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

Comparing Coro/Coro.pm (file contents):
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs.
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 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), that is, a coroutine has it's own callchain, it's	27	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30	own set of lexicals and it's own set of perl's most important global	28	callchain, it's own set of lexicals and it's own set of perl's most
31	variables.	29	important global variables.
32
33	WARNING: When using this module, make sure that, at program end, no
34	coroutines are still running OR just call exit before falling off the
35	end. The reason for this is that some coroutine of yours might have called
36	into a C function, and falling off the end of main:: results in returning
37	to that C function instead if to the main C interpreter.
38
39	WARNING: Unless you really know what you are doing, do NOT do context
40	switches inside callbacks from the XS level. The reason for this is
41	similar to the reason above: A callback calls a perl function, this
42	perl function does a context switch, some other callback is called, the
43	original function returns from it - to what? To the wrong XS function,
44	with totally different return values. Unfortunately, this includes
45	callbacks done by perl itself (tie'd variables!).
46
47	The only workaround for this is to do coroutines on C level.
48		30
49	=cut	31	=cut
50		32
51	package Coro;	33	package Coro;
52		34
		35	BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
		36
53	use Coro::State;	37	use Coro::State;
54		38
		39	use vars qw($idle $main $current);
		40
55	use base Exporter;	41	use base Exporter;
56		42
57	$VERSION = 0.10;	43	$VERSION = 0.8;
58		44
59	@EXPORT = qw(async cede schedule terminate current);	45	@EXPORT = qw(async cede schedule terminate current);
60	@EXPORT_OK = qw($current);	46	%EXPORT_TAGS = (
		47	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
		48	);
		49	@EXPORT_OK = @{$EXPORT_TAGS{prio}};
61		50
62	{	51	{
63	my @async;	52	my @async;
		53	my $init;
64		54
65	# this way of handling attributes simply is NOT scalable ;()	55	# this way of handling attributes simply is NOT scalable ;()
66	sub import {	56	sub import {
67	Coro->export_to_level(1, @_);	57	Coro->export_to_level(1, @_);
68	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	58	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
…		…
70	my ($package, $ref) = (shift, shift);	60	my ($package, $ref) = (shift, shift);
71	my @attrs;	61	my @attrs;
72	for (@_) {	62	for (@_) {
73	if ($_ eq "Coro") {	63	if ($_ eq "Coro") {
74	push @async, $ref;	64	push @async, $ref;
		65	unless ($init++) {
		66	eval q{
		67	sub INIT {
		68	&async(pop @async) while @async;
		69	}
		70	};
		71	}
75	} else {	72	} else {
76	push @attrs, $_;	73	push @attrs, $_;
77	}	74	}
78	}	75	}
79	return $old ? $old->($package, $ref, @attrs) : @attrs;	76	return $old ? $old->($package, $ref, @attrs) : @attrs;
80	};	77	};
81	}	78	}
82		79
83	sub INIT {
84	&async(pop @async) while @async;
85	}
86	}	80	}
		81
		82	=over 4
87		83
88	=item $main	84	=item $main
89		85
90	This coroutine represents the main program.	86	This coroutine represents the main program.
91		87
92	=cut	88	=cut
93		89
94	our $main = new Coro;	90	$main = new Coro;
95		91
96	=item $current (or as function: current)	92	=item $current (or as function: current)
97		93
98	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	94	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
99		95
…		…
102	# maybe some other module used Coro::Specific before...	98	# maybe some other module used Coro::Specific before...
103	if ($current) {	99	if ($current) {
104	$main->{specific} = $current->{specific};	100	$main->{specific} = $current->{specific};
105	}	101	}
106		102
107	our $current = $main;	103	$current = $main;
108		104
109	sub current() { $current }	105	sub current() { $current }
110		106
111	=item $idle	107	=item $idle
112		108
…		…
114	implementation prints "FATAL: deadlock detected" and exits.	110	implementation prints "FATAL: deadlock detected" and exits.
