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| 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 |
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| 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 $VERSION = '3.62'; |
| 56 | |
56 | |
| 57 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
57 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
| 58 | our %EXPORT_TAGS = ( |
58 | our %EXPORT_TAGS = ( |
| 59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
| 60 | ); |
60 | ); |
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| 108 | |
108 | |
| 109 | The current coroutine (the last coroutine switched to). The initial value |
109 | The current coroutine (the last coroutine switched to). The initial value |
| 110 | is C<$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 | # maybe some other module used Coro::Specific before... |
118 | # maybe some other module used Coro::Specific before... |
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| 185 | |
185 | |
| 186 | Create a new asynchronous coroutine and return it's coroutine object |
186 | Create a new asynchronous coroutine and return it's coroutine object |
| 187 | (usually unused). When the sub returns the new coroutine is automatically |
187 | (usually unused). When the sub returns the new coroutine is automatically |
| 188 | terminated. |
188 | terminated. |
| 189 | |
189 | |
| 190 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
190 | Calling C<exit> in a coroutine will do the same as calling exit outside |
| 191 | |
191 | 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 |
192 | just as it would in the main program. |
| 193 | program. |
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| 194 | |
193 | |
| 195 | # create a new coroutine that just prints its arguments |
194 | # create a new coroutine that just prints its arguments |
| 196 | async { |
195 | async { |
| 197 | print "@_\n"; |
196 | print "@_\n"; |
| 198 | } 1,2,3,4; |
197 | } 1,2,3,4; |
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| 210 | Similar to C<async>, but uses a coroutine pool, so you should not call |
209 | 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 |
210 | 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 :). |
211 | that might have executed other code already (which can be good or bad :). |
| 213 | |
212 | |
| 214 | Also, the block is executed in an C<eval> context and a warning will be |
213 | 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. |
214 | issued in case of an exception instead of terminating the program, as |
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215 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
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216 | will not work in the expected way, unless you call terminate or cancel, |
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217 | which somehow defeats the purpose of pooling. |
| 216 | |
218 | |
| 217 | The priority will be reset to C<0> after each job, otherwise the coroutine |
219 | The priority will be reset to C<0> after each job, otherwise the coroutine |
| 218 | will be re-used "as-is". |
220 | will be re-used "as-is". |
| 219 | |
221 | |
| 220 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
222 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
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| 230 | our $POOL_SIZE = 8; |
232 | our $POOL_SIZE = 8; |
| 231 | our @pool; |
233 | our @pool; |
| 232 | |
234 | |
| 233 | sub pool_handler { |
235 | sub pool_handler { |
| 234 | while () { |
236 | while () { |
| 235 | my ($cb, @arg) = @{ delete $current->{_invoke} }; |
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| 236 | |
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| 237 | eval { |
237 | eval { |
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238 | my ($cb, @arg) = @{ delete $current->{_invoke} or return }; |
| 238 | $cb->(@arg); |
239 | $cb->(@arg); |
| 239 | }; |
240 | }; |
| 240 | warn $@ if $@; |
241 | warn $@ if $@; |
| 241 | |
242 | |
| 242 | last if @pool >= $POOL_SIZE; |
243 | last if @pool >= $POOL_SIZE; |
| 243 | push @pool, $current; |
244 | push @pool, $current; |
| 244 | |
245 | |
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246 | $current->save (Coro::State::SAVE_DEF); |
| 245 | $current->prio (0); |
247 | $current->prio (0); |
| 246 | schedule; |
248 | schedule; |
| 247 | } |
249 | } |
| 248 | } |
250 | } |
| 249 | |
251 | |
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| 275 | # wake up sleeping coroutine |
277 | # wake up sleeping coroutine |
| 276 | $current->ready; |
278 | $current->ready; |
| 277 | undef $current; |
279 | undef $current; |
| 278 | }; |
280 | }; |
| 279 | |
281 | |
| 280 | # call schedule until event occured. |
282 | # call schedule until event occurred. |
| 281 | # in case we are woken up for other reasons |
283 | # in case we are woken up for other reasons |
| 282 | # (current still defined), loop. |
284 | # (current still defined), loop. |
| 283 | Coro::schedule while $current; |
285 | Coro::schedule while $current; |
| 284 | } |
286 | } |
| 285 | |
287 | |
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| 323 | Create a new coroutine and return it. When the sub returns the coroutine |
