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

Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs.
Revision 1.92 by root, Fri Dec 1 03:47:55 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 $VERSION = '3.0';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current unblock_sub);
44	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
45	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46	);	51	);
47	@EXPORT_OK = @{$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) {	110	if ($current) {
96	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
97	}	112	}
98		113
99	our $current = $main;	114	$current = $main;
100		115
101	sub current() { $current }	116	sub current() { $current }
102		117
103	=item $idle	118	=item $idle
104		119
105	The coroutine to switch to when no other coroutine is running. The default	120	A callback that is called whenever the scheduler finds no ready coroutines
106	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits, because the program has no other way to continue.
107		123
108	=cut	124	This hook is overwritten by modules such as C<Coro::Timer> and
		125	C<Coro::Event> to wait on an external event that hopefully wake up a
		126	coroutine so the scheduler can run it.
109		127
110	# should be done using priorities :(	128	Please note that if your callback recursively invokes perl (e.g. for event
111	our $idle = new Coro sub {	129	handlers), then it must be prepared to be called recursively.
		130
		131	=cut
		132
		133	$idle = sub {
112	print STDERR "FATAL: deadlock detected\n";	134	print STDERR "FATAL: deadlock detected\n";
113	exit(51);	135	exit (51);
114	};	136	};
115		137
116	# this coroutine is necessary because a coroutine	138	# this coroutine is necessary because a coroutine
117	# cannot destroy itself.	139	# cannot destroy itself.
118	my @destroy;	140	my @destroy;
119	my $manager;
120	$manager = new Coro sub {	141	my $manager; $manager = new Coro sub {
121	while() {	142	while () {
122	# by overwriting the state object with the manager we destroy it	143	# by overwriting the state object with the manager we destroy it
123	# while still being able to schedule this coroutine (in case it has	144	# while still being able to schedule this coroutine (in case it has
124	# been readied multiple times. this is harmless since the manager	145	# been readied multiple times. this is harmless since the manager
125	# can be called as many times as neccessary and will always	146	# can be called as many times as neccessary and will always
126	# remove itself from the runqueue	147	# remove itself from the runqueue
127	while (@destroy) {	148	while (@destroy) {
128	my $coro = pop @destroy;	149	my $coro = pop @destroy;
129	$coro->{status} \|\|= [];	150	$coro->{status} \|\|= [];
130	$_->ready for @{delete $coro->{join} \|\| []};	151	$_->ready for @{delete $coro->{join} \|\| []};
131	$coro->{_coro_state} = $manager->{_coro_state};	152
		153	# the next line destroys the coro state, but keeps the
		154	# coroutine itself intact (we basically make it a zombie
		155	# coroutine that always runs the manager thread, so it's possible
		156	# to transfer() to this coroutine).
		157	$coro->_clone_state_from ($manager);
132	}	158	}
133	&schedule;	159	&schedule;
134	}	160	}
135	};	161	};
136		162
137	# static methods. not really.	163	# static methods. not really.
138		164
		165	=back
		166
139	=head2 STATIC METHODS	167	=head2 STATIC METHODS
140		168
141	Static methods are actually functions that operate on the current process only.	169	Static methods are actually functions that operate on the current coroutine only.
142		170
143	=over 4	171	=over 4
144		172
145	=item async { ... } [@args...]	173	=item async { ... } [@args...]
146		174
147	Create a new asynchronous process and return it's process object	175	Create a new asynchronous coroutine and return it's coroutine object
148	(usually unused). When the sub returns the new process is automatically	176	(usually unused). When the sub returns the new coroutine is automatically
149	terminated.	177	terminated.
		178
		179	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		180
		181	When the coroutine dies, the program will exit, just as in the main
		182	program.
150		183
151	# create a new coroutine that just prints its arguments	184	# create a new coroutine that just prints its arguments
152	async {	185	async {
153	print "@_\n";	186	print "@_\n";
154	} 1,2,3,4;	187	} 1,2,3,4;
155		188
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	189	=cut
160		190
161	sub async(&@) {	191	sub async(&@) {
162	my $pid = new Coro @_;	192	my $pid = new Coro @_;
163	$manager->ready; # this ensures that the stack is cloned from the manager
164	$pid->ready;	193	$pid->ready;
165	$pid;	194	$pid
166	}	195	}
167		196
168	=item schedule	197	=item schedule
169		198
170	Calls the scheduler. Please note that the current process will not be put	199	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	200	into the ready queue, so calling this function usually means you will
172	never be called again.	201	never be called again unless something else (e.g. an event handler) calls
		202	ready.
173		203
174	=cut	204	The canonical way to wait on external events is this:
		205
		206	{
		207	# remember current coroutine
		208	my $current = $Coro::current;
		209
		210	# register a hypothetical event handler
		211	on_event_invoke sub {
		212	# wake up sleeping coroutine
		213	$current->ready;
		214	undef $current;
		215	};
		216
		217	# call schedule until event occured.
