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

Comparing Coro/Coro.pm (file contents):
Revision 1.80 by root, Mon Nov 6 19:56:26 2006 UTC vs.
Revision 1.96 by root, Mon Dec 4 03:48:16 2006 UTC

…		…
8		8
9	async {	9	async {
10	# some asynchronous thread of execution	10	# some asynchronous thread of execution
11	};	11	};
12		12
13	# alternatively create an async process like this:	13	# alternatively create an async coroutine like this:
14		14
15	sub some_func : Coro {	15	sub some_func : Coro {
16	# some more async code	16	# some more async code
17	}	17	}
18		18
…		…
35	use strict;	35	use strict;
36	no warnings "uninitialized";	36	no warnings "uninitialized";
37		37
38	use Coro::State;	38	use Coro::State;
39		39
40	use base Exporter::;	40	use base qw(Coro::State Exporter);
41		41
42	our $idle; # idle coroutine	42	our $idle; # idle handler
43	our $main; # main coroutine	43	our $main; # main coroutine
44	our $current; # current coroutine	44	our $current; # current coroutine
45		45
46	our $VERSION = '2.5';	46	our $VERSION = '3.01';
47		47
48	our @EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
49	our %EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
51	);	51	);
52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
53		53
…		…
57		57
58	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
59	sub import {	59	sub import {
60	no strict 'refs';	60	no strict 'refs';
61		61
62	Coro->export_to_level(1, @_);	62	Coro->export_to_level (1, @_);
63		63
64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
66	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
67	my @attrs;	67	my @attrs;
…		…
95		95
96	$main = new Coro;	96	$main = new Coro;
97		97
98	=item $current (or as function: current)	98	=item $current (or as function: current)
99		99
100	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
101		106
102	=cut	107	=cut
103		108
104	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
105	if ($current) {
106	$main->{specific} = $current->{specific};	110	$main->{specific} = $current->{specific}
107	}	111	if $current;
108		112
109	$current = $main;	113	_set_current $main;
110		114
111	sub current() { $current }	115	sub current() { $current }
112		116
113	=item $idle	117	=item $idle
114		118
115	The coroutine to switch to when no other coroutine is running. The default	119	A callback that is called whenever the scheduler finds no ready coroutines
116	implementation prints "FATAL: deadlock detected" and exits.	120	to run. The default implementation prints "FATAL: deadlock detected" and
		121	exits, because the program has no other way to continue.
117		122
118	=cut	123	This hook is overwritten by modules such as C<Coro::Timer> and
		124	C<Coro::Event> to wait on an external event that hopefully wake up a
		125	coroutine so the scheduler can run it.
119		126
120	# should be done using priorities :(	127	Please note that if your callback recursively invokes perl (e.g. for event
121	$idle = new Coro sub {	128	handlers), then it must be prepared to be called recursively.
122	print STDERR "FATAL: deadlock detected\n";	129
123	exit(51);	130	=cut
		131
		132	$idle = sub {
		133	require Carp;
		134	Carp::croak ("FATAL: deadlock detected");
124	};	135	};
125		136
126	# this coroutine is necessary because a coroutine	137	# this coroutine is necessary because a coroutine
127	# cannot destroy itself.	138	# cannot destroy itself.
128	my @destroy;	139	my @destroy;
129	my $manager;
130	$manager = new Coro sub {	140	my $manager; $manager = new Coro sub {
131	while () {	141	while () {
132	# by overwriting the state object with the manager we destroy it	142	# by overwriting the state object with the manager we destroy it
133	# while still being able to schedule this coroutine (in case it has	143	# while still being able to schedule this coroutine (in case it has
134	# been readied multiple times. this is harmless since the manager	144	# been readied multiple times. this is harmless since the manager
135	# can be called as many times as neccessary and will always	145	# can be called as many times as neccessary and will always
…		…
137	while (@destroy) {	147	while (@destroy) {
138	my $coro = pop @destroy;	148	my $coro = pop @destroy;
139	$coro->{status} \|\|= [];	149	$coro->{status} \|\|= [];
140	$_->ready for @{delete $coro->{join} \|\| []};	150	$_->ready for @{delete $coro->{join} \|\| []};
141		151
142	# the next line destroys the _coro_state, but keeps the	152	# the next line destroys the coro state, but keeps the
143	# process itself intact (we basically make it a zombie	153	# coroutine itself intact (we basically make it a zombie
144	# process that always runs the manager thread, so it's possible	154	# coroutine that always runs the manager thread, so it's possible
145	# to transfer() to this process).	155	# to transfer() to this coroutine).
146	$coro->{_coro_state} = $manager->{_coro_state};	156	$coro->_clone_state_from ($manager);
147	}	157	}
148	&schedule;	158	&schedule;
149	}	159	}
150	};	160	};
151		161
…		…
153		163
154	=back	164	=back
155		165
156	=head2 STATIC METHODS	166	=head2 STATIC METHODS
157		167
158	Static methods are actually functions that operate on the current process only.	168	Static methods are actually functions that operate on the current coroutine only.
159		169
160	=over 4	170	=over 4
161		171
162	=item async { ... } [@args...]	172	=item async { ... } [@args...]
163		173
164	Create a new asynchronous process and return it's process object	174	Create a new asynchronous coroutine and return it's coroutine object
165	(usually unused). When the sub returns the new process is automatically	175	(usually unused). When the sub returns the new coroutine is automatically
166	terminated.	176	terminated.
		177
		178	Calling C<exit> in a coroutine will not work correctly, so do not do that.
167		179
168	When the coroutine dies, the program will exit, just as in the main	180	When the coroutine dies, the program will exit, just as in the main
169	program.	181	program.
170		182
171	# create a new coroutine that just prints its arguments	183	# create a new coroutine that just prints its arguments
…		…
175		187
176	=cut	188	=cut
177		189
178	sub async(&@) {	190	sub async(&@) {
179	my $pid = new Coro @_;	191	my $pid = new Coro @_;
180	$manager->ready; # this ensures that the stack is cloned from the manager
181	$pid->ready;	192	$pid->ready;
182	$pid;	193	$pid
183	}	194	}
184		195
185	=item schedule	196	=item schedule
186		197
187	Calls the scheduler. Please note that the current process will not be put	198	Calls the scheduler. Please note that the current coroutine will not be put
188	into the ready queue, so calling this function usually means you will	199	into the ready queue, so calling this function usually means you will
189	never be called again.	200	never be called again unless something else (e.g. an event handler) calls
		201	ready.
190		202
191	=cut	203	The canonical way to wait on external events is this:
		204
		205	{
		206	# remember current coroutine
		207	my $current = $Coro::current;
		208
		209	# register a hypothetical event handler
		210	on_event_invoke sub {
		211	# wake up sleeping coroutine
		212	$current->ready;
		213	undef $current;
		214	};
		215
		216	# call schedule until event occured.
		217	# in case we are woken up for other reasons
		218	# (current still defined), loop.
		219	Coro::schedule while $current;
		220	}
192		221
193	=item cede	222	=item cede
194		223
195	"Cede" to other processes. This function puts the current process into the	224	"Cede" to other coroutines. This function puts the current coroutine into the
196	ready queue and calls C<schedule>, which has the effect of giving up the	225	ready queue and calls C<schedule>, which has the effect of giving up the
197	current "timeslice" to other coroutines of the same or higher priority.	226	current "timeslice" to other coroutines of the same or higher priority.
198		227
199	=cut
200
201	=item terminate [arg...]	228	=item terminate [arg...]
202		229
203	Terminates the current process with the given status values (see L<cancel>).	230	Terminates the current coroutine with the given status values (see L<cancel>).
204		231
205	=cut	232	=cut
206		233
207	sub terminate {	234	sub terminate {
208	$current->cancel (@_);	235	$current->cancel (@_);
…		…
210		237
211	=back	238	=back
212		239
213	# dynamic methods	240	# dynamic methods
214		241
215	=head2 PROCESS METHODS	242	=head2 COROUTINE METHODS
216		243
217	These are the methods you can call on process objects.	244	These are the methods you can call on coroutine objects.
218		245
219	=over 4	246	=over 4
220		247
221	=item new Coro \&sub [, @args...]	248	=item new Coro \&sub [, @args...]
222		249
223	Create a new process and return it. When the sub returns the process	250	Create a new coroutine and return it. When the sub returns the coroutine
224	automatically terminates as if C<terminate> with the returned values were	251	automatically terminates as if C<terminate> with the returned values were
225	called. To make the process run you must first put it into the ready queue	252	called. To make the coroutine run you must first put it into the ready queue
226	by calling the ready method.	253	by calling the ready method.
227		254
228	=cut	255	Calling C<exit> in a coroutine will not work correctly, so do not do that.
229		256
		257	=cut
		258
230	sub _newcoro {	259	sub _run_coro {
231	terminate &{+shift};	260	terminate &{+shift};
232	}	261	}
233		262
234	sub new {	263	sub new {
235	my $class = shift;	264	my $class = shift;
236	bless {
237	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
238	}, $class;
239	}
240		265
241	=item $process->ready	266	$class->SUPER::new (\&_run_coro, @_)
		267	}
242		268
243	Put the given process into the ready queue.	269	=item $success = $coroutine->ready
244		270
245	=cut	271	Put the given coroutine into the ready queue (according to it's priority)
		272	and return true. If the coroutine is already in the ready queue, do nothing
		273	and return false.
246		274
		275	=item $is_ready = $coroutine->is_ready
		276
		277	Return wether the coroutine is currently the ready queue or not,
		278
247	=item $process->cancel (arg...)	279	=item $coroutine->cancel (arg...)
248		280
249	Terminates the given process and makes it return the given arguments as	281	Terminates the given coroutine and makes it return the given arguments as
250	status (default: the empty list).	282	status (default: the empty list).
251		283
252	=cut	284	=cut
253		285
254	sub cancel {	286	sub cancel {
…		…
257	push @destroy, $self;	289	push @destroy, $self;
258	$manager->ready;	290	$manager->ready;
259	&schedule if $current == $self;	291	&schedule if $current == $self;
260	}	292	}
261		293
262	=item $process->join	294	=item $coroutine->join
263		295
264	Wait until the coroutine terminates and return any values given to the	296	Wait until the coroutine terminates and return any values given to the
265	C<terminate> or C<cancel> functions. C<join> can be called multiple times	297	C<terminate> or C<cancel> functions. C<join> can be called multiple times
266	from multiple processes.	298	from multiple coroutine.
267		299
268	=cut	300	=cut
269		301
270	sub join {	302	sub join {
271	my $self = shift;	303	my $self = shift;
…		…
274	&schedule;	306	&schedule;
275	}	307	}
276	wantarray ? @{$self->{status}} : $self->{status}[0];	308	wantarray ? @{$self->{status}} : $self->{status}[0];
277	}	309	}
278		310
279	=item $oldprio = $process->prio($newprio)	311	=item $oldprio = $coroutine->prio ($newprio)
280		312
281	Sets (or gets, if the argument is missing) the priority of the	313	Sets (or gets, if the argument is missing) the priority of the
282	process. Higher priority processes get run before lower priority	314	coroutine. Higher priority coroutines get run before lower priority
283	processes. Priorities are small signed integers (currently -4 .. +3),	315	coroutines. Priorities are small signed integers (currently -4 .. +3),
284	that you can refer to using PRIO_xxx constants (use the import tag :prio	316	that you can refer to using PRIO_xxx constants (use the import tag :prio
285	to get then):	317	to get then):
286		318
287	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	319	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
288	3 > 1 > 0 > -1 > -3 > -4	320	3 > 1 > 0 > -1 > -3 > -4
…		…
291	current->prio(PRIO_HIGH);	323	current->prio(PRIO_HIGH);
292		324
293	The idle coroutine ($Coro::idle) always has a lower priority than any	325	The idle coroutine ($Coro::idle) always has a lower priority than any
294	existing coroutine.	326	existing coroutine.
