ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.40 by root, Sun Oct 28 17:00:05 2001 UTC vs.
Revision 1.89 by root, Mon Nov 27 02:01:33 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+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
30callchain, it's own set of lexicals and it's own set of perl's most 28callchain, it's own set of lexicals and it's own set of perl's most
31important global variables. 29important global variables.
32 30
33=cut 31=cut
34 32
35package Coro; 33package Coro;
36 34
35use strict;
37no warnings qw(uninitialized); 36no warnings "uninitialized";
38 37
39use Coro::State; 38use Coro::State;
40 39
41use base Exporter; 40use base qw(Coro::State Exporter);
42 41
43$VERSION = 0.51; 42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
44 45
46our $VERSION = '3.0';
47
45@EXPORT = qw(async cede schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
46%EXPORT_TAGS = ( 49our %EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48); 51);
49@EXPORT_OK = @{$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
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
93 106
94=cut 107=cut
95 108
96# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
97if ($current) { 110if ($current) {
98 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
99} 112}
100 113
101our $current = $main; 114$current = $main;
102 115
103sub current() { $current } 116sub current() { $current }
104 117
105=item $idle 118=item $idle
106 119
107The coroutine to switch to when no other coroutine is running. The default 120A callback that is called whenever the scheduler finds no ready coroutines
108implementation prints "FATAL: deadlock detected" and exits. 121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
109 123
110=cut 124This hook is overwritten by modules such as C<Coro::Timer> and
125C<Coro::Event> to wait on an external event that hopefully wakes up some
126coroutine.
111 127
112# should be done using priorities :( 128=cut
113our $idle = new Coro sub { 129
130$idle = sub {
114 print STDERR "FATAL: deadlock detected\n"; 131 print STDERR "FATAL: deadlock detected\n";
115 exit(51); 132 exit (51);
116}; 133};
117 134
118# this coroutine is necessary because a coroutine 135# this coroutine is necessary because a coroutine
119# cannot destroy itself. 136# cannot destroy itself.
120my @destroy; 137my @destroy;
121my $manager;
122$manager = new Coro sub { 138my $manager; $manager = new Coro sub {
123 while() { 139 while () {
124 # by overwriting the state object with the manager we destroy it 140 # by overwriting the state object with the manager we destroy it
125 # while still being able to schedule this coroutine (in case it has 141 # while still being able to schedule this coroutine (in case it has
126 # been readied multiple times. this is harmless since the manager 142 # been readied multiple times. this is harmless since the manager
127 # can be called as many times as neccessary and will always 143 # can be called as many times as neccessary and will always
128 # remove itself from the runqueue 144 # remove itself from the runqueue
129 while (@destroy) { 145 while (@destroy) {
130 my $coro = pop @destroy; 146 my $coro = pop @destroy;
131 $coro->{status} ||= []; 147 $coro->{status} ||= [];
132 $_->ready for @{delete $coro->{join} || []}; 148 $_->ready for @{delete $coro->{join} || []};
133 $coro->{_coro_state} = $manager->{_coro_state}; 149
150 # the next line destroys the coro state, but keeps the
151 # process itself intact (we basically make it a zombie
152 # process that always runs the manager thread, so it's possible
153 # to transfer() to this process).
154 $coro->_clone_state_from ($manager);
134 } 155 }
135 &schedule; 156 &schedule;
136 } 157 }
137}; 158};
138 159
139# static methods. not really. 160# static methods. not really.
140 161
162=back
163
141=head2 STATIC METHODS 164=head2 STATIC METHODS
142 165
143Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
144 167
145=over 4 168=over 4
… …
147=item async { ... } [@args...] 170=item async { ... } [@args...]
148 171
149Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
150(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
151terminated. 174terminated.
175
176Calling C<exit> in a coroutine will not work correctly, so do not do that.
177
178When the coroutine dies, the program will exit, just as in the main
179program.
152 180
153 # create a new coroutine that just prints its arguments 181 # create a new coroutine that just prints its arguments
154 async { 182 async {
155 print "@_\n"; 183 print "@_\n";
156 } 1,2,3,4; 184 } 1,2,3,4;
157 185
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 186=cut
162 187
163sub async(&@) { 188sub async(&@) {
164 my $pid = new Coro @_; 189 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
166 $pid->ready; 190 $pid->ready;
167 $pid; 191 $pid
168} 192}
169 193
170=item schedule 194=item schedule
171 195
172Calls the scheduler. Please note that the current process will not be put 196Calls the scheduler. Please note that the current process will not be put
… …
183 207
184=cut 208=cut
185 209
186=item terminate [arg...] 210=item terminate [arg...]
187 211
188Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
189
190Future versions of this function will allow result arguments.
191 213
192=cut 214=cut
193 215
194sub terminate { 216sub terminate {
195 $current->{status} = [@_];
196 $current->cancel; 217 $current->cancel (@_);
197 &schedule;
198 die; # NORETURN
199} 218}
200 219
201=back 220=back
202 221
203# dynamic methods 222# dynamic methods
… …
210 229
211=item new Coro \&sub [, @args...] 230=item new Coro \&sub [, @args...]
212 231
213Create a new process and return it. When the sub returns the process 232Create a new process and return it. When the sub returns the process
214automatically terminates as if C<terminate> with the returned values were 233automatically terminates as if C<terminate> with the returned values were
215called. To start the process you must first put it into the ready queue by 234called. To make the process run you must first put it into the ready queue
216calling the ready method. 235by calling the ready method.
