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

Comparing Coro/Coro.pm (file contents):
Revision 1.103 by root, Thu Jan 4 20:14:19 2007 UTC vs.
Revision 1.151 by root, Sat Oct 6 19:25:00 2007 UTC

…		…
20		20
21	=head1 DESCRIPTION	21	=head1 DESCRIPTION
22		22
23	This module collection manages coroutines. Coroutines are similar	23	This module collection manages coroutines. Coroutines are similar
24	to threads but don't run in parallel at the same time even on SMP	24	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	25	machines. The specific flavor of coroutine used in this module also
26	guarentees you that it will not switch between coroutines unless	26	guarantees you that it will not switch between coroutines unless
27	necessary, at easily-identified points in your program, so locking and	27	necessary, at easily-identified points in your program, so locking and
28	parallel access are rarely an issue, making coroutine programming much	28	parallel access are rarely an issue, making coroutine programming much
29	safer than threads programming.	29	safer than threads programming.
30		30
31	(Perl, however, does not natively support real threads but instead does a	31	(Perl, however, does not natively support real threads but instead does a
…		…
50		50
51	our $idle; # idle handler	51	our $idle; # idle handler
52	our $main; # main coroutine	52	our $main; # main coroutine
53	our $current; # current coroutine	53	our $current; # current coroutine
54		54
55	our $VERSION = '3.3';	55	our $VERSION = '4.03';
56		56
57	our @EXPORT = qw(async cede schedule terminate current unblock_sub);	57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	58	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	60	);
61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));	61	our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62		62
…		…
108		108
109	The current coroutine (the last coroutine switched to). The initial value	109	The current coroutine (the last coroutine switched to). The initial value
110	is C<$main> (of course).	110	is C<$main> (of course).
111		111
112	This variable is B<strictly> I<read-only>. It is provided for performance	112	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	113	reasons. If performance is not essential you are encouraged to use the
114	C<Coro::current> function instead.	114	C<Coro::current> function instead.
115		115
116	=cut	116	=cut
117		117
		118	$main->{desc} = "[main::]";
		119
118	# maybe some other module used Coro::Specific before...	120	# maybe some other module used Coro::Specific before...
119	$main->{specific} = $current->{specific}	121	$main->{_specific} = $current->{_specific}
120	if $current;	122	if $current;
121		123
122	_set_current $main;	124	_set_current $main;
123		125
124	sub current() { $current }	126	sub current() { $current }
…		…
149	# free coroutine data and mark as destructed	151	# free coroutine data and mark as destructed
150	$self->_destroy	152	$self->_destroy
151	or return;	153	or return;
152		154
153	# call all destruction callbacks	155	# call all destruction callbacks
154	$_->(@{$self->{status}})	156	$_->(@{$self->{_status}})
155	for @{(delete $self->{destroy_cb}) \|\| []};	157	for @{(delete $self->{_on_destroy}) \|\| []};
156	}	158	}
157		159
158	# this coroutine is necessary because a coroutine	160	# this coroutine is necessary because a coroutine
159	# cannot destroy itself.	161	# cannot destroy itself.
160	my @destroy;	162	my @destroy;
…		…
166	while @destroy;	168	while @destroy;
167		169
168	&schedule;	170	&schedule;
169	}	171	}
170	};	172	};
171		173	$manager->desc ("[coro manager]");
172	$manager->prio (PRIO_MAX);	174	$manager->prio (PRIO_MAX);
173		175
174	# static methods. not really.	176	# static methods. not really.
175		177
176	=back	178	=back
…		…
185		187
186	Create a new asynchronous coroutine and return it's coroutine object	188	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	189	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	190	terminated.
189		191
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	192	See the C<Coro::State::new> constructor for info about the coroutine
		193	environment.
191		194
192	When the coroutine dies, the program will exit, just as in the main	195	Calling C<exit> in a coroutine will do the same as calling exit outside
193	program.	196	the coroutine. Likewise, when the coroutine dies, the program will exit,
		197	just as it would in the main program.
194		198
195	# create a new coroutine that just prints its arguments	199	# create a new coroutine that just prints its arguments
196	async {	200	async {
197	print "@_\n";	201	print "@_\n";
198	} 1,2,3,4;	202	} 1,2,3,4;
199		203
200	=cut	204	=cut
201		205
202	sub async(&@) {	206	sub async(&@) {
203	my $pid = new Coro @_;	207	my $coro = new Coro @_;
204	$pid->ready;	208	$coro->ready;
205	$pid	209	$coro
		210	}
		211
		212	=item async_pool { ... } [@args...]
		213
		214	Similar to C<async>, but uses a coroutine pool, so you should not call
		215	terminate or join (although you are allowed to), and you get a coroutine
		216	that might have executed other code already (which can be good or bad :).
		217
		218	Also, the block is executed in an C<eval> context and a warning will be
		219	issued in case of an exception instead of terminating the program, as
		220	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		221	will not work in the expected way, unless you call terminate or cancel,
		222	which somehow defeats the purpose of pooling.
		223
		224	The priority will be reset to C<0> after each job, tracing will be
		225	disabled, the description will be reset and the default output filehandle
		226	gets restored, so you can change alkl these. Otherwise the coroutine will
		227	be re-used "as-is": most notably if you change other per-coroutine global
		228	stuff such as C<$/> you need to revert that change, which is most simply
		229	done by using local as in C< local $/ >.
		230
		231	The pool size is limited to 8 idle coroutines (this can be adjusted by
		232	changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
		233	required.
		234
		235	If you are concerned about pooled coroutines growing a lot because a
		236	single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
		237	{ terminate }> once per second or so to slowly replenish the pool. In
		238	addition to that, when the stacks used by a handler grows larger than 16kb
		239	(adjustable with $Coro::POOL_RSS) it will also exit.
		240
		241	=cut
		242
		243	our $POOL_SIZE = 8;
		244	our $POOL_RSS = 16 * 1024;
		245	our @async_pool;
		246
		247	sub pool_handler {
		248	my $cb;
		249
		250	while () {
		251	eval {
		252	while () {
		253	_pool_1 $cb;
		254	&$cb;
		255	_pool_2 $cb;
		256	&schedule;
		257	}
		258	};
		259
		260	last if $@ eq "\3async_pool terminate\2\n";
		261	warn $@ if $@;
		262	}
		263	}
		264
		265	sub async_pool(&@) {
		266	# this is also inlined into the unlock_scheduler
		267	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		268
		269	$coro->{_invoke} = [@_];
		270	$coro->ready;
		271
		272	$coro
206	}	273	}
207		274
208	=item schedule	275	=item schedule
209		276
210	Calls the scheduler. Please note that the current coroutine will not be put	277	Calls the scheduler. Please note that the current coroutine will not be put
…		…
223	# wake up sleeping coroutine	290	# wake up sleeping coroutine
224	$current->ready;	291	$current->ready;
225	undef $current;	292	undef $current;
226	};	293	};
227		294
228	# call schedule until event occured.	295	# call schedule until event occurred.
229	# in case we are woken up for other reasons	296	# in case we are woken up for other reasons
230	# (current still defined), loop.	297	# (current still defined), loop.
231	Coro::schedule while $current;	298	Coro::schedule while $current;
232	}	299	}
233		300
…		…
235		302
236	"Cede" to other coroutines. This function puts the current coroutine into the	303	"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	304	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.	305	current "timeslice" to other coroutines of the same or higher priority.
239		306
		307	Returns true if at least one coroutine switch has happened.
		308
240	=item Coro::cede_notself	309	=item Coro::cede_notself
241		310
242	Works like cede, but is not exported by default and will cede to any	311	Works like cede, but is not exported by default and will cede to any
243	coroutine, regardless of priority, once.	312	coroutine, regardless of priority, once.
244		313
		314	Returns true if at least one coroutine switch has happened.
		315
245	=item terminate [arg...]	316	=item terminate [arg...]
246		317
247	Terminates the current coroutine with the given status values (see L<cancel>).	318	Terminates the current coroutine with the given status values (see L<cancel>).
		319
		320	=item killall
		321
		322	Kills/terminates/cancels all coroutines except the currently running
		323	one. This is useful after a fork, either in the child or the parent, as
		324	usually only one of them should inherit the running coroutines.
248		325
249	=cut	326	=cut
250		327
251	sub terminate {	328	sub terminate {
252	$current->cancel (@_);	329	$current->cancel (@_);
		330	}
		331
		332	sub killall {
		333	for (Coro::State::list) {
		334	$_->cancel
		335	if $_ != $current && UNIVERSAL::isa $_, "Coro";
		336	}
253	}	337	}
254		338
255	=back	339	=back
256		340
257	# dynamic methods	341	# dynamic methods
…		…
267	Create a new coroutine and return it. When the sub returns the coroutine	351	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	352	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	353	called. To make the coroutine run you must first put it into the ready queue
270	by calling the ready method.	354	by calling the ready method.
271		355
272	Calling C<exit> in a coroutine will not work correctly, so do not do that.	356	See C<async> and C<Coro::State::new> for additional info about the
		357	coroutine environment.
273		358
274	=cut	359	=cut
275		360
276	sub _run_coro {	361	sub _run_coro {
277	terminate &{+shift};	362	terminate &{+shift};
…		…
301		386
302	=cut	387	=cut
303		388
304	sub cancel {	389	sub cancel {
305	my $self = shift;	390	my $self = shift;
306	$self->{status} = [@_];	391	$self->{_status} = [@_];
307		392
308	if ($current == $self) {	393	if ($current == $self) {
309	push @destroy, $self;	394	push @destroy, $self;
310	$manager->ready;	395	$manager->ready;
311	&schedule while 1;	396	&schedule while 1;
…		…
315	}	400	}
316		401
317	=item $coroutine->join	402	=item $coroutine->join
318		403
319	Wait until the coroutine terminates and return any values given to the	404	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	405	C<terminate> or C<cancel> functions. C<join> can be called concurrently
321	from multiple coroutine.	406	from multiple coroutines.
322		407
323	=cut	408	=cut
324		409
325	sub join {	410	sub join {
326	my $self = shift;	411	my $self = shift;
327		412
328	unless ($self->{status}) {	413	unless ($self->{_status}) {
329	my $current = $current;	414	my $current = $current;
330		415
331	push @{$self->{destroy_cb}}, sub {	416	push @{$self->{_on_destroy}}, sub {
332	$current->ready;	417	$current->ready;
333	undef $current;	418	undef $current;
334	};	419	};
335		420
336	&schedule while $current;	421	&schedule while $current;
337	}	422	}
338		423
339	wantarray ? @{$self->{status}} : $self->{status}[0];	424	wantarray ? @{$self->{_status}} : $self->{_status}[0];
340	}	425	}
341		426
342	=item $coroutine->on_destroy (\&cb)	427	=item $coroutine->on_destroy (\&cb)
343		428
344	Registers a callback that is called when this coroutine gets destroyed,	429	Registers a callback that is called when this coroutine gets destroyed,
…		…
348	=cut	433	=cut
349		434
350	sub on_destroy {	435	sub on_destroy {
351	my ($self, $cb) = @_;	436	my ($self, $cb) = @_;
352		437
353	push @{ $self->{destroy_cb} }, $cb;	438	push @{ $self->{_on_destroy} }, $cb;
354	}	439	}
355		440
356	=item $oldprio = $coroutine->prio ($newprio)	441	=item $oldprio = $coroutine->prio ($newprio)
357		442
358	Sets (or gets, if the argument is missing) the priority of the	443	Sets (or gets, if the argument is missing) the priority of the
…		…
383	=item $olddesc = $coroutine->desc ($newdesc)	468	=item $olddesc = $coroutine->desc ($newdesc)
384		469
385	Sets (or gets in case the argument is missing) the description for this	470	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.	471	coroutine. This is just a free-form string you can associate with a coroutine.
387		472
		473	This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
		474	can modify this member directly if you wish.
		475
		476	=item $coroutine->throw ([$scalar])
		477
		478	If C<$throw> is specified and defined, it will be thrown as an exception
		479	inside the coroutine at the next convinient point in time (usually after
		480	it gains control at the next schedule/transfer/cede). Otherwise clears the
		481	exception object.
		482
		483	The exception object will be thrown "as is" with the specified scalar in
		484	C<$@>, i.e. if it is a string, no line number or newline will be appended
		485	(unlike with C<die>).
		486
		487	This can be used as a softer means than C<cancel> to ask a coroutine to
		488	end itself, although there is no guarentee that the exception will lead to
		489	termination, and if the exception isn't caught it might well end the whole
		490	program.
		491
388	=cut	492	=cut
389		493
390	sub desc {	494	sub desc {
391	my $old = $_[0]{desc};	495	my $old = $_[0]{desc};
392	$_[0]{desc} = $_[1] if @_ > 1;	496	$_[0]{desc} = $_[1] if @_ > 1;
…		…
400	=over 4	504	=over 4
401		505
402	=item Coro::nready	506	=item Coro::nready
403		507
404	Returns the number of coroutines that are currently in the ready state,	508	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	509	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,	510	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	511	and C<schedule> would cause a deadlock unless there is an idle handler
408	that wakes up some coroutines.	512	that wakes up some coroutines.
409		513
410	=item my $guard = Coro::guard { ... }	514	=item my $guard = Coro::guard { ... }
411		515
412	This creates and returns a guard object. Nothing happens until the objetc	516	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	517	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	518	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	519	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,	520	guard block will be executed. The guard object supports only one method,
417	C<< ->cancel >>, which will keep the codeblock from being executed.	521	C<< ->cancel >>, which will keep the codeblock from being executed.
…		…
446	This utility function takes a BLOCK or code reference and "unblocks" it,	550	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	551	returning the new coderef. This means that the new coderef will return
448	immediately without blocking, returning nothing, while the original code	552	immediately without blocking, returning nothing, while the original code
449	ref will be called (with parameters) from within its own coroutine.	553	ref will be called (with parameters) from within its own coroutine.
450		554
451	The reason this fucntion exists is that many event libraries (such as the	555	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	556	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,	557	of thread-safety). This means you must not block within event callbacks,
454	otherwise you might suffer from crashes or worse.	558	otherwise you might suffer from crashes or worse.
455		559
456	This function allows your callbacks to block by executing them in another	560	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	565	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
462	creating event callbacks that want to block.	566	creating event callbacks that want to block.
463		567
464	=cut	568	=cut
465		569
466	our @unblock_pool;
467	our @unblock_queue;	570	our @unblock_queue;
468	our $UNBLOCK_POOL_SIZE = 2;
469		571
470	sub unblock_handler_ {	572	# we create a special coro because we want to cede,
471	while () {	573	# to reduce pressure on the coro pool (because most callbacks
472	my ($cb, @arg) = @{ delete $Coro::current->{arg} };	574	# return immediately and can be reused) and because we cannot cede
473	$cb->(@arg);	575	# 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 {	576	our $unblock_scheduler = new Coro sub {
482	while () {	577	while () {
483	while (my $cb = pop @unblock_queue) {	578	while (my $cb = pop @unblock_queue) {
484	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);	579	# this is an inlined copy of async_pool
485	$handler->{arg} = $cb;	580	my $coro = (pop @async_pool) \|\| new Coro \&pool_handler;
		581
		582	$coro->{_invoke} = $cb;
486	$handler->ready;	583	$coro->ready;
487	cede;	584	cede; # for short-lived callbacks, this reduces pressure on the coro pool
488	}	585	}
489		586	schedule; # sleep well
490	schedule;
491	}	587	}
492	};	588	};
		589	$unblock_scheduler->desc ("[unblock_sub scheduler]");
493		590
494	sub unblock_sub(&) {	591	sub unblock_sub(&) {
495	my $cb = shift;	592	my $cb = shift;
496		593
497	sub {	594	sub {
498	push @unblock_queue, [$cb, @_];	595	unshift @unblock_queue, [$cb, @_];
499	$unblock_scheduler->ready;	596	$unblock_scheduler->ready;
500	}	597	}
501	}	598	}
502		599
503	=back	600	=back
…		…
510		607
511	- you must make very sure that no coro is still active on global	608	- you must make very sure that no coro is still active on global
512	destruction. very bad things might happen otherwise (usually segfaults).	609	destruction. very bad things might happen otherwise (usually segfaults).
513		610
514	- this module is not thread-safe. You should only ever use this module	611	- 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	612	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	613	to allow per-thread schedulers, but Coro::State does not yet allow
517	this).	614	this).
518		615
519	=head1 SEE ALSO	616	=head1 SEE ALSO
520		617
521	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.	618	Support/Utility: L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
522		619
523	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.	620	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
524		621
525	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.	622	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
526		623

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Comparing Coro/Coro.pm (file contents): Revision 1.103 by root, Thu Jan 4 20:14:19 2007 UTC vs. Revision 1.151 by root, Sat Oct 6 19:25:00 2007 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.103 by root, Thu Jan 4 20:14:19 2007 UTC vs.
Revision 1.151 by root, Sat Oct 6 19:25:00 2007 UTC