295		327
296	Changing the priority of the current process will take effect immediately,	328	Changing the priority of the current coroutine will take effect immediately,
297	but changing the priority of processes in the ready queue (but not	329	but changing the priority of coroutines in the ready queue (but not
298	running) will only take effect after the next schedule (of that	330	running) will only take effect after the next schedule (of that
299	process). This is a bug that will be fixed in some future version.	331	coroutine). This is a bug that will be fixed in some future version.
300		332
301	=cut
302
303	sub prio {
304	my $old = $_[0]{prio};
305	$_[0]{prio} = $_[1] if @_ > 1;
306	$old;
307	}
308
309	=item $newprio = $process->nice($change)	333	=item $newprio = $coroutine->nice ($change)
310		334
311	Similar to C<prio>, but subtract the given value from the priority (i.e.	335	Similar to C<prio>, but subtract the given value from the priority (i.e.
312	higher values mean lower priority, just as in unix).	336	higher values mean lower priority, just as in unix).
313		337
314	=cut
315
316	sub nice {
317	$_[0]{prio} -= $_[1];
318	}
319
320	=item $olddesc = $process->desc($newdesc)	338	=item $olddesc = $coroutine->desc ($newdesc)
321		339
322	Sets (or gets in case the argument is missing) the description for this	340	Sets (or gets in case the argument is missing) the description for this
323	process. This is just a free-form string you can associate with a process.	341	coroutine. This is just a free-form string you can associate with a coroutine.
324		342
325	=cut	343	=cut
326		344
327	sub desc {	345	sub desc {
328	my $old = $_[0]{desc};	346	my $old = $_[0]{desc};
…		…
330	$old;	348	$old;
331	}	349	}
332		350
333	=back	351	=back
334		352
		353	=head2 UTILITY FUNCTIONS
		354
		355	=over 4
		356
		357	=item unblock_sub { ... }
		358
		359	This utility function takes a BLOCK or code reference and "unblocks" it,
		360	returning the new coderef. This means that the new coderef will return
		361	immediately without blocking, returning nothing, while the original code
		362	ref will be called (with parameters) from within its own coroutine.
		363
		364	The reason this fucntion exists is that many event libraries (such as the
		365	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		366	of thread-safety). This means you must not block within event callbacks,
		367	otherwise you might suffer from crashes or worse.
		368
		369	This function allows your callbacks to block by executing them in another
		370	coroutine where it is safe to block. One example where blocking is handy
		371	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		372	disk.
		373
		374	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		375	creating event callbacks that want to block.
		376
		377	=cut
		378
		379	our @unblock_pool;
		380	our @unblock_queue;
		381	our $UNBLOCK_POOL_SIZE = 2;
		382
		383	sub unblock_handler_ {
		384	while () {
		385	my ($cb, @arg) = @{ delete $Coro::current->{arg} };
		386	$cb->(@arg);
		387
		388	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
		389	push @unblock_pool, $Coro::current;
		390	schedule;
		391	}
		392	}
		393
		394	our $unblock_scheduler = async {
		395	while () {
		396	while (my $cb = pop @unblock_queue) {
		397	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);
		398	$handler->{arg} = $cb;
		399	$handler->ready;
		400	cede;
		401	}
		402
		403	schedule;
		404	}
		405	};
		406
		407	sub unblock_sub(&) {
		408	my $cb = shift;
		409
		410	sub {
		411	push @unblock_queue, [$cb, @_];
		412	$unblock_scheduler->ready;
		413	}
		414	}
		415
		416	=back
		417
335	=cut	418	=cut
336		419
337	1;	420	1;
338		421
339	=head1 BUGS/LIMITATIONS	422	=head1 BUGS/LIMITATIONS

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Comparing Coro/Coro.pm (file contents): Revision 1.80 by root, Mon Nov 6 19:56:26 2006 UTC vs. Revision 1.96 by root, Mon Dec 4 03:48:16 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.80 by root, Mon Nov 6 19:56:26 2006 UTC vs.
Revision 1.96 by root, Mon Dec 4 03:48:16 2006 UTC