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Comparing Coro/Coro.pm (file contents):
Revision 1.12 by root, Sun Jul 15 15:58:16 2001 UTC vs.
Revision 1.42 by root, Tue Nov 6 20:37:20 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
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 = 0.05; 41$VERSION = 0.52;
32 42
33@EXPORT = qw(async yield schedule); 43@EXPORT = qw(async cede schedule terminate current);
34@EXPORT_OK = qw($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}
63 79
64=item $main 80=item $main
65 81
66This coroutine represents the main program. 82This coroutine represents the main program.
67 83
68=cut 84=cut
69 85
70our $main = new Coro; 86our $main = new Coro;
71 87
72=item $current 88=item $current (or as function: current)
73 89
74The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 90The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
75 91
76=cut 92=cut
77 93
… …
79if ($current) { 95if ($current) {
80 $main->{specific} = $current->{specific}; 96 $main->{specific} = $current->{specific};
81} 97}
82 98
83our $current = $main; 99our $current = $main;
100
101sub current() { $current }
84 102
85=item $idle 103=item $idle
86 104
87The coroutine to switch to when no other coroutine is running. The default 105The coroutine to switch to when no other coroutine is running. The default
88implementation prints "FATAL: deadlock detected" and exits. 106implementation prints "FATAL: deadlock detected" and exits.
… …
93our $idle = new Coro sub { 111our $idle = new Coro sub {
94 print STDERR "FATAL: deadlock detected\n"; 112 print STDERR "FATAL: deadlock detected\n";
95 exit(51); 113 exit(51);
96}; 114};
97 115
98# we really need priorities... 116# this coroutine is necessary because a coroutine
99my @ready = (); # the ready queue. hehe, rather broken ;) 117# cannot destroy itself.
118my @destroy;
119my $manager;
120$manager = new Coro sub {
121 while() {
122 # by overwriting the state object with the manager we destroy it
123 # while still being able to schedule this coroutine (in case it has
124 # been readied multiple times. this is harmless since the manager
125 # can be called as many times as neccessary and will always
126 # remove itself from the runqueue
127 while (@destroy) {
128 my $coro = pop @destroy;
129 $coro->{status} ||= [];
130 $_->ready for @{delete $coro->{join} || []};
131 $coro->{_coro_state} = $manager->{_coro_state};
132 }
133 &schedule;
134 }
135};
100 136
101# static methods. not really. 137# static methods. not really.
102 138
103=head2 STATIC METHODS 139=head2 STATIC METHODS
104 140
105Static methods are actually functions that operate on the current process only. 141Static methods are actually functions that operate on the current process only.
106 142
107=over 4 143=over 4
108 144
109=item async { ... }; 145=item async { ... } [@args...]
110 146
111Create a new asynchronous process and return it's process object 147Create a new asynchronous process and return it's process object
112(usually unused). When the sub returns the new process is automatically 148(usually unused). When the sub returns the new process is automatically
113terminated. 149terminated.
114 150
115=cut 151 # create a new coroutine that just prints its arguments
152 async {
153 print "@_\n";
154 } 1,2,3,4;
116 155
156The coderef you submit MUST NOT be a closure that refers to variables
157in an outer scope. This does NOT work. Pass arguments into it instead.
158
159=cut
160
117sub async(&) { 161sub async(&@) {
118 my $pid = new Coro $_[0]; 162 my $pid = new Coro @_;
163 $manager->ready; # this ensures that the stack is cloned from the manager
119 $pid->ready; 164 $pid->ready;
120 $pid; 165 $pid;
121} 166}
122 167
123=item schedule 168=item schedule
… …
126into the ready queue, so calling this function usually means you will 171into the ready queue, so calling this function usually means you will
127never be called again. 172never be called again.
128 173
129=cut 174=cut
130 175
131my $prev;
132
133sub schedule {
134 local @_;
135 # should be done using priorities :(
136 ($prev, $current) = ($current, shift @ready || $idle);
137 Coro::State::transfer($prev, $current);
138}
139
140=item yield 176=item cede
141 177
142Yield to other processes. This function puts the current process into the 178"Cede" to other processes. This function puts the current process into the
143ready queue and calls C<schedule>. 179ready queue and calls C<schedule>, which has the effect of giving up the
180current "timeslice" to other coroutines of the same or higher priority.
144 181
145=cut 182=cut
146 183
147sub yield { 184=item terminate [arg...]
185
186Terminates the current process.
187
188Future versions of this function will allow result arguments.
