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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 1.37 by root, Mon Sep 24 02:25:44 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$VERSION = 0.5;
58 44
59@EXPORT = qw(async cede schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
60@EXPORT_OK = qw($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 $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
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70 my ($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 = new Coro sub {
122 while() {
123 # by overwriting the state object with the manager we destroy it
124 # while still being able to schedule this coroutine (in case it has
125 # been readied multiple times. this is harmless since the manager
126 # can be called as many times as neccessary and will always
127 # remove itself from the runqueue
128 (pop @destroy)->{_coro_state} = $manager->{_coro_state} while @destroy;
129 &schedule;
130 }
131};
126 132
127# static methods. not really. 133# static methods. not really.
128 134
129=head2 STATIC METHODS 135=head2 STATIC METHODS
130 136
… …
148 154
149=cut 155=cut
150 156
151sub async(&@) { 157sub async(&@) {
152 my $pid = new Coro @_; 158 my $pid = new Coro @_;
159 $manager->ready; # this ensures that the stack is cloned from the manager
153 $pid->ready; 160 $pid->ready;
154 $pid; 161 $pid;
155} 162}
156 163
157=item schedule 164=item schedule
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160into the ready queue, so calling this function usually means you will 167into the ready queue, so calling this function usually means you will
161never be called again. 168never be called again.
162 169
163=cut 170=cut
164 171
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 172=item cede
174 173
175"Cede" to other processes. This function puts the current process into the 174"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 175ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority. 176current "timeslice" to other coroutines of the same or higher priority.
178 177
179=cut 178=cut
180 179
181sub cede { 180=item terminate
181
182Terminates the current process.
183
184Future versions of this function will allow result arguments.
185
186=cut
187
188sub terminate {
182 $current->ready; 189 $current->cancel;
183 &schedule; 190 &schedule;
184} 191 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} 192}
202 193
203=back 194=back
204 195
205# dynamic methods 196# dynamic methods
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236 227
237Put the current process into the ready queue. 228Put the current process into the ready queue.
238 229
239=cut 230=cut
240 231
241sub ready { 232=item $process->cancel
233
234Like C<terminate>, but terminates the specified process instead.
235
236=cut
237
238sub cancel {
242 push @ready, $_[0]; 239 push @destroy, $_[0];
240 $manager->ready;
241 &schedule if $current == $_[0];
242}
243
244=item $oldprio = $process->prio($newprio)
245
246Sets the priority of the process. Higher priority processes get run before
247lower priority processes. Priorities are smalled signed integer (currently
248-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
249tag :prio to get then):
250
251 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
252 3 > 1 > 0 > -1 > -3 > -4
253
254 # set priority to HIGH
255 current->prio(PRIO_HIGH);
256
257The idle coroutine ($Coro::idle) always has a lower priority than any
258existing coroutine.
259
260Changing the priority of the current process will take effect immediately,
261but changing the priority of processes in the ready queue (but not
262running) will only take effect after the next schedule (of that
263process). This is a bug that will be fixed in some future version.
264
265=cut
266
267sub prio {
268 my $old = $_[0]{prio};
269 $_[0]{prio} = $_[1] if @_ > 1;
270 $old;
271}
272
273=item $newprio = $process->nice($change)
274
275Similar to C<prio>, but subtract the given value from the priority (i.e.
276higher values mean lower priority, just as in unix).
277
278=cut
279
280sub nice {
281 $_[0]{prio} -= $_[1];
243} 282}
244 283
245=back 284=back
246 285
247=cut 286=cut
248 287
2491; 2881;
250 289
251=head1 BUGS/LIMITATIONS 290=head1 BUGS/LIMITATIONS
252 291
253 - could be faster, especially when the core would introduce special 292 - you must make very sure that no coro is still active on global destruction.
254 support for coroutines (like it does for threads). 293 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 294 - 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 295 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). 296 allow per-thread schedulers, but Coro::State does not yet allow this).
264 297
265=head1 SEE ALSO 298=head1 SEE ALSO
266 299
267L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 300L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 301L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
302L<Coro::Handle>, L<Coro::Socket>.
269 303
270=head1 AUTHOR 304=head1 AUTHOR
271 305
272 Marc Lehmann <pcg@goof.com> 306 Marc Lehmann <pcg@goof.com>
273 http://www.goof.com/pcg/marc/ 307 http://www.goof.com/pcg/marc/

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