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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 1.40 by root, Sun Oct 28 17:00:05 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$VERSION = 0.51;
58 44
59@EXPORT = qw(async cede schedule terminate current); 45@EXPORT = qw(async cede schedule terminate current);
60@EXPORT_OK = qw($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
217the 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.
218 217
219The 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
220in 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.
221 220
222=cut 221=cut
… …
232 }, $class; 231 }, $class;
233} 232}
234 233
235=item $process->ready 234=item $process->ready
236 235
237Put the current process into the ready queue. 236Put the given process into the ready queue.
238 237
239=cut 238=cut
240 239
241sub ready { 240=item $process->cancel
241
242Like C<terminate>, but terminates the specified process instead.
243
244=cut
245
246sub cancel {
242 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];
243} 307}
244 308
245=back 309=back
246 310
247=cut 311=cut
248 312
2491; 3131;
250 314
251=head1 BUGS/LIMITATIONS 315=head1 BUGS/LIMITATIONS
252 316
253 - 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.
254 support for coroutines (like it does for threads). 318 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 319 - 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 320 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). 321 allow per-thread schedulers, but Coro::State does not yet allow this).
264 322
265=head1 SEE ALSO 323=head1 SEE ALSO
266 324
267L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 325L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
268L<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>.
269 328
270=head1 AUTHOR 329=head1 AUTHOR
271 330
272 Marc Lehmann <pcg@goof.com> 331 Marc Lehmann <pcg@goof.com>
273 http://www.goof.com/pcg/marc/ 332 http://www.goof.com/pcg/marc/

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