[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 1.88 by root, Sun Nov 26 02:54:55 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 $VERSION = '3.0';
		47
43	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
44	@EXPORT_OK = qw($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;
111	my $manager = new Coro sub {	138	my $manager; $manager = new Coro sub {
112	while() {	139	while () {
113	delete ((pop @destroy)->{_coro_state}) while @destroy;	140	# by overwriting the state object with the manager we destroy it
		141	# while still being able to schedule this coroutine (in case it has
		142	# been readied multiple times. this is harmless since the manager
		143	# can be called as many times as neccessary and will always
		144	# remove itself from the runqueue
		145	while (@destroy) {
		146	my $coro = pop @destroy;
		147	$coro->{status} \|\|= [];
		148	$_->ready for @{delete $coro->{join} \|\| []};
		149
		150	# the next line destroys the coro state, but keeps the
		151	# process itself intact (we basically make it a zombie
		152	# process that always runs the manager thread, so it's possible
		153	# to transfer() to this process).
		154	$coro->_clone_state_from ($manager);
		155	}
114	&schedule;	156	&schedule;
115	}	157	}
116	};	158	};
117		159
118	# we really need priorities...
119	my @ready; # the ready queue. hehe, rather broken ;)
120
121	# static methods. not really.	160	# static methods. not really.
		161
		162	=back
122		163
123	=head2 STATIC METHODS	164	=head2 STATIC METHODS
124		165
125	Static methods are actually functions that operate on the current process only.	166	Static methods are actually functions that operate on the current process only.
126		167
…		…
129	=item async { ... } [@args...]	170	=item async { ... } [@args...]
130		171
131	Create a new asynchronous process and return it's process object	172	Create a new asynchronous process and return it's process object
132	(usually unused). When the sub returns the new process is automatically	173	(usually unused). When the sub returns the new process is automatically
133	terminated.	174	terminated.
		175
		176	When the coroutine dies, the program will exit, just as in the main
		177	program.
134		178
135	# create a new coroutine that just prints its arguments	179	# create a new coroutine that just prints its arguments
136	async {	180	async {
137	print "@_\n";	181	print "@_\n";
138	} 1,2,3,4;	182	} 1,2,3,4;
139		183
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
143	=cut	184	=cut
144		185
145	sub async(&@) {	186	sub async(&@) {
146	my $pid = new Coro @_;	187	my $pid = new Coro @_;
147	$manager->ready; # this ensures that the stack is cloned from the manager
148	$pid->ready;	188	$pid->ready;
149	$pid;	189	$pid
150	}	190	}
151		191
152	=item schedule	192	=item schedule
153		193
154	Calls the scheduler. Please note that the current process will not be put	194	Calls the scheduler. Please note that the current process will not be put
155	into the ready queue, so calling this function usually means you will	195	into the ready queue, so calling this function usually means you will
156	never be called again.	196	never be called again.
157		197
158	=cut	198	=cut
159		199
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	200	=item cede
169		201
170	"Cede" to other processes. This function puts the current process into the	202	"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	203	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.	204	current "timeslice" to other coroutines of the same or higher priority.
173		205
174	=cut	206	=cut
175		207
176	sub cede {
177	$current->ready;
178	&schedule;
179	}
180
181	=item terminate	208	=item terminate [arg...]
182		209
183	Terminates the current process.	210	Terminates the current process with the given status values (see L<cancel>).
184
185	Future versions of this function will allow result arguments.
186		211
187	=cut	212	=cut
188		213
189	sub terminate {	214	sub terminate {
190	push @destroy, $current;	215	$current->cancel (@_);
191	$manager->ready;
192	&schedule;
193	# NORETURN
194	}	216	}
195		217
196	=back	218	=back
197		219
198	# dynamic methods	220	# dynamic methods
…		…
204	=over 4	226	=over 4
205		227
206	=item new Coro \&sub [, @args...]	228	=item new Coro \&sub [, @args...]
207		229
208	Create a new process and return it. When the sub returns the process	230	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	231	automatically terminates as if C<terminate> with the returned values were
		232	called. To make the process run you must first put it into the ready queue
210	the ready queue by calling the ready method.	233	by calling the ready method.
211		234
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	235	=cut
216		236
217	sub _newcoro {	237	sub _new_coro {
218	terminate &{+shift};	238	terminate &{+shift};
219	}	239	}
220		240
221	sub new {	241	sub new {
222	my $class = shift;	242	my $class = shift;
223	bless {	243
224	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),	244	$class->SUPER::new (\&_new_coro, @_)
225	}, $class;
226	}	245	}
227		246
228	=item $process->ready	247	=item $process->ready
229		248
230	Put the current process into the ready queue.	249	Put the given process into the ready queue.
231		250
232	=cut	251	=cut
233		252
234	sub ready {	253	=item $process->cancel (arg...)
235	push @ready, $_[0];	254
		255	Terminates the given process and makes it return the given arguments as
		256	status (default: the empty list).
		257
		258	=cut
		259
		260	sub cancel {
		261	my $self = shift;
		262	$self->{status} = [@_];
		263	push @destroy, $self;
		264	$manager->ready;
		265	&schedule if $current == $self;
		266	}
		267
		268	=item $process->join
		269
		270	Wait until the coroutine terminates and return any values given to the
		271	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		272	from multiple processes.
		273
		274	=cut
		275
		276	sub join {
		277	my $self = shift;
		278	unless ($self->{status}) {
		279	push @{$self->{join}}, $current;
		280	&schedule;
		281	}
		282	wantarray ? @{$self->{status}} : $self->{status}[0];
		283	}
		284
		285	=item $oldprio = $process->prio ($newprio)
		286
		287	Sets (or gets, if the argument is missing) the priority of the
		288	process. Higher priority processes get run before lower priority
		289	processes. Priorities are small signed integers (currently -4 .. +3),
		290	that you can refer to using PRIO_xxx constants (use the import tag :prio
		291	to get then):
		292
		293	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		294	3 > 1 > 0 > -1 > -3 > -4
		295
		296	# set priority to HIGH
		297	current->prio(PRIO_HIGH);
		298
		299	The idle coroutine ($Coro::idle) always has a lower priority than any
		300	existing coroutine.
		301
		302	Changing the priority of the current process will take effect immediately,
		303	but changing the priority of processes in the ready queue (but not
		304	running) will only take effect after the next schedule (of that
		305	process). This is a bug that will be fixed in some future version.
		306
		307	=item $newprio = $process->nice ($change)
		308
		309	Similar to C<prio>, but subtract the given value from the priority (i.e.
		310	higher values mean lower priority, just as in unix).
		311
		312	=item $olddesc = $process->desc ($newdesc)
		313
		314	Sets (or gets in case the argument is missing) the description for this
		315	process. This is just a free-form string you can associate with a process.
		316
		317	=cut
		318
		319	sub desc {
		320	my $old = $_[0]{desc};
		321	$_[0]{desc} = $_[1] if @_ > 1;
		322	$old;
236	}	323	}
237		324
238	=back	325	=back
239		326
240	=cut	327	=cut
241		328
242	1;	329	1;
243		330
244	=head1 BUGS/LIMITATIONS	331	=head1 BUGS/LIMITATIONS
245		332
246	- could be faster, especially when the core would introduce special	333	- you must make very sure that no coro is still active on global
247	support for coroutines (like it does for threads).	334	destruction. very bad things might happen otherwise (usually segfaults).
248	- there is still a memleak on coroutine termination that I could not	335
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	336	- 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	337	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).	338	to allow per-thread schedulers, but Coro::State does not yet allow
		339	this).
257		340
258	=head1 SEE ALSO	341	=head1 SEE ALSO
259		342
260	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	343	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>,	344
262	L<Coro::L<Coro::Handle>, L<Coro::Socket>.	345	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		346
		347	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		348
		349	Embedding: L<Coro:MakeMaker>
263		350
264	=head1 AUTHOR	351	=head1 AUTHOR
265		352
266	Marc Lehmann <pcg@goof.com>	353	Marc Lehmann <schmorp@schmorp.de>
267	http://www.goof.com/pcg/marc/	354	http://home.schmorp.de/
268		355
269	=cut	356	=cut
270		357

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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 1.88 by root, Sun Nov 26 02:54:55 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 1.88 by root, Sun Nov 26 02:54:55 2006 UTC