[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 1.78 by root, Wed Nov 1 01:21:21 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), 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	use strict;
		36	no warnings "uninitialized";
		37
53	use Coro::State;	38	use Coro::State;
54		39
55	use base Exporter;	40	use base Exporter::;
56		41
		42	our $idle; # idle coroutine
		43	our $main; # main coroutine
		44	our $current; # current coroutine
		45
57	$VERSION = 0.10;	46	our $VERSION = '2.1';
58		47
59	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
60	@EXPORT_OK = qw($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}};
61		53
62	{	54	{
63	my @async;	55	my @async;
		56	my $init;
64		57
65	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
66	sub import {	59	sub import {
		60	no strict 'refs';
		61
67	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
68	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
69	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
70	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
71	my @attrs;	67	my @attrs;
72	for (@_) {	68	for (@_) {
73	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
74	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	}
75	} else {	78	} else {
76	push @attrs, $_;	79	push @attrs, $_;
77	}	80	}
78	}	81	}
79	return $old ? $old->($package, $ref, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
80	};	83	};
81	}	84	}
82		85
83	sub INIT {
84	&async(pop @async) while @async;
85	}
86	}	86	}
		87
		88	=over 4
87		89
88	=item $main	90	=item $main
89		91
90	This coroutine represents the main program.	92	This coroutine represents the main program.
91		93
92	=cut	94	=cut
93		95
94	our $main = new Coro;	96	$main = new Coro;
95		97
96	=item $current (or as function: current)	98	=item $current (or as function: current)
97		99
98	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
99		101
…		…
102	# maybe some other module used Coro::Specific before...	104	# maybe some other module used Coro::Specific before...
103	if ($current) {	105	if ($current) {
104	$main->{specific} = $current->{specific};	106	$main->{specific} = $current->{specific};
105	}	107	}
106		108
107	our $current = $main;	109	$current = $main;
108		110
109	sub current() { $current }	111	sub current() { $current }
110		112
111	=item $idle	113	=item $idle
112		114
…		…
114	implementation prints "FATAL: deadlock detected" and exits.	116	implementation prints "FATAL: deadlock detected" and exits.
115		117
116	=cut	118	=cut
117		119
118	# should be done using priorities :(	120	# should be done using priorities :(
119	our $idle = new Coro sub {	121	$idle = new Coro sub {
120	print STDERR "FATAL: deadlock detected\n";	122	print STDERR "FATAL: deadlock detected\n";
121	exit(51);	123	exit(51);
122	};	124	};
123		125
124	# we really need priorities...	126	# this coroutine is necessary because a coroutine
125	my @ready; # the ready queue. hehe, rather broken ;)	127	# cannot destroy itself.
		128	my @destroy;
		129	my $manager;
		130	$manager = new Coro sub {
		131	while () {
		132	# by overwriting the state object with the manager we destroy it
		133	# while still being able to schedule this coroutine (in case it has
		134	# been readied multiple times. this is harmless since the manager
		135	# can be called as many times as neccessary and will always
		136	# remove itself from the runqueue
		137	while (@destroy) {
		138	my $coro = pop @destroy;
		139	$coro->{status} \|\|= [];
		140	$_->ready for @{delete $coro->{join} \|\| []};
		141
		142	# the next line destroys the _coro_state, but keeps the
		143	# process itself intact (we basically make it a zombie
		144	# process that always runs the manager thread, so it's possible
		145	# to transfer() to this process).
		146	$coro->{_coro_state} = $manager->{_coro_state};
		147	}
		148	&schedule;
		149	}
		150	};
126		151
127	# static methods. not really.	152	# static methods. not really.
		153
		154	=back
128		155
129	=head2 STATIC METHODS	156	=head2 STATIC METHODS
130		157
131	Static methods are actually functions that operate on the current process only.	158	Static methods are actually functions that operate on the current process only.
132		159
…		…
141	# create a new coroutine that just prints its arguments	168	# create a new coroutine that just prints its arguments
142	async {	169	async {
143	print "@_\n";	170	print "@_\n";
144	} 1,2,3,4;	171	} 1,2,3,4;
145		172
146	The coderef you submit MUST NOT be a closure that refers to variables
147	in an outer scope. This does NOT work. Pass arguments into it instead.
148
149	=cut	173	=cut
150		174
151	sub async(&@) {	175	sub async(&@) {
152	my $pid = new Coro @_;	176	my $pid = new Coro @_;
		177	$manager->ready; # this ensures that the stack is cloned from the manager
153	$pid->ready;	178	$pid->ready;
154	$pid;	179	$pid;
155	}	180	}
156		181
157	=item schedule	182	=item schedule
…		…
160	into the ready queue, so calling this function usually means you will	185	into the ready queue, so calling this function usually means you will
161	never be called again.	186	never be called again.
162		187
163	=cut	188	=cut
164		189
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	190	=item cede
174		191
175	"Cede" to other processes. This function puts the current process into the	192	"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	193	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.	194	current "timeslice" to other coroutines of the same or higher priority.
178		195
179	=cut	196	=cut
180		197
181	sub cede {
182	$current->ready;
183	&schedule;
184	}
185
186	=item terminate	198	=item terminate [arg...]
187		199
188	Terminates the current process.	200	Terminates the current process with the given status values (see L<cancel>).
189
190	Future versions of this function will allow result arguments.
191		201
192	=cut	202	=cut
193		203
194	sub terminate {	204	sub terminate {
195	my $self = $current;	205	$current->cancel (@_);
196	$self->{_results} = [@_];
197	$current = shift @ready \|\| $idle;
198	Coro::State::transfer(delete $self->{_coro_state}, $current);
199	# cannot return
200	die;
201	}	206	}
202		207
203	=back	208	=back
204		209
205	# dynamic methods	210	# dynamic methods
…		…
211	=over 4	216	=over 4
212		217
213	=item new Coro \&sub [, @args...]	218	=item new Coro \&sub [, @args...]
214		219
215	Create a new process and return it. When the sub returns the process	220	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	221	automatically terminates as if C<terminate> with the returned values were
		222	called. To make the process run you must first put it into the ready queue
217	the ready queue by calling the ready method.	223	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		224
222	=cut	225	=cut
223		226
224	sub _newcoro {	227	sub _newcoro {
225	terminate &{+shift};	228	terminate &{+shift};
…		…
232	}, $class;	235	}, $class;
233	}	236	}
234		237
235	=item $process->ready	238	=item $process->ready
236		239
237	Put the current process into the ready queue.	240	Put the given process into the ready queue.
238		241
239	=cut	242	=cut
240		243
241	sub ready {	244	=item $process->cancel (arg...)
242	push @ready, $_[0];	245
		246	Temrinates the given process and makes it return the given arguments as
		247	status (default: the empty list).
		248
		249	=cut
		250
		251	sub cancel {
		252	my $self = shift;
		253	$self->{status} = [@_];
		254	push @destroy, $self;
		255	$manager->ready;
		256	&schedule if $current == $self;
		257	}
		258
		259	=item $process->join
		260
		261	Wait until the coroutine terminates and return any values given to the
		262	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		263	from multiple processes.
		264
		265	=cut
		266
		267	sub join {
		268	my $self = shift;
		269	unless ($self->{status}) {
		270	push @{$self->{join}}, $current;
		271	&schedule;
		272	}
		273	wantarray ? @{$self->{status}} : $self->{status}[0];
		274	}
		275
		276	=item $oldprio = $process->prio($newprio)
		277
		278	Sets (or gets, if the argument is missing) the priority of the
		279	process. Higher priority processes get run before lower priority
		280	processes. Priorities are small signed integers (currently -4 .. +3),
		281	that you can refer to using PRIO_xxx constants (use the import tag :prio
		282	to get then):
		283
		284	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		285	3 > 1 > 0 > -1 > -3 > -4
		286
		287	# set priority to HIGH
		288	current->prio(PRIO_HIGH);
		289
		290	The idle coroutine ($Coro::idle) always has a lower priority than any
		291	existing coroutine.
		292
		293	Changing the priority of the current process will take effect immediately,
		294	but changing the priority of processes in the ready queue (but not
		295	running) will only take effect after the next schedule (of that
		296	process). This is a bug that will be fixed in some future version.
		297
		298	=cut
		299
		300	sub prio {
		301	my $old = $_[0]{prio};
		302	$_[0]{prio} = $_[1] if @_ > 1;
		303	$old;
		304	}
		305
		306	=item $newprio = $process->nice($change)
		307
		308	Similar to C<prio>, but subtract the given value from the priority (i.e.
		309	higher values mean lower priority, just as in unix).
		310
		311	=cut
		312
		313	sub nice {
		314	$_[0]{prio} -= $_[1];
		315	}
		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;
243	}	328	}
244		329
245	=back	330	=back
246		331
247	=cut	332	=cut
248		333
249	1;	334	1;
250		335
251	=head1 BUGS/LIMITATIONS	336	=head1 BUGS/LIMITATIONS
252		337
253	- could be faster, especially when the core would introduce special	338	- you must make very sure that no coro is still active on global
254	support for coroutines (like it does for threads).	339	destruction. very bad things might happen otherwise (usually segfaults).
255	- there is still a memleak on coroutine termination that I could not	340
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	341	- 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	342	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).	343	to allow per-thread schedulers, but Coro::State does not yet allow
		344	this).
264		345
265	=head1 SEE ALSO	346	=head1 SEE ALSO
266		347
267	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>.
268	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	349
		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>
269		355
270	=head1 AUTHOR	356	=head1 AUTHOR
271		357
272	Marc Lehmann <pcg@goof.com>	358	Marc Lehmann <schmorp@schmorp.de>
273	http://www.goof.com/pcg/marc/	359	http://home.schmorp.de/
274		360
275	=cut	361	=cut
276		362

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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 1.78 by root, Wed Nov 1 01:21:21 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs.
Revision 1.78 by root, Wed Nov 1 01:21:21 2006 UTC