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

Comparing Coro/Coro.pm (file contents):
Revision 1.25 by root, Wed Jul 25 21:12:57 2001 UTC vs.
Revision 1.84 by root, Sat Nov 25 00:40:26 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;
		36	no warnings "uninitialized";
		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 = 0.12;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
42		45
		46	our $VERSION = '2.5';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
44	@EXPORT_OK = qw($current);	49	our %EXPORT_TAGS = (
		50	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
		51	);
		52	our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
45		53
46	{	54	{
47	my @async;	55	my @async;
		56	my $init;
48		57
49	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
50	sub import {	59	sub import {
		60	no strict 'refs';
		61
51	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
52	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
53	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
54	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
55	my @attrs;	67	my @attrs;
56	for (@_) {	68	for (@_) {
57	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
58	push @async, $ref;	70	push @async, $ref;
		71	unless ($init++) {
		72	eval q{
		73	sub INIT {
		74	&async(pop @async) while @async;
		75	}
		76	};
		77	}
59	} else {	78	} else {
60	push @attrs, $_;	79	push @attrs, $_;
61	}	80	}
62	}	81	}
63	return $old ? $old->($package, $ref, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
64	};	83	};
65	}	84	}
66		85
67	sub INIT {
68	&async(pop @async) while @async;
69	}
70	}	86	}
		87
		88	=over 4
71		89
72	=item $main	90	=item $main
73		91
74	This coroutine represents the main program.	92	This coroutine represents the main program.
75		93
76	=cut	94	=cut
77		95
78	our $main = new Coro;	96	$main = new Coro;
79		97
80	=item $current (or as function: current)	98	=item $current (or as function: current)
81		99
82	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
83		106
84	=cut	107	=cut
85		108
86	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
87	if ($current) {	110	if ($current) {
88	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
89	}	112	}
90		113
91	our $current = $main;	114	$current = $main;
92		115
93	sub current() { $current }	116	sub current() { $current }
94		117
95	=item $idle	118	=item $idle
96		119
97	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
98	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
99		123
100	=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 wakes up some
		126	coroutine.
101		127
102	# should be done using priorities :(	128	=cut
103	our $idle = new Coro sub {	129
		130	$idle = sub {
104	print STDERR "FATAL: deadlock detected\n";	131	print STDERR "FATAL: deadlock detected\n";
105	exit(51);	132	exit (51);
106	};	133	};
107		134
108	# this coroutine is necessary because a coroutine	135	# this coroutine is necessary because a coroutine
109	# cannot destroy itself.	136	# cannot destroy itself.
110	my @destroy;	137	my @destroy;
		138	my $manager;
111	my $manager = new Coro sub {	139	$manager = new Coro sub {
112	while() {	140	while () {
113	delete ((pop @destroy)->{_coro_state}) while @destroy;	141	# by overwriting the state object with the manager we destroy it
		142	# while still being able to schedule this coroutine (in case it has
		143	# been readied multiple times. this is harmless since the manager
		144	# can be called as many times as neccessary and will always
		145	# remove itself from the runqueue
		146	while (@destroy) {
		147	my $coro = pop @destroy;
		148	$coro->{status} \|\|= [];
		149	$_->ready for @{delete $coro->{join} \|\| []};
		150
		151	# the next line destroys the coro state, but keeps the
		152	# process itself intact (we basically make it a zombie
		153	# process that always runs the manager thread, so it's possible
		154	# to transfer() to this process).
		155	$coro->_clone_state_from ($manager);
		156	}
114	&schedule;	157	&schedule;
115	}	158	}
116	};	159	};
117		160
118	# we really need priorities...
119	my @ready; # the ready queue. hehe, rather broken ;)
120
121	# static methods. not really.	161	# static methods. not really.
		162
		163	=back
122		164
123	=head2 STATIC METHODS	165	=head2 STATIC METHODS
124		166
125	Static methods are actually functions that operate on the current process only.	167	Static methods are actually functions that operate on the current process only.
