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

Comparing Coro/Coro.pm (file contents):
Revision 1.65 by root, Tue Feb 22 19:51:58 2005 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
…		…
30		30
31	=cut	31	=cut
32		32
33	package Coro;	33	package Coro;
34		34
35	BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }	35	use strict;
		36	no warnings "uninitialized";
36		37
37	use Coro::State;	38	use Coro::State;
38		39
39	use vars qw($idle $main $current);	40	use base qw(Coro::State Exporter);
40		41
41	use base Exporter;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
43	$VERSION = 1.1;	46	our $VERSION = '3.01';
44		47
45	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
46	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
47	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48	);	51	);
49	@EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
50		53
51	{	54	{
52	my @async;	55	my @async;
53	my $init;	56	my $init;
54		57
55	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
56	sub import {	59	sub import {
		60	no strict 'refs';
		61
57	Coro->export_to_level(1, @_);	62	Coro->export_to_level (1, @_);
		63
58	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
59	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
60	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
61	my @attrs;	67	my @attrs;
62	for (@_) {	68	for (@_) {
…		…
89		95
90	$main = new Coro;	96	$main = new Coro;
91		97
92	=item $current (or as function: current)	98	=item $current (or as function: current)
93		99
94	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
95		106
96	=cut	107	=cut
97		108
98	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
99	if ($current) {
100	$main->{specific} = $current->{specific};	110	$main->{specific} = $current->{specific}
101	}	111	if $current;
102		112
103	$current = $main;	113	_set_current $main;
104		114
105	sub current() { $current }	115	sub current() { $current }
106		116
107	=item $idle	117	=item $idle
108		118
109	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
110	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.
111		122
112	=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.
113		126
114	# should be done using priorities :(	127	Please note that if your callback recursively invokes perl (e.g. for event
115	$idle = new Coro sub {	128	handlers), then it must be prepared to be called recursively.
116	print STDERR "FATAL: deadlock detected\n";	129
117	exit(51);	130	=cut
		131
		132	$idle = sub {
		133	require Carp;
		134	Carp::croak ("FATAL: deadlock detected");
118	};	135	};
119		136
120	# this coroutine is necessary because a coroutine	137	# this coroutine is necessary because a coroutine
121	# cannot destroy itself.	138	# cannot destroy itself.
122	my @destroy;	139	my @destroy;
123	my $manager;
124	$manager = new Coro sub {	140	my $manager; $manager = new Coro sub {
125	while () {	141	while () {
126	# by overwriting the state object with the manager we destroy it	142	# by overwriting the state object with the manager we destroy it
127	# 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
128	# been readied multiple times. this is harmless since the manager	144	# been readied multiple times. this is harmless since the manager
129	# can be called as many times as neccessary and will always	145	# can be called as many times as neccessary and will always
…		…
131	while (@destroy) {	147	while (@destroy) {
132	my $coro = pop @destroy;	148	my $coro = pop @destroy;
133	$coro->{status} \|\|= [];	149	$coro->{status} \|\|= [];
134	$_->ready for @{delete $coro->{join} \|\| []};	150	$_->ready for @{delete $coro->{join} \|\| []};
135		151
136	# the next line destroys the _coro_state, but keeps the	152	# the next line destroys the coro state, but keeps the
137	# process itself intact (we basically make it a zombie	153	# coroutine itself intact (we basically make it a zombie
138	# process that always runs the manager thread, so it's possible	154	# coroutine that always runs the manager thread, so it's possible
139	# to transfer() to this process).	155	# to transfer() to this coroutine).
140	$coro->{_coro_state} = $manager->{_coro_state};	156	$coro->_clone_state_from ($manager);
141	}	157	}
142	&schedule;	158	&schedule;
143	}	159	}
144	};	160	};
145		161
…		…
147		163
148	=back	164	=back
149		165
150	=head2 STATIC METHODS	166	=head2 STATIC METHODS
151		167
152	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.
153		169
154	=over 4	170	=over 4
155		171
156	=item async { ... } [@args...]	172	=item async { ... } [@args...]
157		173
158	Create a new asynchronous process and return it's process object	174	Create a new asynchronous coroutine and return it's coroutine object
159	(usually unused). When the sub returns the new process is automatically	175	(usually unused). When the sub returns the new coroutine is automatically
160	terminated.	176	terminated.
		177
		178	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		179
		180	When the coroutine dies, the program will exit, just as in the main
		181	program.
161		182
162	# create a new coroutine that just prints its arguments	183	# create a new coroutine that just prints its arguments
163	async {	184	async {
164	print "@_\n";	185	print "@_\n";
165	} 1,2,3,4;	186	} 1,2,3,4;
166		187
167	=cut	188	=cut
168		189
169	sub async(&@) {	190	sub async(&@) {
170	my $pid = new Coro @_;	191	my $pid = new Coro @_;
171	$manager->ready; # this ensures that the stack is cloned from the manager
172	$pid->ready;	192	$pid->ready;
173	$pid;	193	$pid
174	}	194	}
175		195
176	=item schedule	196	=item schedule
177		197
178	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
179	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
180	never be called again.	200	never be called again unless something else (e.g. an event handler) calls
		201	ready.
181		202
182	=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	}
183		221
184	=item cede	222	=item cede
185		223
186	"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
187	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
188	current "timeslice" to other coroutines of the same or higher priority.	226	current "timeslice" to other coroutines of the same or higher priority.
189		227
190	=cut
191
192	=item terminate [arg...]	228	=item terminate [arg...]
193		229
194	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>).
