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

Comparing Coro/Coro.pm (file contents):
Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs.
Revision 1.128 by root, Wed Sep 19 21:39:15 2007 UTC

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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
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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 $VERSION = '3.7';
56		56
57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);	57	our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58	our %EXPORT_TAGS = (	58	our %EXPORT_TAGS = (
59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	59	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60	);	60	);
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108		108
109	The current coroutine (the last coroutine switched to). The initial value	109	The current coroutine (the last coroutine switched to). The initial value
110	is C<$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	# maybe some other module used Coro::Specific before...	118	# maybe some other module used Coro::Specific before...
…		…
185		185
186	Create a new asynchronous coroutine and return it's coroutine object	186	Create a new asynchronous coroutine and return it's coroutine object
187	(usually unused). When the sub returns the new coroutine is automatically	187	(usually unused). When the sub returns the new coroutine is automatically
188	terminated.	188	terminated.
189		189
190	Calling C<exit> in a coroutine will not work correctly, so do not do that.	190	Calling C<exit> in a coroutine will do the same as calling exit outside
191		191	the coroutine. Likewise, when the coroutine dies, the program will exit,
192	When the coroutine dies, the program will exit, just as in the main	192	just as it would in the main program.
193	program.
194		193
195	# create a new coroutine that just prints its arguments	194	# create a new coroutine that just prints its arguments
196	async {	195	async {
197	print "@_\n";	196	print "@_\n";
198	} 1,2,3,4;	197	} 1,2,3,4;
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210	Similar to C<async>, but uses a coroutine pool, so you should not call	209	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	210	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 :).	211	that might have executed other code already (which can be good or bad :).
213		212
214	Also, the block is executed in an C<eval> context and a warning will be	213	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.	214	issued in case of an exception instead of terminating the program, as
		215	C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
		216	will not work in the expected way, unless you call terminate or cancel,
		217	which somehow defeats the purpose of pooling.
216		218
217	The priority will be reset to C<0> after each job, otherwise the coroutine	219	The priority will be reset to C<0> after each job, otherwise the coroutine
218	will be re-used "as-is".	220	will be re-used "as-is".
219		221
220	The pool size is limited to 8 idle coroutines (this can be adjusted by	222	The pool size is limited to 8 idle coroutines (this can be adjusted by
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230	our $POOL_SIZE = 8;	232	our $POOL_SIZE = 8;
231	our @pool;	233	our @pool;
232		234
233	sub pool_handler {	235	sub pool_handler {
234	while () {	236	while () {
235	my ($cb, @arg) = @{ delete $current->{_invoke} };
236
237	eval {	237	eval {
		238	my ($cb, @arg) = @{ delete $current->{_invoke} or return };
238	$cb->(@arg);	239	$cb->(@arg);
239	};	240	};
240	warn $@ if $@;	241	warn $@ if $@;
241		242
242	last if @pool >= $POOL_SIZE;	243	last if @pool >= $POOL_SIZE;
243	push @pool, $current;	244	push @pool, $current;
244		245
		246	$current->save (Coro::State::SAVE_DEF);
245	$current->prio (0);	247	$current->prio (0);
246	schedule;	248	schedule;
247	}	249	}
248	}	250	}
249		251
250	sub async_pool(&@) {	252	sub async_pool(&@) {
251	# this is also inlined into the unlock_scheduler	253	# this is also inlined into the unlock_scheduler
		254	my $coro = (pop @pool) \|\| do {
252	my $coro = (pop @pool or new Coro \&pool_handler);	255	my $coro = new Coro \&pool_handler;
		256	$coro->{desc} = "async_pool";
		257	$coro
		258	};
253		259
254	$coro->{_invoke} = [@_];	260	$coro->{_invoke} = [@_];
255	$coro->ready;	261	$coro->ready;
256		262
257	$coro	263	$coro
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275	# wake up sleeping coroutine	281	# wake up sleeping coroutine
276	$current->ready;	282	$current->ready;
277	undef $current;	283	undef $current;
278	};	284	};
279		285
280	# call schedule until event occured.	286	# call schedule until event occurred.
281	# in case we are woken up for other reasons	287	# in case we are woken up for other reasons
282	# (current still defined), loop.	288	# (current still defined), loop.
283	Coro::schedule while $current;	289	Coro::schedule while $current;
284	}	290	}
285		291
…		…
287		293
288	"Cede" to other coroutines. This function puts the current coroutine into the	294	"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	295	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.	296	current "timeslice" to other coroutines of the same or higher priority.
291		297
		298	Returns true if at least one coroutine switch has happened.
		299
292	=item Coro::cede_notself	300	=item Coro::cede_notself
293		301
294	Works like cede, but is not exported by default and will cede to any	302	Works like cede, but is not exported by default and will cede to any
295	coroutine, regardless of priority, once.	303	coroutine, regardless of priority, once.
