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Comparing Coro/Coro.pm (file contents):
Revision 1.102 by root, Fri Dec 29 11:37:49 2006 UTC vs.
Revision 1.106 by root, Fri Jan 5 17:44:17 2007 UTC

52our $main; # main coroutine 52our $main; # main coroutine
53our $current; # current coroutine 53our $current; # current coroutine
54 54
55our $VERSION = '3.3'; 55our $VERSION = '3.3';
56 56
57our @EXPORT = qw(async cede schedule terminate current unblock_sub); 57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 58our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 60);
61our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); 61our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62 62
141$idle = sub { 141$idle = sub {
142 require Carp; 142 require Carp;
143 Carp::croak ("FATAL: deadlock detected"); 143 Carp::croak ("FATAL: deadlock detected");
144}; 144};
145 145
146sub _cancel {
147 my ($self) = @_;
148
149 # free coroutine data and mark as destructed
150 $self->_destroy
151 or return;
152
153 # call all destruction callbacks
154 $_->(@{$self->{status}})
155 for @{(delete $self->{destroy_cb}) || []};
156}
157
146# this coroutine is necessary because a coroutine 158# this coroutine is necessary because a coroutine
147# cannot destroy itself. 159# cannot destroy itself.
148my @destroy; 160my @destroy;
161my $manager;
162
149my $manager; $manager = new Coro sub { 163$manager = new Coro sub {
150 while () { 164 while () {
151 # by overwriting the state object with the manager we destroy it 165 (shift @destroy)->_cancel
152 # while still being able to schedule this coroutine (in case it has
153 # been readied multiple times. this is harmless since the manager
154 # can be called as many times as neccessary and will always
155 # remove itself from the runqueue
156 while (@destroy) { 166 while @destroy;
157 my $coro = pop @destroy;
158 167
159 $coro->{status} ||= [];
160
161 $_->ready for @{(delete $coro->{join} ) || []};
162 $_->(@{$coro->{status}}) for @{(delete $coro->{destroy_cb}) || []};
163
164 # the next line destroys the coro state, but keeps the
165 # coroutine itself intact (we basically make it a zombie
166 # coroutine that always runs the manager thread, so it's possible
167 # to transfer() to this coroutine).
168 $coro->_clone_state_from ($manager);
169 }
170 &schedule; 168 &schedule;
171 } 169 }
172}; 170};
171
172$manager->prio (PRIO_MAX);
173 173
174# static methods. not really. 174# static methods. not really.
175 175
176=back 176=back
177 177
198 } 1,2,3,4; 198 } 1,2,3,4;
199 199
200=cut 200=cut
201 201
202sub async(&@) { 202sub async(&@) {
203 my $pid = new Coro @_; 203 my $coro = new Coro @_;
204 $pid->ready; 204 $coro->ready;
205 $pid 205 $coro
206}
207
208=item async_pool { ... } [@args...]
209
210Similar to C<async>, but uses a coroutine pool, so you should not call
211terminate or join (although you are allowed to), and you get a coroutine
212that might have executed other code already (which can be good or bad :).
213
214Also, the block is executed in an C<eval> context and a warning will be
215issued in case of an exception instead of terminating the program, as C<async> does.
216
217The priority will be reset to C<0> after each job, otherwise the coroutine
218will be re-used "as-is".
219
220The pool size is limited to 8 idle coroutines (this can be adjusted by
221changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
222required.
223
224If you are concerned about pooled coroutines growing a lot because a
225single C<async_pool> used a lot of stackspace you can e.g. C<async_pool {
226terminate }> once per second or so to slowly replenish the pool.
227
228=cut
229
230our $POOL_SIZE = 8;
231our @pool;
232
233sub pool_handler {
234 while () {
235 my ($cb, @arg) = @{ delete $current->{_invoke} };
236
237 eval {
238 $cb->(@arg);
239 };
240 warn $@ if $@;
241
242 last if @pool >= $POOL_SIZE;
243 push @pool, $current;
244
245 $current->prio (0);
246 schedule;
247 }
248}
249
250sub async_pool(&@) {
251 # this is also inlined into the unlock_scheduler
252 my $coro = (pop @pool or new Coro \&pool_handler);
253
254 $coro->{_invoke} = [@_];
255 $coro->ready;
256
257 $coro
206} 258}
207 259
208=item schedule 260=item schedule
209 261
210Calls the scheduler. Please note that the current coroutine will not be put 262Calls the scheduler. Please note that the current coroutine will not be put
294Return wether the coroutine is currently the ready queue or not, 346Return wether the coroutine is currently the ready queue or not,
295 347
296=item $coroutine->cancel (arg...) 348=item $coroutine->cancel (arg...)
297 349
298Terminates the given coroutine and makes it return the given arguments as 350Terminates the given coroutine and makes it return the given arguments as
299status (default: the empty list). 351status (default: the empty list). Never returns if the coroutine is the
352current coroutine.
