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

Comparing Coro/Coro.pm (file contents):
Revision 1.21 by root, Sun Jul 22 03:24:10 2001 UTC vs.
Revision 1.40 by root, Sun Oct 28 17:00:05 2001 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. 26This module is still experimental, see the BUGS section below.
27 27
28In this module, coroutines are defined as "callchain + lexical variables 28In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W), that is, a coroutine has it's own callchain, it's 29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30own set of lexicals and it's own set of perl's most important global 30callchain, it's own set of lexicals and it's own set of perl's most
31variables. 31important global variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38 32
39=cut 33=cut
40 34
41package Coro; 35package Coro;
42 36
37no warnings qw(uninitialized);
38
43use Coro::State; 39use Coro::State;
44 40
45use base Exporter; 41use base Exporter;
46 42
47$VERSION = 0.10; 43$VERSION = 0.51;
48 44
49@EXPORT = qw(async yield schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
50@EXPORT_OK = qw($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}};
51 50
52{ 51{
53 my @async; 52 my @async;
53 my $init;
54 54
55 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
56 sub import { 56 sub import {
57 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
60 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
61 my @attrs; 61 my @attrs;
62 for (@_) { 62 for (@_) {
63 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
64 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 }
65 } else { 72 } else {
66 push @attrs, $_; 73 push @attrs, $_;
67 } 74 }
68 } 75 }
69 return $old ? $old->($package, $ref, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
70 }; 77 };
71 } 78 }
72 79
73 sub INIT {
74 &async(pop @async) while @async;
75 }
76} 80}
77 81
78=item $main 82=item $main
79 83
80This coroutine represents the main program. 84This coroutine represents the main program.
… …
109our $idle = new Coro sub { 113our $idle = new Coro sub {
110 print STDERR "FATAL: deadlock detected\n"; 114 print STDERR "FATAL: deadlock detected\n";
111 exit(51); 115 exit(51);
112}; 116};
113 117
114# we really need priorities... 118# this coroutine is necessary because a coroutine
115my @ready; # the ready queue. hehe, rather broken ;) 119# cannot destroy itself.
120my @destroy;
121my $manager;
122$manager = new Coro sub {
123 while() {
124 # by overwriting the state object with the manager we destroy it
125 # while still being able to schedule this coroutine (in case it has
126 # been readied multiple times. this is harmless since the manager
127 # can be called as many times as neccessary and will always
128 # remove itself from the runqueue
129 while (@destroy) {
130 my $coro = pop @destroy;
131 $coro->{status} ||= [];
132 $_->ready for @{delete $coro->{join} || []};
133 $coro->{_coro_state} = $manager->{_coro_state};
134 }
135 &schedule;
136 }
137};
116 138
117# static methods. not really. 139# static methods. not really.
118 140
119=head2 STATIC METHODS 141=head2 STATIC METHODS
120 142
… …
138 160
139=cut 161=cut
140 162
141sub async(&@) { 163sub async(&@) {
142 my $pid = new Coro @_; 164 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
143 $pid->ready; 166 $pid->ready;
144 $pid; 167 $pid;
145} 168}
146 169
147=item schedule 170=item schedule
… …
150into the ready queue, so calling this function usually means you will 173into the ready queue, so calling this function usually means you will
151never be called again. 174never be called again.
152 175
153=cut 176=cut
154 177
155my $prev;
156
157sub schedule {
158 # should be done using priorities :(
159 ($prev, $current) = ($current, shift @ready || $idle);
160 Coro::State::transfer($prev, $current);
161}
162
163=item yield 178=item cede
164 179
165Yield to other processes. This function puts the current process into the 180"Cede" to other processes. This function puts the current process into the
166ready queue and calls C<schedule>. 181ready queue and calls C<schedule>, which has the effect of giving up the
182current "timeslice" to other coroutines of the same or higher priority.
167 183
168=cut 184=cut
169 185
170sub yield { 186=item terminate [arg...]
187
188Terminates the current process.
189
190Future versions of this function will allow result arguments.
191
192=cut
193
194sub terminate {
195 $current->{status} = [@_];
171 $current->ready; 196 $current->cancel;
172 &schedule; 197 &schedule;
173} 198 die; # NORETURN
174
175=item terminate
176
177Terminates the current process.
178
179Future versions of this function will allow result arguments.
180
181=cut
182
183sub terminate {
184 $current->{_results} = [@_];
185 delete $current->{_coro_state};
186 &schedule;
187} 199}
188 200
189=back 201=back
190 202
191# dynamic methods 203# dynamic methods
… …
197=over 4 209=over 4
198 210
199=item new Coro \&sub [, @args...] 211=item new Coro \&sub [, @args...]
200 212
201Create a new process and return it. When the sub returns the process 213Create a new process and return it. When the sub returns the process
202automatically terminates. To start the process you must first put it into 214automatically terminates as if C<terminate> with the returned values were
203the ready queue by calling the ready method. 215called. To start the process you must first put it into the ready queue by
216calling the ready method.
204 217
205The coderef you submit MUST NOT be a closure that refers to variables 218The coderef you submit MUST NOT be a closure that refers to variables
206in an outer scope. This does NOT work. Pass arguments into it instead. 219in an outer scope. This does NOT work. Pass arguments into it instead.
207 220
208=cut 221=cut
… …
218 }, $class; 231 }, $class;
219} 232}
220 233
221=item $process->ready 234=item $process->ready
222 235
223Put the current process into the ready queue. 236Put the given process into the ready queue.
224 237
225=cut 238=cut
226 239
227sub ready { 240=item $process->cancel
241
242Like C<terminate>, but terminates the specified process instead.
243
244=cut
245
246sub cancel {
228 push @ready, $_[0]; 247 push @destroy, $_[0];
248 $manager->ready;
249 &schedule if $current == $_[0];
250}
251
252=item $process->join
253
254Wait until the coroutine terminates and return any values given to the
255C<terminate> function. C<join> can be called multiple times from multiple
256processes.
257
258=cut
259
260sub join {
261 my $self = shift;
262 unless ($self->{status}) {
263 push @{$self->{join}}, $current;
264 &schedule;
265 }
266 wantarray ? @{$self->{status}} : $self->{status}[0];
267}
268
269=item $oldprio = $process->prio($newprio)
270
271Sets the priority of the process. Higher priority processes get run before
272lower priority processes. Priorities are smalled signed integer (currently
273-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
274tag :prio to get then):
275
276 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
277 3 > 1 > 0 > -1 > -3 > -4
278
279 # set priority to HIGH
280 current->prio(PRIO_HIGH);
281
282The idle coroutine ($Coro::idle) always has a lower priority than any
283existing coroutine.
284
285Changing the priority of the current process will take effect immediately,
286but changing the priority of processes in the ready queue (but not
287running) will only take effect after the next schedule (of that
288process). This is a bug that will be fixed in some future version.
289
290=cut
291
292sub prio {
293 my $old = $_[0]{prio};
294 $_[0]{prio} = $_[1] if @_ > 1;
295 $old;
296}
297
298=item $newprio = $process->nice($change)
299
300Similar to C<prio>, but subtract the given value from the priority (i.e.
301higher values mean lower priority, just as in unix).
302
303=cut
304
305sub nice {
306 $_[0]{prio} -= $_[1];
229} 307}
230 308
231=back 309=back
232 310
233=cut 311=cut
234 312
2351; 3131;
236 314
237=head1 BUGS/LIMITATIONS 315=head1 BUGS/LIMITATIONS
238 316
239 - could be faster, especially when the core would introduce special 317 - you must make very sure that no coro is still active on global destruction.
240 support for coroutines (like it does for threads). 318 very bad things might happen otherwise (usually segfaults).
241 - there is still a memleak on coroutine termination that I could not
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 319 - this module is not thread-safe. You must only ever use this module from
248 the same thread (this requirement might be loosened in the future to 320 the same thread (this requirement might be loosened in the future to
249 allow per-thread schedulers, but Coro::State does not yet allow this). 321 allow per-thread schedulers, but Coro::State does not yet allow this).
250 322
251=head1 SEE ALSO 323=head1 SEE ALSO
252 324
253L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 325L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
254L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 326L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
327L<Coro::Handle>, L<Coro::Socket>.
255 328
256=head1 AUTHOR 329=head1 AUTHOR
257 330
258 Marc Lehmann <pcg@goof.com> 331 Marc Lehmann <pcg@goof.com>
259 http://www.goof.com/pcg/marc/ 332 http://www.goof.com/pcg/marc/

Diff Legend

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