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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 1.41 by root, Tue Nov 6 20:34:09 2001 UTC

… …
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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30own set of lexicals and it's own set of perl's most important global 30callchain, it's own set of lexicals and it's own set of perl's most
31variables. 31important global variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38
39WARNING: Unless you really know what you are doing, do NOT do context
40switches inside callbacks from the XS level. The reason for this is
41similar to the reason above: A callback calls a perl function, this
42perl function does a context switch, some other callback is called, the
43original function returns from it - to what? To the wrong XS function,
44with totally different return values. Unfortunately, this includes
45callbacks done by perl itself (tie'd variables!).
46
47The only workaround for this is to do coroutines on C level.
48 32
49=cut 33=cut
50 34
51package Coro; 35package Coro;
52 36
37no warnings qw(uninitialized);
38
53use Coro::State; 39use Coro::State;
54 40
55use base Exporter; 41use base Exporter;
56 42
57$VERSION = 0.10; 43$VERSION = 0.52;
58 44
59@EXPORT = qw(async cede schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
60@EXPORT_OK = qw($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}};
61 50
62{ 51{
63 my @async; 52 my @async;
53 my $init;
64 54
65 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
66 sub import { 56 sub import {
67 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
68 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
70 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
71 my @attrs; 61 my @attrs;
72 for (@_) { 62 for (@_) {
73 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
74 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 }
75 } else { 72 } else {
76 push @attrs, $_; 73 push @attrs, $_;
77 } 74 }
78 } 75 }
79 return $old ? $old->($package, $ref, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
80 }; 77 };
81 } 78 }
82 79
83 sub INIT {
84 &async(pop @async) while @async;
85 }
86} 80}
87 81
88=item $main 82=item $main
89 83
90This coroutine represents the main program. 84This coroutine represents the main program.
… …
119our $idle = new Coro sub { 113our $idle = new Coro sub {
120 print STDERR "FATAL: deadlock detected\n"; 114 print STDERR "FATAL: deadlock detected\n";
121 exit(51); 115 exit(51);
122}; 116};
123 117
124# we really need priorities... 118# this coroutine is necessary because a coroutine
125my @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};
126 138
127# static methods. not really. 139# static methods. not really.
128 140
129=head2 STATIC METHODS 141=head2 STATIC METHODS
130 142
… …
148 160
149=cut 161=cut
150 162
151sub async(&@) { 163sub async(&@) {
152 my $pid = new Coro @_; 164 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
153 $pid->ready; 166 $pid->ready;
154 $pid; 167 $pid;
155} 168}
156 169
157=item schedule 170=item schedule
… …
160into the ready queue, so calling this function usually means you will 173into the ready queue, so calling this function usually means you will
161never be called again. 174never be called again.
162 175
163=cut 176=cut
164 177
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 178=item cede
174 179
175"Cede" to other processes. This function puts the current process into the 180"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 181ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority. 182current "timeslice" to other coroutines of the same or higher priority.
178 183
179=cut 184=cut
180 185
181sub cede { 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} = [@_];
182 $current->ready; 196 $current->cancel;
183 &schedule; 197 &schedule;
184} 198 die; # NORETURN
185
186=item terminate
187
188Terminates the current process.
189
190Future versions of this function will allow result arguments.
191
192=cut
193
194sub terminate {
195 my $self = $current;
196 $self->{_results} = [@_];
197 $current = shift @ready || $idle;
198 Coro::State::transfer(delete $self->{_coro_state}, $current);
199 # cannot return
200 die;
201} 199}
202 200
203=back 201=back
204 202
205# dynamic methods 203# dynamic methods
… …
211=over 4 209=over 4
212 210
213=item new Coro \&sub [, @args...] 211=item new Coro \&sub [, @args...]
214 212
215Create 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
216automatically terminates. To start the process you must first put it into 214automatically terminates as if C<terminate> with the returned values were
215called. To make the process run you must first put it into the ready queue
217the ready queue by calling the ready method. 216by calling the ready method.
218
219The coderef you submit MUST NOT be a closure that refers to variables
220in an outer scope. This does NOT work. Pass arguments into it instead.
221 217
222=cut 218=cut
223 219
224sub _newcoro { 220sub _newcoro {
225 terminate &{+shift}; 221 terminate &{+shift};
… …
232 }, $class; 228 }, $class;
233} 229}
234 230
235=item $process->ready 231=item $process->ready
236 232
237Put the current process into the ready queue. 233Put the given process into the ready queue.
238 234
239=cut 235=cut
240 236
241sub ready { 237=item $process->cancel
238
239Like C<terminate>, but terminates the specified process instead.
240
241=cut
242
243sub cancel {
242 push @ready, $_[0]; 244 push @destroy, $_[0];
245 $manager->ready;
246 &schedule if $current == $_[0];
247}
248
249=item $process->join
250
251Wait until the coroutine terminates and return any values given to the
252C<terminate> function. C<join> can be called multiple times from multiple
253processes.
254
255=cut
256
257sub join {
258 my $self = shift;
259 unless ($self->{status}) {
260 push @{$self->{join}}, $current;
261 &schedule;
262 }
263 wantarray ? @{$self->{status}} : $self->{status}[0];
264}
265
266=item $oldprio = $process->prio($newprio)
267
268Sets (or gets, if the argument is missing) the priority of the
269process. Higher priority processes get run before lower priority
270processes. Priorities are smalled signed integer (currently -4 .. +3),
271that you can refer to using PRIO_xxx constants (use the import tag :prio
272to get then):
273
274 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
275 3 > 1 > 0 > -1 > -3 > -4
276
277 # set priority to HIGH
278 current->prio(PRIO_HIGH);
279
280The idle coroutine ($Coro::idle) always has a lower priority than any
281existing coroutine.
282
283Changing the priority of the current process will take effect immediately,
284but changing the priority of processes in the ready queue (but not
285running) will only take effect after the next schedule (of that
286process). This is a bug that will be fixed in some future version.
287
288=cut
289
290sub prio {
291 my $old = $_[0]{prio};
292 $_[0]{prio} = $_[1] if @_ > 1;
293 $old;
294}
295
296=item $newprio = $process->nice($change)
297
298Similar to C<prio>, but subtract the given value from the priority (i.e.
299higher values mean lower priority, just as in unix).
300
301=cut
302
303sub nice {
304 $_[0]{prio} -= $_[1];
305}
306
307=item $olddesc = $process->desc($newdesc)
308
309Sets (or gets in case the argument is missing) the description for this
310process. This is just a free-form string you can associate with a process.
311
312=cut
313
314sub desc {
315 my $old = $_[0]{desc};
316 $_[0]{desc} = $_[1] if @_ > 1;
317 $old;
243} 318}
244 319
245=back 320=back
246 321
247=cut 322=cut
248 323
2491; 3241;
250 325
251=head1 BUGS/LIMITATIONS 326=head1 BUGS/LIMITATIONS
252 327
253 - could be faster, especially when the core would introduce special 328 - you must make very sure that no coro is still active on global destruction.
254 support for coroutines (like it does for threads). 329 very bad things might happen otherwise (usually segfaults).
255 - there is still a memleak on coroutine termination that I could not
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 330 - this module is not thread-safe. You must only ever use this module from
262 the same thread (this requirement might be loosened in the future to 331 the same thread (this requirement might be loosened in the future to
263 allow per-thread schedulers, but Coro::State does not yet allow this). 332 allow per-thread schedulers, but Coro::State does not yet allow this).
264 333
265=head1 SEE ALSO 334=head1 SEE ALSO
266 335
267L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 336L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 337L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
338L<Coro::Handle>, L<Coro::Socket>.
269 339
270=head1 AUTHOR 340=head1 AUTHOR
271 341
272 Marc Lehmann <pcg@goof.com> 342 Marc Lehmann <pcg@goof.com>
273 http://www.goof.com/pcg/marc/ 343 http://www.goof.com/pcg/marc/

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