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

Comparing Coro/Coro.pm (file contents):
Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs.
Revision 1.95 by root, Sun Dec 3 22:50:06 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	use strict;
35	no warnings qw(uninitialized);	36	no warnings "uninitialized";
36		37
37	use Coro::State;	38	use Coro::State;
38		39
39	use base Exporter;	40	use base qw(Coro::State Exporter);
40		41
41	$VERSION = 0.52;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
		46	our $VERSION = '3.01';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
44	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
45	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46	);	51	);
47	@EXPORT_OK = @{$EXPORT_TAGS{prio}};	52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
48		53
49	{	54	{
50	my @async;	55	my @async;
51	my $init;	56	my $init;
52		57
53	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
54	sub import {	59	sub import {
		60	no strict 'refs';
		61
55	Coro->export_to_level(1, @_);	62	Coro->export_to_level (1, @_);
		63
56	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
57	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
58	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
59	my @attrs;	67	my @attrs;
60	for (@_) {	68	for (@_) {
…		…
75	};	83	};
76	}	84	}
77		85
78	}	86	}
79		87
		88	=over 4
		89
80	=item $main	90	=item $main
81		91
82	This coroutine represents the main program.	92	This coroutine represents the main program.
83		93
84	=cut	94	=cut
85		95
86	our $main = new Coro;	96	$main = new Coro;
87		97
88	=item $current (or as function: current)	98	=item $current (or as function: current)
89		99
90	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
91		106
92	=cut	107	=cut
93		108
94	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
95	if ($current) {
96	$main->{specific} = $current->{specific};	110	$main->{specific} = $current->{specific}
97	}	111	if $current;
98		112
99	our $current = $main;	113	_set_current $main;
100		114
101	sub current() { $current }	115	sub current() { $current }
102		116
103	=item $idle	117	=item $idle
104		118
105	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
106	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.
107		122
108	=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.
109		126
110	# should be done using priorities :(	127	Please note that if your callback recursively invokes perl (e.g. for event
111	our $idle = new Coro sub {	128	handlers), then it must be prepared to be called recursively.
		129
		130	=cut
		131
		132	$idle = sub {
112	print STDERR "FATAL: deadlock detected\n";	133	print STDERR "FATAL: deadlock detected\n";
113	exit(51);	134	exit (51);
114	};	135	};
115		136
116	# this coroutine is necessary because a coroutine	137	# this coroutine is necessary because a coroutine
117	# cannot destroy itself.	138	# cannot destroy itself.
118	my @destroy;	139	my @destroy;
119	my $manager;
120	$manager = new Coro sub {	140	my $manager; $manager = new Coro sub {
121	while() {	141	while () {
122	# by overwriting the state object with the manager we destroy it	142	# by overwriting the state object with the manager we destroy it
123	# 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
124	# been readied multiple times. this is harmless since the manager	144	# been readied multiple times. this is harmless since the manager
125	# can be called as many times as neccessary and will always	145	# can be called as many times as neccessary and will always
126	# remove itself from the runqueue	146	# remove itself from the runqueue
127	while (@destroy) {	147	while (@destroy) {
128	my $coro = pop @destroy;	148	my $coro = pop @destroy;
129	$coro->{status} \|\|= [];	149	$coro->{status} \|\|= [];
130	$_->ready for @{delete $coro->{join} \|\| []};	150	$_->ready for @{delete $coro->{join} \|\| []};
131	$coro->{_coro_state} = $manager->{_coro_state};	151
		152	# the next line destroys the coro state, but keeps the
		153	# coroutine itself intact (we basically make it a zombie
		154	# coroutine that always runs the manager thread, so it's possible
		155	# to transfer() to this coroutine).
		156	$coro->_clone_state_from ($manager);
132	}	157	}
133	&schedule;	158	&schedule;
134	}	159	}
135	};	160	};
136		161
137	# static methods. not really.	162	# static methods. not really.
138		163
		164	=back
		165
139	=head2 STATIC METHODS	166	=head2 STATIC METHODS
140		167
141	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.
142		169
143	=over 4	170	=over 4
144		171
145	=item async { ... } [@args...]	172	=item async { ... } [@args...]
146		173
147	Create a new asynchronous process and return it's process object	174	Create a new asynchronous coroutine and return it's coroutine object
148	(usually unused). When the sub returns the new process is automatically	175	(usually unused). When the sub returns the new coroutine is automatically
149	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.
150		182
151	# create a new coroutine that just prints its arguments	183	# create a new coroutine that just prints its arguments
152	async {	184	async {
153	print "@_\n";	185	print "@_\n";
154	} 1,2,3,4;	186	} 1,2,3,4;
155		187
156	The coderef you submit MUST NOT be a closure that refers to variables
157	in an outer scope. This does NOT work. Pass arguments into it instead.
158
159	=cut	188	=cut
160		189
161	sub async(&@) {	190	sub async(&@) {
162	my $pid = new Coro @_;	191	my $pid = new Coro @_;
163	$manager->ready; # this ensures that the stack is cloned from the manager
164	$pid->ready;	192	$pid->ready;
165	$pid;	193	$pid
166	}	194	}
167		195
168	=item schedule	196	=item schedule
169		197
170	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
171	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
172	never be called again.	200	never be called again unless something else (e.g. an event handler) calls
		201	ready.
173		202
174	=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	}
175		221
176	=item cede	222	=item cede
177		223
178	"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
179	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
180	current "timeslice" to other coroutines of the same or higher priority.	226	current "timeslice" to other coroutines of the same or higher priority.
181		227
182	=cut
183
184	=item terminate [arg...]	228	=item terminate [arg...]
185		229
186	Terminates the current process.	230	Terminates the current coroutine with the given status values (see L<cancel>).
187
188	Future versions of this function will allow result arguments.
189		231
190	=cut	232	=cut
191		233
192	sub terminate {	234	sub terminate {
193	$current->{status} = [@_];
194	$current->cancel;	235	$current->cancel (@_);
195	&schedule;
196	die; # NORETURN
197	}	236	}
198		237
199	=back	238	=back
200		239
201	# dynamic methods	240	# dynamic methods
202		241
203	=head2 PROCESS METHODS	242	=head2 COROUTINE METHODS
204		243
205	These are the methods you can call on process objects.	244	These are the methods you can call on coroutine objects.
206		245
207	=over 4	246	=over 4
208		247
209	=item new Coro \&sub [, @args...]	248	=item new Coro \&sub [, @args...]
210		249
211	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
212	automatically terminates as if C<terminate> with the returned values were	251	automatically terminates as if C<terminate> with the returned values were
213	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
214	by calling the ready method.	253	by calling the ready method.
215		254
216	=cut	255	Calling C<exit> in a coroutine will not work correctly, so do not do that.
217		256
		257	=cut
		258
218	sub _newcoro {	259	sub _run_coro {
219	terminate &{+shift};	260	terminate &{+shift};
220	}	261	}
221		262
222	sub new {	263	sub new {
223	my $class = shift;	264	my $class = shift;
224	bless {
225	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
226	}, $class;
227	}
228		265
229	=item $process->ready	266	$class->SUPER::new (\&_run_coro, @_)
		267	}
230		268
231	Put the given process into the ready queue.	269	=item $success = $coroutine->ready
232		270
233	=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.
234		274
235	=item $process->cancel	275	=item $is_ready = $coroutine->is_ready
236		276
237	Like C<terminate>, but terminates the specified process instead.	277	Return wether the coroutine is currently the ready queue or not,
		278
		279	=item $coroutine->cancel (arg...)
		280
		281	Terminates the given coroutine and makes it return the given arguments as
		282	status (default: the empty list).
238		283
239	=cut	284	=cut
240		285
241	sub cancel {	286	sub cancel {
		287	my $self = shift;
		288	$self->{status} = [@_];
242	push @destroy, $_[0];	289	push @destroy, $self;
243	$manager->ready;	290	$manager->ready;
244	&schedule if $current == $_[0];	291	&schedule if $current == $self;
245	}	292	}
246		293
247	=item $process->join	294	=item $coroutine->join
248		295
249	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
250	C<terminate> function. C<join> can be called multiple times from multiple	297	C<terminate> or C<cancel> functions. C<join> can be called multiple times
251	processes.	298	from multiple coroutine.
