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

Comparing Coro/Coro.pm (file contents):
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs.
Revision 1.90 by root, Thu Nov 30 18:21:14 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 = 0.10;	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	# we really need priorities...	135	# this coroutine is necessary because a coroutine
109	my @ready; # the ready queue. hehe, rather broken ;)	136	# cannot destroy itself.
		137	my @destroy;
		138	my $manager; $manager = new Coro sub {
		139	while () {
		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	}
		156	&schedule;
		157	}
		158	};
110		159
111	# static methods. not really.	160	# static methods. not really.
		161
		162	=back
112		163
113	=head2 STATIC METHODS	164	=head2 STATIC METHODS
114		165
115	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.
116		167
…		…
119	=item async { ... } [@args...]	170	=item async { ... } [@args...]
120		171
121	Create a new asynchronous process and return it's process object	172	Create a new asynchronous process and return it's process object
122	(usually unused). When the sub returns the new process is automatically	173	(usually unused). When the sub returns the new process is automatically
123	terminated.	174	terminated.
		175
		176	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		177
		178	When the coroutine dies, the program will exit, just as in the main
		179	program.
124		180
125	# create a new coroutine that just prints its arguments	181	# create a new coroutine that just prints its arguments
126	async {	182	async {
127	print "@_\n";	183	print "@_\n";
128	} 1,2,3,4;	184	} 1,2,3,4;
129		185
130	The coderef you submit MUST NOT be a closure that refers to variables
131	in an outer scope. This does NOT work. Pass arguments into it instead.
132
133	=cut	186	=cut
134		187
135	sub async(&@) {	188	sub async(&@) {
136	my $pid = new Coro @_;	189	my $pid = new Coro @_;
137	$pid->ready;	190	$pid->ready;
138	$pid;	191	$pid
139	}	192	}
140		193
141	=item schedule	194	=item schedule
142		195
143	Calls the scheduler. Please note that the current process will not be put	196	Calls the scheduler. Please note that the current process will not be put
144	into the ready queue, so calling this function usually means you will	197	into the ready queue, so calling this function usually means you will
145	never be called again.	198	never be called again.
146		199
147	=cut	200	=cut
148		201
149	my $prev;
150
151	sub schedule {
152	# should be done using priorities :(
153	($prev, $current) = ($current, shift @ready \|\| $idle);
154	Coro::State::transfer($prev, $current);
155	}
156
157	=item cede	202	=item cede
158		203
159	"Cede" to other processes. This function puts the current process into the	204	"Cede" to other processes. This function puts the current process into the
160	ready queue and calls C<schedule>, which has the effect of giving up the	205	ready queue and calls C<schedule>, which has the effect of giving up the
161	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
162		207
163	=cut	208	=cut
164		209
165	sub cede {
166	$current->ready;
167	&schedule;
168	}
169
170	=item terminate	210	=item terminate [arg...]
171		211
172	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
173		213
174	Future versions of this function will allow result arguments.
175
176	=cut	214	=cut
177		215
178	# this coroutine is necessary because a coroutine	216	sub terminate {
179	# cannot destroy itself.	217	$current->cancel (@_);
180	my @destroy;	218	}
181	my $terminate = new Coro sub {	219
182	while() {	220	=back
183	delete ((pop @destroy)->{_coro_state}) while @destroy;	221
		222	# dynamic methods
		223
		224	=head2 PROCESS METHODS
		225
		226	These are the methods you can call on process objects.
		227
		228	=over 4
		229
		230	=item new Coro \&sub [, @args...]
		231
		232	Create a new process and return it. When the sub returns the process
		233	automatically terminates as if C<terminate> with the returned values were
		234	called. To make the process run you must first put it into the ready queue
		235	by calling the ready method.
		236
		237	Calling C<exit> in a coroutine will not work correctly, so do not do that.
		238
		239	=cut
		240
		241	sub _new_coro {
		242	terminate &{+shift};
		243	}
		244
		245	sub new {
		246	my $class = shift;
		247
		248	$class->SUPER::new (\&_new_coro, @_)
		249	}
		250
		251	=item $success = $process->ready
		252
		253	Put the given process into the ready queue (according to it's priority)
		254	and return true. If the process is already in the ready queue, do nothing
		255	and return false.
		256
		257	=item $is_ready = $process->is_ready
		258
		259	Return wether the process is currently the ready queue or not,
		260
		261	=item $process->cancel (arg...)
		262
		263	Terminates the given process and makes it return the given arguments as
		264	status (default: the empty list).
