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Comparing Coro/Coro.pm (file contents):
Revision 1.14 by root, Tue Jul 17 02:21:56 2001 UTC vs.
Revision 1.58 by pcg, Fri Feb 13 23:17:41 2004 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 23This module collection manages coroutines. Coroutines are similar to
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. 26In this module, coroutines are defined as "callchain + lexical variables
27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") }
36
32use Coro::State; 37use Coro::State;
33 38
39use vars qw($idle $main $current);
40
34use base Exporter; 41use base Exporter;
35 42
36$VERSION = 0.05; 43$VERSION = 0.95;
37 44
38@EXPORT = qw(async yield schedule terminate); 45@EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($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}};
40 50
41{ 51{
42 use subs 'async';
43
44 my @async; 52 my @async;
53 my $init;
45 54
46 # this way of handling attributes simply is NOT scalable ;() 55 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 56 sub import {
48 Coro->export_to_level(1, @_); 57 Coro->export_to_level(1, @_);
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
51 my ($package, $ref) = (shift, shift); 60 my ($package, $ref) = (shift, shift);
52 my @attrs; 61 my @attrs;
53 for (@_) { 62 for (@_) {
54 if ($_ eq "Coro") { 63 if ($_ eq "Coro") {
55 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 }
56 } else { 72 } else {
57 push @attrs, @_; 73 push @attrs, $_;
58 } 74 }
59 } 75 }
60 return $old ? $old->($package, $name, @attrs) : @attrs; 76 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 77 };
62 } 78 }
63 79
64 sub INIT {
65 async pop @async while @async;
66 }
67} 80}
81
82=over 4
68 83
69=item $main 84=item $main
70 85
71This coroutine represents the main program. 86This coroutine represents the main program.
72 87
73=cut 88=cut
74 89
75our $main = new Coro; 90$main = new Coro;
76 91
77=item $current 92=item $current (or as function: current)
78 93
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 94The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
80 95
81=cut 96=cut
82 97
83# maybe some other module used Coro::Specific before... 98# maybe some other module used Coro::Specific before...
84if ($current) { 99if ($current) {
85 $main->{specific} = $current->{specific}; 100 $main->{specific} = $current->{specific};
86} 101}
87 102
88our $current = $main; 103$current = $main;
104
105sub current() { $current }
89 106
90=item $idle 107=item $idle
91 108
92The 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
93implementation prints "FATAL: deadlock detected" and exits. 110implementation prints "FATAL: deadlock detected" and exits.
94 111
95=cut 112=cut
96 113
97# should be done using priorities :( 114# should be done using priorities :(
98our $idle = new Coro sub { 115$idle = new Coro sub {
99 print STDERR "FATAL: deadlock detected\n"; 116 print STDERR "FATAL: deadlock detected\n";
100 exit(51); 117 exit(51);
101}; 118};
102 119
103# we really need priorities... 120# this coroutine is necessary because a coroutine
104## my @ready; #d# 121# cannot destroy itself.
105our @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 $coro->{_coro_state} = $manager->{_coro_state};
136 }
137 &schedule;
138 }
139};
106 140
107# static methods. not really. 141# static methods. not really.
142
143=back
108 144
109=head2 STATIC METHODS 145=head2 STATIC METHODS
110 146
111Static methods are actually functions that operate on the current process only. 147Static methods are actually functions that operate on the current process only.
112 148
… …
121 # create a new coroutine that just prints its arguments 157 # create a new coroutine that just prints its arguments
122 async { 158 async {
123 print "@_\n"; 159 print "@_\n";
124 } 1,2,3,4; 160 } 1,2,3,4;
125 161
126The coderef you submit MUST NOT be a closure that refers to variables
127in an outer scope. This does NOT work. Pass arguments into it instead.
128
129=cut 162=cut
130 163
131sub async(&@) { 164sub async(&@) {
132 my $pid = new Coro @_; 165 my $pid = new Coro @_;
166 $manager->ready; # this ensures that the stack is cloned from the manager
133 $pid->ready; 167 $pid->ready;
134 $pid; 168 $pid;
135} 169}
136 170
137=item schedule 171=item schedule
… …
140into the ready queue, so calling this function usually means you will 174into the ready queue, so calling this function usually means you will
141never be called again. 175never be called again.
142 176
143=cut 177=cut
144 178
145my $prev;
146
147sub schedule {
148 # should be done using priorities :(
149 ($prev, $current) = ($current, shift @ready || $idle);
150 Coro::State::transfer($prev, $current);
151}
152
153=item yield 179=item cede
154 180
155Yield to other processes. This function puts the current process into the 181"Cede" to other processes. This function puts the current process into the
156ready queue and calls C<schedule>. 182ready queue and calls C<schedule>, which has the effect of giving up the
183current "timeslice" to other coroutines of the same or higher priority.
157 184
158=cut 185=cut
159 186
160sub yield { 187=item terminate [arg...]
188
189Terminates the current process.
190
191Future versions of this function will allow result arguments.
192
193=cut
194
195sub terminate {
196 $current->{status} = [@_];
161 $current->ready; 197 $current->cancel;
162 &schedule; 198 &schedule;
163} 199 die; # NORETURN
164
165=item terminate
166
167Terminates the current process.
168
169Future versions of this function will allow result arguments.
170
171=cut
172
173sub terminate {
174 $current->{_results} = [@_];
175 &schedule;
176} 200}
177 201
178=back 202=back
179 203
180# dynamic methods 204# dynamic methods
… …
186=over 4 210=over 4
187 211
188=item new Coro \&sub [, @args...] 212=item new Coro \&sub [, @args...]
189 213
190Create 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
191automatically 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
192the ready queue by calling the ready method. 217by calling the ready method.
193
194The coderef you submit MUST NOT be a closure that refers to variables
195in an outer scope. This does NOT work. Pass arguments into it instead.
196 218
197=cut 219=cut
198 220
199sub _newcoro { 221sub _newcoro {
200 terminate &{+shift}; 222 terminate &{+shift};
… …
207 }, $class; 229 }, $class;
208} 230}
209 231
210=item $process->ready 232=item $process->ready
211 233
212Put the current process into the ready queue. 234Put the given process into the ready queue.
213 235
214=cut 236=cut
215 237
216sub ready { 238=item $process->cancel
239
240Like C<terminate>, but terminates the specified process instead.
241
242=cut
243
244sub cancel {
217 push @ready, $_[0]; 245 push @destroy, $_[0];
246 $manager->ready;
247 &schedule if $current == $_[0];
248}
249
250=item $process->join
251
252Wait until the coroutine terminates and return any values given to the
253C<terminate> function. C<join> can be called multiple times from multiple
254processes.
255
256=cut
257
258sub join {
259 my $self = shift;
260 unless ($self->{status}) {
261 push @{$self->{join}}, $current;
262 &schedule;
263 }
264 wantarray ? @{$self->{status}} : $self->{status}[0];
265}
266
267=item $oldprio = $process->prio($newprio)
268
269Sets (or gets, if the argument is missing) the priority of the
270process. Higher priority processes get run before lower priority
271processes. Priorities are small signed integers (currently -4 .. +3),
272that you can refer to using PRIO_xxx constants (use the import tag :prio
273to get then):
274
275 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
276 3 > 1 > 0 > -1 > -3 > -4
277
278 # set priority to HIGH
279 current->prio(PRIO_HIGH);
280
281The idle coroutine ($Coro::idle) always has a lower priority than any
282existing coroutine.
283
284Changing the priority of the current process will take effect immediately,
285but changing the priority of processes in the ready queue (but not
286running) will only take effect after the next schedule (of that
287process). This is a bug that will be fixed in some future version.
288
289=cut
290
291sub prio {
292 my $old = $_[0]{prio};
293 $_[0]{prio} = $_[1] if @_ > 1;
294 $old;
295}
296
297=item $newprio = $process->nice($change)
298
299Similar to C<prio>, but subtract the given value from the priority (i.e.
300higher values mean lower priority, just as in unix).
301
302=cut
303
304sub nice {
305 $_[0]{prio} -= $_[1];
306}
307
308=item $olddesc = $process->desc($newdesc)
309
310Sets (or gets in case the argument is missing) the description for this
311process. This is just a free-form string you can associate with a process.
312
313=cut
314
315sub desc {
316 my $old = $_[0]{desc};
317 $_[0]{desc} = $_[1] if @_ > 1;
318 $old;
218} 319}
219 320
220=back 321=back
221 322
222=cut 323=cut
223 324
2241; 3251;
225 326
226=head1 BUGS 327=head1 BUGS/LIMITATIONS
227 328
228 - could be faster, especially when the core would introduce special 329 - you must make very sure that no coro is still active on global
229 support for coroutines (like it does for threads). 330 destruction. very bad things might happen otherwise (usually segfaults).
230 - there is still a memleak on coroutine termination that I could not 331
231 identify. Could be as small as a single SV. 332 - this module is not thread-safe. You should only ever use this module
232 - this module is not well-tested. 333 from the same thread (this requirement might be losened in the future
334 to allow per-thread schedulers, but Coro::State does not yet allow
335 this).
233 336
234=head1 SEE ALSO 337=head1 SEE ALSO
235 338
236L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 339L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
237L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 340L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>,
341L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>.
238 342
239=head1 AUTHOR 343=head1 AUTHOR
240 344
241 Marc Lehmann <pcg@goof.com> 345 Marc Lehmann <pcg@goof.com>
242 http://www.goof.com/pcg/marc/ 346 http://www.goof.com/pcg/marc/

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