252		299
253	=cut	300	=cut
254		301
255	sub join {	302	sub join {
256	my $self = shift;	303	my $self = shift;
…		…
259	&schedule;	306	&schedule;
260	}	307	}
261	wantarray ? @{$self->{status}} : $self->{status}[0];	308	wantarray ? @{$self->{status}} : $self->{status}[0];
262	}	309	}
263		310
264	=item $oldprio = $process->prio($newprio)	311	=item $oldprio = $coroutine->prio ($newprio)
265		312
266	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
267	process. Higher priority processes get run before lower priority	314	coroutine. Higher priority coroutines get run before lower priority
268	processes. Priorities are smalled signed integer (currently -4 .. +3),	315	coroutines. Priorities are small signed integers (currently -4 .. +3),
269	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
270	to get then):	317	to get then):
271		318
272	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
273	3 > 1 > 0 > -1 > -3 > -4	320	3 > 1 > 0 > -1 > -3 > -4
…		…
276	current->prio(PRIO_HIGH);	323	current->prio(PRIO_HIGH);
277		324
278	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
279	existing coroutine.	326	existing coroutine.
280		327
281	Changing the priority of the current process will take effect immediately,	328	Changing the priority of the current coroutine will take effect immediately,
282	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
283	running) will only take effect after the next schedule (of that	330	running) will only take effect after the next schedule (of that
284	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.
285		332
286	=cut
287
288	sub prio {
289	my $old = $_[0]{prio};
290	$_[0]{prio} = $_[1] if @_ > 1;
291	$old;
292	}
293
294	=item $newprio = $process->nice($change)	333	=item $newprio = $coroutine->nice ($change)
295		334
296	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.
297	higher values mean lower priority, just as in unix).	336	higher values mean lower priority, just as in unix).
298		337
299	=cut
300
301	sub nice {
302	$_[0]{prio} -= $_[1];
303	}
304
305	=item $olddesc = $process->desc($newdesc)	338	=item $olddesc = $coroutine->desc ($newdesc)
306		339
307	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
308	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.
309		342
310	=cut	343	=cut
311		344
312	sub desc {	345	sub desc {
313	my $old = $_[0]{desc};	346	my $old = $_[0]{desc};
…		…
315	$old;	348	$old;
316	}	349	}
317		350
318	=back	351	=back
319		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
320	=cut	418	=cut
321		419
322	1;	420	1;
323		421
324	=head1 BUGS/LIMITATIONS	422	=head1 BUGS/LIMITATIONS
325		423
326	- you must make very sure that no coro is still active on global destruction.	424	- you must make very sure that no coro is still active on global
327	very bad things might happen otherwise (usually segfaults).	425	destruction. very bad things might happen otherwise (usually segfaults).
		426
328	- this module is not thread-safe. You should only ever use this module from	427	- this module is not thread-safe. You should only ever use this module
329	the same thread (this requirement might be loosened in the future to	428	from the same thread (this requirement might be losened in the future
330	allow per-thread schedulers, but Coro::State does not yet allow this).	429	to allow per-thread schedulers, but Coro::State does not yet allow
		430	this).
331		431
332	=head1 SEE ALSO	432	=head1 SEE ALSO
333		433
334	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>.
335	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	435
336	L<Coro::Handle>, 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>
337		441
338	=head1 AUTHOR	442	=head1 AUTHOR
339		443
340	Marc Lehmann <pcg@goof.com>	444	Marc Lehmann <schmorp@schmorp.de>
341	http://www.goof.com/pcg/marc/	445	http://home.schmorp.de/
342		446
343	=cut	447	=cut
344		448

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Comparing Coro/Coro.pm (file contents): Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs. Revision 1.95 by root, Sun Dec 3 22:50:06 2006 UTC

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Comparing Coro/Coro.pm (file contents):
Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs.
Revision 1.95 by root, Sun Dec 3 22:50:06 2006 UTC