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Comparing Coro/Coro.pm (file contents):
Revision 1.13 by root, Tue Jul 17 00:24:14 2001 UTC vs.
Revision 1.65 by root, Tue Feb 22 19:51:58 2005 UTC

… …
14 14
15 sub some_func : Coro { 15 sub some_func : Coro {
16 # some more async code 16 # some more async code
17 } 17 }
18 18
19 yield; 19 cede;
20 20
21=head1 DESCRIPTION 21=head1 DESCRIPTION
22 22
23This module collection manages coroutines. Coroutines are similar to
24threads but don't run in parallel.
25
26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
27use Coro::State; 37use Coro::State;
28 38
39use vars qw($idle $main $current);
40
29use base Exporter; 41use base Exporter;
30 42
31$VERSION = 0.05; 43$VERSION = 1.1;
32 44
33@EXPORT = qw(async yield schedule terminate); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}};
35 50
36{ 51{
37 use subs 'async';
38
39 my @async; 52 my @async;
53 my $init;
40 54
41 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 56 sub import {
43 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
46 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
47 my @attrs; 61 my @attrs;
48 for (@_) { 62 for (@_) {
49 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
50 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 }
51 } else { 72 } else {
52 push @attrs, @_; 73 push @attrs, $_;
53 } 74 }
54 } 75 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 77 };
57 } 78 }
58 79
59 sub INIT {
60 async pop @async while @async;
61 }
62} 80}
81
82=over 4
63 83
64=item $main 84=item $main
65 85
66This coroutine represents the main program. 86This coroutine represents the main program.
67 87
68=cut 88=cut
69 89
70our $main = new Coro; 90$main = new Coro;
71 91
72=item $current 92=item $current (or as function: current)
73 93
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 95
76=cut 96=cut
77 97
78# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
79if ($current) { 99if ($current) {
80 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
81} 101}
82 102
83our $current = $main; 103$current = $main;
104
105sub current() { $current }
84 106
85=item $idle 107=item $idle
86 108
87The coroutine to switch to when no other coroutine is running. The default 109The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
89 111
90=cut 112=cut
91 113
92# should be done using priorities :( 114# should be done using priorities :(
93our $idle = new Coro sub { 115$idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 117 exit(51);
96}; 118};
97 119
98# we really need priorities... 120# this coroutine is necessary because a coroutine
99## my @ready; #d# 121# cannot destroy itself.
100our @ready = (); # the ready queue. hehe, rather broken ;) 122my @destroy;
123my $manager;
124$manager = new Coro sub {
125 while () {
126 # by overwriting the state object with the manager we destroy it
127 # while still being able to schedule this coroutine (in case it has
128 # been readied multiple times. this is harmless since the manager
129 # can be called as many times as neccessary and will always
130 # remove itself from the runqueue
131 while (@destroy) {
132 my $coro = pop @destroy;
133 $coro->{status} ||= [];
134 $_->ready for @{delete $coro->{join} || []};
135
136 # the next line destroys the _coro_state, but keeps the
137 # process itself intact (we basically make it a zombie
138 # process that always runs the manager thread, so it's possible
139 # to transfer() to this process).
140 $coro->{_coro_state} = $manager->{_coro_state};
141 }
142 &schedule;
143 }
144};
101 145
102# static methods. not really. 146# static methods. not really.
147
148=back
103 149
104=head2 STATIC METHODS 150=head2 STATIC METHODS
105 151
106Static methods are actually functions that operate on the current process only. 152Static methods are actually functions that operate on the current process only.
107 153
… …
116 # create a new coroutine that just prints its arguments 162 # create a new coroutine that just prints its arguments
117 async { 163 async {
118 print "@_\n"; 164 print "@_\n";
119 } 1,2,3,4; 165 } 1,2,3,4;
120 166
121The coderef you submit MUST NOT be a closure that refers to variables
122in an outer scope. This does NOT work. Pass arguments into it instead.
123
124=cut 167=cut
125 168
126sub async(&@) { 169sub async(&@) {
127 my $pid = new Coro @_; 170 my $pid = new Coro @_;
171 $manager->ready; # this ensures that the stack is cloned from the manager
128 $pid->ready; 172 $pid->ready;
129 $pid; 173 $pid;
130} 174}
131 175
132=item schedule 176=item schedule
… …
135into the ready queue, so calling this function usually means you will 179into the ready queue, so calling this function usually means you will
136never be called again. 180never be called again.
137 181
138=cut 182=cut
139 183
140my $prev;
141
142sub schedule {
143 # should be done using priorities :(
144 ($prev, $current) = ($current, shift @ready || $idle);
145 Coro::State::transfer($prev, $current);
146}
147
148=item yield 184=item cede
149 185
150Yield to other processes. This function puts the current process into the 186"Cede" to other processes. This function puts the current process into the
151ready queue and calls C<schedule>. 187ready queue and calls C<schedule>, which has the effect of giving up the
188current "timeslice" to other coroutines of the same or higher priority.
