… | |
… | |
6 | |
6 | |
7 | use Coro; |
7 | use Coro; |
8 | |
8 | |
9 | async { |
9 | async { |
10 | # some asynchronous thread of execution |
10 | # some asynchronous thread of execution |
|
|
11 | print "2\n"; |
|
|
12 | cede; # yield back to main |
|
|
13 | print "4\n"; |
11 | }; |
14 | }; |
|
|
15 | print "1\n"; |
|
|
16 | cede; # yield to coroutine |
|
|
17 | print "3\n"; |
|
|
18 | cede; # and again |
12 | |
19 | |
13 | # alternatively create an async coroutine like this: |
20 | # use locking |
|
|
21 | my $lock = new Coro::Semaphore; |
|
|
22 | my $locked; |
14 | |
23 | |
15 | sub some_func : Coro { |
24 | $lock->down; |
16 | # some more async code |
25 | $locked = 1; |
17 | } |
26 | $lock->up; |
18 | |
|
|
19 | cede; |
|
|
20 | |
27 | |
21 | =head1 DESCRIPTION |
28 | =head1 DESCRIPTION |
22 | |
29 | |
23 | This module collection manages coroutines. Coroutines are similar |
30 | This module collection manages coroutines. Coroutines are similar |
24 | to threads but don't run in parallel at the same time even on SMP |
31 | 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 |
32 | machines. The specific flavor of coroutine used in this module also |
26 | guarentees you that it will not switch between coroutines unless |
33 | guarantees you that it will not switch between coroutines unless |
27 | necessary, at easily-identified points in your program, so locking and |
34 | necessary, at easily-identified points in your program, so locking and |
28 | parallel access are rarely an issue, making coroutine programming much |
35 | parallel access are rarely an issue, making coroutine programming much |
29 | safer than threads programming. |
36 | safer than threads programming. |
30 | |
37 | |
31 | (Perl, however, does not natively support real threads but instead does a |
38 | (Perl, however, does not natively support real threads but instead does a |
… | |
… | |
33 | is a performance win on Windows machines, and a loss everywhere else). |
40 | is a performance win on Windows machines, and a loss everywhere else). |
34 | |
41 | |
35 | In this module, coroutines are defined as "callchain + lexical variables + |
42 | In this module, coroutines are defined as "callchain + lexical variables + |
36 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
43 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
37 | its own set of lexicals and its own set of perls most important global |
44 | its own set of lexicals and its own set of perls most important global |
38 | variables. |
45 | variables (see L<Coro::State> for more configuration). |
39 | |
46 | |
40 | =cut |
47 | =cut |
41 | |
48 | |
42 | package Coro; |
49 | package Coro; |
43 | |
50 | |
… | |
… | |
50 | |
57 | |
51 | our $idle; # idle handler |
58 | our $idle; # idle handler |
52 | our $main; # main coroutine |
59 | our $main; # main coroutine |
53 | our $current; # current coroutine |
60 | our $current; # current coroutine |
54 | |
61 | |
55 | our $VERSION = '3.1'; |
62 | our $VERSION = '4.51'; |
56 | |
63 | |
57 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
64 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
58 | our %EXPORT_TAGS = ( |
65 | our %EXPORT_TAGS = ( |
59 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
66 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
60 | ); |
67 | ); |
61 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
68 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
62 | |
69 | |
… | |
… | |
108 | |
115 | |
109 | The current coroutine (the last coroutine switched to). The initial value |
116 | The current coroutine (the last coroutine switched to). The initial value |
110 | is C<$main> (of course). |
117 | is C<$main> (of course). |
111 | |
118 | |
112 | This variable is B<strictly> I<read-only>. It is provided for performance |
119 | 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 |
120 | reasons. If performance is not essential you are encouraged to use the |
114 | C<Coro::current> function instead. |
121 | C<Coro::current> function instead. |
115 | |
122 | |
116 | =cut |
123 | =cut |
117 | |
124 | |
|
|
125 | $main->{desc} = "[main::]"; |
|
|
126 | |
118 | # maybe some other module used Coro::Specific before... |
127 | # maybe some other module used Coro::Specific before... |
119 | $main->{specific} = $current->{specific} |
128 | $main->{_specific} = $current->{_specific} |
120 | if $current; |
129 | if $current; |
121 | |
130 | |
122 | _set_current $main; |
131 | _set_current $main; |
123 | |
132 | |
124 | sub current() { $current } |
133 | sub current() { $current } |
… | |
… | |
132 | This hook is overwritten by modules such as C<Coro::Timer> and |
141 | This hook is overwritten by modules such as C<Coro::Timer> and |
133 | C<Coro::Event> to wait on an external event that hopefully wake up a |
142 | C<Coro::Event> to wait on an external event that hopefully wake up a |
134 | coroutine so the scheduler can run it. |
143 | coroutine so the scheduler can run it. |
135 | |
144 | |
136 | Please note that if your callback recursively invokes perl (e.g. for event |
145 | Please note that if your callback recursively invokes perl (e.g. for event |
137 | handlers), then it must be prepared to be called recursively. |
146 | handlers), then it must be prepared to be called recursively itself. |
138 | |
147 | |
139 | =cut |
148 | =cut |
140 | |
149 | |
141 | $idle = sub { |
150 | $idle = sub { |
142 | require Carp; |
151 | require Carp; |
143 | Carp::croak ("FATAL: deadlock detected"); |
152 | Carp::croak ("FATAL: deadlock detected"); |
144 | }; |
153 | }; |
145 | |
154 | |
|
|
155 | sub _cancel { |
|
|
156 | my ($self) = @_; |
|
|
157 | |
|
|
158 | # free coroutine data and mark as destructed |
|
|
159 | $self->_destroy |
|
|
160 | or return; |
|
|
161 | |
|
|
162 | # call all destruction callbacks |
|
|
163 | $_->(@{$self->{_status}}) |
|
|
164 | for @{(delete $self->{_on_destroy}) || []}; |
|
|
165 | } |
|
|
166 | |
146 | # this coroutine is necessary because a coroutine |
167 | # this coroutine is necessary because a coroutine |
147 | # cannot destroy itself. |
168 | # cannot destroy itself. |
148 | my @destroy; |
169 | my @destroy; |
|
|
170 | my $manager; |
|
|
171 | |
149 | my $manager; $manager = new Coro sub { |
172 | $manager = new Coro sub { |
150 | while () { |
173 | while () { |
151 | # by overwriting the state object with the manager we destroy it |
174 | (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) { |
175 | while @destroy; |
157 | my $coro = pop @destroy; |
|
|
158 | $coro->{status} ||= []; |
|
|
159 | $_->ready for @{delete $coro->{join} || []}; |
|
|
160 | |
176 | |
161 | # the next line destroys the coro state, but keeps the |
|
|
162 | # coroutine itself intact (we basically make it a zombie |
|
|
163 | # coroutine that always runs the manager thread, so it's possible |
|
|
164 | # to transfer() to this coroutine). |
|
|
165 | $coro->_clone_state_from ($manager); |
|
|
166 | } |
|
|
167 | &schedule; |
177 | &schedule; |
168 | } |
178 | } |
169 | }; |
179 | }; |
170 | |
180 | $manager->desc ("[coro manager]"); |
171 | # static methods. not really. |
181 | $manager->prio (PRIO_MAX); |
172 | |
182 | |
173 | =back |
183 | =back |
174 | |
184 | |
175 | =head2 STATIC METHODS |
185 | =head2 STATIC METHODS |
176 | |
186 | |
… | |
… | |
182 | |
192 | |
183 | Create a new asynchronous coroutine and return it's coroutine object |
193 | Create a new asynchronous coroutine and return it's coroutine object |
184 | (usually unused). When the sub returns the new coroutine is automatically |
194 | (usually unused). When the sub returns the new coroutine is automatically |
185 | terminated. |
195 | terminated. |
186 | |
196 | |
187 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
197 | See the C<Coro::State::new> constructor for info about the coroutine |
|
|
198 | environment in which coroutines run. |
188 | |
199 | |
189 | When the coroutine dies, the program will exit, just as in the main |
200 | Calling C<exit> in a coroutine will do the same as calling exit outside |
190 | program. |
201 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
|
|
202 | just as it would in the main program. |
191 | |
203 | |
192 | # create a new coroutine that just prints its arguments |
204 | # create a new coroutine that just prints its arguments |
193 | async { |
205 | async { |
194 | print "@_\n"; |
206 | print "@_\n"; |
195 | } 1,2,3,4; |
207 | } 1,2,3,4; |
196 | |
208 | |
197 | =cut |
209 | =cut |
198 | |
210 | |
199 | sub async(&@) { |
211 | sub async(&@) { |
200 | my $pid = new Coro @_; |
212 | my $coro = new Coro @_; |
201 | $pid->ready; |
213 | $coro->ready; |
202 | $pid |
214 | $coro |
|
|
215 | } |
|
|
216 | |
|
|
217 | =item async_pool { ... } [@args...] |
|
|
218 | |
|
|
219 | Similar to C<async>, but uses a coroutine pool, so you should not call |
|
|
220 | terminate or join (although you are allowed to), and you get a coroutine |
|
|
221 | that might have executed other code already (which can be good or bad :). |
|
|
222 | |
|
|
223 | Also, the block is executed in an C<eval> context and a warning will be |
|
|
224 | issued in case of an exception instead of terminating the program, as |
|
|
225 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
|
|
226 | will not work in the expected way, unless you call terminate or cancel, |
|
|
227 | which somehow defeats the purpose of pooling. |
|
|
228 | |
|
|
229 | The priority will be reset to C<0> after each job, tracing will be |
|
|
230 | disabled, the description will be reset and the default output filehandle |
|
|
231 | gets restored, so you can change alkl these. Otherwise the coroutine will |
|
|
232 | be re-used "as-is": most notably if you change other per-coroutine global |
|
|
233 | stuff such as C<$/> you need to revert that change, which is most simply |
|
|
234 | done by using local as in C< local $/ >. |
|
|
235 | |
|
|
236 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
|
|
237 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
|
|
238 | required. |
|
|
239 | |
|
|
240 | If you are concerned about pooled coroutines growing a lot because a |
|
|
241 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
|
|
242 | { terminate }> once per second or so to slowly replenish the pool. In |
|
|
243 | addition to that, when the stacks used by a handler grows larger than 16kb |
|
|
244 | (adjustable with $Coro::POOL_RSS) it will also exit. |
|
|
245 | |
|
|
246 | =cut |
|
|
247 | |
|
|
248 | our $POOL_SIZE = 8; |
|
|
249 | our $POOL_RSS = 16 * 1024; |
|
|
250 | our @async_pool; |
|
|
251 | |
|
|
252 | sub pool_handler { |
|
|
253 | my $cb; |
|
|
254 | |
|
|
255 | while () { |
|
|
256 | eval { |
|
|
257 | while () { |
|
|
258 | _pool_1 $cb; |
|
|
259 | &$cb; |
|
|
260 | _pool_2 $cb; |
|
|
261 | &schedule; |
|
|
262 | } |
|
|
263 | }; |
|
|
264 | |
|
|
265 | last if $@ eq "\3async_pool terminate\2\n"; |
|
|
266 | warn $@ if $@; |
|
|
267 | } |
|
|
268 | } |
|
|
269 | |
|
|
270 | sub async_pool(&@) { |
|
|
271 | # this is also inlined into the unlock_scheduler |
|
|
272 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
|
|
273 | |
|
|
274 | $coro->{_invoke} = [@_]; |
|
|
275 | $coro->ready; |
|
|
276 | |
|
|
277 | $coro |
203 | } |
278 | } |
204 | |
279 | |
205 | =item schedule |
280 | =item schedule |
206 | |
281 | |
207 | Calls the scheduler. Please note that the current coroutine will not be put |
282 | Calls the scheduler. Please note that the current coroutine will not be put |
… | |
… | |
220 | # wake up sleeping coroutine |
295 | # wake up sleeping coroutine |
221 | $current->ready; |
296 | $current->ready; |
222 | undef $current; |
297 | undef $current; |
223 | }; |
298 | }; |
224 | |
299 | |
225 | # call schedule until event occured. |
300 | # call schedule until event occurred. |
226 | # in case we are woken up for other reasons |
301 | # in case we are woken up for other reasons |
227 | # (current still defined), loop. |
302 | # (current still defined), loop. |
228 | Coro::schedule while $current; |
303 | Coro::schedule while $current; |
229 | } |
304 | } |
230 | |
305 | |
… | |
… | |
232 | |
307 | |
233 | "Cede" to other coroutines. This function puts the current coroutine into the |
308 | "Cede" to other coroutines. This function puts the current coroutine into the |
234 | ready queue and calls C<schedule>, which has the effect of giving up the |
309 | ready queue and calls C<schedule>, which has the effect of giving up the |
235 | current "timeslice" to other coroutines of the same or higher priority. |
310 | current "timeslice" to other coroutines of the same or higher priority. |
236 | |
311 | |
|
|
312 | =item Coro::cede_notself |
|
|
313 | |
|
|
314 | Works like cede, but is not exported by default and will cede to any |
|
|
315 | coroutine, regardless of priority, once. |
|
|
316 | |
237 | =item terminate [arg...] |
317 | =item terminate [arg...] |
238 | |
318 | |
239 | Terminates the current coroutine with the given status values (see L<cancel>). |
319 | Terminates the current coroutine with the given status values (see L<cancel>). |
|
|
320 | |
|
|
321 | =item killall |
|
|
322 | |
|
|
323 | Kills/terminates/cancels all coroutines except the currently running |
|
|
324 | one. This is useful after a fork, either in the child or the parent, as |
|
|
325 | usually only one of them should inherit the running coroutines. |
240 | |
326 | |
241 | =cut |
327 | =cut |
242 | |
328 | |
243 | sub terminate { |
329 | sub terminate { |
244 | $current->cancel (@_); |
330 | $current->cancel (@_); |
245 | } |
331 | } |
246 | |
332 | |
|
|
333 | sub killall { |
|
|
334 | for (Coro::State::list) { |
|
|
335 | $_->cancel |
|
|
336 | if $_ != $current && UNIVERSAL::isa $_, "Coro"; |
|
|
337 | } |
|
|
338 | } |
|
|
339 | |
247 | =back |
340 | =back |
248 | |
|
|
249 | # dynamic methods |
|
|
250 | |
341 | |
251 | =head2 COROUTINE METHODS |
342 | =head2 COROUTINE METHODS |
252 | |
343 | |
253 | These are the methods you can call on coroutine objects. |
344 | These are the methods you can call on coroutine objects. |
254 | |
345 | |
… | |
… | |
259 | Create a new coroutine and return it. When the sub returns the coroutine |
350 | Create a new coroutine and return it. When the sub returns the coroutine |
260 | automatically terminates as if C<terminate> with the returned values were |
351 | automatically terminates as if C<terminate> with the returned values were |
261 | called. To make the coroutine run you must first put it into the ready queue |
352 | called. To make the coroutine run you must first put it into the ready queue |
262 | by calling the ready method. |
353 | by calling the ready method. |
263 | |
354 | |
264 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
355 | See C<async> and C<Coro::State::new> for additional info about the |
|
|
356 | coroutine environment. |
265 | |
357 | |
266 | =cut |
358 | =cut |
267 | |
359 | |
268 | sub _run_coro { |
360 | sub _run_coro { |
269 | terminate &{+shift}; |
361 | terminate &{+shift}; |
… | |
… | |
286 | Return wether the coroutine is currently the ready queue or not, |
378 | Return wether the coroutine is currently the ready queue or not, |
287 | |
379 | |
288 | =item $coroutine->cancel (arg...) |
380 | =item $coroutine->cancel (arg...) |
289 | |
381 | |
290 | Terminates the given coroutine and makes it return the given arguments as |
382 | Terminates the given coroutine and makes it return the given arguments as |
291 | status (default: the empty list). |
383 | status (default: the empty list). Never returns if the coroutine is the |
|
|
384 | current coroutine. |
292 | |
385 | |
293 | =cut |
386 | =cut |
294 | |
387 | |
295 | sub cancel { |
388 | sub cancel { |
296 | my $self = shift; |
389 | my $self = shift; |
297 | $self->{status} = [@_]; |
390 | $self->{_status} = [@_]; |
|
|
391 | |
|
|
392 | if ($current == $self) { |
298 | push @destroy, $self; |
393 | push @destroy, $self; |
299 | $manager->ready; |
394 | $manager->ready; |
300 | &schedule if $current == $self; |
395 | &schedule while 1; |
|
|
396 | } else { |
|
|
397 | $self->_cancel; |
|
|
398 | } |
301 | } |
399 | } |
302 | |
400 | |
303 | =item $coroutine->join |
401 | =item $coroutine->join |
304 | |
402 | |
305 | Wait until the coroutine terminates and return any values given to the |
403 | Wait until the coroutine terminates and return any values given to the |
306 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
404 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
307 | from multiple coroutine. |
405 | from multiple coroutines. |
308 | |
406 | |
309 | =cut |
407 | =cut |
310 | |
408 | |
311 | sub join { |
409 | sub join { |
312 | my $self = shift; |
410 | my $self = shift; |
|
|
411 | |
313 | unless ($self->{status}) { |
412 | unless ($self->{_status}) { |
314 | push @{$self->{join}}, $current; |
413 | my $current = $current; |
315 | &schedule; |
414 | |
|
|
415 | push @{$self->{_on_destroy}}, sub { |
|
|
416 | $current->ready; |
|
|
417 | undef $current; |
|
|
418 | }; |
|
|
419 | |
|
|
420 | &schedule while $current; |
316 | } |
421 | } |
|
|
422 | |
317 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
423 | wantarray ? @{$self->{_status}} : $self->{_status}[0]; |
|
|
424 | } |
|
|
425 | |
|
|
426 | =item $coroutine->on_destroy (\&cb) |
|
|
427 | |
|
|
428 | Registers a callback that is called when this coroutine gets destroyed, |
|
|
429 | but before it is joined. The callback gets passed the terminate arguments, |
|
|
430 | if any. |
|
|
431 | |
|
|
432 | =cut |
|
|
433 | |
|
|
434 | sub on_destroy { |
|
|
435 | my ($self, $cb) = @_; |
|
|
436 | |
|
|
437 | push @{ $self->{_on_destroy} }, $cb; |
318 | } |
438 | } |
319 | |
439 | |
320 | =item $oldprio = $coroutine->prio ($newprio) |
440 | =item $oldprio = $coroutine->prio ($newprio) |
321 | |
441 | |
322 | Sets (or gets, if the argument is missing) the priority of the |
442 | Sets (or gets, if the argument is missing) the priority of the |
… | |
… | |
347 | =item $olddesc = $coroutine->desc ($newdesc) |
467 | =item $olddesc = $coroutine->desc ($newdesc) |
348 | |
468 | |
349 | Sets (or gets in case the argument is missing) the description for this |
469 | Sets (or gets in case the argument is missing) the description for this |
350 | coroutine. This is just a free-form string you can associate with a coroutine. |
470 | coroutine. This is just a free-form string you can associate with a coroutine. |
351 | |
471 | |
|
|
472 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
|
|
473 | can modify this member directly if you wish. |
|
|
474 | |
|
|
475 | =item $coroutine->throw ([$scalar]) |
|
|
476 | |
|
|
477 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
478 | inside the coroutine at the next convinient point in time (usually after |
|
|
479 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
480 | exception object. |
|
|
481 | |
|
|
482 | The exception object will be thrown "as is" with the specified scalar in |
|
|
483 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
484 | (unlike with C<die>). |
|
|
485 | |
|
|
486 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
487 | end itself, although there is no guarentee that the exception will lead to |
|
|
488 | termination, and if the exception isn't caught it might well end the whole |
|
|
489 | program. |
|
|
490 | |
352 | =cut |
491 | =cut |
353 | |
492 | |
354 | sub desc { |
493 | sub desc { |
355 | my $old = $_[0]{desc}; |
494 | my $old = $_[0]{desc}; |
356 | $_[0]{desc} = $_[1] if @_ > 1; |
495 | $_[0]{desc} = $_[1] if @_ > 1; |
… | |
… | |
364 | =over 4 |
503 | =over 4 |
365 | |
504 | |
366 | =item Coro::nready |
505 | =item Coro::nready |
367 | |
506 | |
368 | Returns the number of coroutines that are currently in the ready state, |
507 | Returns the number of coroutines that are currently in the ready state, |
369 | i.e. that can be swicthed to. The value C<0> means that the only runnable |
508 | i.e. that can be switched to. The value C<0> means that the only runnable |
370 | coroutine is the currently running one, so C<cede> would have no effect, |
509 | coroutine is the currently running one, so C<cede> would have no effect, |
371 | and C<schedule> would cause a deadlock unless there is an idle handler |
510 | and C<schedule> would cause a deadlock unless there is an idle handler |
372 | that wakes up some coroutines. |
511 | that wakes up some coroutines. |
|
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512 | |
|
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513 | =item my $guard = Coro::guard { ... } |
|
|
514 | |
|
|
515 | This creates and returns a guard object. Nothing happens until the object |
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|
516 | gets destroyed, in which case the codeblock given as argument will be |
|
|
517 | executed. This is useful to free locks or other resources in case of a |
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518 | runtime error or when the coroutine gets canceled, as in both cases the |
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519 | guard block will be executed. The guard object supports only one method, |
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520 | C<< ->cancel >>, which will keep the codeblock from being executed. |
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521 | |
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522 | Example: set some flag and clear it again when the coroutine gets canceled |
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523 | or the function returns: |
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524 | |
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525 | sub do_something { |
|
|
526 | my $guard = Coro::guard { $busy = 0 }; |
|
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527 | $busy = 1; |
|
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528 | |
|
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529 | # do something that requires $busy to be true |
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530 | } |
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531 | |
|
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532 | =cut |
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533 | |
|
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534 | sub guard(&) { |
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535 | bless \(my $cb = $_[0]), "Coro::guard" |
|
|
536 | } |
|
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537 | |
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538 | sub Coro::guard::cancel { |
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539 | ${$_[0]} = sub { }; |
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540 | } |
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541 | |
|
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542 | sub Coro::guard::DESTROY { |
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543 | ${$_[0]}->(); |
|
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544 | } |
|
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545 | |
373 | |
546 | |
374 | =item unblock_sub { ... } |
547 | =item unblock_sub { ... } |
375 | |
548 | |
376 | This utility function takes a BLOCK or code reference and "unblocks" it, |
549 | This utility function takes a BLOCK or code reference and "unblocks" it, |
377 | returning the new coderef. This means that the new coderef will return |
550 | returning the new coderef. This means that the new coderef will return |
378 | immediately without blocking, returning nothing, while the original code |
551 | immediately without blocking, returning nothing, while the original code |
379 | ref will be called (with parameters) from within its own coroutine. |
552 | ref will be called (with parameters) from within its own coroutine. |
380 | |
553 | |
381 | The reason this fucntion exists is that many event libraries (such as the |
554 | The reason this function exists is that many event libraries (such as the |
382 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
555 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
383 | of thread-safety). This means you must not block within event callbacks, |
556 | of thread-safety). This means you must not block within event callbacks, |
384 | otherwise you might suffer from crashes or worse. |
557 | otherwise you might suffer from crashes or worse. |
385 | |
558 | |
386 | This function allows your callbacks to block by executing them in another |
559 | This function allows your callbacks to block by executing them in another |
… | |
… | |
391 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
564 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
392 | creating event callbacks that want to block. |
565 | creating event callbacks that want to block. |
393 | |
566 | |
394 | =cut |
567 | =cut |
395 | |
568 | |
396 | our @unblock_pool; |
|
|
397 | our @unblock_queue; |
569 | our @unblock_queue; |
398 | our $UNBLOCK_POOL_SIZE = 2; |
|
|
399 | |
570 | |
400 | sub unblock_handler_ { |
571 | # we create a special coro because we want to cede, |
401 | while () { |
572 | # to reduce pressure on the coro pool (because most callbacks |
402 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
573 | # return immediately and can be reused) and because we cannot cede |
403 | $cb->(@arg); |
574 | # inside an event callback. |
404 | |
|
|
405 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
|
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406 | push @unblock_pool, $Coro::current; |
|
|
407 | schedule; |
|
|
408 | } |
|
|
409 | } |
|
|
410 | |
|
|
411 | our $unblock_scheduler = async { |
575 | our $unblock_scheduler = new Coro sub { |
412 | while () { |
576 | while () { |
413 | while (my $cb = pop @unblock_queue) { |
577 | while (my $cb = pop @unblock_queue) { |
414 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
578 | # this is an inlined copy of async_pool |
415 | $handler->{arg} = $cb; |
579 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
|
|
580 | |
|
|
581 | $coro->{_invoke} = $cb; |
416 | $handler->ready; |
582 | $coro->ready; |
417 | cede; |
583 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
418 | } |
584 | } |
419 | |
585 | schedule; # sleep well |
420 | schedule; |
|
|
421 | } |
586 | } |
422 | }; |
587 | }; |
|
|
588 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
423 | |
589 | |
424 | sub unblock_sub(&) { |
590 | sub unblock_sub(&) { |
425 | my $cb = shift; |
591 | my $cb = shift; |
426 | |
592 | |
427 | sub { |
593 | sub { |
428 | push @unblock_queue, [$cb, @_]; |
594 | unshift @unblock_queue, [$cb, @_]; |
429 | $unblock_scheduler->ready; |
595 | $unblock_scheduler->ready; |
430 | } |
596 | } |
431 | } |
597 | } |
432 | |
598 | |
433 | =back |
599 | =back |
… | |
… | |
440 | |
606 | |
441 | - you must make very sure that no coro is still active on global |
607 | - you must make very sure that no coro is still active on global |
442 | destruction. very bad things might happen otherwise (usually segfaults). |
608 | destruction. very bad things might happen otherwise (usually segfaults). |
443 | |
609 | |
444 | - this module is not thread-safe. You should only ever use this module |
610 | - this module is not thread-safe. You should only ever use this module |
445 | from the same thread (this requirement might be losened in the future |
611 | from the same thread (this requirement might be loosened in the future |
446 | to allow per-thread schedulers, but Coro::State does not yet allow |
612 | to allow per-thread schedulers, but Coro::State does not yet allow |
447 | this). |
613 | this). |
448 | |
614 | |
449 | =head1 SEE ALSO |
615 | =head1 SEE ALSO |
450 | |
616 | |
|
|
617 | Lower level Configuration, Coroutine Environment: L<Coro::State>. |
|
|
618 | |
|
|
619 | Debugging: L<Coro::Debug>. |
|
|
620 | |
451 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
621 | Support/Utility: L<Coro::Specific>, L<Coro::Util>. |
452 | |
622 | |
453 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
623 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
454 | |
624 | |
455 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
625 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>. |
456 | |
626 | |
|
|
627 | Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>. |
|
|
628 | |
457 | Embedding: L<Coro:MakeMaker> |
629 | Embedding: L<Coro::MakeMaker>. |
458 | |
630 | |
459 | =head1 AUTHOR |
631 | =head1 AUTHOR |
460 | |
632 | |
461 | Marc Lehmann <schmorp@schmorp.de> |
633 | Marc Lehmann <schmorp@schmorp.de> |
462 | http://home.schmorp.de/ |
634 | http://home.schmorp.de/ |