		218	# in case we are woken up for other reasons
		219	# (current still defined), loop.
		220	Coro::schedule while $current;
		221	}
175		222
176	=item cede	223	=item cede
177		224
178	"Cede" to other processes. This function puts the current process into the	225	"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	226	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.	227	current "timeslice" to other coroutines of the same or higher priority.
181		228
182	=cut
183
184	=item terminate [arg...]	229	=item terminate [arg...]
185		230
186	Terminates the current process.	231	Terminates the current coroutine with the given status values (see L<cancel>).
187
188	Future versions of this function will allow result arguments.
189		232
190	=cut	233	=cut
191		234
192	sub terminate {	235	sub terminate {
193	$current->{status} = [@_];
194	$current->cancel;	236	$current->cancel (@_);
195	&schedule;
196	die; # NORETURN
197	}	237	}
198		238
199	=back	239	=back
200		240
201	# dynamic methods	241	# dynamic methods
202		242
203	=head2 PROCESS METHODS	243	=head2 COROUTINE METHODS
204		244
205	These are the methods you can call on process objects.	245	These are the methods you can call on coroutine objects.
206		246
207	=over 4	247	=over 4
208		248
209	=item new Coro \&sub [, @args...]	249	=item new Coro \&sub [, @args...]
210		250
211	Create a new process and return it. When the sub returns the process	251	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	252	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	253	called. To make the coroutine run you must first put it into the ready queue
214	by calling the ready method.	254	by calling the ready method.
215		255
216	=cut	256	Calling C<exit> in a coroutine will not work correctly, so do not do that.
217		257
		258	=cut
		259
218	sub _newcoro {	260	sub _new_coro {
219	terminate &{+shift};	261	terminate &{+shift};
220	}	262	}
221		263
222	sub new {	264	sub new {
223	my $class = shift;	265	my $class = shift;
224	bless {
225	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
226	}, $class;
227	}
228		266
229	=item $process->ready	267	$class->SUPER::new (\&_new_coro, @_)
		268	}
230		269
231	Put the given process into the ready queue.	270	=item $success = $coroutine->ready
232		271
233	=cut	272	Put the given coroutine into the ready queue (according to it's priority)
		273	and return true. If the coroutine is already in the ready queue, do nothing
		274	and return false.
234		275
235	=item $process->cancel	276	=item $is_ready = $coroutine->is_ready
236		277
237	Like C<terminate>, but terminates the specified process instead.	278	Return wether the coroutine is currently the ready queue or not,
		279
		280	=item $coroutine->cancel (arg...)
		281
		282	Terminates the given coroutine and makes it return the given arguments as
		283	status (default: the empty list).
238		284
239	=cut	285	=cut
240		286
241	sub cancel {	287	sub cancel {
		288	my $self = shift;
		289	$self->{status} = [@_];
242	push @destroy, $_[0];	290	push @destroy, $self;
243	$manager->ready;	291	$manager->ready;
244	&schedule if $current == $_[0];	292	&schedule if $current == $self;
245	}	293	}
246		294
247	=item $process->join	295	=item $coroutine->join
248		296
249	Wait until the coroutine terminates and return any values given to the	297	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	298	C<terminate> or C<cancel> functions. C<join> can be called multiple times
251	processes.	299	from multiple coroutine.
252		300
253	=cut	301	=cut
254		302
255	sub join {	303	sub join {
256	my $self = shift;	304	my $self = shift;
…		…
259	&schedule;	307	&schedule;
260	}	308	}
261	wantarray ? @{$self->{status}} : $self->{status}[0];	309	wantarray ? @{$self->{status}} : $self->{status}[0];
262	}	310	}
263		311
264	=item $oldprio = $process->prio($newprio)	312	=item $oldprio = $coroutine->prio ($newprio)
265		313
266	Sets (or gets, if the argument is missing) the priority of the	314	Sets (or gets, if the argument is missing) the priority of the
267	process. Higher priority processes get run before lower priority	315	coroutine. Higher priority coroutines get run before lower priority
268	processes. Priorities are smalled signed integer (currently -4 .. +3),	316	coroutines. Priorities are small signed integers (currently -4 .. +3),
269	that you can refer to using PRIO_xxx constants (use the import tag :prio	317	that you can refer to using PRIO_xxx constants (use the import tag :prio
270	to get then):	318	to get then):
271		319
272	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	320	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
273	3 > 1 > 0 > -1 > -3 > -4	321	3 > 1 > 0 > -1 > -3 > -4
…		…
276	current->prio(PRIO_HIGH);	324	current->prio(PRIO_HIGH);
277		325
278	The idle coroutine ($Coro::idle) always has a lower priority than any	326	The idle coroutine ($Coro::idle) always has a lower priority than any
279	existing coroutine.	327	existing coroutine.
280		328
281	Changing the priority of the current process will take effect immediately,	329	Changing the priority of the current coroutine will take effect immediately,
282	but changing the priority of processes in the ready queue (but not	330	but changing the priority of coroutines in the ready queue (but not
283	running) will only take effect after the next schedule (of that	331	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.	332	coroutine). This is a bug that will be fixed in some future version.
285		333
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)	334	=item $newprio = $coroutine->nice ($change)
295		335
296	Similar to C<prio>, but subtract the given value from the priority (i.e.	336	Similar to C<prio>, but subtract the given value from the priority (i.e.
297	higher values mean lower priority, just as in unix).	337	higher values mean lower priority, just as in unix).
298		338
299	=cut
300
301	sub nice {
302	$_[0]{prio} -= $_[1];
303	}
304
305	=item $olddesc = $process->desc($newdesc)	339	=item $olddesc = $coroutine->desc ($newdesc)
306		340
307	Sets (or gets in case the argument is missing) the description for this	341	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.	342	coroutine. This is just a free-form string you can associate with a coroutine.
309		343
310	=cut	344	=cut
311		345
312	sub desc {	346	sub desc {
313	my $old = $_[0]{desc};	347	my $old = $_[0]{desc};
…		…
315	$old;	349	$old;
316	}	350	}
317		351
318	=back	352	=back
319		353
		354	=head2 UTILITY FUNCTIONS
		355
		356	=over 4
		357
		358	=item unblock_sub { ... }
		359
		360	This utility function takes a BLOCK or code reference and "unblocks" it,
		361	returning the new coderef. This means that the new coderef will return
		362	immediately without blocking, returning nothing, while the original code
		363	ref will be called (with parameters) from within its own coroutine.
		364
		365	The reason this fucntion exists is that many event libraries (such as the
		366	venerable L<Event\|Event> module) are not coroutine-safe (a weaker form
		367	of thread-safety). This means you must not block within event callbacks,
		368	otherwise you might suffer from crashes or worse.
		369
		370	This function allows your callbacks to block by executing them in another
		371	coroutine where it is safe to block. One example where blocking is handy
		372	is when you use the L<Coro::AIO\|Coro::AIO> functions to save results to
		373	disk.
		374
		375	In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
		376	creating event callbacks that want to block.
		377
		378	=cut
		379
		380	our @unblock_pool;
		381	our @unblock_queue;
		382	our $UNBLOCK_POOL_SIZE = 2;
		383
		384	sub unblock_handler_ {
		385	while () {
		386	my ($cb, @arg) = @{ delete $Coro::current->{arg} };
		387	$cb->(@arg);
		388
		389	last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
		390	push @unblock_pool, $Coro::current;
		391	schedule;
		392	}
		393	}
		394
		395	our $unblock_scheduler = async {
		396	while () {
		397	while (my $cb = pop @unblock_queue) {
		398	my $handler = (pop @unblock_pool or new Coro \&unblock_handler_);
		399	$handler->{arg} = $cb;
		400	$handler->ready;
		401	cede;
		402	}
		403
		404	schedule;
		405	}
		406	};
		407
		408	sub unblock_sub(&) {
		409	my $cb = shift;
		410
		411	sub {
		412	push @unblock_queue, [$cb, @_];
		413	$unblock_scheduler->ready;
		414	}
		415	}
		416
		417	=back
		418
320	=cut	419	=cut
321		420
322	1;	421	1;
323		422
324	=head1 BUGS/LIMITATIONS	423	=head1 BUGS/LIMITATIONS
325		424
326	- you must make very sure that no coro is still active on global destruction.	425	- you must make very sure that no coro is still active on global
327	very bad things might happen otherwise (usually segfaults).	426	destruction. very bad things might happen otherwise (usually segfaults).
		427
328	- this module is not thread-safe. You should only ever use this module from	428	- 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	429	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).	430	to allow per-thread schedulers, but Coro::State does not yet allow
		431	this).
331		432
332	=head1 SEE ALSO	433	=head1 SEE ALSO
333		434
334	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	435	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>,	436
336	L<Coro::Handle>, L<Coro::Socket>.	437	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		438
		439	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		440
		441	Embedding: L<Coro:MakeMaker>
337		442
338	=head1 AUTHOR	443	=head1 AUTHOR
339		444
340	Marc Lehmann <pcg@goof.com>	445	Marc Lehmann <schmorp@schmorp.de>
341	http://www.goof.com/pcg/marc/	446	http://home.schmorp.de/
342		447
343	=cut	448	=cut
344		449

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Comparing cvsroot/Coro/Coro.pm (file contents): Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs. Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC

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Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC vs.
Revision 1.92 by root, Fri Dec 1 03:47:55 2006 UTC