		265
		266	=cut
		267
		268	sub cancel {
		269	my $self = shift;
		270	$self->{status} = [@_];
		271	push @destroy, $self;
		272	$manager->ready;
		273	&schedule if $current == $self;
		274	}
		275
		276	=item $process->join
		277
		278	Wait until the coroutine terminates and return any values given to the
		279	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		280	from multiple processes.
		281
		282	=cut
		283
		284	sub join {
		285	my $self = shift;
		286	unless ($self->{status}) {
		287	push @{$self->{join}}, $current;
184	&schedule;	288	&schedule;
185	}	289	}
186	};	290	wantarray ? @{$self->{status}} : $self->{status}[0];
		291	}
187		292
188	sub terminate {	293	=item $oldprio = $process->prio ($newprio)
189	push @destroy, $current;	294
190	$terminate->ready;	295	Sets (or gets, if the argument is missing) the priority of the
191	&schedule;	296	process. Higher priority processes get run before lower priority
192	# NORETURN	297	processes. Priorities are small signed integers (currently -4 .. +3),
		298	that you can refer to using PRIO_xxx constants (use the import tag :prio
		299	to get then):
		300
		301	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		302	3 > 1 > 0 > -1 > -3 > -4
		303
		304	# set priority to HIGH
		305	current->prio(PRIO_HIGH);
		306
		307	The idle coroutine ($Coro::idle) always has a lower priority than any
		308	existing coroutine.
		309
		310	Changing the priority of the current process will take effect immediately,
		311	but changing the priority of processes in the ready queue (but not
		312	running) will only take effect after the next schedule (of that
		313	process). This is a bug that will be fixed in some future version.
		314
		315	=item $newprio = $process->nice ($change)
		316
		317	Similar to C<prio>, but subtract the given value from the priority (i.e.
		318	higher values mean lower priority, just as in unix).
		319
		320	=item $olddesc = $process->desc ($newdesc)
		321
		322	Sets (or gets in case the argument is missing) the description for this
		323	process. This is just a free-form string you can associate with a process.
		324
		325	=cut
		326
		327	sub desc {
		328	my $old = $_[0]{desc};
		329	$_[0]{desc} = $_[1] if @_ > 1;
		330	$old;
193	}	331	}
194		332
195	=back	333	=back
196		334
197	# dynamic methods
198
199	=head2 PROCESS METHODS
200
201	These are the methods you can call on process objects.
202
203	=over 4
204
205	=item new Coro \&sub [, @args...]
206
207	Create a new process and return it. When the sub returns the process
208	automatically terminates. To start the process you must first put it into
209	the ready queue by calling the ready method.
210
211	The coderef you submit MUST NOT be a closure that refers to variables
212	in an outer scope. This does NOT work. Pass arguments into it instead.
213
214	=cut
215
216	sub _newcoro {
217	terminate &{+shift};
218	}
219
220	sub new {
221	my $class = shift;
222	bless {
223	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
224	}, $class;
225	}
226
227	=item $process->ready
228
229	Put the current process into the ready queue.
230
231	=cut
232
233	sub ready {
234	push @ready, $_[0];
235	}
236
237	=back
238
239	=cut	335	=cut
240		336
241	1;	337	1;
242		338
243	=head1 BUGS/LIMITATIONS	339	=head1 BUGS/LIMITATIONS
244		340
245	- could be faster, especially when the core would introduce special	341	- you must make very sure that no coro is still active on global
246	support for coroutines (like it does for threads).	342	destruction. very bad things might happen otherwise (usually segfaults).
247	- there is still a memleak on coroutine termination that I could not	343
248	identify. Could be as small as a single SV.
249	- this module is not well-tested.
250	- if variables or arguments "disappear" (become undef) or become
251	corrupted please contact the author so he cen iron out the
252	remaining bugs.
253	- this module is not thread-safe. You must only ever use this module from	344	- this module is not thread-safe. You should only ever use this module
254	the same thread (this requirement might be loosened in the future to	345	from the same thread (this requirement might be losened in the future
255	allow per-thread schedulers, but Coro::State does not yet allow this).	346	to allow per-thread schedulers, but Coro::State does not yet allow
		347	this).
256		348
257	=head1 SEE ALSO	349	=head1 SEE ALSO
258		350
259	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	351	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
260	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	352
		353	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		354
		355	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		356
		357	Embedding: L<Coro:MakeMaker>
261		358
262	=head1 AUTHOR	359	=head1 AUTHOR
263		360
264	Marc Lehmann <pcg@goof.com>	361	Marc Lehmann <schmorp@schmorp.de>
265	http://www.goof.com/pcg/marc/	362	http://home.schmorp.de/
266		363
267	=cut	364	=cut
268		365

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing Coro/Coro.pm (file contents): Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs. Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC vs.
Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC