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

Comparing Coro/Coro.pm (file contents):
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs.
Revision 1.82 by root, Fri Nov 24 13:40:36 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), 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
39	WARNING: Unless you really know what you are doing, do NOT do context
40	switches inside callbacks from the XS level. The reason for this is
41	similar to the reason above: A callback calls a perl function, this
42	perl function does a context switch, some other callback is called, the
43	original function returns from it - to what? To the wrong XS function,
44	with totally different return values. Unfortunately, this includes
45	callbacks done by perl itself (tie'd variables!).
46
47	The only workaround for this is to do coroutines on C level.
48		30
49	=cut	31	=cut
50		32
51	package Coro;	33	package Coro;
52		34
		35	use strict;
		36	no warnings "uninitialized";
		37
53	use Coro::State;	38	use Coro::State;
54		39
55	use base Exporter;	40	use base Exporter::;
56		41
57	$VERSION = 0.10;	42	our $idle; # idle coroutine
		43	our $main; # main coroutine
		44	our $current; # current coroutine
58		45
		46	our $VERSION = '2.5';
		47
59	@EXPORT = qw(async cede schedule terminate current);	48	our @EXPORT = qw(async cede schedule terminate current);
60	@EXPORT_OK = qw($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}};
61		53
62	{	54	{
63	my @async;	55	my @async;
		56	my $init;
64		57
65	# this way of handling attributes simply is NOT scalable ;()	58	# this way of handling attributes simply is NOT scalable ;()
66	sub import {	59	sub import {
		60	no strict 'refs';
		61
67	Coro->export_to_level(1, @_);	62	Coro->export_to_level(1, @_);
		63
68	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};	64	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
69	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {	65	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
70	my ($package, $ref) = (shift, shift);	66	my ($package, $ref) = (shift, shift);
71	my @attrs;	67	my @attrs;
72	for (@_) {	68	for (@_) {
73	if ($_ eq "Coro") {	69	if ($_ eq "Coro") {
74	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	}
75	} else {	78	} else {
76	push @attrs, $_;	79	push @attrs, $_;
77	}	80	}
78	}	81	}
79	return $old ? $old->($package, $ref, @attrs) : @attrs;	82	return $old ? $old->($package, $ref, @attrs) : @attrs;
80	};	83	};
81	}	84	}
82		85
83	sub INIT {
84	&async(pop @async) while @async;
85	}
86	}	86	}
		87
		88	=over 4
87		89
88	=item $main	90	=item $main
89		91
90	This coroutine represents the main program.	92	This coroutine represents the main program.
91		93
92	=cut	94	=cut
93		95
94	our $main = new Coro;	96	$main = new Coro;
95		97
96	=item $current (or as function: current)	98	=item $current (or as function: current)
97		99
98	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).	100	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
99		101
…		…
102	# maybe some other module used Coro::Specific before...	104	# maybe some other module used Coro::Specific before...
103	if ($current) {	105	if ($current) {
104	$main->{specific} = $current->{specific};	106	$main->{specific} = $current->{specific};
105	}	107	}
106		108
107	our $current = $main;	109	$current = $main;
108		110
109	sub current() { $current }	111	sub current() { $current }
110		112
111	=item $idle	113	=item $idle
112		114
…		…
114	implementation prints "FATAL: deadlock detected" and exits.	116	implementation prints "FATAL: deadlock detected" and exits.
115		117
116	=cut	118	=cut
117		119
118	# should be done using priorities :(	120	# should be done using priorities :(
119	our $idle = new Coro sub {	121	$idle = new Coro sub {
120	print STDERR "FATAL: deadlock detected\n";	122	print STDERR "FATAL: deadlock detected\n";
121	exit(51);	123	exit(51);
122	};	124	};
123		125
124	# we really need priorities...	126	# this coroutine is necessary because a coroutine
125	my @ready; # the ready queue. hehe, rather broken ;)	127	# cannot destroy itself.
		128	my @destroy;
		129	my $manager;
		130	$manager = new Coro sub {
		131	while () {
		132	# by overwriting the state object with the manager we destroy it
		133	# while still being able to schedule this coroutine (in case it has
		134	# been readied multiple times. this is harmless since the manager
		135	# can be called as many times as neccessary and will always
		136	# remove itself from the runqueue
		137	while (@destroy) {
		138	my $coro = pop @destroy;
		139	$coro->{status} \|\|= [];
		140	$_->ready for @{delete $coro->{join} \|\| []};
		141
		142	# the next line destroys the _coro_state, but keeps the
		143	# process itself intact (we basically make it a zombie
		144	# process that always runs the manager thread, so it's possible
		145	# to transfer() to this process).
		146	$coro->{_coro_state}->_clone_state_from ($manager->{_coro_state});
		147	}
		148	&schedule;
		149	}
		150	};
126		151
127	# static methods. not really.	152	# static methods. not really.
		153
		154	=back
128		155
129	=head2 STATIC METHODS	156	=head2 STATIC METHODS
130		157
131	Static methods are actually functions that operate on the current process only.	158	Static methods are actually functions that operate on the current process only.
132		159
…		…
135	=item async { ... } [@args...]	162	=item async { ... } [@args...]
136		163
137	Create a new asynchronous process and return it's process object	164	Create a new asynchronous process and return it's process object
138	(usually unused). When the sub returns the new process is automatically	165	(usually unused). When the sub returns the new process is automatically
139	terminated.	166	terminated.
		167
		168	When the coroutine dies, the program will exit, just as in the main
		169	program.
140		170
141	# create a new coroutine that just prints its arguments	171	# create a new coroutine that just prints its arguments
142	async {	172	async {
143	print "@_\n";	173	print "@_\n";
144	} 1,2,3,4;	174	} 1,2,3,4;
145		175
146	The coderef you submit MUST NOT be a closure that refers to variables
147	in an outer scope. This does NOT work. Pass arguments into it instead.
148
149	=cut	176	=cut
150		177
151	sub async(&@) {	178	sub async(&@) {
152	my $pid = new Coro @_;	179	my $pid = new Coro @_;
		180	$manager->ready; # this ensures that the stack is cloned from the manager
153	$pid->ready;	181	$pid->ready;
154	$pid;	182	$pid;
155	}	183	}
156		184
157	=item schedule	185	=item schedule
…		…
160	into the ready queue, so calling this function usually means you will	188	into the ready queue, so calling this function usually means you will
161	never be called again.	189	never be called again.
162		190
163	=cut	191	=cut
164		192
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	193	=item cede
174		194
175	"Cede" to other processes. This function puts the current process into the	195	"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	196	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.	197	current "timeslice" to other coroutines of the same or higher priority.
178		198
179	=cut	199	=cut
180		200
181	sub cede {
182	$current->ready;
183	&schedule;
184	}
185
186	=item terminate	201	=item terminate [arg...]
187		202
188	Terminates the current process.	203	Terminates the current process with the given status values (see L<cancel>).
189
190	Future versions of this function will allow result arguments.
191		204
192	=cut	205	=cut
193		206
194	sub terminate {	207	sub terminate {
195	my $self = $current;	208	$current->cancel (@_);
196	$self->{_results} = [@_];
197	$current = shift @ready \|\| $idle;
198	Coro::State::transfer(delete $self->{_coro_state}, $current);
199	# cannot return
200	die;
201	}	209	}
202		210
203	=back	211	=back
204		212
205	# dynamic methods	213	# dynamic methods
…		…
211	=over 4	219	=over 4
212		220
213	=item new Coro \&sub [, @args...]	221	=item new Coro \&sub [, @args...]
214		222
215	Create a new process and return it. When the sub returns the process	223	Create a new process and return it. When the sub returns the process
216	automatically terminates. To start the process you must first put it into	224	automatically terminates as if C<terminate> with the returned values were
		225	called. To make the process run you must first put it into the ready queue
217	the ready queue by calling the ready method.	226	by calling the ready method.
218
219	The coderef you submit MUST NOT be a closure that refers to variables
220	in an outer scope. This does NOT work. Pass arguments into it instead.
221		227
222	=cut	228	=cut
223		229
224	sub _newcoro {	230	sub _newcoro {
225	terminate &{+shift};	231	terminate &{+shift};
226	}	232	}
227		233
228	sub new {	234	sub new {
229	my $class = shift;	235	my $class = shift;
230	bless {	236	bless {
231	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),	237	_coro_state => (new Coro::State \&_newcoro, @_),
232	}, $class;	238	}, $class;
233	}	239	}
234		240
235	=item $process->ready	241	=item $process->ready
236		242
237	Put the current process into the ready queue.	243	Put the given process into the ready queue.
238		244
239	=cut	245	=cut
240		246
241	sub ready {	247	=item $process->cancel (arg...)
