… | |
… | |
8 | |
8 | |
9 | async { |
9 | async { |
10 | # some asynchronous thread of execution |
10 | # some asynchronous thread of execution |
11 | }; |
11 | }; |
12 | |
12 | |
13 | # alternatively create an async process like this: |
13 | # alternatively create an async coroutine like this: |
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 | |
… | |
… | |
41 | |
41 | |
42 | our $idle; # idle handler |
42 | our $idle; # idle handler |
43 | our $main; # main coroutine |
43 | our $main; # main coroutine |
44 | our $current; # current coroutine |
44 | our $current; # current coroutine |
45 | |
45 | |
46 | our $VERSION = '2.5'; |
46 | our $VERSION = '3.0'; |
47 | |
47 | |
48 | our @EXPORT = qw(async cede schedule terminate current); |
48 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
49 | our %EXPORT_TAGS = ( |
49 | our %EXPORT_TAGS = ( |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
51 | ); |
51 | ); |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
53 | |
53 | |
… | |
… | |
117 | |
117 | |
118 | =item $idle |
118 | =item $idle |
119 | |
119 | |
120 | A callback that is called whenever the scheduler finds no ready coroutines |
120 | A callback that is called whenever the scheduler finds no ready coroutines |
121 | to run. The default implementation prints "FATAL: deadlock detected" and |
121 | to run. The default implementation prints "FATAL: deadlock detected" and |
122 | exits. |
122 | exits, because the program has no other way to continue. |
123 | |
123 | |
124 | This hook is overwritten by modules such as C<Coro::Timer> and |
124 | This hook is overwritten by modules such as C<Coro::Timer> and |
125 | C<Coro::Event> to wait on an external event that hopefully wakes up some |
125 | C<Coro::Event> to wait on an external event that hopefully wake up a |
126 | coroutine. |
126 | coroutine so the scheduler can run it. |
|
|
127 | |
|
|
128 | Please note that if your callback recursively invokes perl (e.g. for event |
|
|
129 | handlers), then it must be prepared to be called recursively. |
127 | |
130 | |
128 | =cut |
131 | =cut |
129 | |
132 | |
130 | $idle = sub { |
133 | $idle = sub { |
131 | print STDERR "FATAL: deadlock detected\n"; |
134 | print STDERR "FATAL: deadlock detected\n"; |
… | |
… | |
133 | }; |
136 | }; |
134 | |
137 | |
135 | # this coroutine is necessary because a coroutine |
138 | # this coroutine is necessary because a coroutine |
136 | # cannot destroy itself. |
139 | # cannot destroy itself. |
137 | my @destroy; |
140 | my @destroy; |
138 | my $manager; |
|
|
139 | $manager = new Coro sub { |
141 | my $manager; $manager = new Coro sub { |
140 | while () { |
142 | while () { |
141 | # by overwriting the state object with the manager we destroy it |
143 | # by overwriting the state object with the manager we destroy it |
142 | # while still being able to schedule this coroutine (in case it has |
144 | # while still being able to schedule this coroutine (in case it has |
143 | # been readied multiple times. this is harmless since the manager |
145 | # been readied multiple times. this is harmless since the manager |
144 | # can be called as many times as neccessary and will always |
146 | # can be called as many times as neccessary and will always |
… | |
… | |
147 | my $coro = pop @destroy; |
149 | my $coro = pop @destroy; |
148 | $coro->{status} ||= []; |
150 | $coro->{status} ||= []; |
149 | $_->ready for @{delete $coro->{join} || []}; |
151 | $_->ready for @{delete $coro->{join} || []}; |
150 | |
152 | |
151 | # the next line destroys the coro state, but keeps the |
153 | # the next line destroys the coro state, but keeps the |
152 | # process itself intact (we basically make it a zombie |
154 | # coroutine itself intact (we basically make it a zombie |
153 | # process that always runs the manager thread, so it's possible |
155 | # coroutine that always runs the manager thread, so it's possible |
154 | # to transfer() to this process). |
156 | # to transfer() to this coroutine). |
155 | $coro->_clone_state_from ($manager); |
157 | $coro->_clone_state_from ($manager); |
156 | } |
158 | } |
157 | &schedule; |
159 | &schedule; |
158 | } |
160 | } |
159 | }; |
161 | }; |
… | |
… | |
162 | |
164 | |
163 | =back |
165 | =back |
164 | |
166 | |
165 | =head2 STATIC METHODS |
167 | =head2 STATIC METHODS |
166 | |
168 | |
167 | Static methods are actually functions that operate on the current process only. |
169 | Static methods are actually functions that operate on the current coroutine only. |
168 | |
170 | |
169 | =over 4 |
171 | =over 4 |
170 | |
172 | |
171 | =item async { ... } [@args...] |
173 | =item async { ... } [@args...] |
172 | |
174 | |
173 | Create a new asynchronous process and return it's process object |
175 | Create a new asynchronous coroutine and return it's coroutine object |
174 | (usually unused). When the sub returns the new process is automatically |
176 | (usually unused). When the sub returns the new coroutine is automatically |
175 | terminated. |
177 | terminated. |
|
|
178 | |
|
|
179 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
176 | |
180 | |
177 | When the coroutine dies, the program will exit, just as in the main |
181 | When the coroutine dies, the program will exit, just as in the main |
178 | program. |
182 | program. |
179 | |
183 | |
180 | # create a new coroutine that just prints its arguments |
184 | # create a new coroutine that just prints its arguments |
… | |
… | |
184 | |
188 | |
185 | =cut |
189 | =cut |
186 | |
190 | |
187 | sub async(&@) { |
191 | sub async(&@) { |
188 | my $pid = new Coro @_; |
192 | my $pid = new Coro @_; |
189 | $manager->ready; # this ensures that the stack is cloned from the manager |
|
|
190 | $pid->ready; |
193 | $pid->ready; |
191 | $pid; |
194 | $pid |
192 | } |
195 | } |
193 | |
196 | |
194 | =item schedule |
197 | =item schedule |
195 | |
198 | |
196 | Calls the scheduler. Please note that the current process will not be put |
199 | Calls the scheduler. Please note that the current coroutine will not be put |
197 | into the ready queue, so calling this function usually means you will |
200 | into the ready queue, so calling this function usually means you will |
198 | never be called again. |
201 | never be called again unless something else (e.g. an event handler) calls |
|
|
202 | ready. |
199 | |
203 | |
200 | =cut |
204 | The canonical way to wait on external events is this: |
|
|
205 | |
|
|
206 | { |
|
|
207 | # remember current coroutine |
|
|
208 | my $current = $Coro::current; |
|
|
209 | |
|
|
210 | # register a hypothetical event handler |
|
|
211 | on_event_invoke sub { |
|
|
212 | # wake up sleeping coroutine |
|
|
213 | $current->ready; |
|
|
214 | undef $current; |
|
|
215 | }; |
|
|
216 | |
|
|
217 | # call schedule until event occured. |
|
|
218 | # in case we are woken up for other reasons |
|
|
219 | # (current still defined), loop. |
|
|
220 | Coro::schedule while $current; |
|
|
221 | } |
201 | |
222 | |
202 | =item cede |
223 | =item cede |
203 | |
224 | |
204 | "Cede" to other processes. This function puts the current process into the |
225 | "Cede" to other coroutines. This function puts the current coroutine into the |
205 | ready queue and calls C<schedule>, which has the effect of giving up the |
226 | ready queue and calls C<schedule>, which has the effect of giving up the |
206 | current "timeslice" to other coroutines of the same or higher priority. |
227 | current "timeslice" to other coroutines of the same or higher priority. |
207 | |
228 | |
208 | =cut |
|
|
209 | |
|
|
210 | =item terminate [arg...] |
229 | =item terminate [arg...] |
211 | |
230 | |
212 | Terminates the current process with the given status values (see L<cancel>). |
231 | Terminates the current coroutine with the given status values (see L<cancel>). |
213 | |
232 | |
214 | =cut |
233 | =cut |
215 | |
234 | |
216 | sub terminate { |
235 | sub terminate { |
217 | $current->cancel (@_); |
236 | $current->cancel (@_); |
… | |
… | |
219 | |
238 | |
220 | =back |
239 | =back |
221 | |
240 | |
222 | # dynamic methods |
241 | # dynamic methods |
223 | |
242 | |
224 | =head2 PROCESS METHODS |
243 | =head2 COROUTINE METHODS |
225 | |
244 | |
226 | These are the methods you can call on process objects. |
245 | These are the methods you can call on coroutine objects. |
227 | |
246 | |
228 | =over 4 |
247 | =over 4 |
229 | |
248 | |
230 | =item new Coro \&sub [, @args...] |
249 | =item new Coro \&sub [, @args...] |
231 | |
250 | |
232 | Create a new process and return it. When the sub returns the process |
