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

Comparing Coro/Coro.pm (file contents):
Revision 1.29 by root, Sat Aug 11 00:37:31 2001 UTC vs.
Revision 1.42 by root, Tue Nov 6 20:37:20 2001 UTC

… …
19 cede; 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
26This module is still experimental, see the BUGS section below.
27 25
28In this module, coroutines are defined as "callchain + lexical variables 26In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own 27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most 28callchain, it's own set of lexicals and it's own set of perl's most
31important global variables. 29important global variables.
32 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35no warnings qw(uninitialized);
36
37use Coro::State; 37use Coro::State;
38 38
39use base Exporter; 39use base Exporter;
40 40
41$VERSION = 0.45; 41$VERSION = 0.52;
42 42
43@EXPORT = qw(async cede schedule terminate current); 43@EXPORT = qw(async cede schedule terminate current);
44@EXPORT_OK = qw($current); 44%EXPORT_TAGS = (
45 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46);
47@EXPORT_OK = @{$EXPORT_TAGS{prio}};
45 48
46{ 49{
47 my @async; 50 my @async;
48 my $init; 51 my $init;
49 52
… …
111}; 114};
112 115
113# this coroutine is necessary because a coroutine 116# this coroutine is necessary because a coroutine
114# cannot destroy itself. 117# cannot destroy itself.
115my @destroy; 118my @destroy;
119my $manager;
116my $manager = new Coro sub { 120$manager = new Coro sub {
117 while() { 121 while() {
118 delete ((pop @destroy)->{_coro_state}) while @destroy; 122 # by overwriting the state object with the manager we destroy it
123 # while still being able to schedule this coroutine (in case it has
124 # been readied multiple times. this is harmless since the manager
125 # can be called as many times as neccessary and will always
126 # remove itself from the runqueue
127 while (@destroy) {
128 my $coro = pop @destroy;
129 $coro->{status} ||= [];
130 $_->ready for @{delete $coro->{join} || []};
131 $coro->{_coro_state} = $manager->{_coro_state};
132 }
119 &schedule; 133 &schedule;
120 } 134 }
121}; 135};
122
123# we really need priorities...
124my @ready; # the ready queue. hehe, rather broken ;)
125 136
126# static methods. not really. 137# static methods. not really.
127 138
128=head2 STATIC METHODS 139=head2 STATIC METHODS
129 140
… …
160into the ready queue, so calling this function usually means you will 171into the ready queue, so calling this function usually means you will
161never be called again. 172never be called again.
162 173
163=cut 174=cut
164 175
165my $prev;
166
167sub schedule {
168 # should be done using priorities :(
169 ($prev, $current) = ($current, shift @ready || $idle);
170 Coro::State::transfer($prev, $current);
171}
172
173=item cede 176=item cede
174 177
175"Cede" to other processes. This function puts the current process into the 178"Cede" to other processes. This function puts the current process into the
176ready queue and calls C<schedule>, which has the effect of giving up the 179ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority. 180current "timeslice" to other coroutines of the same or higher priority.
178 181
179=cut 182=cut
180 183
181sub cede {
182 $current->ready;
183 &schedule;
184}
185
186=item terminate 184=item terminate [arg...]
187 185
188Terminates the current process. 186Terminates the current process.
189 187
190Future versions of this function will allow result arguments. 188Future versions of this function will allow result arguments.
191 189
192=cut 190=cut
193 191
194sub terminate { 192sub terminate {
193 $current->{status} = [@_];
195 $current->cancel; 194 $current->cancel;
196 &schedule; 195 &schedule;
197 die; # NORETURN 196 die; # NORETURN
198} 197}
199 198
… …
208=over 4 207=over 4
209 208
210=item new Coro \&sub [, @args...] 209=item new Coro \&sub [, @args...]
211 210
212Create a new process and return it. When the sub returns the process 211Create a new process and return it. When the sub returns the process
213automatically terminates. To start the process you must first put it into 212automatically terminates as if C<terminate> with the returned values were