115		111
116	=cut	112	=cut
117		113
118	# should be done using priorities :(	114	# should be done using priorities :(
119	our $idle = new Coro sub {	115	$idle = new Coro sub {
120	print STDERR "FATAL: deadlock detected\n";	116	print STDERR "FATAL: deadlock detected\n";
121	exit(51);	117	exit(51);
122	};	118	};
123		119
124	# we really need priorities...	120	# this coroutine is necessary because a coroutine
125	my @ready; # the ready queue. hehe, rather broken ;)	121	# cannot destroy itself.
		122	my @destroy;
		123	my $manager;
		124	$manager = new Coro sub {
		125	while() {
		126	# by overwriting the state object with the manager we destroy it
		127	# while still being able to schedule this coroutine (in case it has
		128	# been readied multiple times. this is harmless since the manager
		129	# can be called as many times as neccessary and will always
		130	# remove itself from the runqueue
		131	while (@destroy) {
		132	my $coro = pop @destroy;
		133	$coro->{status} \|\|= [];
		134	$_->ready for @{delete $coro->{join} \|\| []};
		135	$coro->{_coro_state} = $manager->{_coro_state};
		136	}
		137	&schedule;
		138	}
		139	};
126		140
127	# static methods. not really.	141	# static methods. not really.
		142
		143	=back
128		144
129	=head2 STATIC METHODS	145	=head2 STATIC METHODS
130		146
131	Static methods are actually functions that operate on the current process only.	147	Static methods are actually functions that operate on the current process only.
132		148
…		…
148		164
149	=cut	165	=cut
150		166
151	sub async(&@) {	167	sub async(&@) {
152	my $pid = new Coro @_;	168	my $pid = new Coro @_;
		169	$manager->ready; # this ensures that the stack is cloned from the manager
153	$pid->ready;	170	$pid->ready;
154	$pid;	171	$pid;
155	}	172	}
156		173
157	=item schedule	174	=item schedule
…		…
160	into the ready queue, so calling this function usually means you will	177	into the ready queue, so calling this function usually means you will
161	never be called again.	178	never be called again.
162		179
163	=cut	180	=cut
164		181
165	my $prev;
166
167	sub schedule {
168	# should be done using priorities :(
169	($prev, $current) = ($current, shift @ready \|\| $idle);
170	Coro::State::transfer($prev, $current);
171	}
172
173	=item cede	182	=item cede
174		183
175	"Cede" to other processes. This function puts the current process into the	184	"Cede" to other processes. This function puts the current process into the
176	ready queue and calls C<schedule>, which has the effect of giving up the	185	ready queue and calls C<schedule>, which has the effect of giving up the
177	current "timeslice" to other coroutines of the same or higher priority.	186	current "timeslice" to other coroutines of the same or higher priority.
178		187
179	=cut	188	=cut
180		189
181	sub cede {	190	=item terminate [arg...]
		191
		192	Terminates the current process.
		193
		194	Future versions of this function will allow result arguments.
		195
		196	=cut
		197
		198	sub terminate {
		199	$current->{status} = [@_];
182	$current->ready;	200	$current->cancel;
183	&schedule;	201	&schedule;
184	}	202	die; # NORETURN
185
186	=item terminate
187
188	Terminates the current process.
189
190	Future versions of this function will allow result arguments.
191
192	=cut
193
194	sub terminate {
195	my $self = $current;
196	$self->{_results} = [@_];
197	$current = shift @ready \|\| $idle;
198	Coro::State::transfer(delete $self->{_coro_state}, $current);
199	# cannot return
200	die;
201	}	203	}
202		204
203	=back	205	=back
204		206
205	# dynamic methods	207	# dynamic methods
…		…
211	=over 4	213	=over 4
212		214
213	=item new Coro \&sub [, @args...]	215	=item new Coro \&sub [, @args...]
214		216
215	Create a new process and return it. When the sub returns the process	217	Create a new process and return it. When the sub returns the process
216	automatically terminates. To start the process you must first put it into	218	automatically terminates as if C<terminate> with the returned values were
		219	called. To make the process run you must first put it into the ready queue
217	the ready queue by calling the ready method.	220	by calling the ready method.
218
219	The coderef you submit MUST NOT be a closure that refers to variables
220	in an outer scope. This does NOT work. Pass arguments into it instead.
