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

Comparing Coro/Coro.pm (file contents):
Revision 1.24 by root, Wed Jul 25 04:14:37 2001 UTC vs.
Revision 1.91 by root, Fri Dec 1 02:17:37 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, because the program has no other way to continue.
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 wake up a
		126	coroutine so the scheduler can run it.
101		127
102	# should be done using priorities :(	128	Please note that if your callback recursively invokes perl (e.g. for event
103	our $idle = new Coro sub {	129	handlers), then it must be prepared to be called recursively.
		130
		131	=cut
		132
		133	$idle = sub {
104	print STDERR "FATAL: deadlock detected\n";	134	print STDERR "FATAL: deadlock detected\n";
105	exit(51);	135	exit (51);
106	};	136	};
107		137
108	# this coroutine is necessary because a coroutine	138	# this coroutine is necessary because a coroutine
109	# cannot destroy itself.	139	# cannot destroy itself.
110	my @destroy;	140	my @destroy;
111	my $manager = new Coro sub {	141	my $manager; $manager = new Coro sub {
112	while() {	142	while () {
113	delete ((pop @destroy)->{_coro_state}) while @destroy;	143	# by overwriting the state object with the manager we destroy it
		144	# while still being able to schedule this coroutine (in case it has
		145	# been readied multiple times. this is harmless since the manager
		146	# can be called as many times as neccessary and will always
		147	# remove itself from the runqueue
		148	while (@destroy) {
		149	my $coro = pop @destroy;
		150	$coro->{status} \|\|= [];
		151	$_->ready for @{delete $coro->{join} \|\| []};
		152
		153	# the next line destroys the coro state, but keeps the
		154	# process itself intact (we basically make it a zombie
		155	# process that always runs the manager thread, so it's possible
		156	# to transfer() to this process).
		157	$coro->_clone_state_from ($manager);
		158	}
114	&schedule;	159	&schedule;
115	}	160	}
116	};	161	};
117		162
118	# we really need priorities...
119	my @ready; # the ready queue. hehe, rather broken ;)
120
121	# static methods. not really.	163	# static methods. not really.
		164
		165	=back
122		166
123	=head2 STATIC METHODS	167	=head2 STATIC METHODS
124		168
125	Static methods are actually functions that operate on the current process only.	169	Static methods are actually functions that operate on the current process only.
126		170
…		…
129	=item async { ... } [@args...]	173	=item async { ... } [@args...]
130		174
131	Create a new asynchronous process and return it's process object	175	Create a new asynchronous process and return it's process object
132	(usually unused). When the sub returns the new process is automatically	176	(usually unused). When the sub returns the new process is automatically
133	terminated.	177	terminated.
		178
		179	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		180
		181	When the coroutine dies, the program will exit, just as in the main
		182	program.
134		183
135	# create a new coroutine that just prints its arguments	184	# create a new coroutine that just prints its arguments
136	async {	185	async {
137	print "@_\n";	186	print "@_\n";
138	} 1,2,3,4;	187	} 1,2,3,4;
139		188
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	189	=cut
144		190
145	sub async(&@) {	191	sub async(&@) {
146	my $pid = new Coro @_;	192	my $pid = new Coro @_;
147	$manager->ready; # this ensures that the stack is cloned from the manager
148	$pid->ready;	193	$pid->ready;
149	$pid;	194	$pid
150	}	195	}
151		196
152	=item schedule	197	=item schedule
153		198
154	Calls the scheduler. Please note that the current process will not be put	199	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	200	into the ready queue, so calling this function usually means you will
156	never be called again.	201	never be called again unless something else (e.g. an event handler) calls
		202	ready.
157		203
158	=cut	204	The canonical way to wait on external events is this:
159		205
160	my $prev;	206	{
		207	# remember current process
		208	my $current = $Coro::current;
161		209
162	sub schedule {	210	# register a hypothetical event handler
163	# should be done using priorities :(	211	on_event_invoke sub {
164	($prev, $current) = ($current, shift @ready \|\| $idle);	212	# wake up sleeping coroutine
165	Coro::State::transfer($prev, $current);	213	$current->ready;
166	}	214	undef $current;
		215	};
		216
		217	# call schedule until event occured.
		218	# in case we are woken up for other reasons
		219	# (current still defined), loop.
		220	Coro::schedule while $current;
		221	}
		222
		223	=cut
167		224
168	=item cede	225	=item cede
169		226
170	"Cede" to other processes. This function puts the current process into the	227	"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	228	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.	229	current "timeslice" to other coroutines of the same or higher priority.
173		230
174	=cut	231	=cut
175		232
176	sub cede {
177	$current->ready;
178	&schedule;
179	}
180
181	=item terminate	233	=item terminate [arg...]
182		234
183	Terminates the current process.	235	Terminates the current process with the given status values (see L<cancel>).
184
185	Future versions of this function will allow result arguments.
186		236
187	=cut	237	=cut
188		238
189	sub terminate {	239	sub terminate {
190	push @destroy, $current;	240	$current->cancel (@_);
191	$manager->ready;
192	&schedule;
193	# NORETURN
194	}	241	}
195		242
196	=back	243	=back
197		244
198	# dynamic methods	245	# dynamic methods
…		…
204	=over 4	251	=over 4
205		252
206	=item new Coro \&sub [, @args...]	253	=item new Coro \&sub [, @args...]
