ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.14 by root, Tue Jul 17 02:21:56 2001 UTC vs.
Revision 1.66 by root, Thu Mar 3 17:20:31 2005 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
23This module collection manages coroutines. Coroutines are similar to 23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel. 24threads but don't run in parallel.
25 25
26This module is still experimental, see the BUGS section below. 26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
32use Coro::State; 37use Coro::State;
33 38
39use vars qw($idle $main $current);
40
34use base Exporter; 41use base Exporter;
35 42
36$VERSION = 0.05; 43$VERSION = 1.11;
37 44
38@EXPORT = qw(async yield schedule terminate); 45@EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($current); 46%EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48);
49@EXPORT_OK = @{$EXPORT_TAGS{prio}};
40 50
41{ 51{
42 use subs 'async';
43
44 my @async; 52 my @async;
53 my $init;
45 54
46 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 56 sub import {
48 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
51 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
52 my @attrs; 61 my @attrs;
53 for (@_) { 62 for (@_) {
54 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
55 push @async, $ref; 64 push @async, $ref;
65 unless ($init++) {
66 eval q{
67 sub INIT {
68 &async(pop @async) while @async;
69 }
70 };
71 }
56 } else { 72 } else {
57 push @attrs, @_; 73 push @attrs, $_;
58 } 74 }
59 } 75 }
60 return $old ? $old->($package, $name, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 77 };
62 } 78 }
63 79
64 sub INIT {
65 async pop @async while @async;
66 }
67} 80}
81
82=over 4
68 83
69=item $main 84=item $main
70 85
71This coroutine represents the main program. 86This coroutine represents the main program.
72 87
73=cut 88=cut
74 89
75our $main = new Coro; 90$main = new Coro;
76 91
77=item $current 92=item $current (or as function: current)
78 93
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
80 95
81=cut 96=cut
82 97
83# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
84if ($current) { 99if ($current) {
85 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
86} 101}
87 102
88our $current = $main; 103$current = $main;
104
105sub current() { $current }
89 106
90=item $idle 107=item $idle
91 108
92The coroutine to switch to when no other coroutine is running. The default 109The coroutine to switch to when no other coroutine is running. The default
93implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
94 111
95=cut 112=cut
96 113
97# should be done using priorities :( 114# should be done using priorities :(
98our $idle = new Coro sub { 115$idle = new Coro sub {
99 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
100 exit(51); 117 exit(51);
101}; 118};
102 119
103# we really need priorities... 120# this coroutine is necessary because a coroutine
104## my @ready; #d# 121# cannot destroy itself.
105our @ready = (); # the ready queue. hehe, rather broken ;) 122my @destroy;
123my $manager;
124$manager = new Coro sub {
125 while () {
126 # by overwriting the state object with the manager we destroy it
127 # while still being able to schedule this coroutine (in case it has
128 # been readied multiple times. this is harmless since the manager
129 # can be called as many times as neccessary and will always
130 # remove itself from the runqueue
131 while (@destroy) {
132 my $coro = pop @destroy;
133 $coro->{status} ||= [];
134 $_->ready for @{delete $coro->{join} || []};
135
136 # the next line destroys the _coro_state, but keeps the
137 # process itself intact (we basically make it a zombie
138 # process that always runs the manager thread, so it's possible
139 # to transfer() to this process).
140 $coro->{_coro_state} = $manager->{_coro_state};
141 }
142 &schedule;
143 }
144};
106 145
107# static methods. not really. 146# static methods. not really.
147
148=back
108 149
109=head2 STATIC METHODS 150=head2 STATIC METHODS
110 151
111Static methods are actually functions that operate on the current process only. 152Static methods are actually functions that operate on the current process only.
112 153
121 # create a new coroutine that just prints its arguments 162 # create a new coroutine that just prints its arguments
122 async { 163 async {
123 print "@_\n"; 164 print "@_\n";
124 } 1,2,3,4; 165 } 1,2,3,4;
125 166
126The coderef you submit MUST NOT be a closure that refers to variables
127in an outer scope. This does NOT work. Pass arguments into it instead.
128
129=cut 167=cut
130 168
131sub async(&@) { 169sub async(&@) {
132 my $pid = new Coro @_; 170 my $pid = new Coro @_;
171 $manager->ready; # this ensures that the stack is cloned from the manager
133 $pid->ready; 172 $pid->ready;
134 $pid; 173 $pid;
135} 174}
136 175
137=item schedule 176=item schedule
140into the ready queue, so calling this function usually means you will 179into the ready queue, so calling this function usually means you will
141never be called again. 180never be called again.
142 181
143=cut 182=cut
144 183
145my $prev;
146
147sub schedule {
148 # should be done using priorities :(
149 ($prev, $current) = ($current, shift @ready || $idle);
150 Coro::State::transfer($prev, $current);
151}
152
153=item yield 184=item cede
154 185
155Yield to other processes. This function puts the current process into the 186"Cede" to other processes. This function puts the current process into the
156ready queue and calls C<schedule>. 187ready queue and calls C<schedule>, which has the effect of giving up the
188current "timeslice" to other coroutines of the same or higher priority.
