the default output filehandle
		231	gets restored, so you can change alkl these. Otherwise the coroutine will
		232	be re-used "as-is": most notably if you change other per-coroutine global
		233	stuff such as C<$/> you need to revert that change, which is most simply
		234	done by using local as in C< local $/ >.
		235
		236	The pool size is limited to 8 idle coroutines (this can be adjusted by
		237	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
		238	required.
		239
		240	If you are concerned about pooled coroutines growing a lot because a
		241	single C<async_pool> used a lot of stackspace you can e.g. C<async_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.
		245
		246	=cut
		247
		248	our $POOL_SIZE = 8;
		249	our $POOL_RSS = 16 * 1024;
		250	our @async_pool;
		251
		252	sub pool_handler {
		253	my $cb;
		254
		255	while () {
		256	eval {
		257	while () {
		258	_pool_1 $cb;
		259	&$cb;
		260	_pool_2 $cb;
		261	&schedule;
		262	}
		263	};
		264
		265	last if $@ eq "\3async_pool terminate\2\n";
		266	warn $@ if $@;
		267	}
		268	}
		269
		270	sub async_pool(&@) {
		271	# this is also inlined into the unlock_scheduler
		272	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		273
		274	$coro->{_invoke} = [@_];
		275	$coro->ready;
		276
205	$coro	277	$coro
206	}	278	}
207		279
208	=item schedule	280	=item schedule
209		281
…		…
223	# wake up sleeping coroutine	295	# wake up sleeping coroutine
224	$current->ready;	296	$current->ready;
225	undef $current;	297	undef $current;
226	};	298	};
227		299
228	# call schedule until event occured.	300	# call schedule until event occurred.
229	# in case we are woken up for other reasons	301	# in case we are woken up for other reasons
230	# (current still defined), loop.	302	# (current still defined), loop.
231	Coro::schedule while $current;	303	Coro::schedule while $current;
232	}	304	}
233		305
…		…
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
		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.
		326
249	=cut	327	=cut
250		328
251	sub terminate {	329	sub terminate {
252	$current->cancel (@_);	330	$current->cancel (@_);
253	}	331	}
254		332
		333	sub killall {
		334	for (Coro::State::list) {
		335	$_->cancel
		336	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		337	}
		338	}
		339
255	=back	340	=back
256
257	# dynamic methods
258		341
259	=head2 COROUTINE METHODS	342	=head2 COROUTINE METHODS
260		343
261	These are the methods you can call on coroutine objects.	344	These are the methods you can call on coroutine objects.
262		345
…		…
267	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
268	automatically terminates as if C<terminate> with the returned values were	351	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	352	called. To make the coroutine run you must first put it into the ready queue
270	by calling the ready method.	353	by calling the ready method.
271		354
272	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.
273		357
274	=cut	358	=cut
275		359
276	sub _run_coro {	360	sub _run_coro {
277	terminate &{+shift};	361	terminate &{+shift};
…		…
301		385
302	=cut	386	=cut
303		387
304	sub cancel {	388	sub cancel {
305	my $self = shift;	389	my $self = shift;
306	$self->{status} = [@_];	390	$self->{_status} = [@_];
307		391
308	if ($current == $self) {	392	if ($current == $self) {
309	push @destroy, $self;	393	push @destroy, $self;
310	$manager->ready;	394	$manager->ready;
311	&schedule while 1;	395	&schedule while 1;
…		…
315	}	399	}
316		400
317	=item $coroutine->join	401	=item $coroutine->join
318		402
319	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
320	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
321	from multiple coroutine.	405	from multiple coroutines.
322		406
323	=cut	407	=cut
324		408
325	sub join {	409	sub join {
326	my $self = shift;	410	my $self = shift;
327		411
328	unless ($self->{status}) {	412	unless ($self->{_status}) {
329	my $current = $current;	413	my $current = $current;
330		414
331	push @{$self->{destroy_cb}}, sub {	415	push @{$self->{_on_destroy}}, sub {
332	$current->ready;	416	$current->ready;
333	undef $current;	417	undef $current;
334	};	418	};
335		419
336	&schedule while $current;	420	&schedule while $current;
337	}	421	}
338		422
339	wantarray ? @{$self->{status}} : $self->{status}[0];	423	wantarray ? @{$self->{_status}} : $self->{_status}[0];
340	}	424	}
341		425
342	=item $coroutine->on_destroy (\&cb)	426	=item $coroutine->on_destroy (\&cb)
343		427
344	Registers a callback that is called when this coroutine gets destroyed,	428	Registers a callback that is called when this coroutine gets destroyed,
…		…
348	=cut	432	=cut
349		433
350	sub on_destroy {	434	sub on_destroy {
351	my ($self, $cb) = @_;	435	my ($self, $cb) = @_;
352		436
353	push @{ $self->{destroy_cb} }, $cb;	437	push @{ $self->{_on_destroy} }, $cb;
354	}	438	}
355		439
356	=item $oldprio = $coroutine->prio ($newprio)	440	=item $oldprio = $coroutine->prio ($newprio)
357		441
358	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
…		…
383	=item $olddesc = $coroutine->desc ($newdesc)	467	=item $olddesc = $coroutine->desc ($newdesc)
384		468
385	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
386	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.