152 189
153=cut 190=cut
154 191
155sub yield {
156 $current->ready;
157 &schedule;
158}
159
160=item terminate 192=item terminate [arg...]
161 193
162Terminates the current process. 194Terminates the current process with the given status values (see L<cancel>).
163
164Future versions of this function will allow result arguments.
165 195
166=cut 196=cut
167 197
168sub terminate { 198sub terminate {
169 $current->{_results} = [@_]; 199 $current->cancel (@_);
170 &schedule;
171} 200}
172 201
173=back 202=back
174 203
175# dynamic methods 204# dynamic methods
… …
181=over 4 210=over 4
182 211
183=item new Coro \&sub [, @args...] 212=item new Coro \&sub [, @args...]
184 213
185Create a new process and return it. When the sub returns the process 214Create a new process and return it. When the sub returns the process
186automatically terminates. To start the process you must first put it into 215automatically terminates as if C<terminate> with the returned values were
216called. To make the process run you must first put it into the ready queue
187the ready queue by calling the ready method. 217by calling the ready method.
188
189The coderef you submit MUST NOT be a closure that refers to variables
190in an outer scope. This does NOT work. Pass arguments into it instead.
191 218
192=cut 219=cut
193 220
194sub _newcoro { 221sub _newcoro {
195 terminate &{+shift}; 222 terminate &{+shift};
… …
202 }, $class; 229 }, $class;
203} 230}
204 231
205=item $process->ready 232=item $process->ready
206 233
207Put the current process into the ready queue. 234Put the given process into the ready queue.
208 235
209=cut 236=cut
210 237
211sub ready { 238=item $process->cancel (arg...)
212 push @ready, $_[0]; 239
240Temrinates the given process and makes it return the given arguments as
241status (default: the empty list).
242
243=cut
244
245sub cancel {
246 my $self = shift;
247 $self->{status} = [@_];
248 push @destroy, $self;
249 $manager->ready;
250 &schedule if $current == $self;
251}
252
253=item $process->join
254
255Wait until the coroutine terminates and return any values given to the
256C<terminate> or C<cancel> functions. C<join> can be called multiple times
257from multiple processes.
258
259=cut
260
261sub join {
262 my $self = shift;
263 unless ($self->{status}) {
264 push @{$self->{join}}, $current;
265 &schedule;
266 }
267 wantarray ? @{$self->{status}} : $self->{status}[0];
268}
269
270=item $oldprio = $process->prio($newprio)
271
272Sets (or gets, if the argument is missing) the priority of the
273process. Higher priority processes get run before lower priority
274processes. Priorities are small signed integers (currently -4 .. +3),
275that you can refer to using PRIO_xxx constants (use the import tag :prio
276to get then):
277
278 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
279 3 > 1 > 0 > -1 > -3 > -4
280
281 # set priority to HIGH
282 current->prio(PRIO_HIGH);
283
284The idle coroutine ($Coro::idle) always has a lower priority than any
285existing coroutine.
286
287Changing the priority of the current process will take effect immediately,
288but changing the priority of processes in the ready queue (but not
289running) will only take effect after the next schedule (of that
290process). This is a bug that will be fixed in some future version.
291
292=cut
293
294sub prio {
295 my $old = $_[0]{prio};
296 $_[0]{prio} = $_[1] if @_ > 1;
297 $old;
298}
299
300=item $newprio = $process->nice($change)
301
302Similar to C<prio>, but subtract the given value from the priority (i.e.
303higher values mean lower priority, just as in unix).
304
305=cut
306
307sub nice {
308 $_[0]{prio} -= $_[1];
309}
310
311=item $olddesc = $process->desc($newdesc)
312
313Sets (or gets in case the argument is missing) the description for this
314process. This is just a free-form string you can associate with a process.
315
316=cut
317
318sub desc {
319 my $old = $_[0]{desc};
320 $_[0]{desc} = $_[1] if @_ > 1;
321 $old;
213} 322}
214 323
215=back 324=back
216 325
217=cut 326=cut
218 327
2191; 3281;
220 329
330=head1 BUGS/LIMITATIONS
331
332 - you must make very sure that no coro is still active on global
333 destruction. very bad things might happen otherwise (usually segfaults).
334
335 - this module is not thread-safe. You should only ever use this module
336 from the same thread (this requirement might be losened in the future
337 to allow per-thread schedulers, but Coro::State does not yet allow
338 this).
339
221=head1 SEE ALSO 340=head1 SEE ALSO
222 341
223L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 342L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
224L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 343L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
344L<Coro::Handle>, L<Coro::RWLock>, L<Coro::Socket>.
225 345
226=head1 AUTHOR 346=head1 AUTHOR
227 347
228 Marc Lehmann <pcg@goof.com> 348 Marc Lehmann <pcg@goof.com>
229 http://www.goof.com/pcg/marc/ 349 http://home.schmorp.de/
230 350
231=cut 351=cut
232 352

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