157 189
158=cut 190=cut
159 191
160sub yield {
161 $current->ready;
162 &schedule;
163}
164
165=item terminate 192=item terminate [arg...]
166 193
167Terminates the current process. 194Terminates the current process with the given status values (see L<cancel>).
168
169Future versions of this function will allow result arguments.
170 195
171=cut 196=cut
172 197
173sub terminate { 198sub terminate {
174 $current->{_results} = [@_]; 199 $current->cancel (@_);
175 &schedule;
176} 200}
177 201
178=back 202=back
179 203
180# dynamic methods 204# dynamic methods
186=over 4 210=over 4
187 211
188=item new Coro \&sub [, @args...] 212=item new Coro \&sub [, @args...]
189 213
190Create a new process and return it. When the sub returns the process 214Create a new process and return it. When the sub returns the process
191automatically terminates. To start the process you must first put it into 215automatically terminates as if C<terminate> with the returned values were
216called. To make the process run you must first put it into the ready queue
192the ready queue by calling the ready method. 217by calling the ready method.
193
194The coderef you submit MUST NOT be a closure that refers to variables
195in an outer scope. This does NOT work. Pass arguments into it instead.
196 218
197=cut 219=cut
198 220
199sub _newcoro { 221sub _newcoro {
200 terminate &{+shift}; 222 terminate &{+shift};
207 }, $class; 229 }, $class;
208} 230}
209 231
210=item $process->ready 232=item $process->ready
211 233
212Put the current process into the ready queue. 234Put the given process into the ready queue.
213 235
214=cut 236=cut
215 237
216sub ready { 238=item $process->cancel (arg...)
217 push @ready, $_[0]; 239
240Temrinates the given process and makes it return the given arguments as
241status (default: the empty list).
242
243=cut
244
245sub cancel {
246 my $self = shift;
247 $self->{status} = [@_];
248 push @destroy, $self;
249 $manager->ready;
250 &schedule if $current == $self;
251}
252
253=item $process->join
254
255Wait until the coroutine terminates and return any values given to the
256C<terminate> or C<cancel> functions. C<join> can be called multiple times
257from multiple processes.
258
259=cut
260
261sub join {
262 my $self = shift;
263 unless ($self->{status}) {
264 push @{$self->{join}}, $current;
265 &schedule;
266 }
267 wantarray ? @{$self->{status}} : $self->{status}[0];
268}
269
270=item $oldprio = $process->prio($newprio)
271
272Sets (or gets, if the argument is missing) the priority of the
273process. Higher priority processes get run before lower priority
274processes. Priorities are small signed integers (currently -4 .. +3),
275that you can refer to using PRIO_xxx constants (use the import tag :prio
276to get then):
277
278 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279 3 > 1 > 0 > -1 > -3 > -4
280
281 # set priority to HIGH
282 current->prio(PRIO_HIGH);
283
284The idle coroutine ($Coro::idle) always has a lower priority than any
285existing coroutine.
286
287Changing the priority of the current process will take effect immediately,
288but changing the priority of processes in the ready queue (but not
289running) will only take effect after the next schedule (of that
290process). This is a bug that will be fixed in some future version.
291
292=cut
293
294sub prio {
295 my $old = $_[0]{prio};
296 $_[0]{prio} = $_[1] if @_ > 1;
297 $old;
298}
299
300=item $newprio = $process->nice($change)
301
302Similar to C<prio>, but subtract the given value from the priority (i.e.
303higher values mean lower priority, just as in unix).
304
305=cut
306
307sub nice {
308 $_[0]{prio} -= $_[1];
309}
310
311=item $olddesc = $process->desc($newdesc)
312
313Sets (or gets in case the argument is missing) the description for this
314process. This is just a free-form string you can associate with a process.
315
316=cut
317
318sub desc {
319 my $old = $_[0]{desc};
320 $_[0]{desc} = $_[1] if @_ > 1;
321 $old;
218} 322}
219 323
220=back 324=back
221 325
222=cut 326=cut
223 327
2241; 3281;
225 329
226=head1 BUGS 330=head1 BUGS/LIMITATIONS
227 331
228 - could be faster, especially when the core would introduce special 332 - you must make very sure that no coro is still active on global
229 support for coroutines (like it does for threads). 333 destruction. very bad things might happen otherwise (usually segfaults).
230 - there is still a memleak on coroutine termination that I could not 334
231 identify. Could be as small as a single SV. 335 - this module is not thread-safe. You should only ever use this module
232 - this module is not well-tested. 336 from the same thread (this requirement might be losened in the future
337 to allow per-thread schedulers, but Coro::State does not yet allow
338 this).
233 339
234=head1 SEE ALSO 340=head1 SEE ALSO
235 341
236L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
237L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::Handle>, L<Coro::RWLock>, L<Coro::Socket>.
238 345
239=head1 AUTHOR 346=head1 AUTHOR
240 347
241 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <schmorp@schmorp.de>
242 http://www.goof.com/pcg/marc/ 349 http://home.schmorp.de/
243 350
244=cut 351=cut
245 352

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines