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Revision 1.34 by root, Sun Sep 16 01:34:35 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most 28callchain, it's own set of lexicals and it's own set of perl's most
31important global variables. 29important global variables.
32 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35use strict;
36no warnings "uninitialized";
37
37use Coro::State; 38use Coro::State;
38 39
39use base Exporter; 40use base Exporter::;
40 41
41$VERSION = 0.5; 42our $idle; # idle coroutine
43our $main; # main coroutine
44our $current; # current coroutine
42 45
46our $VERSION = '2.1';
47
43@EXPORT = qw(async cede schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
44%EXPORT_TAGS = ( 49our %EXPORT_TAGS = (
45 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
46); 51);
47@EXPORT_OK = @{$EXPORT_TAGS{prio}}; 52our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
48 53
49{ 54{
50 my @async; 55 my @async;
51 my $init; 56 my $init;
52 57
53 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
54 sub import { 59 sub import {
60 no strict 'refs';
61
55 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
56 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
57 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
58 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
59 my @attrs; 67 my @attrs;
60 for (@_) { 68 for (@_) {
75 }; 83 };
76 } 84 }
77 85
78} 86}
79 87
88=over 4
89
80=item $main 90=item $main
81 91
82This coroutine represents the main program. 92This coroutine represents the main program.
83 93
84=cut 94=cut
85 95
86our $main = new Coro; 96$main = new Coro;
87 97
88=item $current (or as function: current) 98=item $current (or as function: current)
89 99
90The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
91 101
94# maybe some other module used Coro::Specific before... 104# maybe some other module used Coro::Specific before...
95if ($current) { 105if ($current) {
96 $main->{specific} = $current->{specific}; 106 $main->{specific} = $current->{specific};
97} 107}
98 108
99our $current = $main; 109$current = $main;
100 110
101sub current() { $current } 111sub current() { $current }
102 112
103=item $idle 113=item $idle
104 114
106implementation prints "FATAL: deadlock detected" and exits. 116implementation prints "FATAL: deadlock detected" and exits.
107 117
108=cut 118=cut
109 119
110# should be done using priorities :( 120# should be done using priorities :(
111our $idle = new Coro sub { 121$idle = new Coro sub {
112 print STDERR "FATAL: deadlock detected\n"; 122 print STDERR "FATAL: deadlock detected\n";
113 exit(51); 123 exit(51);
114}; 124};
115 125
116# this coroutine is necessary because a coroutine 126# this coroutine is necessary because a coroutine
117# cannot destroy itself. 127# cannot destroy itself.
118my @destroy; 128my @destroy;
129my $manager;
119my $manager = new Coro sub { 130$manager = new Coro sub {
120 while() { 131 while () {
121 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 }
122 &schedule; 148 &schedule;
123 } 149 }
124}; 150};
125 151
126# static methods. not really. 152# static methods. not really.
153
154=back
127 155
128=head2 STATIC METHODS 156=head2 STATIC METHODS
129 157
130Static methods are actually functions that operate on the current process only. 158Static methods are actually functions that operate on the current process only.
131 159
139 167
140 # create a new coroutine that just prints its arguments 168 # create a new coroutine that just prints its arguments
141 async { 169 async {
142 print "@_\n"; 170 print "@_\n";
143 } 1,2,3,4; 171 } 1,2,3,4;
144
145The coderef you submit MUST NOT be a closure that refers to variables
146in an outer scope. This does NOT work. Pass arguments into it instead.
147 172
148=cut 173=cut
149 174
150sub async(&@) { 175sub async(&@) {
151 my $pid = new Coro @_; 176 my $pid = new Coro @_;
168ready 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
169current "timeslice" to other coroutines of the same or higher priority. 194current "timeslice" to other coroutines of the same or higher priority.
170 195
171=cut 196=cut
172 197
173=item terminate 198=item terminate [arg...]
174 199
175Terminates the current process. 200Terminates the current process with the given status values (see L<cancel>).
176
177Future versions of this function will allow result arguments.
178 201
179=cut 202=cut
180 203
181sub terminate { 204sub terminate {
182 $current->cancel; 205 $current->cancel (@_);
183 &schedule;
184 die; # NORETURN
185} 206}
186 207
187=back 208=back
188 209
189# dynamic methods 210# dynamic methods
195=over 4 216=over 4
196 217
197=item new Coro \&sub [, @args...] 218=item new Coro \&sub [, @args...]
198 219
199Create 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
200automatically 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
201the ready queue by calling the ready method. 223by calling the ready method.
202
203The coderef you submit MUST NOT be a closure that refers to variables
204in an outer scope. This does NOT work. Pass arguments into it instead.
205 224
206=cut 225=cut
207 226
208sub _newcoro { 227sub _newcoro {
209 terminate &{+shift}; 228 terminate &{+shift};
216 }, $class; 235 }, $class;
217} 236}
218 237
219=item $process->ready 238=item $process->ready
220 239
221Put the current process into the ready queue. 240Put the given process into the ready queue.
222 241
223=cut 242=cut
224 243
225=item $process->cancel 244=item $process->cancel (arg...)
226 245
227Like 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).
228 248
229=cut 249=cut
230 250
231sub cancel { 251sub cancel {
252 my $self = shift;
253 $self->{status} = [@_];
232 push @destroy, $_[0]; 254 push @destroy, $self;
233 $manager->ready; 255 $manager->ready;
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];
234} 274}
235 275
236=item $oldprio = $process->prio($newprio) 276=item $oldprio = $process->prio($newprio)
237 277
238Sets 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
239lower priority processes. Priorities are smalled signed integer (currently 280processes. Priorities are small signed integers (currently -4 .. +3),
240-4 .. +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
241tag :prio to get then): 282to get then):
242 283
243 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
244 3 > 1 > 0 > -1 > -3 > -4 285 3 > 1 > 0 > -1 > -3 > -4
245 286
246 # set priority to HIGH 287 # set priority to HIGH
271 312
272sub nice { 313sub nice {
273 $_[0]{prio} -= $_[1]; 314 $_[0]{prio} -= $_[1];
274} 315}
275 316
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
276=back 330=back
277 331
278=cut 332=cut
279 333
2801; 3341;
281 335
282=head1 BUGS/LIMITATIONS 336=head1 BUGS/LIMITATIONS
283 337
284 - 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
285 very bad things might happen otherwise (usually segfaults). 339 destruction. very bad things might happen otherwise (usually segfaults).
340
286 - 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
287 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
288 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).
289 345
290=head1 SEE ALSO 346=head1 SEE ALSO
291 347
292L<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>.
293L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, 349
294L<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>
295 355
296=head1 AUTHOR 356=head1 AUTHOR
297 357
298 Marc Lehmann <pcg@goof.com> 358 Marc Lehmann <schmorp@schmorp.de>
299 http://www.goof.com/pcg/marc/ 359 http://home.schmorp.de/
300 360
301=cut 361=cut
302 362

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