| … | |
… | |
| 20 | |
20 | |
| 21 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
| 22 | |
22 | |
| 23 | This module collection manages coroutines. Coroutines are similar |
23 | This module collection manages coroutines. Coroutines are similar |
| 24 | to threads but don't run in parallel at the same time even on SMP |
24 | to threads but don't run in parallel at the same time even on SMP |
| 25 | machines. The specific flavor of coroutine use din this module also |
25 | machines. The specific flavor of coroutine used in this module also |
| 26 | guarentees you that it will not switch between coroutines unless |
26 | guarantees you that it will not switch between coroutines unless |
| 27 | necessary, at easily-identified points in your program, so locking and |
27 | necessary, at easily-identified points in your program, so locking and |
| 28 | parallel access are rarely an issue, making coroutine programming much |
28 | parallel access are rarely an issue, making coroutine programming much |
| 29 | safer than threads programming. |
29 | safer than threads programming. |
| 30 | |
30 | |
| 31 | (Perl, however, does not natively support real threads but instead does a |
31 | (Perl, however, does not natively support real threads but instead does a |
| … | |
… | |
| 50 | |
50 | |
| 51 | our $idle; # idle handler |
51 | our $idle; # idle handler |
| 52 | our $main; # main coroutine |
52 | our $main; # main coroutine |
| 53 | our $current; # current coroutine |
53 | our $current; # current coroutine |
| 54 | |
54 | |
| 55 | our $VERSION = '3.3'; |
55 | our $VERSION = '4.0'; |
| 56 | |
56 | |
| 57 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
57 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
| 58 | our %EXPORT_TAGS = ( |
58 | our %EXPORT_TAGS = ( |
| 59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
| 60 | ); |
60 | ); |
| … | |
… | |
| 108 | |
108 | |
| 109 | The current coroutine (the last coroutine switched to). The initial value |
109 | The current coroutine (the last coroutine switched to). The initial value |
| 110 | is C<$main> (of course). |
110 | is C<$main> (of course). |
| 111 | |
111 | |
| 112 | This variable is B<strictly> I<read-only>. It is provided for performance |
112 | This variable is B<strictly> I<read-only>. It is provided for performance |
| 113 | reasons. If performance is not essentiel you are encouraged to use the |
113 | reasons. If performance is not essential you are encouraged to use the |
| 114 | C<Coro::current> function instead. |
114 | C<Coro::current> function instead. |
| 115 | |
115 | |
| 116 | =cut |
116 | =cut |
| 117 | |
117 | |
|
|
118 | $main->{desc} = "[main::]"; |
|
|
119 | |
| 118 | # maybe some other module used Coro::Specific before... |
120 | # maybe some other module used Coro::Specific before... |
| 119 | $main->{specific} = $current->{specific} |
121 | $main->{_specific} = $current->{_specific} |
| 120 | if $current; |
122 | if $current; |
| 121 | |
123 | |
| 122 | _set_current $main; |
124 | _set_current $main; |
| 123 | |
125 | |
| 124 | sub current() { $current } |
126 | sub current() { $current } |
| … | |
… | |
| 149 | # free coroutine data and mark as destructed |
151 | # free coroutine data and mark as destructed |
| 150 | $self->_destroy |
152 | $self->_destroy |
| 151 | or return; |
153 | or return; |
| 152 | |
154 | |
| 153 | # call all destruction callbacks |
155 | # call all destruction callbacks |
| 154 | $_->(@{$self->{status}}) |
156 | $_->(@{$self->{_status}}) |
| 155 | for @{(delete $self->{destroy_cb}) || []}; |
157 | for @{(delete $self->{_on_destroy}) || []}; |
| 156 | } |
158 | } |
| 157 | |
159 | |
| 158 | # this coroutine is necessary because a coroutine |
160 | # this coroutine is necessary because a coroutine |
| 159 | # cannot destroy itself. |
161 | # cannot destroy itself. |
| 160 | my @destroy; |
162 | my @destroy; |
| … | |
… | |
| 166 | while @destroy; |
168 | while @destroy; |
| 167 | |
169 | |
| 168 | &schedule; |
170 | &schedule; |
| 169 | } |
171 | } |
| 170 | }; |
172 | }; |
| 171 | |
173 | $manager->desc ("[coro manager]"); |
| 172 | $manager->prio (PRIO_MAX); |
174 | $manager->prio (PRIO_MAX); |
| 173 | |
175 | |
| 174 | # static methods. not really. |
176 | # static methods. not really. |
| 175 | |
177 | |
| 176 | =back |
178 | =back |
| … | |
… | |
| 185 | |
187 | |
| 186 | Create a new asynchronous coroutine and return it's coroutine object |