207		254
208	Create a new process and return it. When the sub returns the process	255	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	256	automatically terminates as if C<terminate> with the returned values were
		257	called. To make the process run you must first put it into the ready queue
210	the ready queue by calling the ready method.	258	by calling the ready method.
211		259
212	The coderef you submit MUST NOT be a closure that refers to variables	260	Calling C<exit> in a coroutine will not work correctly, so do not do that.
213	in an outer scope. This does NOT work. Pass arguments into it instead.
214		261
215	=cut	262	=cut
216		263
217	sub _newcoro {	264	sub _new_coro {
218	terminate &{+shift};	265	terminate &{+shift};
219	}	266	}
220		267
221	sub new {	268	sub new {
222	my $class = shift;	269	my $class = shift;
223	bless {
224	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
225	}, $class;
226	}
227		270
		271	$class->SUPER::new (\&_new_coro, @_)
		272	}
		273
228	=item $process->ready	274	=item $success = $process->ready
229		275
230	Put the current process into the ready queue.	276	Put the given process into the ready queue (according to it's priority)
		277	and return true. If the process is already in the ready queue, do nothing
		278	and return false.
231		279
232	=cut	280	=item $is_ready = $process->is_ready
233		281
234	sub ready {	282	Return wether the process is currently the ready queue or not,
235	push @ready, $_[0];	283
		284	=item $process->cancel (arg...)
		285
		286	Terminates the given process and makes it return the given arguments as
		287	status (default: the empty list).
		288
		289	=cut
		290
		291	sub cancel {
		292	my $self = shift;
		293	$self->{status} = [@_];
		294	push @destroy, $self;
		295	$manager->ready;
		296	&schedule if $current == $self;
		297	}
		298
		299	=item $process->join
		300
		301	Wait until the coroutine terminates and return any values given to the
		302	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		303	from multiple processes.
		304
		305	=cut
		306
		307	sub join {
		308	my $self = shift;
		309	unless ($self->{status}) {
		310	push @{$self->{join}}, $current;
		311	&schedule;
		312	}
		313	wantarray ? @{$self->{status}} : $self->{status}[0];
		314	}
		315
		316	=item $oldprio = $process->prio ($newprio)
		317
		318	Sets (or gets, if the argument is missing) the priority of the
		319	process. Higher priority processes get run before lower priority
		320	processes. Priorities are small signed integers (currently -4 .. +3),
		321	that you can refer to using PRIO_xxx constants (use the import tag :prio
		322	to get then):
		323
		324	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		325	3 > 1 > 0 > -1 > -3 > -4
		326
		327	# set priority to HIGH
		328	current->prio(PRIO_HIGH);
		329
		330	The idle coroutine ($Coro::idle) always has a lower priority than any
		331	existing coroutine.
		332
		333	Changing the priority of the current process will take effect immediately,
		334	but changing the priority of processes in the ready queue (but not
		335	running) will only take effect after the next schedule (of that
		336	process). This is a bug that will be fixed in some future version.
		337
		338	=item $newprio = $process->nice ($change)
		339
		340	Similar to C<prio>, but subtract the given value from the priority (i.e.
		341	higher values mean lower priority, just as in unix).
		342
		343	=item $olddesc = $process->desc ($newdesc)
		344
		345	Sets (or gets in case the argument is missing) the description for this
		346	process. This is just a free-form string you can associate with a process.
		347
		348	=cut
		349
		350	sub desc {
		351	my $old = $_[0]{desc};
		352	$_[0]{desc} = $_[1] if @_ > 1;
		353	$old;
236	}	354	}
237		355
238	=back	356	=back
239		357
240	=cut	358	=cut
241		359
242	1;	360	1;
243		361
244	=head1 BUGS/LIMITATIONS	362	=head1 BUGS/LIMITATIONS
245		363
246	- could be faster, especially when the core would introduce special	364	- you must make very sure that no coro is still active on global
247	support for coroutines (like it does for threads).	365	destruction. very bad things might happen otherwise (usually segfaults).
248	- there is still a memleak on coroutine termination that I could not	366
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	367	- 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	368	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).	369	to allow per-thread schedulers, but Coro::State does not yet allow
		370	this).
257		371
258	=head1 SEE ALSO	372	=head1 SEE ALSO
259		373
260	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	374	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
261	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	375
		376	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		377
		378	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		379
		380	Embedding: L<Coro:MakeMaker>
262		381
263	=head1 AUTHOR	382	=head1 AUTHOR
264		383
265	Marc Lehmann <pcg@goof.com>	384	Marc Lehmann <schmorp@schmorp.de>
266	http://www.goof.com/pcg/marc/	385	http://home.schmorp.de/
267		386
268	=cut	387	=cut
269		388

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Comparing Coro/Coro.pm (file contents): Revision 1.24 by root, Wed Jul 25 04:14:37 2001 UTC vs. Revision 1.91 by root, Fri Dec 1 02:17:37 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.24 by root, Wed Jul 25 04:14:37 2001 UTC vs.
Revision 1.91 by root, Fri Dec 1 02:17:37 2006 UTC