300 353
301=cut 354=cut
302 355
303sub cancel { 356sub cancel {
304 my $self = shift; 357 my $self = shift;
305 $self->{status} = [@_]; 358 $self->{status} = [@_];
359
360 if ($current == $self) {
306 push @destroy, $self; 361 push @destroy, $self;
307 $manager->ready; 362 $manager->ready;
308 &schedule if $current == $self; 363 &schedule while 1;
364 } else {
365 $self->_cancel;
366 }
309} 367}
310 368
311=item $coroutine->join 369=item $coroutine->join
312 370
313Wait until the coroutine terminates and return any values given to the 371Wait until the coroutine terminates and return any values given to the
316 374
317=cut 375=cut
318 376
319sub join { 377sub join {
320 my $self = shift; 378 my $self = shift;
379
321 unless ($self->{status}) { 380 unless ($self->{status}) {
322 push @{$self->{join}}, $current; 381 my $current = $current;
323 &schedule; 382
383 push @{$self->{destroy_cb}}, sub {
384 $current->ready;
385 undef $current;
386 };
387
388 &schedule while $current;
324 } 389 }
390
325 wantarray ? @{$self->{status}} : $self->{status}[0]; 391 wantarray ? @{$self->{status}} : $self->{status}[0];
326} 392}
327 393
328=item $coroutine->on_destroy (\&cb) 394=item $coroutine->on_destroy (\&cb)
329 395
391i.e. that can be swicthed to. The value C<0> means that the only runnable 457i.e. that can be swicthed to. The value C<0> means that the only runnable
392coroutine is the currently running one, so C<cede> would have no effect, 458coroutine is the currently running one, so C<cede> would have no effect,
393and C<schedule> would cause a deadlock unless there is an idle handler 459and C<schedule> would cause a deadlock unless there is an idle handler
394that wakes up some coroutines. 460that wakes up some coroutines.
395 461
462=item my $guard = Coro::guard { ... }
463
464This creates and returns a guard object. Nothing happens until the objetc
465gets destroyed, in which case the codeblock given as argument will be
466executed. This is useful to free locks or other resources in case of a
467runtime error or when the coroutine gets canceled, as in both cases the
468guard block will be executed. The guard object supports only one method,
469C<< ->cancel >>, which will keep the codeblock from being executed.
470
471Example: set some flag and clear it again when the coroutine gets canceled
472or the function returns:
473
474 sub do_something {
475 my $guard = Coro::guard { $busy = 0 };
476 $busy = 1;
477
478 # do something that requires $busy to be true
479 }
480
481=cut
482
483sub guard(&) {
484 bless \(my $cb = $_[0]), "Coro::guard"
485}
486
487sub Coro::guard::cancel {
488 ${$_[0]} = sub { };
489}
490
491sub Coro::guard::DESTROY {
492 ${$_[0]}->();
493}
494
495
396=item unblock_sub { ... } 496=item unblock_sub { ... }
397 497
398This utility function takes a BLOCK or code reference and "unblocks" it, 498This utility function takes a BLOCK or code reference and "unblocks" it,
399returning the new coderef. This means that the new coderef will return 499returning the new coderef. This means that the new coderef will return
400immediately without blocking, returning nothing, while the original code 500immediately without blocking, returning nothing, while the original code
413In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when 513In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when
414creating event callbacks that want to block. 514creating event callbacks that want to block.
415 515
416=cut 516=cut
417 517
418our @unblock_pool;
419our @unblock_queue; 518our @unblock_queue;
420our $UNBLOCK_POOL_SIZE = 2;
421 519
422sub unblock_handler_ { 520# we create a special coro because we want to cede,
423 while () { 521# to reduce pressure on the coro pool (because most callbacks
424 my ($cb, @arg) = @{ delete $Coro::current->{arg} }; 522# return immediately and can be reused) and because we cannot cede
425 $cb->(@arg); 523# inside an event callback.
426
427 last if @unblock_pool >= $UNBLOCK_POOL_SIZE;
428 push @unblock_pool, $Coro::current;
429 schedule;
430 }
431}
432
433our $unblock_scheduler = async { 524our $unblock_scheduler = async {
434 while () { 525 while () {
435 while (my $cb = pop @unblock_queue) { 526 while (my $cb = pop @unblock_queue) {
527 # this is an inlined copy of async_pool
436 my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); 528 my $coro = (pop @pool or new Coro \&pool_handler);
437 $handler->{arg} = $cb; 529
530 $coro->{_invoke} = $cb;
438 $handler->ready; 531 $coro->ready;
439 cede; 532 cede; # for short-lived callbacks, this reduces pressure on the coro pool
440 } 533 }
441 534 schedule; # sleep well
442 schedule;
443 } 535 }
444}; 536};
445 537
446sub unblock_sub(&) { 538sub unblock_sub(&) {
447 my $cb = shift; 539 my $cb = shift;
448 540
449 sub { 541 sub {
450 push @unblock_queue, [$cb, @_]; 542 unshift @unblock_queue, [$cb, @_];
451 $unblock_scheduler->ready; 543 $unblock_scheduler->ready;
452 } 544 }
453} 545}
454 546
455=back 547=back

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