		304
		305	Returns true if at least one coroutine switch has happened.
296		306
297	=item terminate [arg...]	307	=item terminate [arg...]
298		308
299	Terminates the current coroutine with the given status values (see L<cancel>).	309	Terminates the current coroutine with the given status values (see L<cancel>).
300		310
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319	Create a new coroutine and return it. When the sub returns the coroutine	329	Create a new coroutine and return it. When the sub returns the coroutine
320	automatically terminates as if C<terminate> with the returned values were	330	automatically terminates as if C<terminate> with the returned values were
321	called. To make the coroutine run you must first put it into the ready queue	331	called. To make the coroutine run you must first put it into the ready queue
322	by calling the ready method.	332	by calling the ready method.
323		333
324	Calling C<exit> in a coroutine will not work correctly, so do not do that.	334	See C<async> for additional discussion.
325		335
326	=cut	336	=cut
327		337
328	sub _run_coro {	338	sub _run_coro {
329	terminate &{+shift};	339	terminate &{+shift};
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452	=over 4	462	=over 4
453		463
454	=item Coro::nready	464	=item Coro::nready
455		465
456	Returns the number of coroutines that are currently in the ready state,	466	Returns the number of coroutines that are currently in the ready state,
457	i.e. that can be swicthed to. The value C<0> means that the only runnable	467	i.e. that can be switched to. The value C<0> means that the only runnable
458	coroutine is the currently running one, so C<cede> would have no effect,	468	coroutine is the currently running one, so C<cede> would have no effect,
459	and C<schedule> would cause a deadlock unless there is an idle handler	469	and C<schedule> would cause a deadlock unless there is an idle handler
460	that wakes up some coroutines.	470	that wakes up some coroutines.
461		471
462	=item my $guard = Coro::guard { ... }	472	=item my $guard = Coro::guard { ... }
463		473
464	This creates and returns a guard object. Nothing happens until the objetc	474	This creates and returns a guard object. Nothing happens until the object
465	gets destroyed, in which case the codeblock given as argument will be	475	gets destroyed, in which case the codeblock given as argument will be
466	executed. This is useful to free locks or other resources in case of a	476	executed. This is useful to free locks or other resources in case of a
467	runtime error or when the coroutine gets canceled, as in both cases the	477	runtime error or when the coroutine gets canceled, as in both cases the
468	guard block will be executed. The guard object supports only one method,	478	guard block will be executed. The guard object supports only one method,
469	C<< ->cancel >>, which will keep the codeblock from being executed.	479	C<< ->cancel >>, which will keep the codeblock from being executed.
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498	This utility function takes a BLOCK or code reference and "unblocks" it,	508	This utility function takes a BLOCK or code reference and "unblocks" it,
499	returning the new coderef. This means that the new coderef will return	509	returning the new coderef. This means that the new coderef will return
500	immediately without blocking, returning nothing, while the original code	510	immediately without blocking, returning nothing, while the original code
501	ref will be called (with parameters) from within its own coroutine.	511	ref will be called (with parameters) from within its own coroutine.
502		512
503	The reason this fucntion exists is that many event libraries (such as the	513	The reason this function exists is that many event libraries (such as the
504	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form	514	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
505	of thread-safety). This means you must not block within event callbacks,	515	of thread-safety). This means you must not block within event callbacks,
506	otherwise you might suffer from crashes or worse.	516	otherwise you might suffer from crashes or worse.
507		517
508	This function allows your callbacks to block by executing them in another	518	This function allows your callbacks to block by executing them in another
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554		564
555	- you must make very sure that no coro is still active on global	565	- you must make very sure that no coro is still active on global
556	destruction. very bad things might happen otherwise (usually segfaults).	566	destruction. very bad things might happen otherwise (usually segfaults).
557		567
558	- this module is not thread-safe. You should only ever use this module	568	- this module is not thread-safe. You should only ever use this module
559	from the same thread (this requirement might be losened in the future	569	from the same thread (this requirement might be loosened in the future
560	to allow per-thread schedulers, but Coro::State does not yet allow	570	to allow per-thread schedulers, but Coro::State does not yet allow
561	this).	571	this).
562		572
563	=head1 SEE ALSO	573	=head1 SEE ALSO
564		574

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Comparing Coro/Coro.pm (file contents): Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs. Revision 1.128 by root, Wed Sep 19 21:39:15 2007 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC vs.
Revision 1.128 by root, Wed Sep 19 21:39:15 2007 UTC