189
190=cut
191
192sub terminate {
193 $current->{status} = [@_];
148 $current->ready; 194 $current->cancel;
149 &schedule; 195 &schedule;
150} 196 die; # NORETURN
151
152=item terminate
153
154Terminates the current process.
155
156=cut
157
158sub terminate {
159 &schedule;
160} 197}
161 198
162=back 199=back
163 200
164# dynamic methods 201# dynamic methods
… …
167 204
168These are the methods you can call on process objects. 205These are the methods you can call on process objects.
169 206
170=over 4 207=over 4
171 208
172=item new Coro \&sub; 209=item new Coro \&sub [, @args...]
173 210
174Create a new process and return it. When the sub returns the process 211Create a new process and return it. When the sub returns the process
175automatically terminates. To start the process you must first put it into 212automatically terminates as if C<terminate> with the returned values were
213called. To make the process run you must first put it into the ready queue
176the ready queue by calling the ready method. 214by calling the ready method.
177 215
178=cut 216=cut
217
218sub _newcoro {
219 terminate &{+shift};
220}
179 221
180sub new { 222sub new {
181 my $class = shift; 223 my $class = shift;
182 my $proc = $_[0];
183 bless { 224 bless {
184 _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), 225 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
185 }, $class; 226 }, $class;
186} 227}
187 228
188=item $process->ready 229=item $process->ready
189 230
190Put the current process into the ready queue. 231Put the given process into the ready queue.
191 232
192=cut 233=cut
193 234
194sub ready { 235=item $process->cancel
236
237Like C<terminate>, but terminates the specified process instead.
238
239=cut
240
241sub cancel {
195 push @ready, $_[0]; 242 push @destroy, $_[0];
243 $manager->ready;
244 &schedule if $current == $_[0];
245}
246
247=item $process->join
248
249Wait until the coroutine terminates and return any values given to the
250C<terminate> function. C<join> can be called multiple times from multiple
251processes.
252
253=cut
254
255sub join {
256 my $self = shift;
257 unless ($self->{status}) {
258 push @{$self->{join}}, $current;
259 &schedule;
260 }
261 wantarray ? @{$self->{status}} : $self->{status}[0];
262}
263
264=item $oldprio = $process->prio($newprio)
265
266Sets (or gets, if the argument is missing) the priority of the
267process. Higher priority processes get run before lower priority
268processes. Priorities are smalled signed integer (currently -4 .. +3),
269that you can refer to using PRIO_xxx constants (use the import tag :prio
270to get then):
271
272 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
273 3 > 1 > 0 > -1 > -3 > -4
274
275 # set priority to HIGH
276 current->prio(PRIO_HIGH);
277
278The idle coroutine ($Coro::idle) always has a lower priority than any
279existing coroutine.
280
281Changing the priority of the current process will take effect immediately,
282but changing the priority of processes in the ready queue (but not
283running) will only take effect after the next schedule (of that
284process). This is a bug that will be fixed in some future version.
285
286=cut
287
288sub prio {
289 my $old = $_[0]{prio};
290 $_[0]{prio} = $_[1] if @_ > 1;
291 $old;
292}
293
294=item $newprio = $process->nice($change)
295
296Similar to C<prio>, but subtract the given value from the priority (i.e.
297higher values mean lower priority, just as in unix).
298
299=cut
300
301sub nice {
302 $_[0]{prio} -= $_[1];
303}
304
305=item $olddesc = $process->desc($newdesc)
306
307Sets (or gets in case the argument is missing) the description for this
308process. This is just a free-form string you can associate with a process.
309
310=cut
311
312sub desc {
313 my $old = $_[0]{desc};
314 $_[0]{desc} = $_[1] if @_ > 1;
315 $old;
196} 316}
197 317
198=back 318=back
199 319
200=cut 320=cut
201 321
2021; 3221;
203 323
324=head1 BUGS/LIMITATIONS
325
326 - you must make very sure that no coro is still active on global destruction.
327 very bad things might happen otherwise (usually segfaults).
328 - this module is not thread-safe. You should only ever use this module from
329 the same thread (this requirement might be loosened in the future to
330 allow per-thread schedulers, but Coro::State does not yet allow this).
331
204=head1 SEE ALSO 332=head1 SEE ALSO
205 333
206L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 334L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
207L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 335L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>,
336L<Coro::Handle>, L<Coro::Socket>.
208 337
209=head1 AUTHOR 338=head1 AUTHOR
210 339
211 Marc Lehmann <pcg@goof.com> 340 Marc Lehmann <pcg@goof.com>
212 http://www.goof.com/pcg/marc/ 341 http://www.goof.com/pcg/marc/

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