126		168
…		…
129	=item async { ... } [@args...]	171	=item async { ... } [@args...]
130		172
131	Create a new asynchronous process and return it's process object	173	Create a new asynchronous process and return it's process object
132	(usually unused). When the sub returns the new process is automatically	174	(usually unused). When the sub returns the new process is automatically
133	terminated.	175	terminated.
		176
		177	When the coroutine dies, the program will exit, just as in the main
		178	program.
134		179
135	# create a new coroutine that just prints its arguments	180	# create a new coroutine that just prints its arguments
136	async {	181	async {
137	print "@_\n";	182	print "@_\n";
138	} 1,2,3,4;	183	} 1,2,3,4;
139
140	The coderef you submit MUST NOT be a closure that refers to variables
141	in an outer scope. This does NOT work. Pass arguments into it instead.
142		184
143	=cut	185	=cut
144		186
145	sub async(&@) {	187	sub async(&@) {
146	my $pid = new Coro @_;	188	my $pid = new Coro @_;
…		…
155	into the ready queue, so calling this function usually means you will	197	into the ready queue, so calling this function usually means you will
156	never be called again.	198	never be called again.
157		199
158	=cut	200	=cut
159		201
160	my $prev;
161
162	sub schedule {
163	# should be done using priorities :(
164	($prev, $current) = ($current, shift @ready \|\| $idle);
165	Coro::State::transfer($prev, $current);
166	}
167
168	=item cede	202	=item cede
169		203
170	"Cede" to other processes. This function puts the current process into the	204	"Cede" to other processes. This function puts the current process into the
171	ready queue and calls C<schedule>, which has the effect of giving up the	205	ready queue and calls C<schedule>, which has the effect of giving up the
172	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
173		207
174	=cut	208	=cut
175		209
176	sub cede {
177	$current->ready;
178	&schedule;
179	}
180
181	=item terminate	210	=item terminate [arg...]
182		211
183	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
184
185	Future versions of this function will allow result arguments.
186		213
187	=cut	214	=cut
188		215
189	sub terminate {	216	sub terminate {
190	push @destroy, $current;	217	$current->cancel (@_);
191	$manager->ready;
192	&schedule;
193	# NORETURN
194	}	218	}
195		219
196	=back	220	=back
197		221
198	# dynamic methods	222	# dynamic methods
…		…
204	=over 4	228	=over 4
205		229
206	=item new Coro \&sub [, @args...]	230	=item new Coro \&sub [, @args...]
207		231
208	Create a new process and return it. When the sub returns the process	232	Create a new process and return it. When the sub returns the process
209	automatically terminates. To start the process you must first put it into	233	automatically terminates as if C<terminate> with the returned values were
		234	called. To make the process run you must first put it into the ready queue
210	the ready queue by calling the ready method.	235	by calling the ready method.
211		236
212	The coderef you submit MUST NOT be a closure that refers to variables
213	in an outer scope. This does NOT work. Pass arguments into it instead.
214
215	=cut	237	=cut
216		238
217	sub _newcoro {	239	sub _new_coro {
		240	# $current->_clear_idle_sp; # set the idle sp on the following cede
		241	_set_cede_self; # ensures that cede cede's us first
		242	cede;
218	terminate &{+shift};	243	terminate &{+shift};
219	}	244	}
220		245
221	sub new {	246	sub new {
222	my $class = shift;	247	my $class = shift;
223	bless {	248
224	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),	249	$class->SUPER::new (\&_new_coro, @_)
225	}, $class;
226	}	250	}
227		251
228	=item $process->ready	252	=item $process->ready
229		253
230	Put the current process into the ready queue.	254	Put the given process into the ready queue.
231		255
232	=cut	256	=cut
233		257
234	sub ready {	258	=item $process->cancel (arg...)
235	push @ready, $_[0];	259
		260	Terminates the given process and makes it return the given arguments as
		261	status (default: the empty list).
