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

Comparing Coro/Coro.pm (file contents):
Revision 1.21 by root, Sun Jul 22 03:24:10 2001 UTC vs.
Revision 1.88 by root, Sun Nov 26 02:54:55 2006 UTC

…		…
14		14
15	sub some_func : Coro {	15	sub some_func : Coro {
16	# some more async code	16	# some more async code
17	}	17	}
18		18
19	yield;	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), that is, a coroutine has it's own callchain, it's	27	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30	own set of lexicals and it's own set of perl's most important global	28	callchain, it's own set of lexicals and it's own set of perl's most
31	variables.	29	important global variables.
32
33	WARNING: When using this module, make sure that, at program end, no
34	coroutines are still running OR just call exit before falling off the
35	end. The reason for this is that some coroutine of yours might have called
36	into a C function, and falling off the end of main:: results in returning
37	to that C function instead if to the main C interpreter.
38		30
39	=cut	31	=cut
40		32
41	package Coro;	33	package Coro;
42		34
		35	use strict;
		36	no warnings "uninitialized";
		37
43	use Coro::State;	38	use Coro::State;
44		39
45	use base Exporter;	40	use base qw(Coro::State Exporter);
46		41
47	$VERSION = 0.10;	42	our $idle; # idle handler
		43	our $main; # main coroutine
		44	our $current; # current coroutine
48		45
		46	our $VERSION = '3.0';
		47
49	@EXPORT = qw(async yield schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
50	@EXPORT_OK = qw($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}};
51		53
52	{	54	{
53	my @async;	55	my @async;
		56	my $init;
54		57
55	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
56	sub import {	59	sub import {
		60	no strict 'refs';
		61
57	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
58	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
59	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
60	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
61	my @attrs;	67	my @attrs;
62	for (@_) {	68	for (@_) {
63	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
64	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	}
65	} else {	78	} else {
66	push @attrs, $_;	79	push @attrs, $_;
67	}	80	}
68	}	81	}
69	return $old ? $old->($package, $ref, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
70	};	83	};
71	}	84	}
72		85
73	sub INIT {
74	&async(pop @async) while @async;
75	}
76	}	86	}
		87
		88	=over 4
77		89
78	=item $main	90	=item $main
79		91
80	This coroutine represents the main program.	92	This coroutine represents the main program.
81		93
82	=cut	94	=cut
83		95
84	our $main = new Coro;	96	$main = new Coro;
85		97
86	=item $current (or as function: current)	98	=item $current (or as function: current)
87		99
88	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value
		101	is C<$main> (of course).
		102
		103	This variable is B<strictly> I<read-only>. It is provided for performance
		104	reasons. If performance is not essentiel you are encouraged to use the
		105	C<Coro::current> function instead.
89		106
90	=cut	107	=cut
91		108
92	# maybe some other module used Coro::Specific before...	109	# maybe some other module used Coro::Specific before...
93	if ($current) {	110	if ($current) {
94	$main->{specific} = $current->{specific};	111	$main->{specific} = $current->{specific};
95	}	112	}
96		113
97	our $current = $main;	114	$current = $main;
98		115
99	sub current() { $current }	116	sub current() { $current }
100		117
101	=item $idle	118	=item $idle
102		119
103	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
104	implementation prints "FATAL: deadlock detected" and exits.	121	to run. The default implementation prints "FATAL: deadlock detected" and
		122	exits.
105		123
106	=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.
107		127
108	# should be done using priorities :(	128	=cut
109	our $idle = new Coro sub {	129
		130	$idle = sub {
110	print STDERR "FATAL: deadlock detected\n";	131	print STDERR "FATAL: deadlock detected\n";
111	exit(51);	132	exit (51);
112	};	133	};
113		134
114	# we really need priorities...	135	# this coroutine is necessary because a coroutine
115	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	};
116		159
117	# static methods. not really.	160	# static methods. not really.
		161
		162	=back
118		163
119	=head2 STATIC METHODS	164	=head2 STATIC METHODS
120		165
121	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.
122		167
…		…
125	=item async { ... } [@args...]	170	=item async { ... } [@args...]
126		171
127	Create a new asynchronous process and return it's process object	172	Create a new asynchronous process and return it's process object
128	(usually unused). When the sub returns the new process is automatically	173	(usually unused). When the sub returns the new process is automatically
129	terminated.	174	terminated.
		175
		176	When the coroutine dies, the program will exit, just as in the main
		177	program.
130		178
131	# create a new coroutine that just prints its arguments	179	# create a new coroutine that just prints its arguments
132	async {	180	async {
133	print "@_\n";	181	print "@_\n";
134	} 1,2,3,4;	182	} 1,2,3,4;
135		183
136	The coderef you submit MUST NOT be a closure that refers to variables
137	in an outer scope. This does NOT work. Pass arguments into it instead.
138
139	=cut	184	=cut
140		185
141	sub async(&@) {	186	sub async(&@) {
142	my $pid = new Coro @_;	187	my $pid = new Coro @_;
143	$pid->ready;	188	$pid->ready;
144	$pid;	189	$pid
145	}	190	}
146		191
147	=item schedule	192	=item schedule
148		193
149	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
150	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
151	never be called again.	196	never be called again.
152		197
153	=cut	198	=cut
154		199
155	my $prev;
156
157	sub schedule {
158	# should be done using priorities :(
159	($prev, $current) = ($current, shift @ready \|\| $idle);
160	Coro::State::transfer($prev, $current);
161	}
162
163	=item yield	200	=item cede
164		201
165	Yield to other processes. This function puts the current process into the	202	"Cede" to other processes. This function puts the current process into the
166	ready queue and calls C<schedule>.	203	ready queue and calls C<schedule>, which has the effect of giving up the
		204	current "timeslice" to other coroutines of the same or higher priority.
167		205
168	=cut	206	=cut
169		207
170	sub yield {
171	$current->ready;
172	&schedule;
173	}
174
175	=item terminate	208	=item terminate [arg...]
176		209
177	Terminates the current process.	210	Terminates the current process with the given status values (see L<cancel>).
178
179	Future versions of this function will allow result arguments.
180		211
181	=cut	212	=cut
182		213
183	sub terminate {	214	sub terminate {
184	$current->{_results} = [@_];	215	$current->cancel (@_);
185	delete $current->{_coro_state};
186	&schedule;
187	}	216	}
188		217
189	=back	218	=back
190		219
191	# dynamic methods	220	# dynamic methods
…		…
197	=over 4	226	=over 4
198		227
199	=item new Coro \&sub [, @args...]	228	=item new Coro \&sub [, @args...]
200		229
201	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
202	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
203	the ready queue by calling the ready method.	233	by calling the ready method.
204		234
205	The coderef you submit MUST NOT be a closure that refers to variables
206	in an outer scope. This does NOT work. Pass arguments into it instead.
207
208	=cut	235	=cut
209		236
210	sub _newcoro {	237	sub _new_coro {
211	terminate &{+shift};	238	terminate &{+shift};
212	}	239	}
213		240
214	sub new {	241	sub new {
215	my $class = shift;	242	my $class = shift;
216	bless {	243
217	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),	244	$class->SUPER::new (\&_new_coro, @_)
218	}, $class;
219	}	245	}
220		246
221	=item $process->ready	247	=item $process->ready
222		248
223	Put the current process into the ready queue.	249	Put the given process into the ready queue.
224		250
225	=cut	251	=cut
226		252
227	sub ready {	253	=item $process->cancel (arg...)
228	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;
229	}	323	}
230		324
231	=back	325	=back
232		326
233	=cut	327	=cut
234		328
235	1;	329	1;
236		330
237	=head1 BUGS/LIMITATIONS	331	=head1 BUGS/LIMITATIONS
238		332
239	- could be faster, especially when the core would introduce special	333	- you must make very sure that no coro is still active on global
240	support for coroutines (like it does for threads).	334	destruction. very bad things might happen otherwise (usually segfaults).
241	- there is still a memleak on coroutine termination that I could not	335
242	identify. Could be as small as a single SV.
243	- this module is not well-tested.
244	- if variables or arguments "disappear" (become undef) or become
245	corrupted please contact the author so he cen iron out the
246	remaining bugs.
247	- 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
248	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
249	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).
250		340
251	=head1 SEE ALSO	341	=head1 SEE ALSO
252		342
253	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>.
254	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	344
		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>
255		350
256	=head1 AUTHOR	351	=head1 AUTHOR
257		352
258	Marc Lehmann <pcg@goof.com>	353	Marc Lehmann <schmorp@schmorp.de>
259	http://www.goof.com/pcg/marc/	354	http://home.schmorp.de/
260		355
261	=cut	356	=cut
262		357

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Comparing Coro/Coro.pm (file contents): Revision 1.21 by root, Sun Jul 22 03:24:10 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 1.21 by root, Sun Jul 22 03:24:10 2001 UTC vs.
Revision 1.88 by root, Sun Nov 26 02:54:55 2006 UTC