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 1.85 by root, Sat Nov 25 00:56:35 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
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
43$VERSION = 0.51; 46our $VERSION = '2.5';
44 47
45@EXPORT = qw(async cede schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
46%EXPORT_TAGS = ( 49our %EXPORT_TAGS = (
47 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
48); 51);
49@EXPORT_OK = @{$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; 138my $manager;
122$manager = new Coro sub { 139$manager = new Coro sub {
123 while() { 140 while () {
124 # by overwriting the state object with the manager we destroy it 141 # by overwriting the state object with the manager we destroy it
125 # while still being able to schedule this coroutine (in case it has 142 # while still being able to schedule this coroutine (in case it has
126 # been readied multiple times. this is harmless since the manager 143 # been readied multiple times. this is harmless since the manager
127 # can be called as many times as neccessary and will always 144 # can be called as many times as neccessary and will always
128 # remove itself from the runqueue 145 # remove itself from the runqueue
129 while (@destroy) { 146 while (@destroy) {
130 my $coro = pop @destroy; 147 my $coro = pop @destroy;
131 $coro->{status} ||= []; 148 $coro->{status} ||= [];
132 $_->ready for @{delete $coro->{join} || []}; 149 $_->ready for @{delete $coro->{join} || []};
133 $coro->{_coro_state} = $manager->{_coro_state}; 150
151 # the next line destroys the coro state, but keeps the
152 # process itself intact (we basically make it a zombie
153 # process that always runs the manager thread, so it's possible
154 # to transfer() to this process).
155 $coro->_clone_state_from ($manager);
134 } 156 }
135 &schedule; 157 &schedule;
136 } 158 }
137}; 159};
138 160
139# static methods. not really. 161# static methods. not really.
140 162
163=back
164
141=head2 STATIC METHODS 165=head2 STATIC METHODS
142 166
143Static methods are actually functions that operate on the current process only. 167Static methods are actually functions that operate on the current process only.
144 168
145=over 4 169=over 4
… …
147=item async { ... } [@args...] 171=item async { ... } [@args...]
148 172
149Create a new asynchronous process and return it's process object 173Create a new asynchronous process and return it's process object
150(usually unused). When the sub returns the new process is automatically 174(usually unused). When the sub returns the new process is automatically
151terminated. 175terminated.
176
177When the coroutine dies, the program will exit, just as in the main
178program.
152 179
153 # create a new coroutine that just prints its arguments 180 # create a new coroutine that just prints its arguments
154 async { 181 async {
155 print "@_\n"; 182 print "@_\n";
156 } 1,2,3,4; 183 } 1,2,3,4;
157 184
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 185=cut
162 186
163sub async(&@) { 187sub async(&@) {
164 my $pid = new Coro @_; 188 my $pid = new Coro @_;
165 $manager->ready; # this ensures that the stack is cloned from the manager
166 $pid->ready; 189 $pid->ready;
167 $pid; 190 $pid
168} 191}
169 192
170=item schedule 193=item schedule
171 194
172Calls the scheduler. Please note that the current process will not be put 195Calls the scheduler. Please note that the current process will not be put
… …
183 206
184=cut 207=cut
185 208
186=item terminate [arg...] 209=item terminate [arg...]
187 210
188Terminates the current process. 211Terminates the current process with the given status values (see L<cancel>).
189
190Future versions of this function will allow result arguments.
191 212
192=cut 213=cut
193 214
194sub terminate { 215sub terminate {
195 $current->{status} = [@_];
196 $current->cancel; 216 $current->cancel (@_);
197 &schedule;
198 die; # NORETURN
199} 217}
200 218
201=back 219=back
202 220
203# dynamic methods 221# dynamic methods
… …
210 228
211=item new Coro \&sub [, @args...] 229=item new Coro \&sub [, @args...]
212 230
213Create a new process and return it. When the sub returns the process 231Create a new process and return it. When the sub returns the process
214automatically terminates as if C<terminate> with the returned values were 232automatically 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 233called. To make the process run you must first put it into the ready queue
216calling the ready method. 234by calling the ready method.
217 235
218The coderef you submit MUST NOT be a closure that refers to variables
219in an outer scope. This does NOT work. Pass arguments into it instead.
220
221=cut 236=cut
222 237
223sub _newcoro { 238sub _new_coro {
239 $current->_clear_idle_sp; # set the idle sp on the following cede
240 _set_cede_self; # ensures that cede cede's us first
241 cede;
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