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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 1.35 by root, Mon Sep 24 00:16:30 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30own set of lexicals and it's own set of perl's most important global 30callchain, it's own set of lexicals and it's own set of perl's most
31variables. 31important global variables.
32
33WARNING: When using this module, make sure that, at program end, no
34coroutines are still running OR just call exit before falling off the
35end. The reason for this is that some coroutine of yours might have called
36into a C function, and falling off the end of main:: results in returning
37to that C function instead if to the main C interpreter.
38
39WARNING: Unless you really know what you are doing, do NOT do context
40switches inside callbacks from the XS level. The reason for this is
41similar to the reason above: A callback calls a perl function, this
42perl function does a context switch, some other callback is called, the
43original function returns from it - to what? To the wrong XS function,
44with totally different return values. Unfortunately, this includes
45callbacks done by perl itself (tie'd variables!).
46
47The only workaround for this is to do coroutines on C level.
48 32
49=cut 33=cut
50 34
51package Coro; 35package Coro;
52 36
53use Coro::State; 37use Coro::State;
54 38
55use base Exporter; 39use base Exporter;
56 40
57$VERSION = 0.10; 41$VERSION = 0.5;
58 42
59@EXPORT = qw(async cede schedule terminate current); 43@EXPORT = qw(async cede schedule terminate current);
60@EXPORT_OK = qw($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}};
61 48
62{ 49{
63 my @async; 50 my @async;
51 my $init;
64 52
65 # this way of handling attributes simply is NOT scalable ;() 53 # this way of handling attributes simply is NOT scalable ;()
66 sub import { 54 sub import {
67 Coro->export_to_level(1, @_); 55 Coro->export_to_level(1, @_);
68 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
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70 my ($package, $ref) = (shift, shift); 58 my ($package, $ref) = (shift, shift);
71 my @attrs; 59 my @attrs;
72 for (@_) { 60 for (@_) {
73 if ($_ eq "Coro") { 61 if ($_ eq "Coro") {
74 push @async, $ref; 62 push @async, $ref;
63 unless ($init++) {
64 eval q{
65 sub INIT {
66 &async(pop @async) while @async;
67 }
68 };
69 }
75 } else { 70 } else {
76 push @attrs, $_; 71 push @attrs, $_;
77 } 72 }
78 } 73 }
79 return $old ? $old->($package, $ref, @attrs) : @attrs; 74 return $old ? $old->($package, $ref, @attrs) : @attrs;
80 }; 75 };
81 } 76 }
82 77
83 sub INIT {
84 &async(pop @async) while @async;
85 }
86} 78}
87 79
88=item $main 80=item $main
89 81
90This coroutine represents the main program. 82This coroutine represents the main program.
… …
119our $idle = new Coro sub { 111our $idle = new Coro sub {
120 print STDERR "FATAL: deadlock detected\n"; 112 print STDERR "FATAL: deadlock detected\n";
121 exit(51); 113 exit(51);
122}; 114};
123 115
124# we really need priorities... 116# this coroutine is necessary because a coroutine
125my @ready; # the ready queue. hehe, rather broken ;) 117# cannot destroy itself.
118my @destroy;
119my $manager = new Coro sub {
120 while() {
121 delete ((pop @destroy)->{_coro_state}) while @destroy;
122 &schedule;
123 }
124};
126 125
127# static methods. not really. 126# static methods. not really.
128 127
129=head2 STATIC METHODS 128=head2 STATIC METHODS
130 129
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148 147
149=cut 148=cut
150 149
151sub async(&@) { 150sub async(&@) {
152 my $pid = new Coro @_; 151 my $pid = new Coro @_;
152 $manager->ready; # this ensures that the stack is cloned from the manager
153 $pid->ready; 153 $pid->ready;
154 $pid; 154 $pid;
155} 155}
156 156
157=item schedule 157=item schedule
… …
160into the ready queue, so calling this function usually means you will 160into the ready queue, so calling this function usually means you will
161never be called again. 161never be called again.
162 162
163=cut 163=cut
164 164
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 165=item cede
174 166
175"Cede" to other processes. This function puts the current process into the 167"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 168ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority. 169current "timeslice" to other coroutines of the same or higher priority.
178 170
179=cut 171=cut
180 172
181sub cede { 173=item terminate
174
175Terminates the current process.
176
177Future versions of this function will allow result arguments.
178
179=cut
180
181sub terminate {
182 $current->ready; 182 $current->cancel;
183 &schedule; 183 &schedule;
184} 184 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} 185}
202 186
203=back 187=back
204 188
205# dynamic methods 189# dynamic methods
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236 220
237Put the current process into the ready queue. 221Put the current process into the ready queue.
238 222
239=cut 223=cut
240 224
241sub ready { 225=item $process->cancel
226
227Like C<terminate>, but terminates the specified process instead.
228
229=cut
230
231sub cancel {
242 push @ready, $_[0]; 232 push @destroy, $_[0];
233 $manager->ready;
234 &schedule if $current == $_[0];
235}
236
237=item $oldprio = $process->prio($newprio)
238
239Sets the priority of the process. Higher priority processes get run before
240lower priority processes. Priorities are smalled signed integer (currently
241-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
242tag :prio to get then):
243
244 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
245 3 > 1 > 0 > -1 > -3 > -4
246
247 # set priority to HIGH
248 current->prio(PRIO_HIGH);
249
250The idle coroutine ($Coro::idle) always has a lower priority than any
251existing coroutine.
252
253Changing the priority of the current process will take effect immediately,
254but changing the priority of processes in the ready queue (but not
255running) will only take effect after the next schedule (of that
256process). This is a bug that will be fixed in some future version.
257
258=cut
259
260sub prio {
261 my $old = $_[0]{prio};
262 $_[0]{prio} = $_[1] if @_ > 1;
263 $old;
264}
265
266=item $newprio = $process->nice($change)
267
268Similar to C<prio>, but subtract the given value from the priority (i.e.
269higher values mean lower priority, just as in unix).
270
271=cut
272
273sub nice {
274 $_[0]{prio} -= $_[1];
243} 275}
244 276
245=back 277=back
246 278
247=cut 279=cut
248 280
2491; 2811;
250 282
251=head1 BUGS/LIMITATIONS 283=head1 BUGS/LIMITATIONS
252 284
253 - could be faster, especially when the core would introduce special 285 - you must make very sure that no coro is still active on global destruction.
254 support for coroutines (like it does for threads). 286 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 287 - 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 288 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). 289 allow per-thread schedulers, but Coro::State does not yet allow this).
264 290
265=head1 SEE ALSO 291=head1 SEE ALSO
266 292
267L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 293L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 294L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
295L<Coro::Handle>, L<Coro::Socket>.
269 296
270=head1 AUTHOR 297=head1 AUTHOR
271 298
272 Marc Lehmann <pcg@goof.com> 299 Marc Lehmann <pcg@goof.com>
273 http://www.goof.com/pcg/marc/ 300 http://www.goof.com/pcg/marc/

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