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

Comparing Coro/Coro.pm (file contents):
Revision 1.36 by root, Mon Sep 24 01:36:20 2001 UTC vs.
Revision 1.91 by root, Fri Dec 1 02:17:37 2006 UTC

…		…
19	cede;	19	cede;
20		20
21	=head1 DESCRIPTION	21	=head1 DESCRIPTION
22		22
23	This module collection manages coroutines. Coroutines are similar to	23	This module collection manages coroutines. Coroutines are similar to
24	Threads but don't run in parallel.	24	threads but don't run in parallel.
25
26	This module is still experimental, see the BUGS section below.
27		25
28	In this module, coroutines are defined as "callchain + lexical variables	26	In this module, coroutines are defined as "callchain + lexical variables
29	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own	27	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30	callchain, it's own set of lexicals and it's own set of perl's most	28	callchain, it's own set of lexicals and it's own set of perl's most
31	important global variables.	29	important global variables.
32		30
33	=cut	31	=cut
34		32
35	package Coro;	33	package Coro;
36		34
		35	use strict;
37	no warnings qw(uninitialized);	36	no warnings "uninitialized";
38		37
39	use Coro::State;	38	use Coro::State;
40		39
41	use base Exporter;	40	use base qw(Coro::State Exporter);
42		41
43	$VERSION = 0.5;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
44		45
		46	our $VERSION = '3.0';
		47
45	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
46	%EXPORT_TAGS = (	49	our %EXPORT_TAGS = (
47	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],	50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48	);	51	);
49	@EXPORT_OK = @{$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 (@_) {
…		…
77	};	83	};
78	}	84	}
79		85
80	}	86	}
81		87
		88	=over 4
		89
82	=item $main	90	=item $main
83		91
84	This coroutine represents the main program.	92	This coroutine represents the main program.
85		93
86	=cut	94	=cut
87		95
88	our $main = new Coro;	96	$main = new Coro;
89		97
90	=item $current (or as function: current)	98	=item $current (or as function: current)
91		99
92	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
93		106
94	=cut	107	=cut
95		108
96	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
97	if ($current) {	110	if ($current) {
98	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
99	}	112	}
100		113
101	our $current = $main;	114	$current = $main;
102		115
103	sub current() { $current }	116	sub current() { $current }
104		117
105	=item $idle	118	=item $idle
106		119
107	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
108	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.
109		123
110	=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.
111		127
112	# should be done using priorities :(	128	Please note that if your callback recursively invokes perl (e.g. for event
113	our $idle = new Coro sub {	129	handlers), then it must be prepared to be called recursively.
		130
		131	=cut
		132
		133	$idle = sub {
114	print STDERR "FATAL: deadlock detected\n";	134	print STDERR "FATAL: deadlock detected\n";
115	exit(51);	135	exit (51);
116	};	136	};
117		137
118	# this coroutine is necessary because a coroutine	138	# this coroutine is necessary because a coroutine
119	# cannot destroy itself.	139	# cannot destroy itself.
120	my @destroy;	140	my @destroy;
121	my $manager = new Coro sub {	141	my $manager; $manager = new Coro sub {
122	while() {	142	while () {
123	delete ((pop @destroy)->{_coro_state}) while @destroy;	143	# by overwriting the state object with the manager we destroy it
		144	# while still being able to schedule this coroutine (in case it has
		145	# been readied multiple times. this is harmless since the manager
		146	# can be called as many times as neccessary and will always
		147	# remove itself from the runqueue
		148	while (@destroy) {
		149	my $coro = pop @destroy;
		150	$coro->{status} \|\|= [];
		151	$_->ready for @{delete $coro->{join} \|\| []};
		152
		153	# the next line destroys the coro state, but keeps the
		154	# process itself intact (we basically make it a zombie
		155	# process that always runs the manager thread, so it's possible
		156	# to transfer() to this process).
		157	$coro->_clone_state_from ($manager);
		158	}
124	&schedule;	159	&schedule;
125	}	160	}
126	};	161	};
127		162
128	# static methods. not really.	163	# static methods. not really.
129		164
		165	=back
		166
130	=head2 STATIC METHODS	167	=head2 STATIC METHODS
131		168
132	Static methods are actually functions that operate on the current process only.	169	Static methods are actually functions that operate on the current process only.
133		170
134	=over 4	171	=over 4
…		…
136	=item async { ... } [@args...]	173	=item async { ... } [@args...]
137		174
138	Create a new asynchronous process and return it's process object	175	Create a new asynchronous process and return it's process object
139	(usually unused). When the sub returns the new process is automatically	176	(usually unused). When the sub returns the new process is automatically
140	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.
141		183
142	# create a new coroutine that just prints its arguments	184	# create a new coroutine that just prints its arguments
143	async {	185	async {
144	print "@_\n";	186	print "@_\n";
145	} 1,2,3,4;	187	} 1,2,3,4;
146		188
147	The coderef you submit MUST NOT be a closure that refers to variables
148	in an outer scope. This does NOT work. Pass arguments into it instead.
149
150	=cut	189	=cut
151		190
152	sub async(&@) {	191	sub async(&@) {
153	my $pid = new Coro @_;	192	my $pid = new Coro @_;
154	$manager->ready; # this ensures that the stack is cloned from the manager
155	$pid->ready;	193	$pid->ready;
156	$pid;	194	$pid
157	}	195	}
158		196
159	=item schedule	197	=item schedule
160		198
161	Calls the scheduler. Please note that the current process will not be put	199	Calls the scheduler. Please note that the current process will not be put
162	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
163	never be called again.	201	never be called again unless something else (e.g. an event handler) calls
		202	ready.
		203
		204	The canonical way to wait on external events is this:
		205
		206	{
		207	# remember current process
		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	}
164		222
165	=cut	223	=cut
166		224
167	=item cede	225	=item cede
168		226
…		…
170	ready queue and calls C<schedule>, which has the effect of giving up the	228	ready queue and calls C<schedule>, which has the effect of giving up the
171	current "timeslice" to other coroutines of the same or higher priority.	229	current "timeslice" to other coroutines of the same or higher priority.
172		230
173	=cut	231	=cut
174		232
175	=item terminate	233	=item terminate [arg...]
176		234
177	Terminates the current process.	235	Terminates the current process with the given status values (see L<cancel>).
178
179	Future versions of this function will allow result arguments.
180		236
181	=cut	237	=cut
182		238
183	sub terminate {	239	sub terminate {
184	$current->cancel;	240	$current->cancel (@_);
185	&schedule;
186	die; # NORETURN
187	}	241	}
188		242
189	=back	243	=back
190		244
191	# dynamic methods	245	# dynamic methods
…		…
197	=over 4	251	=over 4
198		252
199	=item new Coro \&sub [, @args...]	253	=item new Coro \&sub [, @args...]
200		254
201	Create a new process and return it. When the sub returns the process	255	Create a new process and return it. When the sub returns the process
202	automatically terminates. To start the process you must first put it into	256	automatically terminates as if C<terminate> with the returned values were
		257	called. To make the process run you must first put it into the ready queue
203	the ready queue by calling the ready method.	258	by calling the ready method.
204		259
205	The coderef you submit MUST NOT be a closure that refers to variables	260	Calling C<exit> in a coroutine will not work correctly, so do not do that.
206	in an outer scope. This does NOT work. Pass arguments into it instead.
207		261
208	=cut	262	=cut
209		263
210	sub _newcoro {	264	sub _new_coro {
211	terminate &{+shift};	265	terminate &{+shift};
212	}	266	}
213		267
214	sub new {	268	sub new {
215	my $class = shift;	269	my $class = shift;
216	bless {
217	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
218	}, $class;
219	}
220		270
		271	$class->SUPER::new (\&_new_coro, @_)
		272	}
		273
221	=item $process->ready	274	=item $success = $process->ready
222		275
223	Put the current process into the ready queue.	276	Put the given process into the ready queue (according to it's priority)
		277	and return true. If the process is already in the ready queue, do nothing
		278	and return false.
224		279
225	=cut	280	=item $is_ready = $process->is_ready
226		281
		282	Return wether the process is currently the ready queue or not,
		283
227	=item $process->cancel	284	=item $process->cancel (arg...)
228		285
229	Like C<terminate>, but terminates the specified process instead.	286	Terminates the given process and makes it return the given arguments as
		287	status (default: the empty list).
230		288
231	=cut	289	=cut
232		290
233	sub cancel {	291	sub cancel {
		292	my $self = shift;
		293	$self->{status} = [@_];
234	push @destroy, $_[0];	294	push @destroy, $self;
235	$manager->ready;	295	$manager->ready;
236	&schedule if $current == $_[0];	296	&schedule if $current == $self;
237	}	297	}
238		298
		299	=item $process->join
		300
		301	Wait until the coroutine terminates and return any values given to the
		302	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		303	from multiple processes.
		304
		305	=cut
		306
		307	sub join {
		308	my $self = shift;
		309	unless ($self->{status}) {
		310	push @{$self->{join}}, $current;
		311	&schedule;
		312	}
		313	wantarray ? @{$self->{status}} : $self->{status}[0];
		314	}
		315
239	=item $oldprio = $process->prio($newprio)	316	=item $oldprio = $process->prio ($newprio)
240		317
241	Sets the priority of the process. Higher priority processes get run before	318	Sets (or gets, if the argument is missing) the priority of the
		319	process. Higher priority processes get run before lower priority
242	lower priority processes. Priorities are smalled signed integer (currently	320	processes. Priorities are small signed integers (currently -4 .. +3),
243	-4 .. +3), that you can refer to using PRIO_xxx constants (use the import	321	that you can refer to using PRIO_xxx constants (use the import tag :prio
244	tag :prio to get then):	322	to get then):
245		323
246	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN	324	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
247	3 > 1 > 0 > -1 > -3 > -4	325	3 > 1 > 0 > -1 > -3 > -4
248		326
249	# set priority to HIGH	327	# set priority to HIGH
…		…
255	Changing the priority of the current process will take effect immediately,	333	Changing the priority of the current process will take effect immediately,
256	but changing the priority of processes in the ready queue (but not	334	but changing the priority of processes in the ready queue (but not
257	running) will only take effect after the next schedule (of that	335	running) will only take effect after the next schedule (of that
258	process). This is a bug that will be fixed in some future version.	336	process). This is a bug that will be fixed in some future version.
259		337
260	=cut
261
262	sub prio {
263	my $old = $_[0]{prio};
264	$_[0]{prio} = $_[1] if @_ > 1;
265	$old;
266	}
267
268	=item $newprio = $process->nice($change)	338	=item $newprio = $process->nice ($change)
269		339
270	Similar to C<prio>, but subtract the given value from the priority (i.e.	340	Similar to C<prio>, but subtract the given value from the priority (i.e.
271	higher values mean lower priority, just as in unix).	341	higher values mean lower priority, just as in unix).
272		342
273	=cut	343	=item $olddesc = $process->desc ($newdesc)
274		344
275	sub nice {	345	Sets (or gets in case the argument is missing) the description for this
276	$_[0]{prio} -= $_[1];	346	process. This is just a free-form string you can associate with a process.
		347
		348	=cut
		349
		350	sub desc {
		351	my $old = $_[0]{desc};
		352	$_[0]{desc} = $_[1] if @_ > 1;
		353	$old;
277	}	354	}
278		355
279	=back	356	=back
280		357
281	=cut	358	=cut
282		359
283	1;	360	1;
284		361
285	=head1 BUGS/LIMITATIONS	362	=head1 BUGS/LIMITATIONS
286		363
287	- you must make very sure that no coro is still active on global destruction.	364	- you must make very sure that no coro is still active on global
288	very bad things might happen otherwise (usually segfaults).	365	destruction. very bad things might happen otherwise (usually segfaults).
		366
289	- this module is not thread-safe. You must only ever use this module from	367	- this module is not thread-safe. You should only ever use this module
290	the same thread (this requirement might be loosened in the future to	368	from the same thread (this requirement might be losened in the future
291	allow per-thread schedulers, but Coro::State does not yet allow this).	369	to allow per-thread schedulers, but Coro::State does not yet allow
		370	this).
292		371
293	=head1 SEE ALSO	372	=head1 SEE ALSO
294		373
295	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	374	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
296	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	375
297	L<Coro::Handle>, L<Coro::Socket>.	376	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		377
		378	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		379
		380	Embedding: L<Coro:MakeMaker>
298		381
299	=head1 AUTHOR	382	=head1 AUTHOR
300		383
301	Marc Lehmann <pcg@goof.com>	384	Marc Lehmann <schmorp@schmorp.de>
302	http://www.goof.com/pcg/marc/	385	http://home.schmorp.de/
303		386
304	=cut	387	=cut
305		388

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Comparing Coro/Coro.pm (file contents): Revision 1.36 by root, Mon Sep 24 01:36:20 2001 UTC vs. Revision 1.91 by root, Fri Dec 1 02:17:37 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.36 by root, Mon Sep 24 01:36:20 2001 UTC vs.
Revision 1.91 by root, Fri Dec 1 02:17:37 2006 UTC