195		231
196	=cut	232	=cut
197		233
198	sub terminate {	234	sub terminate {
199	$current->cancel (@_);	235	$current->cancel (@_);
…		…
201		237
202	=back	238	=back
203		239
204	# dynamic methods	240	# dynamic methods
205		241
206	=head2 PROCESS METHODS	242	=head2 COROUTINE METHODS
207		243
208	These are the methods you can call on process objects.	244	These are the methods you can call on coroutine objects.
209		245
210	=over 4	246	=over 4
211		247
212	=item new Coro \&sub [, @args...]	248	=item new Coro \&sub [, @args...]
213		249
214	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
215	automatically terminates as if C<terminate> with the returned values were	251	automatically terminates as if C<terminate> with the returned values were
216	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
217	by calling the ready method.	253	by calling the ready method.
218		254
219	=cut	255	Calling C<exit> in a coroutine will not work correctly, so do not do that.
220		256
		257	=cut
		258
221	sub _newcoro {	259	sub _run_coro {
222	terminate &{+shift};	260	terminate &{+shift};
223	}	261	}
224		262
225	sub new {	263	sub new {
226	my $class = shift;	264	my $class = shift;
227	bless {
228	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
229	}, $class;
230	}
231		265
232	=item $process->ready	266	$class->SUPER::new (\&_run_coro, @_)
		267	}
233		268
234	Put the given process into the ready queue.	269	=item $success = $coroutine->ready
235		270
236	=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.
237		274
		275	=item $is_ready = $coroutine->is_ready
		276
		277	Return wether the coroutine is currently the ready queue or not,
		278
238	=item $process->cancel (arg...)	279	=item $coroutine->cancel (arg...)
239		280
240	Temrinates the given process and makes it return the given arguments as	281	Terminates the given coroutine and makes it return the given arguments as
241	status (default: the empty list).	282	status (default: the empty list).
242		283
243	=cut	284	=cut
244		285
245	sub cancel {	286	sub cancel {
…		…
248	push @destroy, $self;	289	push @destroy, $self;
249	$manager->ready;	290	$manager->ready;
250	&schedule if $current == $self;	291	&schedule if $current == $self;
251	}	292	}
252		293
253	=item $process->join	294	=item $coroutine->join
254		295
255	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
256	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
257	from multiple processes.	298	from multiple coroutine.
258		299
259	=cut	300	=cut
260		301
261	sub join {	302	sub join {
262	my $self = shift;	303	my $self = shift;
…		…
265	&schedule;	306	&schedule;
266	}	307	}
267	wantarray ? @{$self->{status}} : $self->{status}[0];	308	wantarray ? @{$self->{status}} : $self->{status}[0];
268	}	309	}
269		310
270	=item $oldprio = $process->prio($newprio)	311	=item $oldprio = $coroutine->prio ($newprio)
271		312
272	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
273	process. Higher priority processes get run before lower priority	314	coroutine. Higher priority coroutines get run before lower priority
274	processes. Priorities are small signed integers (currently -4 .. +3),	315	coroutines. Priorities are small signed integers (currently -4 .. +3),
275	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
276	to get then):	317	to get then):
277		318
278	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
279	3 > 1 > 0 > -1 > -3 > -4	320	3 > 1 > 0 > -1 > -3 > -4
…		…
282	current->prio(PRIO_HIGH);	323	current->prio(PRIO_HIGH);
283		324
284	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
285	existing coroutine.	326	existing coroutine.
286		327
287	Changing the priority of the current process will take effect immediately,	328	Changing the priority of the current coroutine will take effect immediately,
288	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
289	running) will only take effect after the next schedule (of that	330	running) will only take effect after the next schedule (of that
290	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.
291		332
292	=cut
293
294	sub prio {
295	my $old = $_[0]{prio};
296	$_[0]{prio} = $_[1] if @_ > 1;
297	$old;
298	}
299
300	=item $newprio = $process->nice($change)	333	=item $newprio = $coroutine->nice ($change)
301		334
302	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.
303	higher values mean lower priority, just as in unix).	336	higher values mean lower priority, just as in unix).
304		337
305	=cut
306
307	sub nice {
308	$_[0]{prio} -= $_[1];
309	}
310
311	=item $olddesc = $process->desc($newdesc)	338	=item $olddesc = $coroutine->desc ($newdesc)
312		339
313	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
314	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.
315		342
316	=cut	343	=cut
317		344
318	sub desc {	345	sub desc {
319	my $old = $_[0]{desc};	346	my $old = $_[0]{desc};
…		…
321	$old;	348	$old;
322	}	349	}
323		350
324	=back	351	=back
325		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
326	=cut	418	=cut
327		419
328	1;	420	1;
329		421
330	=head1 BUGS/LIMITATIONS	422	=head1 BUGS/LIMITATIONS
…		…
337	to allow per-thread schedulers, but Coro::State does not yet allow	429	to allow per-thread schedulers, but Coro::State does not yet allow
338	this).	430	this).
339		431
340	=head1 SEE ALSO	432	=head1 SEE ALSO
341		433
342	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	434	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
343	L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,	435
344	L<Coro::Handle>, L<Coro::RWLock>, L<Coro::Socket>.	436	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		437
		438	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		439
		440	Embedding: L<Coro:MakeMaker>
345		441
346	=head1 AUTHOR	442	=head1 AUTHOR
347		443
348	Marc Lehmann <pcg@goof.com>	444	Marc Lehmann <schmorp@schmorp.de>
349	http://home.schmorp.de/	445	http://home.schmorp.de/
350		446
351	=cut	447	=cut
352		448

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Comparing Coro/Coro.pm (file contents): Revision 1.65 by root, Tue Feb 22 19:51:58 2005 UTC vs. Revision 1.96 by root, Mon Dec 4 03:48:16 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.65 by root, Tue Feb 22 19:51:58 2005 UTC vs.
Revision 1.96 by root, Mon Dec 4 03:48:16 2006 UTC