[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 1.90 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 = 0.12;	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	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.
134		180
135	# create a new coroutine that just prints its arguments	181	# create a new coroutine that just prints its arguments
136	async {	182	async {
137	print "@_\n";	183	print "@_\n";
138	} 1,2,3,4;	184	} 1,2,3,4;
139		185
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	186	=cut
144		187
145	sub async(&@) {	188	sub async(&@) {
146	my $pid = new Coro @_;	189	my $pid = new Coro @_;
147	$manager->ready; # this ensures that the stack is cloned from the manager
148	$pid->ready;	190	$pid->ready;
149	$pid;	191	$pid
150	}	192	}
151		193
152	=item schedule	194	=item schedule
153		195
154	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
155	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
156	never be called again.	198	never be called again.
157		199
158	=cut	200	=cut
159		201
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	202	=item cede
169		203
170	"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
171	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
172	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
173		207
174	=cut	208	=cut
175		209
176	sub cede {
177	$current->ready;
178	&schedule;
179	}
180
181	=item terminate	210	=item terminate [arg...]
182		211
183	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
184
185	Future versions of this function will allow result arguments.
186		213
187	=cut	214	=cut
188		215
189	sub terminate {	216	sub terminate {
190	push @destroy, $current;	217	$current->cancel (@_);
191	$manager->ready;
192	&schedule;
193	# NORETURN
194	}	218	}
195		219
196	=back	220	=back
197		221
198	# dynamic methods	222	# dynamic methods
…		…
204	=over 4	228	=over 4
205		229
206	=item new Coro \&sub [, @args...]	230	=item new Coro \&sub [, @args...]
207		231
208	Create a new process and return it. When the sub returns the process	232	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	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
210	the ready queue by calling the ready method.	235	by calling the ready method.
211		236
212	The coderef you submit MUST NOT be a closure that refers to variables	237	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		238
215	=cut	239	=cut
216		240
217	sub _newcoro {	241	sub _new_coro {
218	terminate &{+shift};	242	terminate &{+shift};
219	}	243	}
220		244
221	sub new {	245	sub new {
222	my $class = shift;	246	my $class = shift;
223	bless {
224	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
225	}, $class;
226	}
227		247
		248	$class->SUPER::new (\&_new_coro, @_)
		249	}
		250
228	=item $process->ready	251	=item $success = $process->ready
229		252
230	Put the current process into the ready queue.	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.
231		256
232	=cut	257	=item $is_ready = $process->is_ready
233		258
234	sub ready {	259	Return wether the process is currently the ready queue or not,
235	push @ready, $_[0];	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}}, $current;
		288	&schedule;
		289	}
		290	wantarray ? @{$self->{status}} : $self->{status}[0];
		291	}
		292
		293	=item $oldprio = $process->prio ($newprio)
		294
		295	Sets (or gets, if the argument is missing) the priority of the
		296	process. Higher priority processes get run before lower priority
		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;
236	}	331	}
237		332
238	=back	333	=back
239		334
240	=cut	335	=cut
241		336
242	1;	337	1;
243		338
244	=head1 BUGS/LIMITATIONS	339	=head1 BUGS/LIMITATIONS
245		340
246	- could be faster, especially when the core would introduce special	341	- you must make very sure that no coro is still active on global
247	support for coroutines (like it does for threads).	342	destruction. very bad things might happen otherwise (usually segfaults).
248	- there is still a memleak on coroutine termination that I could not	343
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	344	- 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	345	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).	346	to allow per-thread schedulers, but Coro::State does not yet allow
		347	this).
257		348
258	=head1 SEE ALSO	349	=head1 SEE ALSO
259		350
260	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>.
261	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	352
262	L<Coro::L<Coro::Handle>, L<Coro::Socket>.	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>
263		358
264	=head1 AUTHOR	359	=head1 AUTHOR
265		360
266	Marc Lehmann <pcg@goof.com>	361	Marc Lehmann <schmorp@schmorp.de>
267	http://www.goof.com/pcg/marc/	362	http://home.schmorp.de/
268		363
269	=cut	364	=cut
270		365

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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 1.90 by root, Thu Nov 30 18:21:14 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 1.90 by root, Thu Nov 30 18:21:14 2006 UTC