325 | Create a new coroutine and return it. When the sub returns the coroutine |
| 324 | automatically terminates as if C<terminate> with the returned values were |
326 | automatically terminates as if C<terminate> with the returned values were |
| 325 | called. To make the coroutine run you must first put it into the ready queue |
327 | called. To make the coroutine run you must first put it into the ready queue |
| 326 | by calling the ready method. |
328 | by calling the ready method. |
| 327 | |
329 | |
| 328 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
330 | See C<async> for additional discussion. |
| 329 | |
331 | |
| 330 | =cut |
332 | =cut |
| 331 | |
333 | |
| 332 | sub _run_coro { |
334 | sub _run_coro { |
| 333 | terminate &{+shift}; |
335 | terminate &{+shift}; |
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| 456 | =over 4 |
458 | =over 4 |
| 457 | |
459 | |
| 458 | =item Coro::nready |
460 | =item Coro::nready |
| 459 | |
461 | |
| 460 | Returns the number of coroutines that are currently in the ready state, |
462 | Returns the number of coroutines that are currently in the ready state, |
| 461 | i.e. that can be swicthed to. The value C<0> means that the only runnable |
463 | i.e. that can be switched to. The value C<0> means that the only runnable |
| 462 | coroutine is the currently running one, so C<cede> would have no effect, |
464 | coroutine is the currently running one, so C<cede> would have no effect, |
| 463 | and C<schedule> would cause a deadlock unless there is an idle handler |
465 | and C<schedule> would cause a deadlock unless there is an idle handler |
| 464 | that wakes up some coroutines. |
466 | that wakes up some coroutines. |
| 465 | |
467 | |
| 466 | =item my $guard = Coro::guard { ... } |
468 | =item my $guard = Coro::guard { ... } |
| 467 | |
469 | |
| 468 | This creates and returns a guard object. Nothing happens until the objetc |
470 | This creates and returns a guard object. Nothing happens until the object |
| 469 | gets destroyed, in which case the codeblock given as argument will be |
471 | gets destroyed, in which case the codeblock given as argument will be |
| 470 | executed. This is useful to free locks or other resources in case of a |
472 | executed. This is useful to free locks or other resources in case of a |
| 471 | runtime error or when the coroutine gets canceled, as in both cases the |
473 | runtime error or when the coroutine gets canceled, as in both cases the |
| 472 | guard block will be executed. The guard object supports only one method, |
474 | guard block will be executed. The guard object supports only one method, |
| 473 | C<< ->cancel >>, which will keep the codeblock from being executed. |
475 | C<< ->cancel >>, which will keep the codeblock from being executed. |
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| 502 | This utility function takes a BLOCK or code reference and "unblocks" it, |
504 | This utility function takes a BLOCK or code reference and "unblocks" it, |
| 503 | returning the new coderef. This means that the new coderef will return |
505 | returning the new coderef. This means that the new coderef will return |
| 504 | immediately without blocking, returning nothing, while the original code |
506 | immediately without blocking, returning nothing, while the original code |
| 505 | ref will be called (with parameters) from within its own coroutine. |
507 | ref will be called (with parameters) from within its own coroutine. |
| 506 | |
508 | |
| 507 | The reason this fucntion exists is that many event libraries (such as the |
509 | The reason this function exists is that many event libraries (such as the |
| 508 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
510 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
| 509 | of thread-safety). This means you must not block within event callbacks, |
511 | of thread-safety). This means you must not block within event callbacks, |
| 510 | otherwise you might suffer from crashes or worse. |
512 | otherwise you might suffer from crashes or worse. |
| 511 | |
513 | |
| 512 | This function allows your callbacks to block by executing them in another |
514 | This function allows your callbacks to block by executing them in another |
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| 558 | |
560 | |
| 559 | - you must make very sure that no coro is still active on global |
561 | - you must make very sure that no coro is still active on global |
| 560 | destruction. very bad things might happen otherwise (usually segfaults). |
562 | destruction. very bad things might happen otherwise (usually segfaults). |
| 561 | |
563 | |
| 562 | - this module is not thread-safe. You should only ever use this module |
564 | - this module is not thread-safe. You should only ever use this module |
| 563 | from the same thread (this requirement might be losened in the future |
565 | from the same thread (this requirement might be loosened in the future |
| 564 | to allow per-thread schedulers, but Coro::State does not yet allow |
566 | to allow per-thread schedulers, but Coro::State does not yet allow |
| 565 | this). |
567 | this). |
| 566 | |
568 | |
| 567 | =head1 SEE ALSO |
569 | =head1 SEE ALSO |
| 568 | |
570 | |
