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Comparing Coro/Coro.pm (file contents):
Revision 1.11 by root, Sun Jul 15 03:24:18 2001 UTC vs.
Revision 1.41 by root, Tue Nov 6 20:34:09 2001 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
26This module is still experimental, see the BUGS section below.
27
28In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most
31important global variables.
32
23=cut 33=cut
24 34
25package Coro; 35package Coro;
26 36
37no warnings qw(uninitialized);
38
27use Coro::State; 39use Coro::State;
28 40
29use base Exporter; 41use base Exporter;
30 42
31$VERSION = 0.04; 43$VERSION = 0.52;
32 44
33@EXPORT = qw(async yield schedule); 45@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}
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
103=head2 STATIC METHODS 141=head2 STATIC METHODS
104 142
105Static methods are actually functions that operate on the current process only. 143Static methods are actually functions that operate on the current process only.
106 144
107=over 4 145=over 4
108 146
109=item async { ... }; 147=item async { ... } [@args...]
110 148
111Create a new asynchronous process and return it's process object 149Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 150(usually unused). When the sub returns the new process is automatically
113terminated. 151terminated.
114 152
115=cut 153 # create a new coroutine that just prints its arguments
154 async {
155 print "@_\n";
156 } 1,2,3,4;
116 157
158The coderef you submit MUST NOT be a closure that refers to variables
159in an outer scope. This does NOT work. Pass arguments into it instead.
160
161=cut
162
117sub async(&) { 163sub async(&@) {
118 my $pid = new Coro $_[0]; 164 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 166 $pid->ready;
120 $pid; 167 $pid;
121} 168}
122 169
123=item schedule 170=item schedule
… …
126into the ready queue, so calling this function usually means you will 173into the ready queue, so calling this function usually means you will
127never be called again. 174never be called again.
128 175
129=cut 176=cut
130 177
131my $prev;
132
133sub schedule {
134 # should be done using priorities :(
135 ($prev, $current) = ($current, shift @ready || $idle);
136 Coro::State::transfer($prev, $current);
137}
138
139=item yield 178=item cede
140 179
141Yield to other processes. This function puts the current process into the 180"Cede" to other processes. This function puts the current process into the
142ready queue and calls C<schedule>. 181ready queue and calls C<schedule>, which has the effect of giving up the
182current "timeslice" to other coroutines of the same or higher priority.
143 183
144=cut 184=cut
145 185
146sub yield { 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} = [@_];
147 $current->ready; 196 $current->cancel;
148 &schedule; 197 &schedule;
149} 198 die; # NORETURN
150
151=item terminate
152
153Terminates the current process.
154
155=cut
156
157sub terminate {
158 &schedule;
159} 199}
160 200
161=back 201=back
162 202
163# dynamic methods 203# dynamic methods
… …
166 206
167These are the methods you can call on process objects. 207These are the methods you can call on process objects.
168 208
169=over 4 209=over 4
170 210
171=item new Coro \&sub; 211=item new Coro \&sub [, @args...]
172 212
173Create 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
174automatically terminates. To start the process you must first put it into 214automatically terminates as if C<terminate> with the returned values were
215called. To make the process run you must first put it into the ready queue
175the ready queue by calling the ready method. 216by calling the ready method.
176 217
177=cut 218=cut
219
220sub _newcoro {
221 terminate &{+shift};
222}
178 223
179sub new { 224sub new {
180 my $class = shift; 225 my $class = shift;
181 my $proc = $_[0];
182 bless { 226 bless {
183 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 227 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
184 }, $class; 228 }, $class;
185} 229}
186 230
187=item $process->ready 231=item $process->ready
188 232
189Put the current process into the ready queue. 233Put the given process into the ready queue.
190 234
191=cut 235=cut
192 236
193sub ready { 237=item $process->cancel
238
239Like C<terminate>, but terminates the specified process instead.
240
241=cut
242
243sub cancel {
194 push @ready, $_[0]; 244 push @destroy, $_[0];
245 $manager->ready;
246 &schedule if $current == $_[0];
247}
248
249=item $process->join
250
251Wait until the coroutine terminates and return any values given to the
252C<terminate> function. C<join> can be called multiple times from multiple
253processes.
254
255=cut
256
257sub join {
258 my $self = shift;
259 unless ($self->{status}) {
260 push @{$self->{join}}, $current;
261 &schedule;
262 }
263 wantarray ? @{$self->{status}} : $self->{status}[0];
264}
265
266=item $oldprio = $process->prio($newprio)
267
268Sets (or gets, if the argument is missing) the priority of the
269process. Higher priority processes get run before lower priority
270processes. Priorities are smalled signed integer (currently -4 .. +3),
271that you can refer to using PRIO_xxx constants (use the import tag :prio
272to get then):
273
274 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
275 3 > 1 > 0 > -1 > -3 > -4
276
277 # set priority to HIGH
278 current->prio(PRIO_HIGH);
279
280The idle coroutine ($Coro::idle) always has a lower priority than any
281existing coroutine.
282
283Changing the priority of the current process will take effect immediately,
284but changing the priority of processes in the ready queue (but not
285running) will only take effect after the next schedule (of that
286process). This is a bug that will be fixed in some future version.
287
288=cut
289
290sub prio {
291 my $old = $_[0]{prio};
292 $_[0]{prio} = $_[1] if @_ > 1;
293 $old;
294}
295
296=item $newprio = $process->nice($change)
297
298Similar to C<prio>, but subtract the given value from the priority (i.e.
299higher values mean lower priority, just as in unix).
300
301=cut
302
303sub nice {
304 $_[0]{prio} -= $_[1];
305}
306
307=item $olddesc = $process->desc($newdesc)
308
309Sets (or gets in case the argument is missing) the description for this
310process. This is just a free-form string you can associate with a process.
311
312=cut
313
314sub desc {
315 my $old = $_[0]{desc};
316 $_[0]{desc} = $_[1] if @_ > 1;
317 $old;
195} 318}
196 319
197=back 320=back
198 321
199=cut 322=cut
200 323
2011; 3241;
202 325
326=head1 BUGS/LIMITATIONS
327
328 - you must make very sure that no coro is still active on global destruction.
329 very bad things might happen otherwise (usually segfaults).
330 - this module is not thread-safe. You must only ever use this module from
331 the same thread (this requirement might be loosened in the future to
332 allow per-thread schedulers, but Coro::State does not yet allow this).
333
203=head1 SEE ALSO 334=head1 SEE ALSO
204 335
205L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 336L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
206L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 337L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
338L<Coro::Handle>, L<Coro::Socket>.
207 339
208=head1 AUTHOR 340=head1 AUTHOR
209 341
210 Marc Lehmann <pcg@goof.com> 342 Marc Lehmann <pcg@goof.com>
211 http://www.goof.com/pcg/marc/ 343 http://www.goof.com/pcg/marc/

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