217 236
218The coderef you submit MUST NOT be a closure that refers to variables 237Calling C<exit> in a coroutine will not work correctly, so do not do that.
219in an outer scope. This does NOT work. Pass arguments into it instead.
220 238
221=cut 239=cut
222 240
223sub _newcoro { 241sub _new_coro {
224 terminate &{+shift}; 242 terminate &{+shift};
225} 243}
226 244
227sub new { 245sub new {
228 my $class = shift; 246 my $class = shift;
229 bless { 247
230 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 248 $class->SUPER::new (\&_new_coro, @_)
231 }, $class;
232} 249}
233 250
234=item $process->ready 251=item $process->ready
235 252
236Put the given process into the ready queue. 253Put the given process into the ready queue.
237 254
238=cut 255=cut
239 256
240=item $process->cancel 257=item $process->cancel (arg...)
241 258
242Like C<terminate>, but terminates the specified process instead. 259Terminates the given process and makes it return the given arguments as
260status (default: the empty list).
243 261
244=cut 262=cut
245 263
246sub cancel { 264sub cancel {
265 my $self = shift;
266 $self->{status} = [@_];
247 push @destroy, $_[0]; 267 push @destroy, $self;
248 $manager->ready; 268 $manager->ready;
249 &schedule if $current == $_[0]; 269 &schedule if $current == $self;
250} 270}
251 271
252=item $process->join 272=item $process->join
253 273
254Wait until the coroutine terminates and return any values given to the 274Wait until the coroutine terminates and return any values given to the
255C<terminate> function. C<join> can be called multiple times from multiple 275C<terminate> or C<cancel> functions. C<join> can be called multiple times
256processes. 276from multiple processes.
257 277
258=cut 278=cut
259 279
260sub join { 280sub join {
261 my $self = shift; 281 my $self = shift;
… …
264 &schedule; 284 &schedule;
265 } 285 }
266 wantarray ? @{$self->{status}} : $self->{status}[0]; 286 wantarray ? @{$self->{status}} : $self->{status}[0];
267} 287}
268 288
269=item $oldprio = $process->prio($newprio) 289=item $oldprio = $process->prio ($newprio)
270 290
271Sets the priority of the process. Higher priority processes get run before 291Sets (or gets, if the argument is missing) the priority of the
292process. Higher priority processes get run before lower priority
272lower priority processes. Priorities are smalled signed integer (currently 293processes. Priorities are small signed integers (currently -4 .. +3),
273-4 .. +3), that you can refer to using PRIO_xxx constants (use the import 294that you can refer to using PRIO_xxx constants (use the import tag :prio
274tag :prio to get then): 295to get then):
275 296
276 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN 297 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
277 3 > 1 > 0 > -1 > -3 > -4 298 3 > 1 > 0 > -1 > -3 > -4
278 299
279 # set priority to HIGH 300 # set priority to HIGH
… …
285Changing the priority of the current process will take effect immediately, 306Changing the priority of the current process will take effect immediately,
286but changing the priority of processes in the ready queue (but not 307but changing the priority of processes in the ready queue (but not
287running) will only take effect after the next schedule (of that 308running) will only take effect after the next schedule (of that
288process). This is a bug that will be fixed in some future version. 309process). This is a bug that will be fixed in some future version.
289 310
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) 311=item $newprio = $process->nice ($change)
299 312
300Similar to C<prio>, but subtract the given value from the priority (i.e. 313Similar to C<prio>, but subtract the given value from the priority (i.e.
301higher values mean lower priority, just as in unix). 314higher values mean lower priority, just as in unix).
302 315
303=cut 316=item $olddesc = $process->desc ($newdesc)
304 317
305sub nice { 318Sets (or gets in case the argument is missing) the description for this
306 $_[0]{prio} -= $_[1]; 319process. This is just a free-form string you can associate with a process.
320
321=cut
322
323sub desc {
324 my $old = $_[0]{desc};
325 $_[0]{desc} = $_[1] if @_ > 1;
326 $old;
307} 327}
308 328
309=back 329=back
310 330
311=cut 331=cut
312 332
3131; 3331;
314 334
315=head1 BUGS/LIMITATIONS 335=head1 BUGS/LIMITATIONS
316 336
317 - you must make very sure that no coro is still active on global destruction. 337 - you must make very sure that no coro is still active on global
318 very bad things might happen otherwise (usually segfaults). 338 destruction. very bad things might happen otherwise (usually segfaults).
339
319 - this module is not thread-safe. You must only ever use this module from 340 - this module is not thread-safe. You should only ever use this module
320 the same thread (this requirement might be loosened in the future to 341 from the same thread (this requirement might be losened in the future
321 allow per-thread schedulers, but Coro::State does not yet allow this). 342 to allow per-thread schedulers, but Coro::State does not yet allow
343 this).
322 344
323=head1 SEE ALSO 345=head1 SEE ALSO
324 346
325L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, 347Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>.
326L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, 348
327L<Coro::Handle>, L<Coro::Socket>. 349Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
350
351Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>.
352
353Embedding: L<Coro:MakeMaker>
328 354
329=head1 AUTHOR 355=head1 AUTHOR
330 356
331 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
332 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
333 359
334=cut 360=cut
335 361

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines