[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 1.53 by root, Tue May 27 01:15:26 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	no warnings qw(uninitialized);
		36
53	use Coro::State;	37	use Coro::State;
54		38
55	use base Exporter;	39	use base Exporter;
56		40
57	$VERSION = 0.10;	41	$VERSION = 0.7;
58		42
59	@EXPORT = qw(async cede schedule terminate current);	43	@EXPORT = qw(async cede schedule terminate current);
60	@EXPORT_OK = qw($current);	44	%EXPORT_TAGS = (
		45	prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
		46	);
		47	@EXPORT_OK = @{$EXPORT_TAGS{prio}};
61		48
62	{	49	{
63	my @async;	50	my @async;
		51	my $init;
64		52
65	# this way of handling attributes simply is NOT scalable ;()	53	# this way of handling attributes simply is NOT scalable ;()
66	sub import {	54	sub import {
67	Coro->export_to_level(1, @_);	55	Coro->export_to_level(1, @_);
68	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	56	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
…		…
70	my ($package, $ref) = (shift, shift);	58	my ($package, $ref) = (shift, shift);
71	my @attrs;	59	my @attrs;
72	for (@_) {	60	for (@_) {
73	if ($_ eq "Coro") {	61	if ($_ eq "Coro") {
74	push @async, $ref;	62	push @async, $ref;
		63	unless ($init++) {
		64	eval q{
		65	sub INIT {
		66	&async(pop @async) while @async;
		67	}
		68	};
		69	}
75	} else {	70	} else {
76	push @attrs, $_;	71	push @attrs, $_;
77	}	72	}
78	}	73	}
79	return $old ? $old->($package, $ref, @attrs) : @attrs;	74	return $old ? $old->($package, $ref, @attrs) : @attrs;
80	};	75	};
81	}	76	}
82		77
83	sub INIT {
84	&async(pop @async) while @async;
85	}
86	}	78	}
		79
		80	=over 4
87		81
88	=item $main	82	=item $main
89		83
90	This coroutine represents the main program.	84	This coroutine represents the main program.
91		85
…		…
119	our $idle = new Coro sub {	113	our $idle = new Coro sub {
120	print STDERR "FATAL: deadlock detected\n";	114	print STDERR "FATAL: deadlock detected\n";
121	exit(51);	115	exit(51);
122	};	116	};
123		117
124	# we really need priorities...	118	# this coroutine is necessary because a coroutine
125	my @ready; # the ready queue. hehe, rather broken ;)	119	# cannot destroy itself.
		120	my @destroy;
		121	my $manager;
		122	$manager = new Coro sub {
		123	while() {
		124	# by overwriting the state object with the manager we destroy it
		125	# while still being able to schedule this coroutine (in case it has
		126	# been readied multiple times. this is harmless since the manager
		127	# can be called as many times as neccessary and will always
		128	# remove itself from the runqueue
		129	while (@destroy) {
		130	my $coro = pop @destroy;
		131	$coro->{status} \|\|= [];
		132	$_->ready for @{delete $coro->{join} \|\| []};
		133	$coro->{_coro_state} = $manager->{_coro_state};
		134	}
		135	&schedule;
		136	}
		137	};
126		138
127	# static methods. not really.	139	# static methods. not really.
		140
		141	=back
128		142
129	=head2 STATIC METHODS	143	=head2 STATIC METHODS
130		144
131	Static methods are actually functions that operate on the current process only.	145	Static methods are actually functions that operate on the current process only.
132		146
…		…
148		162
149	=cut	163	=cut
150		164
151	sub async(&@) {	165	sub async(&@) {
152	my $pid = new Coro @_;	166	my $pid = new Coro @_;
		167	$manager->ready; # this ensures that the stack is cloned from the manager
153	$pid->ready;	168	$pid->ready;
154	$pid;	169	$pid;
155	}	170	}
156		171
157	=item schedule	172	=item schedule
…		…
160	into the ready queue, so calling this function usually means you will	175	into the ready queue, so calling this function usually means you will
161	never be called again.	176	never be called again.
162		177
163	=cut	178	=cut
164		179
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	180	=item cede
174		181
175	"Cede" to other processes. This function puts the current process into the	182	"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	183	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.	184	current "timeslice" to other coroutines of the same or higher priority.
178		185
179	=cut	186	=cut
180		187
181	sub cede {	188	=item terminate [arg...]