188 | Create a new asynchronous coroutine and return it's coroutine object |
| 187 | (usually unused). When the sub returns the new coroutine is automatically |
189 | (usually unused). When the sub returns the new coroutine is automatically |
| 188 | terminated. |
190 | terminated. |
| 189 | |
191 | |
| 190 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
192 | Calling C<exit> in a coroutine will do the same as calling exit outside |
| 191 | |
193 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
| 192 | When the coroutine dies, the program will exit, just as in the main |
194 | just as it would in the main program. |
| 193 | program. |
|
|
| 194 | |
195 | |
| 195 | # create a new coroutine that just prints its arguments |
196 | # create a new coroutine that just prints its arguments |
| 196 | async { |
197 | async { |
| 197 | print "@_\n"; |
198 | print "@_\n"; |
| 198 | } 1,2,3,4; |
199 | } 1,2,3,4; |
| … | |
… | |
| 210 | Similar to C<async>, but uses a coroutine pool, so you should not call |
211 | Similar to C<async>, but uses a coroutine pool, so you should not call |
| 211 | terminate or join (although you are allowed to), and you get a coroutine |
212 | terminate or join (although you are allowed to), and you get a coroutine |
| 212 | that might have executed other code already (which can be good or bad :). |
213 | that might have executed other code already (which can be good or bad :). |
| 213 | |
214 | |
| 214 | Also, the block is executed in an C<eval> context and a warning will be |
215 | Also, the block is executed in an C<eval> context and a warning will be |
| 215 | issued in case of an exception instead of terminating the program, as C<async> does. |
216 | issued in case of an exception instead of terminating the program, as |
|
|
217 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
|
|
218 | will not work in the expected way, unless you call terminate or cancel, |
|
|
219 | which somehow defeats the purpose of pooling. |
| 216 | |
220 | |
| 217 | The priority will be reset to C<0> after each job, otherwise the coroutine |
221 | The priority will be reset to C<0> after each job, otherwise the coroutine |
| 218 | will be re-used "as-is". |
222 | will be re-used "as-is". |
| 219 | |
223 | |
| 220 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
224 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
| 221 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
225 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
| 222 | required. |
226 | required. |
| 223 | |
227 | |
| 224 | If you are concerned about pooled coroutines growing a lot because a |
228 | If you are concerned about pooled coroutines growing a lot because a |
| 225 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool { |
229 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
| 226 | terminate }> once per second or so to slowly replenish the pool. |
230 | { terminate }> once per second or so to slowly replenish the pool. In |
|
|
231 | addition to that, when the stacks used by a handler grows larger than 16kb |
|
|
232 | (adjustable with $Coro::POOL_RSS) it will also exit. |
| 227 | |
233 | |
| 228 | =cut |
234 | =cut |
| 229 | |
235 | |
| 230 | our $POOL_SIZE = 8; |
236 | our $POOL_SIZE = 8; |
|
|
237 | our $POOL_RSS = 16 * 1024; |
| 231 | our @pool; |
238 | our @async_pool; |
| 232 | |
239 | |
| 233 | sub pool_handler { |
240 | sub pool_handler { |
|
|
241 | my $cb; |
|
|
242 | |
| 234 | while () { |
243 | while () { |
| 235 | my ($cb, @arg) = @{ delete $current->{_invoke} }; |
|
|
| 236 | |
|
|
| 237 | eval { |
244 | eval { |
| 238 | $cb->(@arg); |
245 | while () { |
|
|
246 | _pool_1 $cb; |
|
|
247 | &$cb; |
|
|
248 | _pool_2 $cb; |
|
|
249 | &schedule; |
|
|
250 | } |
| 239 | }; |
251 | }; |
|
|
252 | |
|
|
253 | last if $@ eq "\3terminate\2\n"; |
| 240 | warn $@ if $@; |
254 | warn $@ if $@; |
| 241 | |
|
|
| 242 | last if @pool >= $POOL_SIZE; |
|
|
| 243 | push @pool, $current; |
|
|
| 244 | |
|
|
| 245 | $current->prio (0); |
|
|
| 246 | schedule; |
|
|
| 247 | } |
255 | } |
| 248 | } |
256 | } |
| 249 | |
257 | |
| 250 | sub async_pool(&@) { |
258 | sub async_pool(&@) { |
| 251 | # this is also inlined into the unlock_scheduler |
259 | # this is also inlined into the unlock_scheduler |
| 252 | my $coro = (pop @pool or new Coro \&pool_handler); |
260 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
| 253 | |
261 | |
| 254 | $coro->{_invoke} = [@_]; |
262 | $coro->{_invoke} = [@_]; |
| 255 | $coro->ready; |
263 | $coro->ready; |
| 256 | |
264 | |
| 257 | $coro |
265 | $coro |
| … | |
… | |
| 275 | # wake up sleeping coroutine |
283 | # wake up sleeping coroutine |
| 276 | $current->ready; |
284 | $current->ready; |
| 277 | undef $current; |
285 | undef $current; |
| 278 | }; |
286 | }; |
| 279 | |
287 | |
| 280 | # call schedule until event occured. |
288 | # call schedule until event occurred. |
| 281 | # in case we are woken up for other reasons |
289 | # in case we are woken up for other reasons |
| 282 | # (current still defined), loop. |
290 | # (current still defined), loop. |
| 283 | Coro::schedule while $current; |
291 | Coro::schedule while $current; |
| 284 | } |
292 | } |
| 285 | |
293 | |
| … | |
… | |
| 287 | |
295 | |
| 288 | "Cede" to other coroutines. This function puts the current coroutine into the |
296 | "Cede" to other coroutines. This function puts the current coroutine into the |
| 289 | ready queue and calls C<schedule>, which has the effect of giving up the |
297 | ready queue and calls C<schedule>, which has the effect of giving up the |
| 290 | current "timeslice" to other coroutines of the same or higher priority. |
298 | current "timeslice" to other coroutines of the same or higher priority. |
| 291 | |
299 | |
|
|
300 | Returns true if at least one coroutine switch has happened. |
|
|
301 | |
| 292 | =item Coro::cede_notself |
302 | =item Coro::cede_notself |
| 293 | |
303 | |
| 294 | Works like cede, but is not exported by default and will cede to any |
304 | Works like cede, but is not exported by default and will cede to any |
| 295 | coroutine, regardless of priority, once. |
305 | coroutine, regardless of priority, once. |
| 296 | |
306 | |
|
|
307 | Returns true if at least one coroutine switch has happened. |
|
|
308 | |
| 297 | =item terminate [arg...] |
309 | =item terminate [arg...] |
| 298 | |
310 | |
| 299 | Terminates the current coroutine with the given status values (see L<cancel>). |
311 | Terminates the current coroutine with the given status values (see L<cancel>). |
|
|
312 | |
|
|
313 | =item killall |
|
|
314 | |
|
|
315 | Kills/terminates/cancels all coroutines except the currently running |
|
|
316 | one. This is useful after a fork, either in the child or the parent, as |
|
|
317 | usually only one of them should inherit the running coroutines. |
| 300 | |
318 | |
| 301 | =cut |
319 | =cut |
| 302 | |
320 | |
| 303 | sub terminate { |
321 | sub terminate { |
| 304 | $current->cancel (@_); |
322 | $current->cancel (@_); |
|
|
323 | } |
|
|
324 | |
|
|
325 | sub killall { |
|
|
326 | for (Coro::State::list) { |
|
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327 | $_->cancel |
|
|
328 | if $_ != $current && UNIVERSAL::isa $_, "Coro"; |
|
|
329 | } |
| 305 | } |
330 | } |
| 306 | |
331 | |
| 307 | =back |
332 | =back |
| 308 | |
333 | |
| 309 | # dynamic methods |
334 | # dynamic methods |
| … | |
… | |
| 319 | Create a new coroutine and return it. When the sub returns the coroutine |
344 | Create a new coroutine and return it. When the sub returns the coroutine |
| 320 | automatically terminates as if C<terminate> with the returned values were |
345 | automatically terminates as if C<terminate> with the returned values were |
| 321 | called. To make the coroutine run you must first put it into the ready queue |
346 | called. To make the coroutine run you must first put it into the ready queue |
| 322 | by calling the ready method. |
347 | by calling the ready method. |
| 323 | |
348 | |
| 324 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
349 | See C<async> for additional discussion. |
| 325 | |
350 | |
| 326 | =cut |
351 | =cut |
| 327 | |
352 | |
| 328 | sub _run_coro { |
353 | sub _run_coro { |
| 329 | terminate &{+shift}; |
354 | terminate &{+shift}; |
| … | |
… | |
| 353 | |
378 | |
| 354 | =cut |
379 | =cut |
| 355 | |
380 | |
| 356 | sub cancel { |
381 | sub cancel { |
| 357 | my $self = shift; |
382 | my $self = shift; |
| 358 | $self->{status} = [@_]; |
383 | $self->{_status} = [@_]; |
| 359 | |
384 | |
| 360 | if ($current == $self) { |
385 | if ($current == $self) { |
| 361 | push @destroy, $self; |
386 | push @destroy, $self; |
| 362 | $manager->ready; |
387 | $manager->ready; |
| 363 | &schedule while 1; |
388 | &schedule while 1; |
| … | |
… | |
| 367 | } |
392 | } |
| 368 | |
393 | |
| 369 | =item $coroutine->join |
394 | =item $coroutine->join |
| 370 | |
395 | |
| 371 | Wait until the coroutine terminates and return any values given to the |
396 | Wait until the coroutine terminates and return any values given to the |
| 372 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
397 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
| 373 | from multiple coroutine. |
398 | from multiple coroutines. |
| 374 | |
399 | |
| 375 | =cut |
400 | =cut |
| 376 | |
401 | |
| 377 | sub join { |
402 | sub join { |
| 378 | my $self = shift; |
403 | my $self = shift; |
| 379 | |
404 | |
| 380 | unless ($self->{status}) { |
405 | unless ($self->{_status}) { |
| 381 | my $current = $current; |
406 | my $current = $current; |
| 382 | |
407 | |
| 383 | push @{$self->{destroy_cb}}, sub { |
408 | push @{$self->{_on_destroy}}, sub { |
| 384 | $current->ready; |
409 | $current->ready; |
| 385 | undef $current; |
410 | undef $current; |
| 386 | }; |
411 | }; |
| 387 | |
412 | |
| 388 | &schedule while $current; |
413 | &schedule while $current; |
| 389 | } |
414 | } |
| 390 | |
415 | |
| 391 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
416 | wantarray ? @{$self->{_status}} : $self->{_status}[0]; |
| 392 | } |
417 | } |
| 393 | |
418 | |
| 394 | =item $coroutine->on_destroy (\&cb) |
419 | =item $coroutine->on_destroy (\&cb) |
| 395 | |
420 | |
| 396 | Registers a callback that is called when this coroutine gets destroyed, |
421 | Registers a callback that is called when this coroutine gets destroyed, |
| … | |
… | |
| 400 | =cut |
425 | =cut |
| 401 | |
426 | |
| 402 | sub on_destroy { |
427 | sub on_destroy { |
| 403 | my ($self, $cb) = @_; |
428 | my ($self, $cb) = @_; |
| 404 | |
429 | |
| 405 | push @{ $self->{destroy_cb} }, $cb; |
430 | push @{ $self->{_on_destroy} }, $cb; |
| 406 | } |
431 | } |
| 407 | |
432 | |
| 408 | =item $oldprio = $coroutine->prio ($newprio) |
433 | =item $oldprio = $coroutine->prio ($newprio) |
| 409 | |
434 | |
| 410 | Sets (or gets, if the argument is missing) the priority of the |
435 | Sets (or gets, if the argument is missing) the priority of the |
| … | |
… | |
| 435 | =item $olddesc = $coroutine->desc ($newdesc) |
460 | =item $olddesc = $coroutine->desc ($newdesc) |
| 436 | |
461 | |
| 437 | Sets (or gets in case the argument is missing) the description for this |
462 | Sets (or gets in case the argument is missing) the description for this |
| 438 | coroutine. This is just a free-form string you can associate with a coroutine. |
463 | coroutine. This is just a free-form string you can associate with a coroutine. |
| 439 | |
464 | |
|
|
465 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
|
|
466 | can modify this member directly if you wish. |
|
|
467 | |
| 440 | =cut |
468 | =cut |
| 441 | |
469 | |
| 442 | sub desc { |
470 | sub desc { |
| 443 | my $old = $_[0]{desc}; |
471 | my $old = $_[0]{desc}; |
| 444 | $_[0]{desc} = $_[1] if @_ > 1; |
472 | $_[0]{desc} = $_[1] if @_ > 1; |
| … | |
… | |
| 452 | =over 4 |
480 | =over 4 |
| 453 | |
481 | |
| 454 | =item Coro::nready |
482 | =item Coro::nready |
| 455 | |
483 | |
| 456 | Returns the number of coroutines that are currently in the ready state, |
484 | Returns the number of coroutines that are currently in the ready state, |
| 457 | i.e. that can be swicthed to. The value C<0> means that the only runnable |
485 | i.e. that can be switched to. The value C<0> means that the only runnable |
| 458 | coroutine is the currently running one, so C<cede> would have no effect, |
486 | coroutine is the currently running one, so C<cede> would have no effect, |
| 459 | and C<schedule> would cause a deadlock unless there is an idle handler |
487 | and C<schedule> would cause a deadlock unless there is an idle handler |
| 460 | that wakes up some coroutines. |
488 | that wakes up some coroutines. |
| 461 | |
489 | |
| 462 | =item my $guard = Coro::guard { ... } |
490 | =item my $guard = Coro::guard { ... } |
| 463 | |
491 | |
| 464 | This creates and returns a guard object. Nothing happens until the objetc |
492 | This creates and returns a guard object. Nothing happens until the object |
| 465 | gets destroyed, in which case the codeblock given as argument will be |
493 | gets destroyed, in which case the codeblock given as argument will be |
| 466 | executed. This is useful to free locks or other resources in case of a |
494 | executed. This is useful to free locks or other resources in case of a |
| 467 | runtime error or when the coroutine gets canceled, as in both cases the |
495 | runtime error or when the coroutine gets canceled, as in both cases the |
| 468 | guard block will be executed. The guard object supports only one method, |
496 | guard block will be executed. The guard object supports only one method, |
| 469 | C<< ->cancel >>, which will keep the codeblock from being executed. |
497 | C<< ->cancel >>, which will keep the codeblock from being executed. |
| … | |
… | |
| 498 | This utility function takes a BLOCK or code reference and "unblocks" it, |
526 | This utility function takes a BLOCK or code reference and "unblocks" it, |
| 499 | returning the new coderef. This means that the new coderef will return |
527 | returning the new coderef. This means that the new coderef will return |
| 500 | immediately without blocking, returning nothing, while the original code |
528 | immediately without blocking, returning nothing, while the original code |
| 501 | ref will be called (with parameters) from within its own coroutine. |
529 | ref will be called (with parameters) from within its own coroutine. |
| 502 | |
530 | |
| 503 | The reason this fucntion exists is that many event libraries (such as the |
531 | The reason this function exists is that many event libraries (such as the |
| 504 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
532 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
| 505 | of thread-safety). This means you must not block within event callbacks, |
533 | of thread-safety). This means you must not block within event callbacks, |
| 506 | otherwise you might suffer from crashes or worse. |
534 | otherwise you might suffer from crashes or worse. |
| 507 | |
535 | |
| 508 | This function allows your callbacks to block by executing them in another |
536 | This function allows your callbacks to block by executing them in another |
| … | |
… | |
| 519 | |
547 | |
| 520 | # we create a special coro because we want to cede, |
548 | # we create a special coro because we want to cede, |
| 521 | # to reduce pressure on the coro pool (because most callbacks |
549 | # to reduce pressure on the coro pool (because most callbacks |
| 522 | # return immediately and can be reused) and because we cannot cede |
550 | # return immediately and can be reused) and because we cannot cede |
| 523 | # inside an event callback. |
551 | # inside an event callback. |
| 524 | our $unblock_scheduler = async { |
552 | our $unblock_scheduler = new Coro sub { |
| 525 | while () { |
553 | while () { |
| 526 | while (my $cb = pop @unblock_queue) { |
554 | while (my $cb = pop @unblock_queue) { |
| 527 | # this is an inlined copy of async_pool |
555 | # this is an inlined copy of async_pool |
| 528 | my $coro = (pop @pool or new Coro \&pool_handler); |
556 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
| 529 | |
557 | |
| 530 | $coro->{_invoke} = $cb; |
558 | $coro->{_invoke} = $cb; |
| 531 | $coro->ready; |
559 | $coro->ready; |
| 532 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
560 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
| 533 | } |
561 | } |
| 534 | schedule; # sleep well |
562 | schedule; # sleep well |
| 535 | } |
563 | } |
| 536 | }; |
564 | }; |
|
|
565 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
| 537 | |
566 | |
| 538 | sub unblock_sub(&) { |
567 | sub unblock_sub(&) { |
| 539 | my $cb = shift; |
568 | my $cb = shift; |
| 540 | |
569 | |
| 541 | sub { |
570 | sub { |
| … | |
… | |
| 554 | |
583 | |
| 555 | - you must make very sure that no coro is still active on global |
584 | - you must make very sure that no coro is still active on global |
| 556 | destruction. very bad things might happen otherwise (usually segfaults). |
585 | destruction. very bad things might happen otherwise (usually segfaults). |
| 557 | |
586 | |
| 558 | - this module is not thread-safe. You should only ever use this module |
587 | - this module is not thread-safe. You should only ever use this module |
| 559 | from the same thread (this requirement might be losened in the future |
588 | from the same thread (this requirement might be loosened in the future |
| 560 | to allow per-thread schedulers, but Coro::State does not yet allow |
589 | to allow per-thread schedulers, but Coro::State does not yet allow |
| 561 | this). |
590 | this). |
| 562 | |
591 | |
| 563 | =head1 SEE ALSO |
592 | =head1 SEE ALSO |
| 564 | |
593 | |