251 | Create a new coroutine and return it. When the sub returns the coroutine |
233 | automatically terminates as if C<terminate> with the returned values were |
252 | automatically terminates as if C<terminate> with the returned values were |
234 | called. To make the process run you must first put it into the ready queue |
253 | called. To make the coroutine run you must first put it into the ready queue |
235 | by calling the ready method. |
254 | by calling the ready method. |
236 | |
255 | |
|
|
256 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
|
|
257 | |
237 | =cut |
258 | =cut |
238 | |
259 | |
239 | sub _new_coro { |
260 | sub _new_coro { |
240 | # $current->_clear_idle_sp; # set the idle sp on the following cede |
|
|
241 | _set_cede_self; # ensures that cede cede's us first |
|
|
242 | cede; |
|
|
243 | terminate &{+shift}; |
261 | terminate &{+shift}; |
244 | } |
262 | } |
245 | |
263 | |
246 | sub new { |
264 | sub new { |
247 | my $class = shift; |
265 | my $class = shift; |
248 | |
266 | |
249 | $class->SUPER::new (\&_new_coro, @_) |
267 | $class->SUPER::new (\&_new_coro, @_) |
250 | } |
268 | } |
251 | |
269 | |
252 | =item $process->ready |
270 | =item $success = $coroutine->ready |
253 | |
271 | |
254 | Put the given process into the ready queue. |
272 | Put the given coroutine into the ready queue (according to it's priority) |
|
|
273 | and return true. If the coroutine is already in the ready queue, do nothing |
|
|
274 | and return false. |
255 | |
275 | |
256 | =cut |
276 | =item $is_ready = $coroutine->is_ready |
257 | |
277 | |
|
|
278 | Return wether the coroutine is currently the ready queue or not, |
|
|
279 | |
258 | =item $process->cancel (arg...) |
280 | =item $coroutine->cancel (arg...) |
259 | |
281 | |
260 | Terminates the given process and makes it return the given arguments as |
282 | Terminates the given coroutine and makes it return the given arguments as |
261 | status (default: the empty list). |
283 | status (default: the empty list). |
262 | |
284 | |
263 | =cut |
285 | =cut |
264 | |
286 | |
265 | sub cancel { |
287 | sub cancel { |
… | |
… | |
268 | push @destroy, $self; |
290 | push @destroy, $self; |
269 | $manager->ready; |
291 | $manager->ready; |
270 | &schedule if $current == $self; |
292 | &schedule if $current == $self; |
271 | } |
293 | } |
272 | |
294 | |
273 | =item $process->join |
295 | =item $coroutine->join |
274 | |
296 | |
275 | Wait until the coroutine terminates and return any values given to the |
297 | Wait until the coroutine terminates and return any values given to the |
276 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
298 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
277 | from multiple processes. |
299 | from multiple coroutine. |
278 | |
300 | |
279 | =cut |
301 | =cut |
280 | |
302 | |
281 | sub join { |
303 | sub join { |
282 | my $self = shift; |
304 | my $self = shift; |
… | |
… | |
285 | &schedule; |
307 | &schedule; |
286 | } |
308 | } |
287 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
309 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
288 | } |
310 | } |
289 | |
311 | |
290 | =item $oldprio = $process->prio ($newprio) |
312 | =item $oldprio = $coroutine->prio ($newprio) |
291 | |
313 | |
292 | Sets (or gets, if the argument is missing) the priority of the |
314 | Sets (or gets, if the argument is missing) the priority of the |
293 | process. Higher priority processes get run before lower priority |
315 | coroutine. Higher priority coroutines get run before lower priority |
294 | processes. Priorities are small signed integers (currently -4 .. +3), |
316 | coroutines. Priorities are small signed integers (currently -4 .. +3), |
295 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
317 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
296 | to get then): |
318 | to get then): |
297 | |
319 | |
298 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
320 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
299 | 3 > 1 > 0 > -1 > -3 > -4 |
321 | 3 > 1 > 0 > -1 > -3 > -4 |
… | |
… | |
302 | current->prio(PRIO_HIGH); |
324 | current->prio(PRIO_HIGH); |
303 | |
325 | |
304 | The idle coroutine ($Coro::idle) always has a lower priority than any |
326 | The idle coroutine ($Coro::idle) always has a lower priority than any |
305 | existing coroutine. |
327 | existing coroutine. |
306 | |
328 | |
307 | Changing the priority of the current process will take effect immediately, |
329 | Changing the priority of the current coroutine will take effect immediately, |
308 | but changing the priority of processes in the ready queue (but not |
330 | but changing the priority of coroutines in the ready queue (but not |
309 | running) will only take effect after the next schedule (of that |
331 | running) will only take effect after the next schedule (of that |
310 | process). This is a bug that will be fixed in some future version. |
332 | coroutine). This is a bug that will be fixed in some future version. |
311 | |
333 | |
312 | =item $newprio = $process->nice ($change) |
334 | =item $newprio = $coroutine->nice ($change) |
313 | |
335 | |
314 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
336 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
315 | higher values mean lower priority, just as in unix). |
337 | higher values mean lower priority, just as in unix). |
316 | |
338 | |
317 | =item $olddesc = $process->desc ($newdesc) |
339 | =item $olddesc = $coroutine->desc ($newdesc) |
318 | |
340 | |
319 | Sets (or gets in case the argument is missing) the description for this |
341 | Sets (or gets in case the argument is missing) the description for this |
320 | process. This is just a free-form string you can associate with a process. |
342 | coroutine. This is just a free-form string you can associate with a coroutine. |
321 | |
343 | |
322 | =cut |
344 | =cut |
323 | |
345 | |
324 | sub desc { |
346 | sub desc { |
325 | my $old = $_[0]{desc}; |
347 | my $old = $_[0]{desc}; |
… | |
… | |
327 | $old; |
349 | $old; |
328 | } |
350 | } |
329 | |
351 | |
330 | =back |
352 | =back |
331 | |
353 | |
|
|
354 | =head2 UTILITY FUNCTIONS |
|
|
355 | |
|
|
356 | =over 4 |
|
|
357 | |
|
|
358 | =item unblock_sub { ... } |
|
|
359 | |
|
|
360 | This utility function takes a BLOCK or code reference and "unblocks" it, |
|
|
361 | returning the new coderef. This means that the new coderef will return |
|
|
362 | immediately without blocking, returning nothing, while the original code |
|
|
363 | ref will be called (with parameters) from within its own coroutine. |
|
|
364 | |
|
|
365 | The reason this fucntion exists is that many event libraries (such as the |
|
|
366 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
|
|
367 | of thread-safety). This means you must not block within event callbacks, |
|
|
368 | otherwise you might suffer from crashes or worse. |
|
|
369 | |
|
|
370 | This function allows your callbacks to block by executing them in another |
|
|
371 | coroutine where it is safe to block. One example where blocking is handy |
|
|
372 | is when you use the L<Coro::AIO|Coro::AIO> functions to save results to |
|
|
373 | disk. |
|
|
374 | |
|
|
375 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
|
|
376 | creating event callbacks that want to block. |
|
|
377 | |
|
|
378 | =cut |
|
|
379 | |
|
|
380 | our @unblock_pool; |
|
|
381 | our @unblock_queue; |
|
|
382 | our $UNBLOCK_POOL_SIZE = 2; |
|
|
383 | |
|
|
384 | sub unblock_handler_ { |
|
|
385 | while () { |
|
|
386 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
|
|
387 | $cb->(@arg); |
|
|
388 | |
|
|
389 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
|
|
390 | push @unblock_pool, $Coro::current; |
|
|
391 | schedule; |
|
|
392 | } |
|
|
393 | } |
|
|
394 | |
|
|
395 | our $unblock_scheduler = async { |
|
|
396 | while () { |
|
|
397 | while (my $cb = pop @unblock_queue) { |
|
|
398 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
|
|
399 | $handler->{arg} = $cb; |
|
|
400 | $handler->ready; |
|
|
401 | cede; |
|
|
402 | } |
|
|
403 | |
|
|
404 | schedule; |
|
|
405 | } |
|
|
406 | }; |
|
|
407 | |
|
|
408 | sub unblock_sub(&) { |
|
|
409 | my $cb = shift; |
|
|
410 | |
|
|
411 | sub { |
|
|
412 | push @unblock_queue, [$cb, @_]; |
|
|
413 | $unblock_scheduler->ready; |
|
|
414 | } |
|
|
415 | } |
|
|
416 | |
|
|
417 | =back |
|
|
418 | |
332 | =cut |
419 | =cut |
333 | |
420 | |
334 | 1; |
421 | 1; |
335 | |
422 | |
336 | =head1 BUGS/LIMITATIONS |
423 | =head1 BUGS/LIMITATIONS |