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Revision 1.36 by root, Mon Sep 24 01:36:20 2001 UTC vs.
Revision 1.78 by root, Wed Nov 1 01:21:21 2006 UTC

… …
19 cede; 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
26This module is still experimental, see the BUGS section below.
27 25
28In this module, coroutines are defined as "callchain + lexical variables 26In this module, coroutines are defined as "callchain + lexical variables
29+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own 27+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most 28callchain, it's own set of lexicals and it's own set of perl's most
31important global variables. 29important global variables.
32 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35use strict;
37no warnings qw(uninitialized); 36no warnings "uninitialized";
38 37
39use Coro::State; 38use Coro::State;
40 39
41use base Exporter; 40use base Exporter::;
42 41
43$VERSION = 0.5; 42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
44 45
46our $VERSION = '2.1';
47
45@EXPORT = qw(async cede schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
46%EXPORT_TAGS = ( 49our %EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48); 51);
49@EXPORT_OK = @{$EXPORT_TAGS{prio}}; 52our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
50 53
51{ 54{
52 my @async; 55 my @async;
53 my $init; 56 my $init;
54 57
55 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
56 sub import { 59 sub import {
60 no strict 'refs';
61
57 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
58 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
59 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
60 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
61 my @attrs; 67 my @attrs;
62 for (@_) { 68 for (@_) {
… …
77 }; 83 };
78 } 84 }
79 85
80} 86}
81 87
88=over 4
89
82=item $main 90=item $main
83 91
84This coroutine represents the main program. 92This coroutine represents the main program.
85 93
86=cut 94=cut
87 95
88our $main = new Coro; 96$main = new Coro;
89 97
90=item $current (or as function: current) 98=item $current (or as function: current)
91 99
92The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
93 101
… …
96# maybe some other module used Coro::Specific before... 104# maybe some other module used Coro::Specific before...
97if ($current) { 105if ($current) {
98 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
99} 107}
100 108
101our $current = $main; 109$current = $main;
102 110
103sub current() { $current } 111sub current() { $current }
104 112
105=item $idle 113=item $idle
106 114
… …
108implementation prints "FATAL: deadlock detected" and exits. 116implementation prints "FATAL: deadlock detected" and exits.
109 117
110=cut 118=cut
111 119
112# should be done using priorities :( 120# should be done using priorities :(
113our $idle = new Coro sub { 121$idle = new Coro sub {
114 print STDERR "FATAL: deadlock detected\n"; 122 print STDERR "FATAL: deadlock detected\n";
115 exit(51); 123 exit(51);
116}; 124};
117 125
118# this coroutine is necessary because a coroutine 126# this coroutine is necessary because a coroutine
119# cannot destroy itself. 127# cannot destroy itself.
120my @destroy; 128my @destroy;
129my $manager;
121my $manager = new Coro sub { 130$manager = new Coro sub {
122 while() { 131 while () {
123 delete ((pop @destroy)->{_coro_state}) while @destroy; 132 # by overwriting the state object with the manager we destroy it
133 # while still being able to schedule this coroutine (in case it has
134 # been readied multiple times. this is harmless since the manager
135 # can be called as many times as neccessary and will always
136 # remove itself from the runqueue
137 while (@destroy) {
138 my $coro = pop @destroy;
139 $coro->{status} ||= [];
140 $_->ready for @{delete $coro->{join} || []};
141
142 # the next line destroys the _coro_state, but keeps the
143 # process itself intact (we basically make it a zombie
144 # process that always runs the manager thread, so it's possible
145 # to transfer() to this process).
146 $coro->{_coro_state} = $manager->{_coro_state};
147 }
124 &schedule; 148 &schedule;
125 } 149 }
126}; 150};
127 151
128# static methods. not really. 152# static methods. not really.
153
154=back
129 155
130=head2 STATIC METHODS 156=head2 STATIC METHODS
131 157
132Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
133 159
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141 167
142 # create a new coroutine that just prints its arguments 168 # create a new coroutine that just prints its arguments
143 async { 169 async {
144 print "@_\n"; 170 print "@_\n";
145 } 1,2,3,4; 171 } 1,2,3,4;
146
147The coderef you submit MUST NOT be a closure that refers to variables
148in an outer scope. This does NOT work. Pass arguments into it instead.
149 172
150=cut 173=cut
151 174
152sub async(&@) { 175sub async(&@) {
153 my $pid = new Coro @_; 176 my $pid = new Coro @_;
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170ready queue and calls C<schedule>, which has the effect of giving up the 193ready queue and calls C<schedule>, which has the effect of giving up the
171current "timeslice" to other coroutines of the same or higher priority. 194current "timeslice" to other coroutines of the same or higher priority.
172 195
173=cut 196=cut
174 197
175=item terminate 198=item terminate [arg...]
176 199
177Terminates the current process. 200Terminates the current process with the given status values (see L<cancel>).
178
179Future versions of this function will allow result arguments.
180 201
181=cut 202=cut
182 203
183sub terminate { 204sub terminate {
184 $current->cancel; 205 $current->cancel (@_);
185 &schedule;
186 die; # NORETURN
187} 206}
188 207
189=back 208=back
190 209
191# dynamic methods 210# dynamic methods
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197=over 4 216=over 4
198 217
199=item new Coro \&sub [, @args...] 218=item new Coro \&sub [, @args...]
200 219
201Create a new process and return it. When the sub returns the process 220Create a new process and return it. When the sub returns the process
202automatically terminates. To start the process you must first put it into 221automatically terminates as if C<terminate> with the returned values were
222called. To make the process run you must first put it into the ready queue
203the ready queue by calling the ready method. 223by calling the ready method.
204
205The coderef you submit MUST NOT be a closure that refers to variables
206in an outer scope. This does NOT work. Pass arguments into it instead.
207 224
208=cut 225=cut
209 226
210sub _newcoro { 227sub _newcoro {
211 terminate &{+shift}; 228 terminate &{+shift};
… …
218 }, $class; 235 }, $class;
219} 236}
220 237
221=item $process->ready 238=item $process->ready
222 239
223Put the current process into the ready queue. 240Put the given process into the ready queue.
224 241
225=cut 242=cut
226 243
227=item $process->cancel 244=item $process->cancel (arg...)
228 245
229Like C<terminate>, but terminates the specified process instead. 246Temrinates the given process and makes it return the given arguments as
247status (default: the empty list).
230 248
231=cut 249=cut
232 250
233sub cancel { 251sub cancel {
252 my $self = shift;
253 $self->{status} = [@_];
234 push @destroy, $_[0]; 254 push @destroy, $self;
235 $manager->ready; 255 $manager->ready;
236 &schedule if $current == $_[0]; 256 &schedule if $current == $self;
257}
258
259=item $process->join
260
261Wait until the coroutine terminates and return any values given to the
262C<terminate> or C<cancel> functions. C<join> can be called multiple times
263from multiple processes.
264
265=cut
266
267sub join {
268 my $self = shift;
269 unless ($self->{status}) {
270 push @{$self->{join}}, $current;
271 &schedule;
272 }
273 wantarray ? @{$self->{status}} : $self->{status}[0];
237} 274}
238 275
239=item $oldprio = $process->prio($newprio) 276=item $oldprio = $process->prio($newprio)
240 277
241Sets the priority of the process. Higher priority processes get run before 278Sets (or gets, if the argument is missing) the priority of the
279process. Higher priority processes get run before lower priority
242lower priority processes. Priorities are smalled signed integer (currently 280processes. Priorities are small signed integers (currently -4 .. +3),
243-4 .. +3), that you can refer to using PRIO_xxx constants (use the import 281that you can refer to using PRIO_xxx constants (use the import tag :prio
244tag :prio to get then): 282to get then):
245 283
246 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN 284 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
247 3 > 1 > 0 > -1 > -3 > -4 285 3 > 1 > 0 > -1 > -3 > -4
248 286
249 # set priority to HIGH 287 # set priority to HIGH
… …
274 312
275sub nice { 313sub nice {
276 $_[0]{prio} -= $_[1]; 314 $_[0]{prio} -= $_[1];
277} 315}
278 316
317=item $olddesc = $process->desc($newdesc)
318
319Sets (or gets in case the argument is missing) the description for this
320process. This is just a free-form string you can associate with a process.
321
322=cut
323
324sub desc {
325 my $old = $_[0]{desc};
326 $_[0]{desc} = $_[1] if @_ > 1;
327 $old;
328}
329
279=back 330=back
280 331
281=cut 332=cut
282 333
2831; 3341;
284 335
285=head1 BUGS/LIMITATIONS 336=head1 BUGS/LIMITATIONS
286 337
287 - you must make very sure that no coro is still active on global destruction. 338 - you must make very sure that no coro is still active on global
288 very bad things might happen otherwise (usually segfaults). 339 destruction. very bad things might happen otherwise (usually segfaults).
340
289 - this module is not thread-safe. You must only ever use this module from 341 - this module is not thread-safe. You should only ever use this module
290 the same thread (this requirement might be loosened in the future to 342 from the same thread (this requirement might be losened in the future
291 allow per-thread schedulers, but Coro::State does not yet allow this). 343 to allow per-thread schedulers, but Coro::State does not yet allow
344 this).
292 345
293=head1 SEE ALSO 346=head1 SEE ALSO
294 347
295L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 348Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
296L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, 349
297L<Coro::Handle>, L<Coro::Socket>. 350Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
351
352Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
353
354Embedding: L<Coro:MakeMaker>
298 355
299=head1 AUTHOR 356=head1 AUTHOR
300 357
301 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
302 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
303 360
304=cut 361=cut
305 362

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