		189
		190	Terminates the current process.
		191
		192	Future versions of this function will allow result arguments.
		193
		194	=cut
		195
		196	sub terminate {
		197	$current->{status} = [@_];
182	$current->ready;	198	$current->cancel;
183	&schedule;	199	&schedule;
184	}	200	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	}	201	}
202		202
203	=back	203	=back
204		204
205	# dynamic methods	205	# dynamic methods
…		…
211	=over 4	211	=over 4
212		212
213	=item new Coro \&sub [, @args...]	213	=item new Coro \&sub [, @args...]
214		214
215	Create a new process and return it. When the sub returns the process	215	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	216	automatically terminates as if C<terminate> with the returned values were
		217	called. To make the process run you must first put it into the ready queue
217	the ready queue by calling the ready method.	218	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		219
222	=cut	220	=cut
223		221
224	sub _newcoro {	222	sub _newcoro {
225	terminate &{+shift};	223	terminate &{+shift};
…		…
232	}, $class;	230	}, $class;
233	}	231	}
234		232
235	=item $process->ready	233	=item $process->ready
236		234
237	Put the current process into the ready queue.	235	Put the given process into the ready queue.
238		236
239	=cut	237	=cut
240		238
241	sub ready {	239	=item $process->cancel
		240
		241	Like C<terminate>, but terminates the specified process instead.
		242
		243	=cut
		244
		245	sub cancel {
242	push @ready, $_[0];	246	push @destroy, $_[0];
		247	$manager->ready;
		248	&schedule if $current == $_[0];
		249	}
		250
		251	=item $process->join
		252
		253	Wait until the coroutine terminates and return any values given to the
		254	C<terminate> function. C<join> can be called multiple times from multiple
		255	processes.
		256
		257	=cut
		258
		259	sub join {
		260	my $self = shift;
		261	unless ($self->{status}) {
		262	push @{$self->{join}}, $current;
		263	&schedule;
		264	}
		265	wantarray ? @{$self->{status}} : $self->{status}[0];
		266	}
		267
		268	=item $oldprio = $process->prio($newprio)
		269
		270	Sets (or gets, if the argument is missing) the priority of the
		271	process. Higher priority processes get run before lower priority
		272	processes. Priorities are small signed integers (currently -4 .. +3),
		273	that you can refer to using PRIO_xxx constants (use the import tag :prio
		274	to get then):
		275
		276	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		277	3 > 1 > 0 > -1 > -3 > -4
		278
		279	# set priority to HIGH
		280	current->prio(PRIO_HIGH);
		281
		282	The idle coroutine ($Coro::idle) always has a lower priority than any
		283	existing coroutine.
		284
		285	Changing the priority of the current process will take effect immediately,
		286	but changing the priority of processes in the ready queue (but not
		287	running) will only take effect after the next schedule (of that
		288	process). This is a bug that will be fixed in some future version.
		289
		290	=cut
		291
		292	sub prio {
		293	my $old = $_[0]{prio};
		294	$_[0]{prio} = $_[1] if @_ > 1;
		295	$old;
		296	}
		297
		298	=item $newprio = $process->nice($change)
		299
		300	Similar to C<prio>, but subtract the given value from the priority (i.e.
		301	higher values mean lower priority, just as in unix).
		302
		303	=cut
		304
		305	sub nice {
		306	$_[0]{prio} -= $_[1];
		307	}
		308
		309	=item $olddesc = $process->desc($newdesc)
		310
		311	Sets (or gets in case the argument is missing) the description for this
		312	process. This is just a free-form string you can associate with a process.
		313
		314	=cut
		315
		316	sub desc {
		317	my $old = $_[0]{desc};
		318	$_[0]{desc} = $_[1] if @_ > 1;
		319	$old;
243	}	320	}
244		321
245	=back	322	=back
246		323
247	=cut	324	=cut
248		325
249	1;	326	1;
250		327
251	=head1 BUGS/LIMITATIONS	328	=head1 BUGS/LIMITATIONS
252		329
253	- could be faster, especially when the core would introduce special	330	- you must make very sure that no coro is still active on global
254	support for coroutines (like it does for threads).	331	destruction. very bad things might happen otherwise (usually segfaults).
255	- there is still a memleak on coroutine termination that I could not	332
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	333	- 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	334	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).	335	to allow per-thread schedulers, but Coro::State does not yet allow
		336	this).
264		337
265	=head1 SEE ALSO	338	=head1 SEE ALSO
266		339
267	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	340	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	341	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
		342	L<Coro::Handle>, L<Coro::Socket>.
269		343
270	=head1 AUTHOR	344	=head1 AUTHOR
271		345
272	Marc Lehmann <pcg@goof.com>	346	Marc Lehmann <pcg@goof.com>
273	http://www.goof.com/pcg/marc/	347	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 1.53 by root, Tue May 27 01:15:26 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 1.53 by root, Tue May 27 01:15:26 2003 UTC