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

Comparing Coro/Coro.pm (file contents):
Revision 1.107 by root, Fri Jan 5 18:25:51 2007 UTC vs.
Revision 1.165 by root, Thu Dec 20 07:29:14 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 $VERSION = '4.34';
56		63
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	64	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	65	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	66	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	67	);
…		…
108		115
109	The current coroutine (the last coroutine switched to). The initial value	116	The current coroutine (the last coroutine switched to). The initial value
110	is C<$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
242	last if @pool >= $POOL_SIZE;
243	push @pool, $current;
244
245	$current->prio (0);
246	schedule;
247	}	269	}
248	}	270	}
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
292	Returns true if at least one coroutine switch has happened.
293
294	=item Coro::cede_notself	314	=item Coro::cede_notself
295		315
296	Works like cede, but is not exported by default and will cede to any	316	Works like cede, but is not exported by default and will cede to any
297	coroutine, regardless of priority, once.	317	coroutine, regardless of priority, once.
298		318
299	Returns true if at least one coroutine switch has happened.
300
301	=item terminate [arg...]	319	=item terminate [arg...]
302		320
303	Terminates the current coroutine with the given status values (see L<cancel>).	321	Terminates the current coroutine with the given status values (see L<cancel>).
		322
		323	=item killall
		324
		325	Kills/terminates/cancels all coroutines except the currently running
		326	one. This is useful after a fork, either in the child or the parent, as
		327	usually only one of them should inherit the running coroutines.
304		328
305	=cut	329	=cut
306		330
307	sub terminate {	331	sub terminate {
308	$current->cancel (@_);	332	$current->cancel (@_);
		333	}
		334
		335	sub killall {
		336	for (Coro::State::list) {
		337	$_->cancel
		338	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		339	}
309	}	340	}
310		341
311	=back	342	=back
312		343
313	# dynamic methods	344	# dynamic methods
…		…
323	Create a new coroutine and return it. When the sub returns the coroutine	354	Create a new coroutine and return it. When the sub returns the coroutine
324	automatically terminates as if C<terminate> with the returned values were	355	automatically terminates as if C<terminate> with the returned values were
325	called. To make the coroutine run you must first put it into the ready queue	356	called. To make the coroutine run you must first put it into the ready queue
326	by calling the ready method.	357	by calling the ready method.
327		358
328	Calling C<exit> in a coroutine will not work correctly, so do not do that.	359	See C<async> and C<Coro::State::new> for additional info about the
		360	coroutine environment.
329		361
330	=cut	362	=cut
331		363
332	sub _run_coro {	364	sub _run_coro {
333	terminate &{+shift};	365	terminate &{+shift};
…		…
357		389
358	=cut	390	=cut
359		391
360	sub cancel {	392	sub cancel {
361	my $self = shift;	393	my $self = shift;
362	$self->{status} = [@_];	394	$self->{_status} = [@_];
363		395
364	if ($current == $self) {	396	if ($current == $self) {
365	push @destroy, $self;	397	push @destroy, $self;
366	$manager->ready;	398	$manager->ready;
367	&schedule while 1;	399	&schedule while 1;
…		…
371	}	403	}
372		404
373	=item $coroutine->join	405	=item $coroutine->join
374		406
375	Wait until the coroutine terminates and return any values given to the	407	Wait until the coroutine terminates and return any values given to the
376	C<terminate> or C<cancel> functions. C<join> can be called multiple times	408	C<terminate> or C<cancel> functions. C<join> can be called concurrently
377	from multiple coroutine.	409	from multiple coroutines.
