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Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.19 by root, Sat Jul 21 03:44:06 2001 UTC vs.
Revision 1.89 by root, Mon Nov 27 02:01:33 2006 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 23This module collection manages coroutines. Coroutines are similar to
24Threads but don't run in parallel. 24threads but don't run in parallel.
25 25
26This module is still experimental, see the BUGS section below. 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.
27 30
28=cut 31=cut
29 32
30package Coro; 33package Coro;
31 34
35use strict;
36no warnings "uninitialized";
37
32use Coro::State; 38use Coro::State;
33 39
34use base Exporter; 40use base qw(Coro::State Exporter);
35 41
42our $idle; # idle handler
43our $main; # main coroutine
44our $current; # current coroutine
45
36$VERSION = 0.09; 46our $VERSION = '3.0';
37 47
38@EXPORT = qw(async yield schedule terminate current); 48our @EXPORT = qw(async cede schedule terminate current);
39@EXPORT_OK = qw($current); 49our %EXPORT_TAGS = (
50 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
51);
52our @EXPORT_OK = @{$EXPORT_TAGS{prio}};
40 53
41{ 54{
42 use subs 'async';
43
44 my @async; 55 my @async;
56 my $init;
45 57
46 # this way of handling attributes simply is NOT scalable ;() 58 # this way of handling attributes simply is NOT scalable ;()
47 sub import { 59 sub import {
60 no strict 'refs';
61
48 Coro->export_to_level(1, @_); 62 Coro->export_to_level(1, @_);
63
49 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; 64 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
50 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { 65 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
51 my ($package, $ref) = (shift, shift); 66 my ($package, $ref) = (shift, shift);
52 my @attrs; 67 my @attrs;
53 for (@_) { 68 for (@_) {
54 if ($_ eq "Coro") { 69 if ($_ eq "Coro") {
55 push @async, $ref; 70 push @async, $ref;
71 unless ($init++) {
72 eval q{
73 sub INIT {
74 &async(pop @async) while @async;
75 }
76 };
77 }
56 } else { 78 } else {
57 push @attrs, $_; 79 push @attrs, $_;
58 } 80 }
59 } 81 }
60 return $old ? $old->($package, $ref, @attrs) : @attrs; 82 return $old ? $old->($package, $ref, @attrs) : @attrs;
61 }; 83 };
62 } 84 }
63 85
64 sub INIT {
65 async pop @async while @async;
66 }
67} 86}
87
88=over 4
68 89
69=item $main 90=item $main
70 91
71This coroutine represents the main program. 92This coroutine represents the main program.
72 93
73=cut 94=cut
74 95
75our $main = new Coro; 96$main = new Coro;
76 97
77=item $current (or as function: current) 98=item $current (or as function: current)
78 99
79The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). 100The current coroutine (the last coroutine switched to). The initial value
101is C<$main> (of course).
102
103This variable is B<strictly> I<read-only>. It is provided for performance
104reasons. If performance is not essentiel you are encouraged to use the
105C<Coro::current> function instead.
80 106
81=cut 107=cut
82 108
83# maybe some other module used Coro::Specific before... 109# maybe some other module used Coro::Specific before...
84if ($current) { 110if ($current) {
85 $main->{specific} = $current->{specific}; 111 $main->{specific} = $current->{specific};
86} 112}
87 113
88our $current = $main; 114$current = $main;
89 115
90sub current() { $current } 116sub current() { $current }
91 117
92=item $idle 118=item $idle
93 119
94The coroutine to switch to when no other coroutine is running. The default 120A callback that is called whenever the scheduler finds no ready coroutines
95implementation prints "FATAL: deadlock detected" and exits. 121to run. The default implementation prints "FATAL: deadlock detected" and
122exits.
96 123
97=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.
98 127
99# should be done using priorities :( 128=cut
100our $idle = new Coro sub { 129
130$idle = sub {
101 print STDERR "FATAL: deadlock detected\n"; 131 print STDERR "FATAL: deadlock detected\n";
102 exit(51); 132 exit (51);
103}; 133};
104 134
105# we really need priorities... 135# this coroutine is necessary because a coroutine
106my @ready; # the ready queue. hehe, rather broken ;) 136# cannot destroy itself.
137my @destroy;
138my $manager; $manager = new Coro sub {
139 while () {
140 # by overwriting the state object with the manager we destroy it
141 # while still being able to schedule this coroutine (in case it has
142 # been readied multiple times. this is harmless since the manager
143 # can be called as many times as neccessary and will always
144 # remove itself from the runqueue
145 while (@destroy) {
146 my $coro = pop @destroy;
147 $coro->{status} ||= [];
148 $_->ready for @{delete $coro->{join} || []};
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);
155 }
156 &schedule;
157 }
158};
107 159
108# static methods. not really. 160# static methods. not really.
161
162=back
109 163
110=head2 STATIC METHODS 164=head2 STATIC METHODS
111 165
112Static methods are actually functions that operate on the current process only. 166Static methods are actually functions that operate on the current process only.
113 167
… …
116=item async { ... } [@args...] 170=item async { ... } [@args...]
117 171
118Create a new asynchronous process and return it's process object 172Create a new asynchronous process and return it's process object
119(usually unused). When the sub returns the new process is automatically 173(usually unused). When the sub returns the new process is automatically
120terminated. 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.
121 180
122 # create a new coroutine that just prints its arguments 181 # create a new coroutine that just prints its arguments
123 async { 182 async {
124 print "@_\n"; 183 print "@_\n";
125 } 1,2,3,4; 184 } 1,2,3,4;
126 185
127The coderef you submit MUST NOT be a closure that refers to variables
128in an outer scope. This does NOT work. Pass arguments into it instead.
129
130=cut 186=cut
131 187
132sub async(&@) { 188sub async(&@) {
133 my $pid = new Coro @_; 189 my $pid = new Coro @_;
134 $pid->ready; 190 $pid->ready;
135 $pid; 191 $pid
136} 192}
137 193
138=item schedule 194=item schedule
139 195
140Calls 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
141into the ready queue, so calling this function usually means you will 197into the ready queue, so calling this function usually means you will
142never be called again. 198never be called again.
143 199
144=cut 200=cut
145 201
146my $prev;
147
148sub schedule {
149 # should be done using priorities :(
150 ($prev, $current) = ($current, shift @ready || $idle);
151 Coro::State::transfer($prev, $current);
152}
153
154=item yield 202=item cede
155 203
156Yield to other processes. This function puts the current process into the 204"Cede" to other processes. This function puts the current process into the
157ready queue and calls C<schedule>. 205ready queue and calls C<schedule>, which has the effect of giving up the
206current "timeslice" to other coroutines of the same or higher priority.
158 207
159=cut 208=cut
160 209
161sub yield {
162 $current->ready;
163 &schedule;
164}
165
166=item terminate 210=item terminate [arg...]
167 211
168Terminates the current process. 212Terminates the current process with the given status values (see L<cancel>).
169
170Future versions of this function will allow result arguments.
171 213
172=cut 214=cut
173 215
174sub terminate { 216sub terminate {
175 $current->{_results} = [@_]; 217 $current->cancel (@_);
176 &schedule;
177} 218}
178 219
179=back 220=back
180 221
181# dynamic methods 222# dynamic methods
… …
187=over 4 228=over 4
188 229
189=item new Coro \&sub [, @args...] 230=item new Coro \&sub [, @args...]
190 231
191Create 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
192automatically terminates. To start the process you must first put it into 233automatically terminates as if C<terminate> with the returned values were
234called. To make the process run you must first put it into the ready queue
193the ready queue by calling the ready method. 235by calling the ready method.
194 236
195The 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.
196in an outer scope. This does NOT work. Pass arguments into it instead.
197 238
198=cut 239=cut
199 240
200sub _newcoro { 241sub _new_coro {
201 terminate &{+shift}; 242 terminate &{+shift};
202} 243}
203 244
204sub new { 245sub new {
205 my $class = shift; 246 my $class = shift;
206 bless { 247
207 _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), 248 $class->SUPER::new (\&_new_coro, @_)
208 }, $class;
209} 249}
210 250
211=item $process->ready 251=item $process->ready
212 252
213Put the current process into the ready queue. 253Put the given process into the ready queue.
214 254
215=cut 255=cut
216 256
217sub ready { 257=item $process->cancel (arg...)
218 push @ready, $_[0]; 258
259Terminates the given process and makes it return the given arguments as
260status (default: the empty list).
261
262=cut
263
264sub cancel {
265 my $self = shift;
266 $self->{status} = [@_];
267 push @destroy, $self;
268 $manager->ready;
269 &schedule if $current == $self;
270}
271
272=item $process->join
273
274Wait until the coroutine terminates and return any values given to the
275C<terminate> or C<cancel> functions. C<join> can be called multiple times
276from multiple processes.
277
278=cut
279
280sub join {
281 my $self = shift;
282 unless ($self->{status}) {
283 push @{$self->{join}}, $current;
284 &schedule;
285 }
286 wantarray ? @{$self->{status}} : $self->{status}[0];
287}
288
289=item $oldprio = $process->prio ($newprio)
290
291Sets (or gets, if the argument is missing) the priority of the
292process. Higher priority processes get run before lower priority
293processes. Priorities are small signed integers (currently -4 .. +3),
294that you can refer to using PRIO_xxx constants (use the import tag :prio
295to get then):
296
297 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
298 3 > 1 > 0 > -1 > -3 > -4
299
300 # set priority to HIGH
301 current->prio(PRIO_HIGH);
302
303The idle coroutine ($Coro::idle) always has a lower priority than any
304existing coroutine.
305
306Changing the priority of the current process will take effect immediately,
307but changing the priority of processes in the ready queue (but not
308running) will only take effect after the next schedule (of that
309process). This is a bug that will be fixed in some future version.
310
311=item $newprio = $process->nice ($change)
312
313Similar to C<prio>, but subtract the given value from the priority (i.e.
314higher values mean lower priority, just as in unix).
315
316=item $olddesc = $process->desc ($newdesc)
317
318Sets (or gets in case the argument is missing) the description for this
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;
219} 327}
220 328
221=back 329=back
222 330
223=cut 331=cut
224 332
2251; 3331;
226 334
227=head1 BUGS/LIMITATIONS 335=head1 BUGS/LIMITATIONS
228 336
229 - could be faster, especially when the core would introduce special 337 - you must make very sure that no coro is still active on global
230 support for coroutines (like it does for threads). 338 destruction. very bad things might happen otherwise (usually segfaults).
231 - there is still a memleak on coroutine termination that I could not 339
232 identify. Could be as small as a single SV.
233 - this module is not well-tested.
234 - if variables or arguments "disappear" (become undef) or become
235 corrupted please contact the author so he cen iron out the
236 remaining bugs.
237 - 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
238 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
239 allow per-thread schedulers, but Coro::Satte does not yet allow this). 342 to allow per-thread schedulers, but Coro::State does not yet allow
343 this).
240 344
241=head1 SEE ALSO 345=head1 SEE ALSO
242 346
243L<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>.
244L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. 348
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>
245 354
246=head1 AUTHOR 355=head1 AUTHOR
247 356
248 Marc Lehmann <pcg@goof.com> 357 Marc Lehmann <schmorp@schmorp.de>
249 http://www.goof.com/pcg/marc/ 358 http://home.schmorp.de/
250 359
251=cut 360=cut
252 361

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