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

Comparing Coro/Coro.pm (file contents):
Revision 1.29 by root, Sat Aug 11 00:37:31 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 = 0.45;	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;
48	my $init;	56	my $init;
49		57
50	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
51	sub import {	59	sub import {
		60	no strict 'refs';
		61
52	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
53	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
54	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
55	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
56	my @attrs;	67	my @attrs;
57	for (@_) {	68	for (@_) {
…		…
72	};	83	};
73	}	84	}
74		85
75	}	86	}
76		87
		88	=over 4
		89
77	=item $main	90	=item $main
78		91
79	This coroutine represents the main program.	92	This coroutine represents the main program.
80		93
81	=cut	94	=cut
82		95
83	our $main = new Coro;	96	$main = new Coro;
84		97
85	=item $current (or as function: current)	98	=item $current (or as function: current)
86		99
87	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
88		106
89	=cut	107	=cut
90		108
91	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
92	if ($current) {	110	if ($current) {
93	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
94	}	112	}
95		113
96	our $current = $main;	114	$current = $main;
97		115
98	sub current() { $current }	116	sub current() { $current }
99		117
100	=item $idle	118	=item $idle
101		119
102	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
103	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
104		123
105	=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.
106		127
107	# should be done using priorities :(	128	=cut
108	our $idle = new Coro sub {	129
		130	$idle = sub {
109	print STDERR "FATAL: deadlock detected\n";	131	print STDERR "FATAL: deadlock detected\n";
110	exit(51);	132	exit (51);
111	};	133	};
112		134
113	# this coroutine is necessary because a coroutine	135	# this coroutine is necessary because a coroutine
114	# cannot destroy itself.	136	# cannot destroy itself.
115	my @destroy;	137	my @destroy;
116	my $manager = new Coro sub {	138	my $manager; $manager = new Coro sub {
117	while() {	139	while () {
118	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	}
119	&schedule;	156	&schedule;
120	}	157	}
121	};	158	};
122		159
123	# we really need priorities...
124	my @ready; # the ready queue. hehe, rather broken ;)
125
126	# static methods. not really.	160	# static methods. not really.
		161
		162	=back
127		163
128	=head2 STATIC METHODS	164	=head2 STATIC METHODS
129		165
130	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.
131		167
…		…
134	=item async { ... } [@args...]	170	=item async { ... } [@args...]
135		171
136	Create a new asynchronous process and return it's process object	172	Create a new asynchronous process and return it's process object
137	(usually unused). When the sub returns the new process is automatically	173	(usually unused). When the sub returns the new process is automatically
138	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.
139		180
140	# create a new coroutine that just prints its arguments	181	# create a new coroutine that just prints its arguments
141	async {	182	async {
142	print "@_\n";	183	print "@_\n";
143	} 1,2,3,4;	184	} 1,2,3,4;
144		185
145	The coderef you submit MUST NOT be a closure that refers to variables
146	in an outer scope. This does NOT work. Pass arguments into it instead.
147
148	=cut	186	=cut
149		187
150	sub async(&@) {	188	sub async(&@) {
151	my $pid = new Coro @_;	189	my $pid = new Coro @_;
152	$manager->ready; # this ensures that the stack is cloned from the manager
153	$pid->ready;	190	$pid->ready;
154	$pid;	191	$pid
155	}	192	}
156		193
157	=item schedule	194	=item schedule
158		195
159	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
160	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
161	never be called again.	198	never be called again.
162		199
163	=cut	200	=cut
164		201
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	202	=item cede
174		203
175	"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
176	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
177	current "timeslice" to other coroutines of the same or higher priority.	206	current "timeslice" to other coroutines of the same or higher priority.
178		207
179	=cut	208	=cut
180		209
181	sub cede {
182	$current->ready;
183	&schedule;
184	}
185
186	=item terminate	210	=item terminate [arg...]
187		211
188	Terminates the current process.	212	Terminates the current process with the given status values (see L<cancel>).
189
190	Future versions of this function will allow result arguments.
191		213
192	=cut	214	=cut
193		215
194	sub terminate {	216	sub terminate {
195	$current->cancel;	217	$current->cancel (@_);
196	&schedule;
197	die; # NORETURN
198	}	218	}
199		219
200	=back	220	=back
201		221
202	# dynamic methods	222	# dynamic methods
…		…
208	=over 4	228	=over 4
209		229
210	=item new Coro \&sub [, @args...]	230	=item new Coro \&sub [, @args...]
211		231
212	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
213	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
214	the ready queue by calling the ready method.	235	by calling the ready method.
215		236
216	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.
217	in an outer scope. This does NOT work. Pass arguments into it instead.
218		238
219	=cut	239	=cut
220		240
221	sub _newcoro {	241	sub _new_coro {
222	terminate &{+shift};	242	terminate &{+shift};
223	}	243	}
224		244
225	sub new {	245	sub new {
226	my $class = shift;	246	my $class = shift;
227	bless {
228	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
229	}, $class;
230	}
231		247
		248	$class->SUPER::new (\&_new_coro, @_)
		249	}
		250
232	=item $process->ready	251	=item $success = $process->ready
233		252
234	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.
235		256
236	=cut	257	=item $is_ready = $process->is_ready
237		258
238	sub ready {	259	Return wether the process is currently the ready queue or not,
239	push @ready, $_[0];
240	}
241		260
242	=item $process->cancel	261	=item $process->cancel (arg...)
243		262
244	Like C<terminate>, but terminates the specified process instead.	263	Terminates the given process and makes it return the given arguments as
		264	status (default: the empty list).
245		265
246	=cut	266	=cut
247		267
248	sub cancel {	268	sub cancel {
		269	my $self = shift;
		270	$self->{status} = [@_];
249	push @destroy, $_[0];	271	push @destroy, $self;
250	$manager->ready;	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;
251	}	331	}
252		332
253	=back	333	=back
254		334
255	=cut	335	=cut
256		336
257	1;	337	1;
258		338
259	=head1 BUGS/LIMITATIONS	339	=head1 BUGS/LIMITATIONS
260		340
261	- could be faster, especially when the core would introduce special	341	- you must make very sure that no coro is still active on global
262	support for coroutines (like it does for threads).	342	destruction. very bad things might happen otherwise (usually segfaults).
263	- there is still a memleak on coroutine termination that I could not	343
264	identify. Could be as small as a single SV.
265	- this module is not well-tested.
266	- if variables or arguments "disappear" (become undef) or become
267	corrupted please contact the author so he cen iron out the
268	remaining bugs.
269	- 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
270	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
271	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).
272		348
273	=head1 SEE ALSO	349	=head1 SEE ALSO
274		350
275	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>.
276	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,	352
277	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>
278		358
279	=head1 AUTHOR	359	=head1 AUTHOR
280		360
281	Marc Lehmann <pcg@goof.com>	361	Marc Lehmann <schmorp@schmorp.de>
282	http://www.goof.com/pcg/marc/	362	http://home.schmorp.de/
283		363
284	=cut	364	=cut
285		365

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Comparing Coro/Coro.pm (file contents): Revision 1.29 by root, Sat Aug 11 00:37:31 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 1.29 by root, Sat Aug 11 00:37:31 2001 UTC vs.
Revision 1.90 by root, Thu Nov 30 18:21:14 2006 UTC