221		221
222	=cut	222	=cut
223		223
224	sub _newcoro {	224	sub _newcoro {
225	terminate &{+shift};	225	terminate &{+shift};
…		…
232	}, $class;	232	}, $class;
233	}	233	}
234		234
235	=item $process->ready	235	=item $process->ready
236		236
237	Put the current process into the ready queue.	237	Put the given process into the ready queue.
238		238
239	=cut	239	=cut
240		240
241	sub ready {	241	=item $process->cancel
		242
		243	Like C<terminate>, but terminates the specified process instead.
		244
		245	=cut
		246
		247	sub cancel {
242	push @ready, $_[0];	248	push @destroy, $_[0];
		249	$manager->ready;
		250	&schedule if $current == $_[0];
		251	}
		252
		253	=item $process->join
		254
		255	Wait until the coroutine terminates and return any values given to the
		256	C<terminate> function. C<join> can be called multiple times from multiple
		257	processes.
		258
		259	=cut
		260
		261	sub join {
		262	my $self = shift;
		263	unless ($self->{status}) {
		264	push @{$self->{join}}, $current;
		265	&schedule;
		266	}
		267	wantarray ? @{$self->{status}} : $self->{status}[0];
		268	}
		269
		270	=item $oldprio = $process->prio($newprio)
		271
		272	Sets (or gets, if the argument is missing) the priority of the
		273	process. Higher priority processes get run before lower priority
		274	processes. Priorities are small signed integers (currently -4 .. +3),
		275	that you can refer to using PRIO_xxx constants (use the import tag :prio
		276	to get then):
		277
		278	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		279	3 > 1 > 0 > -1 > -3 > -4
		280
		281	# set priority to HIGH
		282	current->prio(PRIO_HIGH);
		283
		284	The idle coroutine ($Coro::idle) always has a lower priority than any
		285	existing coroutine.
		286
		287	Changing the priority of the current process will take effect immediately,
		288	but changing the priority of processes in the ready queue (but not
		289	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.
		291
		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)
		301
		302	Similar to C<prio>, but subtract the given value from the priority (i.e.
		303	higher values mean lower priority, just as in unix).
		304
		305	=cut
		306
		307	sub nice {
		308	$_[0]{prio} -= $_[1];
		309	}
		310
		311	=item $olddesc = $process->desc($newdesc)
		312
		313	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.
		315
		316	=cut
		317
		318	sub desc {
		319	my $old = $_[0]{desc};
		320	$_[0]{desc} = $_[1] if @_ > 1;
		321	$old;
243	}	322	}
244		323
245	=back	324	=back
246		325
247	=cut	326	=cut
248		327
249	1;	328	1;
250		329
251	=head1 BUGS/LIMITATIONS	330	=head1 BUGS/LIMITATIONS
252		331
253	- could be faster, especially when the core would introduce special	332	- you must make very sure that no coro is still active on global
254	support for coroutines (like it does for threads).	333	destruction. very bad things might happen otherwise (usually segfaults).
255	- there is still a memleak on coroutine termination that I could not	334
256	identify. Could be as small as a single SV.
257	- this module is not well-tested.
258	- if variables or arguments "disappear" (become undef) or become
259	corrupted please contact the author so he cen iron out the
260	remaining bugs.
261	- this module is not thread-safe. You must only ever use this module from	335	- this module is not thread-safe. You should only ever use this module
262	the same thread (this requirement might be loosened in the future to	336	from the same thread (this requirement might be losened in the future
263	allow per-thread schedulers, but Coro::State does not yet allow this).	337	to allow per-thread schedulers, but Coro::State does not yet allow
		338	this).
264		339
265	=head1 SEE ALSO	340	=head1 SEE ALSO
266		341
267	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	342	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	343	L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
		344	L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
269		345
270	=head1 AUTHOR	346	=head1 AUTHOR
271		347
272	Marc Lehmann <pcg@goof.com>	348	Marc Lehmann <pcg@goof.com>
273	http://www.goof.com/pcg/marc/	349	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs. Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs.
Revision 1.55 by pcg, Wed Nov 5 20:02:44 2003 UTC