378		410
379	=cut	411	=cut
380		412
381	sub join {	413	sub join {
382	my $self = shift;	414	my $self = shift;
383		415
384	unless ($self->{status}) {	416	unless ($self->{_status}) {
385	my $current = $current;	417	my $current = $current;
386		418
387	push @{$self->{destroy_cb}}, sub {	419	push @{$self->{_on_destroy}}, sub {
388	$current->ready;	420	$current->ready;
389	undef $current;	421	undef $current;
390	};	422	};
391		423
392	&schedule while $current;	424	&schedule while $current;
393	}	425	}
394		426
395	wantarray ? @{$self->{status}} : $self->{status}[0];	427	wantarray ? @{$self->{_status}} : $self->{_status}[0];
396	}	428	}
397		429
398	=item $coroutine->on_destroy (\&cb)	430	=item $coroutine->on_destroy (\&cb)
399		431
400	Registers a callback that is called when this coroutine gets destroyed,	432	Registers a callback that is called when this coroutine gets destroyed,
…		…
404	=cut	436	=cut
405		437
406	sub on_destroy {	438	sub on_destroy {
407	my ($self, $cb) = @_;	439	my ($self, $cb) = @_;
408		440
409	push @{ $self->{destroy_cb} }, $cb;	441	push @{ $self->{_on_destroy} }, $cb;
410	}	442	}
411		443
412	=item $oldprio = $coroutine->prio ($newprio)	444	=item $oldprio = $coroutine->prio ($newprio)
413		445
414	Sets (or gets, if the argument is missing) the priority of the	446	Sets (or gets, if the argument is missing) the priority of the
…		…
439	=item $olddesc = $coroutine->desc ($newdesc)	471	=item $olddesc = $coroutine->desc ($newdesc)
440		472
441	Sets (or gets in case the argument is missing) the description for this	473	Sets (or gets in case the argument is missing) the description for this
442	coroutine. This is just a free-form string you can associate with a coroutine.	474	coroutine. This is just a free-form string you can associate with a coroutine.
443		475
		476	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
		477	can modify this member directly if you wish.
		478
		479	=item $coroutine->throw ([$scalar])
		480
		481	If C<$throw> is specified and defined, it will be thrown as an exception
		482	inside the coroutine at the next convinient point in time (usually after
		483	it gains control at the next schedule/transfer/cede). Otherwise clears the
		484	exception object.
		485
		486	The exception object will be thrown "as is" with the specified scalar in
		487	C<$@>, i.e. if it is a string, no line number or newline will be appended
		488	(unlike with C<die>).
		489
		490	This can be used as a softer means than C<cancel> to ask a coroutine to
		491	end itself, although there is no guarentee that the exception will lead to
		492	termination, and if the exception isn't caught it might well end the whole
		493	program.
		494
444	=cut	495	=cut
445		496
446	sub desc {	497	sub desc {
447	my $old = $_[0]{desc};	498	my $old = $_[0]{desc};
448	$_[0]{desc} = $_[1] if @_ > 1;	499	$_[0]{desc} = $_[1] if @_ > 1;
…		…
456	=over 4	507	=over 4
457		508
458	=item Coro::nready	509	=item Coro::nready
459		510
460	Returns the number of coroutines that are currently in the ready state,	511	Returns the number of coroutines that are currently in the ready state,
461	i.e. that can be swicthed to. The value C<0> means that the only runnable	512	i.e. that can be switched to. The value C<0> means that the only runnable
462	coroutine is the currently running one, so C<cede> would have no effect,	513	coroutine is the currently running one, so C<cede> would have no effect,
463	and C<schedule> would cause a deadlock unless there is an idle handler	514	and C<schedule> would cause a deadlock unless there is an idle handler
464	that wakes up some coroutines.	515	that wakes up some coroutines.
465		516
466	=item my $guard = Coro::guard { ... }	517	=item my $guard = Coro::guard { ... }
467		518
468	This creates and returns a guard object. Nothing happens until the objetc	519	This creates and returns a guard object. Nothing happens until the object
469	gets destroyed, in which case the codeblock given as argument will be	520	gets destroyed, in which case the codeblock given as argument will be
470	executed. This is useful to free locks or other resources in case of a	521	executed. This is useful to free locks or other resources in case of a
471	runtime error or when the coroutine gets canceled, as in both cases the	522	runtime error or when the coroutine gets canceled, as in both cases the
472	guard block will be executed. The guard object supports only one method,	523	guard block will be executed. The guard object supports only one method,
473	C<< ->cancel >>, which will keep the codeblock from being executed.	524	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
502	This utility function takes a BLOCK or code reference and "unblocks" it,	553	This utility function takes a BLOCK or code reference and "unblocks" it,
503	returning the new coderef. This means that the new coderef will return	554	returning the new coderef. This means that the new coderef will return
504	immediately without blocking, returning nothing, while the original code	555	immediately without blocking, returning nothing, while the original code
505	ref will be called (with parameters) from within its own coroutine.	556	ref will be called (with parameters) from within its own coroutine.
506		557
507	The reason this fucntion exists is that many event libraries (such as the	558	The reason this function exists is that many event libraries (such as the
508	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	559	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
509	of thread-safety). This means you must not block within event callbacks,	560	of thread-safety). This means you must not block within event callbacks,
510	otherwise you might suffer from crashes or worse.	561	otherwise you might suffer from crashes or worse.
511		562
512	This function allows your callbacks to block by executing them in another	563	This function allows your callbacks to block by executing them in another
…		…
523		574
524	# we create a special coro because we want to cede,	575	# we create a special coro because we want to cede,
525	# to reduce pressure on the coro pool (because most callbacks	576	# to reduce pressure on the coro pool (because most callbacks
526	# return immediately and can be reused) and because we cannot cede	577	# return immediately and can be reused) and because we cannot cede
527	# inside an event callback.	578	# inside an event callback.
528	our $unblock_scheduler = async {	579	our $unblock_scheduler = new Coro sub {
529	while () {	580	while () {
530	while (my $cb = pop @unblock_queue) {	581	while (my $cb = pop @unblock_queue) {
531	# this is an inlined copy of async_pool	582	# this is an inlined copy of async_pool
532	my $coro = (pop @pool or new Coro \&pool_handler);	583	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
533		584
534	$coro->{_invoke} = $cb;	585	$coro->{_invoke} = $cb;
535	$coro->ready;	586	$coro->ready;
536	cede; # for short-lived callbacks, this reduces pressure on the coro pool	587	cede; # for short-lived callbacks, this reduces pressure on the coro pool
537	}	588	}
538	schedule; # sleep well	589	schedule; # sleep well
539	}	590	}
540	};	591	};
		592	$unblock_scheduler->desc ("[unblock_sub scheduler]");
541		593
542	sub unblock_sub(&) {	594	sub unblock_sub(&) {
543	my $cb = shift;	595	my $cb = shift;
544		596
545	sub {	597	sub {
…		…
558		610
559	- you must make very sure that no coro is still active on global	611	- you must make very sure that no coro is still active on global
560	destruction. very bad things might happen otherwise (usually segfaults).	612	destruction. very bad things might happen otherwise (usually segfaults).
561		613
562	- this module is not thread-safe. You should only ever use this module	614	- this module is not thread-safe. You should only ever use this module
563	from the same thread (this requirement might be losened in the future	615	from the same thread (this requirement might be loosened in the future
564	to allow per-thread schedulers, but Coro::State does not yet allow	616	to allow per-thread schedulers, but Coro::State does not yet allow
565	this).	617	this).
566		618
567	=head1 SEE ALSO	619	=head1 SEE ALSO
568		620
		621	Lower level Configuration, Coroutine Environment: L<Coro::State>.
		622
		623	Debugging: L<Coro::Debug>.
		624
569	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	625	Support/Utility: L<Coro::Specific>, L<Coro::Util>.
570		626
571	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	627	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
572		628
573	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	629	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
574		630
		631	Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
		632
575	Embedding: L<Coro:MakeMaker>	633	Embedding: L<Coro::MakeMaker>.
576		634
577	=head1 AUTHOR	635	=head1 AUTHOR
578		636
579	Marc Lehmann <schmorp@schmorp.de>	637	Marc Lehmann <schmorp@schmorp.de>
580	http://home.schmorp.de/	638	http://home.schmorp.de/

Diff Legend

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

Comparing Coro/Coro.pm (file contents): Revision 1.107 by root, Fri Jan 5 18:25:51 2007 UTC vs. Revision 1.165 by root, Thu Dec 20 07:29:14 2007 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.107 by root, Fri Jan 5 18:25:51 2007 UTC vs.
Revision 1.165 by root, Thu Dec 20 07:29:14 2007 UTC