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Comparing Coro/Coro.pm (file contents):
Revision 1.9 by root, Sun Jul 15 02:35:52 2001 UTC vs.
Revision 1.53 by root, Tue May 27 01:15:26 2003 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
28callchain, it's own set of lexicals and it's own set of perl's most
29important global variables.
30
23=cut 31=cut
24 32
25package Coro; 33package Coro;
26 34
35no warnings qw(uninitialized);
36
27use Coro::State; 37use Coro::State;
28 38
29use base Exporter; 39use base Exporter;
30 40
31$VERSION = 0.04; 41$VERSION = 0.7;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}};
35 48
36{ 49{
37 use subs 'async';
38
39 my @async; 50 my @async;
51 my $init;
40 52
41 # this way of handling attributes simply is NOT scalable ;() 53 # this way of handling attributes simply is NOT scalable ;()
42 sub import { 54 sub import {
43 Coro->export_to_level(1, @_); 55 Coro->export_to_level(1, @_);
44 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
… …
46 my ($package, $ref) = (shift, shift); 58 my ($package, $ref) = (shift, shift);
47 my @attrs; 59 my @attrs;
48 for (@_) { 60 for (@_) {
49 if ($_ eq "Coro") { 61 if ($_ eq "Coro") {
50 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 }
51 } else { 70 } else {
52 push @attrs, @_; 71 push @attrs, $_;
53 } 72 }
54 } 73 }
55 return $old ? $old->($package, $name, @attrs) : @attrs; 74 return $old ? $old->($package, $ref, @attrs) : @attrs;
56 }; 75 };
57 } 76 }
58 77
59 sub INIT {
60 async pop @async while @async;
61 }
62} 78}
79
80=over 4
63 81
64=item $main 82=item $main
65 83
66This coroutine represents the main program. 84This coroutine represents the main program.
67 85
68=cut 86=cut
69 87
70our $main = new Coro; 88our $main = new Coro;
71 89
72=item $current 90=item $current (or as function: current)
73 91
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 92The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 93
76=cut 94=cut
77 95
… …
79if ($current) { 97if ($current) {
80 $main->{specific} = $current->{specific}; 98 $main->{specific} = $current->{specific};
81} 99}
82 100
83our $current = $main; 101our $current = $main;
102
103sub current() { $current }
84 104
85=item $idle 105=item $idle
86 106
87The coroutine to switch to when no other coroutine is running. The default 107The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 108implementation prints "FATAL: deadlock detected" and exits.
… …
93our $idle = new Coro sub { 113our $idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 114 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 115 exit(51);
96}; 116};
97 117
98# we really need priorities... 118# this coroutine is necessary because a coroutine
99my @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};
100 138
101# static methods. not really. 139# static methods. not really.
102 140
141=back
142
103=head2 STATIC METHODS 143=head2 STATIC METHODS
104 144
105Static methods are actually functions that operate on the current process only. 145Static methods are actually functions that operate on the current process only.
106 146
107=over 4 147=over 4
108 148
109=item async { ... }; 149=item async { ... } [@args...]
110 150
111Create a new asynchronous process and return it's process object 151Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 152(usually unused). When the sub returns the new process is automatically
113terminated. 153terminated.
114 154
115=cut 155 # create a new coroutine that just prints its arguments
156 async {
157 print "@_\n";
158 } 1,2,3,4;
116 159
160The coderef you submit MUST NOT be a closure that refers to variables
161in an outer scope. This does NOT work. Pass arguments into it instead.
162
163=cut
164
117sub async(&) { 165sub async(&@) {
118 (new Coro $_[0])->ready; 166 my $pid = new Coro @_;
167 $manager->ready; # this ensures that the stack is cloned from the manager
168 $pid->ready;
169 $pid;
119} 170}
120 171
121=item schedule 172=item schedule
122 173
123Calls the scheduler. Please note that the current process will not be put 174Calls the scheduler. Please note that the current process will not be put
124into the ready queue, so calling this function usually means you will 175into the ready queue, so calling this function usually means you will
125never be called again. 176never be called again.