242	push @ready, $_[0];	248
		249	Terminates the given process and makes it return the given arguments as
		250	status (default: the empty list).
		251
		252	=cut
		253
		254	sub cancel {
		255	my $self = shift;
		256	$self->{status} = [@_];
		257	push @destroy, $self;
		258	$manager->ready;
		259	&schedule if $current == $self;
		260	}
		261
		262	=item $process->join
		263
		264	Wait until the coroutine terminates and return any values given to the
		265	C<terminate> or C<cancel> functions. C<join> can be called multiple times
		266	from multiple processes.
		267
		268	=cut
		269
		270	sub join {
		271	my $self = shift;
		272	unless ($self->{status}) {
		273	push @{$self->{join}}, $current;
		274	&schedule;
		275	}
		276	wantarray ? @{$self->{status}} : $self->{status}[0];
		277	}
		278
		279	=item $oldprio = $process->prio ($newprio)
		280
		281	Sets (or gets, if the argument is missing) the priority of the
		282	process. Higher priority processes get run before lower priority
		283	processes. Priorities are small signed integers (currently -4 .. +3),
		284	that you can refer to using PRIO_xxx constants (use the import tag :prio
		285	to get then):
		286
		287	PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
		288	3 > 1 > 0 > -1 > -3 > -4
		289
		290	# set priority to HIGH
		291	current->prio(PRIO_HIGH);
		292
		293	The idle coroutine ($Coro::idle) always has a lower priority than any
		294	existing coroutine.
		295
		296	Changing the priority of the current process will take effect immediately,
		297	but changing the priority of processes in the ready queue (but not
		298	running) will only take effect after the next schedule (of that
		299	process). This is a bug that will be fixed in some future version.
		300
		301	=cut
		302
		303	sub prio {
		304	shift->{_coro_state}->prio (@_)
		305	}
		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	=cut
		313
		314	sub nice {
		315	shift->{_coro_state}->nice (@_)
		316	}
		317
		318	=item $olddesc = $process->desc ($newdesc)
		319
		320	Sets (or gets in case the argument is missing) the description for this
		321	process. This is just a free-form string you can associate with a process.
		322
		323	=cut
		324
		325	sub desc {
		326	my $old = $_[0]{desc};
		327	$_[0]{desc} = $_[1] if @_ > 1;
		328	$old;
243	}	329	}
244		330
245	=back	331	=back
246		332
247	=cut	333	=cut
248		334
249	1;	335	1;
250		336
251	=head1 BUGS/LIMITATIONS	337	=head1 BUGS/LIMITATIONS
252		338
253	- could be faster, especially when the core would introduce special	339	- you must make very sure that no coro is still active on global
254	support for coroutines (like it does for threads).	340	destruction. very bad things might happen otherwise (usually segfaults).
255	- there is still a memleak on coroutine termination that I could not	341
256	identify. Could be as small as a single SV.
257	- this module is not well-tested.
258	- if variables or arguments "disappear" (become undef) or become
259	corrupted please contact the author so he cen iron out the
260	remaining bugs.
261	- this module is not thread-safe. You must only ever use this module from	342	- this module is not thread-safe. You should only ever use this module
262	the same thread (this requirement might be loosened in the future to	343	from the same thread (this requirement might be losened in the future
263	allow per-thread schedulers, but Coro::State does not yet allow this).	344	to allow per-thread schedulers, but Coro::State does not yet allow
		345	this).
264		346
265	=head1 SEE ALSO	347	=head1 SEE ALSO
266		348
267	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,	349	Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
268	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.	350
		351	Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
		352
		353	Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
		354
		355	Embedding: L<Coro:MakeMaker>
269		356
270	=head1 AUTHOR	357	=head1 AUTHOR
271		358
272	Marc Lehmann <pcg@goof.com>	359	Marc Lehmann <schmorp@schmorp.de>
273	http://www.goof.com/pcg/marc/	360	http://home.schmorp.de/
274		361
275	=cut	362	=cut
276		363

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Comparing Coro/Coro.pm (file contents): Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs. Revision 1.82 by root, Fri Nov 24 13:40:36 2006 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.22 by root, Mon Jul 23 02:14:19 2001 UTC vs.
Revision 1.82 by root, Fri Nov 24 13:40:36 2006 UTC