		262
		263	=cut
		264
		265	sub cancel {
		266	my $self = shift;
		267	$self->{status} = [@_];
		268	push @destroy, $self;
		269	$manager->ready;
		270	&schedule if $current == $self;
		271	}
		272
		273	=item $process->join
		274
		275	Wait until the coroutine terminates and return any values given to the
		276	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		277	from multiple processes.
		278
		279	=cut
		280
		281	sub join {
		282	my $self = shift;
		283	unless ($self->{status}) {
		284	push @{$self->{join}}, $current;
		285	&schedule;
		286	}
		287	wantarray ? @{$self->{status}} : $self->{status}[0];
		288	}
		289
		290	=item $oldprio = $process->prio ($newprio)
		291
		292	Sets (or gets, if the argument is missing) the priority of the
		293	process. Higher priority processes get run before lower priority
		294	processes. Priorities are small signed integers (currently -4 .. +3),
		295	that you can refer to using PRIO_xxx constants (use the import tag :prio
		296	to get then):
		297
		298	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		299	3 > 1 > 0 > -1 > -3 > -4
		300
		301	# set priority to HIGH
		302	current->prio(PRIO_HIGH);
		303
		304	The idle coroutine ($Coro::idle) always has a lower priority than any
		305	existing coroutine.
		306
		307	Changing the priority of the current process will take effect immediately,
		308	but changing the priority of processes in the ready queue (but not
		309	running) will only take effect after the next schedule (of that
		310	process). This is a bug that will be fixed in some future version.
		311
		312	=item $newprio = $process->nice ($change)
		313
		314	Similar to C<prio>, but subtract the given value from the priority (i.e.
		315	higher values mean lower priority, just as in unix).
		316
		317	=item $olddesc = $process->desc ($newdesc)
		318
		319	Sets (or gets in case the argument is missing) the description for this
		320	process. This is just a free-form string you can associate with a process.
		321
		322	=cut
		323
		324	sub desc {
		325	my $old = $_[0]{desc};
		326	$_[0]{desc} = $_[1] if @_ > 1;
		327	$old;
236	}	328	}
237		329
238	=back	330	=back
239		331
240	=cut	332	=cut
241		333
242	1;	334	1;
243		335
244	=head1 BUGS/LIMITATIONS	336	=head1 BUGS/LIMITATIONS
245		337
246	- could be faster, especially when the core would introduce special	338	- you must make very sure that no coro is still active on global
247	support for coroutines (like it does for threads).	339	destruction. very bad things might happen otherwise (usually segfaults).
248	- there is still a memleak on coroutine termination that I could not	340
249	identify. Could be as small as a single SV.
250	- this module is not well-tested.
251	- if variables or arguments "disappear" (become undef) or become
252	corrupted please contact the author so he cen iron out the
253	remaining bugs.
254	- this module is not thread-safe. You must only ever use this module from	341	- this module is not thread-safe. You should only ever use this module
255	the same thread (this requirement might be loosened in the future to	342	from the same thread (this requirement might be losened in the future
256	allow per-thread schedulers, but Coro::State does not yet allow this).	343	to allow per-thread schedulers, but Coro::State does not yet allow
		344	this).
257		345
258	=head1 SEE ALSO	346	=head1 SEE ALSO
259		347
260	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	348	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
261	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	349
262	L<Coro::L<Coro::Handle>, L<Coro::Socket>.	350	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		351
		352	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		353
		354	Embedding: L<Coro:MakeMaker>
263		355
264	=head1 AUTHOR	356	=head1 AUTHOR
265		357
266	Marc Lehmann <pcg@goof.com>	358	Marc Lehmann <schmorp@schmorp.de>
267	http://www.goof.com/pcg/marc/	359	http://home.schmorp.de/
268		360
269	=cut	361	=cut
270		362

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Comparing Coro/Coro.pm (file contents): Revision 1.25 by root, Wed Jul 25 21:12:57 2001 UTC vs. Revision 1.84 by root, Sat Nov 25 00:40:26 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.25 by root, Wed Jul 25 21:12:57 2001 UTC vs.
Revision 1.84 by root, Sat Nov 25 00:40:26 2006 UTC