387		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
388	=cut	491	=cut
389		492
390	sub desc {	493	sub desc {
391	my $old = $_[0]{desc};	494	my $old = $_[0]{desc};
392	$_[0]{desc} = $_[1] if @_ > 1;	495	$_[0]{desc} = $_[1] if @_ > 1;
…		…
400	=over 4	503	=over 4
401		504
402	=item Coro::nready	505	=item Coro::nready
403		506
404	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,
405	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
406	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,
407	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
408	that wakes up some coroutines.	511	that wakes up some coroutines.
409		512
410	=item my $guard = Coro::guard { ... }	513	=item my $guard = Coro::guard { ... }
411		514
412	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
413	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
414	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
415	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
416	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,
417	C<< ->cancel >>, which will keep the codeblock from being executed.	520	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
446	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,
447	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
448	immediately without blocking, returning nothing, while the original code	551	immediately without blocking, returning nothing, while the original code
449	ref will be called (with parameters) from within its own coroutine.	552	ref will be called (with parameters) from within its own coroutine.
450		553
451	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
452	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
453	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,
454	otherwise you might suffer from crashes or worse.	557	otherwise you might suffer from crashes or worse.
455		558
456	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
…		…
461	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when	564	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
462	creating event callbacks that want to block.	565	creating event callbacks that want to block.
463		566
464	=cut	567	=cut
465		568
466	our @unblock_pool;
467	our @unblock_queue;	569	our @unblock_queue;
468	our $UNBLOCK_POOL_SIZE = 2;
469		570
470	sub unblock_handler_ {	571	# we create a special coro because we want to cede,
471	while () {	572	# to reduce pressure on the coro pool (because most callbacks
472	my ($cb, @arg) = @{ delete $Coro::current->{arg} };	573	# return immediately and can be reused) and because we cannot cede
473	$cb->(@arg);	574	# 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 {	575	our $unblock_scheduler = new Coro sub {
482	while () {	576	while () {
483	while (my $cb = pop @unblock_queue) {	577	while (my $cb = pop @unblock_queue) {
484	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);	578	# this is an inlined copy of async_pool
485	$handler->{arg} = $cb;	579	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		580
		581	$coro->{_invoke} = $cb;
486	$handler->ready;	582	$coro->ready;
487	cede;	583	cede; # for short-lived callbacks, this reduces pressure on the coro pool
488	}	584	}
489		585	schedule; # sleep well
490	schedule;
491	}	586	}
492	};	587	};
		588	$unblock_scheduler->desc ("[unblock_sub scheduler]");
493		589
494	sub unblock_sub(&) {	590	sub unblock_sub(&) {
495	my $cb = shift;	591	my $cb = shift;
496		592
497	sub {	593	sub {
498	push @unblock_queue, [$cb, @_];	594	unshift @unblock_queue, [$cb, @_];
499	$unblock_scheduler->ready;	595	$unblock_scheduler->ready;
500	}	596	}
501	}	597	}
502		598
503	=back	599	=back
…		…
510		606
511	- 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
512	destruction. very bad things might happen otherwise (usually segfaults).	608	destruction. very bad things might happen otherwise (usually segfaults).
513		609
514	- 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
515	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
516	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
517	this).	613	this).
518		614
519	=head1 SEE ALSO	615	=head1 SEE ALSO
520		616
		617	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		618
		619	Debugging: L<Coro::Debug>.
		620
521	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	621	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
522		622
523	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>.
524		624
525	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>.
526		626
		627	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		628
527	Embedding: L<Coro:MakeMaker>	629	Embedding: L<Coro::MakeMaker>.
528		630
529	=head1 AUTHOR	631	=head1 AUTHOR
530		632
531	Marc Lehmann <schmorp@schmorp.de>	633	Marc Lehmann <schmorp@schmorp.de>
532	http://home.schmorp.de/	634	http://home.schmorp.de/

Diff Legend

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

Comparing cvsroot/Coro/Coro.pm (file contents): Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs. Revision 1.178 by root, Thu Apr 17 22:33:10 2008 UTC

Diff Legend

Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.104 by root, Thu Jan 4 23:49:27 2007 UTC vs.
Revision 1.178 by root, Thu Apr 17 22:33:10 2008 UTC