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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 1.36 by root, Mon Sep 24 01:36:20 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 delete ((pop @destroy)->{_coro_state}) while @destroy;
124 &schedule;
125 }
126};
126 127
127# static methods. not really. 128# static methods. not really.
128 129
129=head2 STATIC METHODS 130=head2 STATIC METHODS
130 131
… …
148 149
149=cut 150=cut
150 151
151sub async(&@) { 152sub async(&@) {
152 my $pid = new Coro @_; 153 my $pid = new Coro @_;
154 $manager->ready; # this ensures that the stack is cloned from the manager
153 $pid->ready; 155 $pid->ready;
154 $pid; 156 $pid;
155} 157}
156 158
157=item schedule 159=item schedule
… …
160into the ready queue, so calling this function usually means you will 162into the ready queue, so calling this function usually means you will
161never be called again. 163never be called again.
162 164
163=cut 165=cut
164 166
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 167=item cede
174 168
175"Cede" to other processes. This function puts the current process into the 169"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 170ready queue and calls C<schedule>, which has the effect of giving up the
177current "timeslice" to other coroutines of the same or higher priority. 171current "timeslice" to other coroutines of the same or higher priority.
178 172
179=cut 173=cut
180 174
181sub cede { 175=item terminate
176
177Terminates the current process.
178
179Future versions of this function will allow result arguments.
180
181=cut
182
183sub terminate {
182 $current->ready; 184 $current->cancel;
183 &schedule; 185 &schedule;
184} 186 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} 187}
202 188
203=back 189=back
204 190
205# dynamic methods 191# dynamic methods
… …
236 222
237Put the current process into the ready queue. 223Put the current process into the ready queue.
238 224
239=cut 225=cut
240 226
241sub ready { 227=item $process->cancel
228
229Like C<terminate>, but terminates the specified process instead.
230
231=cut
232
233sub cancel {
242 push @ready, $_[0]; 234 push @destroy, $_[0];
235 $manager->ready;
236 &schedule if $current == $_[0];
237}
238
239=item $oldprio = $process->prio($newprio)
240
241Sets the priority of the process. Higher priority processes get run before
242lower priority processes. Priorities are smalled signed integer (currently
243-4 .. +3), that you can refer to using PRIO_xxx constants (use the import
244tag :prio to get then):
245
246 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
247 3 > 1 > 0 > -1 > -3 > -4
248
249 # set priority to HIGH
250 current->prio(PRIO_HIGH);
251
252The idle coroutine ($Coro::idle) always has a lower priority than any
253existing coroutine.
254
255Changing the priority of the current process will take effect immediately,
256but changing the priority of processes in the ready queue (but not
257running) will only take effect after the next schedule (of that
258process). This is a bug that will be fixed in some future version.
259
260=cut
261
262sub prio {
263 my $old = $_[0]{prio};
264 $_[0]{prio} = $_[1] if @_ > 1;
265 $old;
266}
267
268=item $newprio = $process->nice($change)
269
270Similar to C<prio>, but subtract the given value from the priority (i.e.
271higher values mean lower priority, just as in unix).
272
273=cut
274
275sub nice {
276 $_[0]{prio} -= $_[1];
243} 277}
244 278
245=back 279=back
246 280
247=cut 281=cut
248 282
2491; 2831;
250 284
251=head1 BUGS/LIMITATIONS 285=head1 BUGS/LIMITATIONS
252 286
253 - could be faster, especially when the core would introduce special 287 - you must make very sure that no coro is still active on global destruction.
254 support for coroutines (like it does for threads). 288 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 289 - 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 290 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). 291 allow per-thread schedulers, but Coro::State does not yet allow this).
264 292
265=head1 SEE ALSO 293=head1 SEE ALSO
266 294
267L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 295L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 296L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
297L<Coro::Handle>, L<Coro::Socket>.
269 298
270=head1 AUTHOR 299=head1 AUTHOR
271 300
272 Marc Lehmann <pcg@goof.com> 301 Marc Lehmann <pcg@goof.com>
273 http://www.goof.com/pcg/marc/ 302 http://www.goof.com/pcg/marc/

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