126 177
127=cut 178=cut
128 179
129my $prev;
130
131sub schedule {
132 # should be done using priorities :(
133 ($prev, $current) = ($current, shift @ready || $idle);
134 Coro::State::transfer($prev, $current);
135}
136
137=item yield 180=item cede
138 181
139Yield to other processes. This function puts the current process into the 182"Cede" to other processes. This function puts the current process into the
140ready queue and calls C<schedule>. 183ready queue and calls C<schedule>, which has the effect of giving up the
184current "timeslice" to other coroutines of the same or higher priority.
141 185
142=cut 186=cut
143 187
144sub yield { 188=item terminate [arg...]
189
190Terminates the current process.
191
192Future versions of this function will allow result arguments.
193
194=cut
195
196sub terminate {
197 $current->{status} = [@_];
145 $current->ready; 198 $current->cancel;
146 &schedule; 199 &schedule;
147} 200 die; # NORETURN
148
149=item terminate
150
151Terminates the current process.
152
153=cut
154
155sub terminate {
156 &schedule;
157} 201}
158 202
159=back 203=back
160 204
161# dynamic methods 205# dynamic methods
… …
164 208
165These are the methods you can call on process objects. 209These are the methods you can call on process objects.
166 210
167=over 4 211=over 4
168 212
169=item new Coro \&sub; 213=item new Coro \&sub [, @args...]
170 214
171Create a new process and return it. When the sub returns the process 215Create a new process and return it. When the sub returns the process
172automatically terminates. To start the process you must first put it into 216automatically terminates as if C<terminate> with the returned values were
217called. To make the process run you must first put it into the ready queue
173the ready queue by calling the ready method. 218by calling the ready method.
174 219
175=cut 220=cut
221
222sub _newcoro {
223 terminate &{+shift};
224}
176 225
177sub new { 226sub new {
178 my $class = shift; 227 my $class = shift;
179 my $proc = $_[0];
180 bless { 228 bless {
181 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 229 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
182 }, $class; 230 }, $class;
183} 231}
184 232
185=item $process->ready 233=item $process->ready
186 234
187Put the current process into the ready queue. 235Put the given process into the ready queue.
188 236
189=cut 237=cut
190 238
191sub ready { 239=item $process->cancel
240
241Like C<terminate>, but terminates the specified process instead.
242
243=cut
244
245sub cancel {
192 push @ready, $_[0]; 246 push @destroy, $_[0];
247 $manager->ready;
248 &schedule if $current == $_[0];
249}
250
251=item $process->join
252
253Wait until the coroutine terminates and return any values given to the
254C<terminate> function. C<join> can be called multiple times from multiple
255processes.
256
257=cut
258
259sub join {
260 my $self = shift;
261 unless ($self->{status}) {
262 push @{$self->{join}}, $current;
263 &schedule;
264 }
265 wantarray ? @{$self->{status}} : $self->{status}[0];
266}
267
268=item $oldprio = $process->prio($newprio)
269
270Sets (or gets, if the argument is missing) the priority of the
271process. Higher priority processes get run before lower priority
272processes. Priorities are small signed integers (currently -4 .. +3),
273that you can refer to using PRIO_xxx constants (use the import tag :prio
274to 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];
307}
308
309=item $olddesc = $process->desc($newdesc)
310
311Sets (or gets in case the argument is missing) the description for this
312process. This is just a free-form string you can associate with a process.
313
314=cut
315
316sub desc {
317 my $old = $_[0]{desc};
318 $_[0]{desc} = $_[1] if @_ > 1;
319 $old;
193} 320}
194 321
195=back 322=back
196 323
197=cut 324=cut
198 325
1991; 3261;
200 327
328=head1 BUGS/LIMITATIONS
329
330 - you must make very sure that no coro is still active on global
331 destruction. very bad things might happen otherwise (usually segfaults).
332
333 - this module is not thread-safe. You should only ever use this module
334 from the same thread (this requirement might be losened in the future
335 to allow per-thread schedulers, but Coro::State does not yet allow
336 this).
337
201=head1 SEE ALSO 338=head1 SEE ALSO
202 339
203L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 340L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
204L<Coro::Signal>, L<Coro::State>. 341L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
342L<Coro::Handle>, L<Coro::Socket>.
205 343
206=head1 AUTHOR 344=head1 AUTHOR
207 345
208 Marc Lehmann <pcg@goof.com> 346 Marc Lehmann <pcg@goof.com>
209 http://www.goof.com/pcg/marc/ 347 http://www.goof.com/pcg/marc/

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