213called. To make the process run you must first put it into the ready queue
214the ready queue by calling the ready method. 214by calling the ready method.
215
216The coderef you submit MUST NOT be a closure that refers to variables
217in an outer scope. This does NOT work. Pass arguments into it instead.
218 215
219=cut 216=cut
220 217
221sub _newcoro { 218sub _newcoro {
222 terminate &{+shift}; 219 terminate &{+shift};
… …
229 }, $class; 226 }, $class;
230} 227}
231 228
232=item $process->ready 229=item $process->ready
233 230
234Put the current process into the ready queue. 231Put the given process into the ready queue.
235 232
236=cut 233=cut
237
238sub ready {
239 push @ready, $_[0];
240}
241 234
242=item $process->cancel 235=item $process->cancel
243 236
244Like C<terminate>, but terminates the specified process instead. 237Like C<terminate>, but terminates the specified process instead.
245 238
246=cut 239=cut
247 240
248sub cancel { 241sub cancel {
249 push @destroy, $_[0]; 242 push @destroy, $_[0];
250 $manager->ready; 243 $manager->ready;
244 &schedule if $current == $_[0];
245}
246
247=item $process->join
248
249Wait until the coroutine terminates and return any values given to the
250C<terminate> function. C<join> can be called multiple times from multiple
251processes.
252
253=cut
254
255sub join {
256 my $self = shift;
257 unless ($self->{status}) {
258 push @{$self->{join}}, $current;
259 &schedule;
260 }
261 wantarray ? @{$self->{status}} : $self->{status}[0];
262}
263
264=item $oldprio = $process->prio($newprio)
265
266Sets (or gets, if the argument is missing) the priority of the
267process. Higher priority processes get run before lower priority
268processes. Priorities are smalled signed integer (currently -4 .. +3),
269that you can refer to using PRIO_xxx constants (use the import tag :prio
270to get then):
271
272 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
273 3 > 1 > 0 > -1 > -3 > -4
274
275 # set priority to HIGH
276 current->prio(PRIO_HIGH);
277
278The idle coroutine ($Coro::idle) always has a lower priority than any
279existing coroutine.
280
281Changing the priority of the current process will take effect immediately,
282but changing the priority of processes in the ready queue (but not
283running) will only take effect after the next schedule (of that
284process). This is a bug that will be fixed in some future version.
285
286=cut
287
288sub prio {
289 my $old = $_[0]{prio};
290 $_[0]{prio} = $_[1] if @_ > 1;
291 $old;
292}
293
294=item $newprio = $process->nice($change)
295
296Similar to C<prio>, but subtract the given value from the priority (i.e.
297higher values mean lower priority, just as in unix).
298
299=cut
300
301sub nice {
302 $_[0]{prio} -= $_[1];
303}
304
305=item $olddesc = $process->desc($newdesc)
306
307Sets (or gets in case the argument is missing) the description for this
308process. This is just a free-form string you can associate with a process.
309
310=cut
311
312sub desc {
313 my $old = $_[0]{desc};
314 $_[0]{desc} = $_[1] if @_ > 1;
315 $old;
251} 316}
252 317
253=back 318=back
254 319
255=cut 320=cut
256 321
2571; 3221;
258 323
259=head1 BUGS/LIMITATIONS 324=head1 BUGS/LIMITATIONS
260 325
261 - could be faster, especially when the core would introduce special 326 - you must make very sure that no coro is still active on global destruction.
262 support for coroutines (like it does for threads). 327 very bad things might happen otherwise (usually segfaults).
263 - there is still a memleak on coroutine termination that I could not
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 328 - this module is not thread-safe. You should only ever use this module from
270 the same thread (this requirement might be loosened in the future to 329 the same thread (this requirement might be loosened in the future to
271 allow per-thread schedulers, but Coro::State does not yet allow this). 330 allow per-thread schedulers, but Coro::State does not yet allow this).
272 331
273=head1 SEE ALSO 332=head1 SEE ALSO
274 333

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines