… | |
… | |
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 | |
… | |
… | |
35 | use strict; |
35 | use strict; |
36 | no warnings "uninitialized"; |
36 | no warnings "uninitialized"; |
37 | |
37 | |
38 | use Coro::State; |
38 | use Coro::State; |
39 | |
39 | |
40 | use base Exporter::; |
40 | use base qw(Coro::State Exporter); |
41 | |
41 | |
42 | our $idle; # idle coroutine |
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 | |
… | |
… | |
57 | |
57 | |
58 | # this way of handling attributes simply is NOT scalable ;() |
58 | # this way of handling attributes simply is NOT scalable ;() |
59 | sub import { |
59 | sub import { |
60 | no strict 'refs'; |
60 | no strict 'refs'; |
61 | |
61 | |
62 | Coro->export_to_level(1, @_); |
62 | Coro->export_to_level (1, @_); |
63 | |
63 | |
64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
66 | my ($package, $ref) = (shift, shift); |
66 | my ($package, $ref) = (shift, shift); |
67 | my @attrs; |
67 | my @attrs; |
… | |
… | |
95 | |
95 | |
96 | $main = new Coro; |
96 | $main = new Coro; |
97 | |
97 | |
98 | =item $current (or as function: current) |
98 | =item $current (or as function: current) |
99 | |
99 | |
100 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
100 | The current coroutine (the last coroutine switched to). The initial value |
|
|
101 | is C<$main> (of course). |
|
|
102 | |
|
|
103 | This variable is B<strictly> I<read-only>. It is provided for performance |
|
|
104 | reasons. If performance is not essentiel you are encouraged to use the |
|
|
105 | C<Coro::current> function instead. |
101 | |
106 | |
102 | =cut |
107 | =cut |
103 | |
108 | |
104 | # maybe some other module used Coro::Specific before... |
109 | # maybe some other module used Coro::Specific before... |
105 | if ($current) { |
|
|
106 | $main->{specific} = $current->{specific}; |
110 | $main->{specific} = $current->{specific} |
107 | } |
111 | if $current; |
108 | |
112 | |
109 | $current = $main; |
113 | _set_current $main; |
110 | |
114 | |
111 | sub current() { $current } |
115 | sub current() { $current } |
112 | |
116 | |
113 | =item $idle |
117 | =item $idle |
114 | |
118 | |
115 | The coroutine to switch to when no other coroutine is running. The default |
119 | A callback that is called whenever the scheduler finds no ready coroutines |
116 | implementation prints "FATAL: deadlock detected" and exits. |
120 | to run. The default implementation prints "FATAL: deadlock detected" and |
|
|
121 | exits, because the program has no other way to continue. |
117 | |
122 | |
118 | =cut |
123 | This hook is overwritten by modules such as C<Coro::Timer> and |
|
|
124 | C<Coro::Event> to wait on an external event that hopefully wake up a |
|
|
125 | coroutine so the scheduler can run it. |
119 | |
126 | |
120 | # should be done using priorities :( |
127 | Please note that if your callback recursively invokes perl (e.g. for event |
121 | $idle = new Coro sub { |
128 | handlers), then it must be prepared to be called recursively. |
|
|
129 | |
|
|
130 | =cut |
|
|
131 | |
|
|
132 | $idle = sub { |
122 | print STDERR "FATAL: deadlock detected\n"; |
133 | print STDERR "FATAL: deadlock detected\n"; |
123 | exit(51); |
134 | exit (51); |
124 | }; |
135 | }; |
125 | |
136 | |
126 | # this coroutine is necessary because a coroutine |
137 | # this coroutine is necessary because a coroutine |
127 | # cannot destroy itself. |
138 | # cannot destroy itself. |
128 | my @destroy; |
139 | my @destroy; |
129 | my $manager; |
|
|
130 | $manager = new Coro sub { |
140 | my $manager; $manager = new Coro sub { |
131 | while () { |
141 | while () { |
132 | # by overwriting the state object with the manager we destroy it |
142 | # by overwriting the state object with the manager we destroy it |
133 | # while still being able to schedule this coroutine (in case it has |
143 | # while still being able to schedule this coroutine (in case it has |
134 | # been readied multiple times. this is harmless since the manager |
144 | # been readied multiple times. this is harmless since the manager |
135 | # can be called as many times as neccessary and will always |
145 | # can be called as many times as neccessary and will always |
… | |
… | |
137 | while (@destroy) { |
147 | while (@destroy) { |
138 | my $coro = pop @destroy; |
148 | my $coro = pop @destroy; |
139 | $coro->{status} ||= []; |
149 | $coro->{status} ||= []; |
140 | $_->ready for @{delete $coro->{join} || []}; |
150 | $_->ready for @{delete $coro->{join} || []}; |
141 | |
151 | |
142 | # the next line destroys the _coro_state, but keeps the |
152 | # the next line destroys the coro state, but keeps the |
143 | # process itself intact (we basically make it a zombie |
153 | # coroutine itself intact (we basically make it a zombie |
144 | # process that always runs the manager thread, so it's possible |
154 | # coroutine that always runs the manager thread, so it's possible |
145 | # to transfer() to this process). |
155 | # to transfer() to this coroutine). |
146 | $coro->{_coro_state} = $manager->{_coro_state}; |
156 | $coro->_clone_state_from ($manager); |
147 | } |
157 | } |
148 | &schedule; |
158 | &schedule; |
149 | } |
159 | } |
150 | }; |
160 | }; |
151 | |
161 | |
… | |
… | |
153 | |
163 | |
154 | =back |
164 | =back |
155 | |
165 | |
156 | =head2 STATIC METHODS |
166 | =head2 STATIC METHODS |
157 | |
167 | |
158 | Static methods are actually functions that operate on the current process only. |
168 | Static methods are actually functions that operate on the current coroutine only. |
159 | |
169 | |
160 | =over 4 |
170 | =over 4 |
161 | |
171 | |
162 | =item async { ... } [@args...] |
172 | =item async { ... } [@args...] |
163 | |
173 | |
164 | Create a new asynchronous process and return it's process object |
174 | Create a new asynchronous coroutine and return it's coroutine object |
165 | (usually unused). When the sub returns the new process is automatically |
175 | (usually unused). When the sub returns the new coroutine is automatically |
166 | terminated. |
176 | terminated. |
|
|
177 | |
|
|
178 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
167 | |
179 | |
168 | When the coroutine dies, the program will exit, just as in the main |
180 | When the coroutine dies, the program will exit, just as in the main |
169 | program. |
181 | program. |
170 | |
182 | |
171 | # create a new coroutine that just prints its arguments |
183 | # create a new coroutine that just prints its arguments |
… | |
… | |
175 | |
187 | |
176 | =cut |
188 | =cut |
177 | |
189 | |
178 | sub async(&@) { |
190 | sub async(&@) { |
179 | my $pid = new Coro @_; |
191 | my $pid = new Coro @_; |
180 | $manager->ready; # this ensures that the stack is cloned from the manager |
|
|
181 | $pid->ready; |
192 | $pid->ready; |
182 | $pid; |
193 | $pid |
183 | } |
194 | } |
184 | |
195 | |
185 | =item schedule |
196 | =item schedule |
186 | |
197 | |
187 | Calls the scheduler. Please note that the current process will not be put |
198 | Calls the scheduler. Please note that the current coroutine will not be put |
188 | into the ready queue, so calling this function usually means you will |
199 | into the ready queue, so calling this function usually means you will |
189 | never be called again. |
200 | never be called again unless something else (e.g. an event handler) calls |
|
|
201 | ready. |
190 | |
202 | |
191 | =cut |
203 | The canonical way to wait on external events is this: |
|
|
204 | |
|
|
205 | { |
|
|
206 | # remember current coroutine |
|
|
207 | my $current = $Coro::current; |
|
|
208 | |
|
|
209 | # register a hypothetical event handler |
|
|
210 | on_event_invoke sub { |
|
|
211 | # wake up sleeping coroutine |
|
|
212 | $current->ready; |
|
|
213 | undef $current; |
|
|
214 | }; |
|
|
215 | |
|
|
216 | # call schedule until event occured. |
|
|
217 | # in case we are woken up for other reasons |
|
|
218 | # (current still defined), loop. |
|
|
219 | Coro::schedule while $current; |
|
|
220 | } |
192 | |
221 | |
193 | =item cede |
222 | =item cede |
194 | |
223 | |
195 | "Cede" to other processes. This function puts the current process into the |
224 | "Cede" to other coroutines. This function puts the current coroutine into the |
196 | ready queue and calls C<schedule>, which has the effect of giving up the |
225 | ready queue and calls C<schedule>, which has the effect of giving up the |
197 | current "timeslice" to other coroutines of the same or higher priority. |
226 | current "timeslice" to other coroutines of the same or higher priority. |
198 | |
227 | |
199 | =cut |
|
|
200 | |
|
|
201 | =item terminate [arg...] |
228 | =item terminate [arg...] |
202 | |
229 | |
203 | Terminates the current process with the given status values (see L<cancel>). |
230 | Terminates the current coroutine with the given status values (see L<cancel>). |
204 | |
231 | |
205 | =cut |
232 | =cut |
206 | |
233 | |
207 | sub terminate { |
234 | sub terminate { |
208 | $current->cancel (@_); |
235 | $current->cancel (@_); |
… | |
… | |
210 | |
237 | |
211 | =back |
238 | =back |
212 | |
239 | |
213 | # dynamic methods |
240 | # dynamic methods |
214 | |
241 | |
215 | =head2 PROCESS METHODS |
242 | =head2 COROUTINE METHODS |
216 | |
243 | |
217 | These are the methods you can call on process objects. |
244 | These are the methods you can call on coroutine objects. |
218 | |
245 | |
219 | =over 4 |
246 | =over 4 |
220 | |
247 | |
221 | =item new Coro \&sub [, @args...] |
248 | =item new Coro \&sub [, @args...] |
222 | |
249 | |
223 | Create a new process and return it. When the sub returns the process |
250 | Create a new coroutine and return it. When the sub returns the coroutine |
224 | automatically terminates as if C<terminate> with the returned values were |
251 | automatically terminates as if C<terminate> with the returned values were |
225 | called. To make the process run you must first put it into the ready queue |
252 | called. To make the coroutine run you must first put it into the ready queue |
226 | by calling the ready method. |
253 | by calling the ready method. |
227 | |
254 | |
228 | =cut |
255 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
229 | |
256 | |
|
|
257 | =cut |
|
|
258 | |
230 | sub _newcoro { |
259 | sub _new_coro { |
231 | terminate &{+shift}; |
260 | terminate &{+shift}; |
232 | } |
261 | } |
233 | |
262 | |
234 | sub new { |
263 | sub new { |
235 | my $class = shift; |
264 | my $class = shift; |
236 | bless { |
|
|
237 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
|
|
238 | }, $class; |
|
|
239 | } |
|
|
240 | |
265 | |
241 | =item $process->ready |
266 | $class->SUPER::new (\&_new_coro, @_) |
|
|
267 | } |
242 | |
268 | |
243 | Put the given process into the ready queue. |
269 | =item $success = $coroutine->ready |
244 | |
270 | |
245 | =cut |
271 | Put the given coroutine into the ready queue (according to it's priority) |
|
|
272 | and return true. If the coroutine is already in the ready queue, do nothing |
|
|
273 | and return false. |
246 | |
274 | |
|
|
275 | =item $is_ready = $coroutine->is_ready |
|
|
276 | |
|
|
277 | Return wether the coroutine is currently the ready queue or not, |
|
|
278 | |
247 | =item $process->cancel (arg...) |
279 | =item $coroutine->cancel (arg...) |
248 | |
280 | |
249 | Terminates the given process and makes it return the given arguments as |
281 | Terminates the given coroutine and makes it return the given arguments as |
250 | status (default: the empty list). |
282 | status (default: the empty list). |
251 | |
283 | |
252 | =cut |
284 | =cut |
253 | |
285 | |
254 | sub cancel { |
286 | sub cancel { |
… | |
… | |
257 | push @destroy, $self; |
289 | push @destroy, $self; |
258 | $manager->ready; |
290 | $manager->ready; |
259 | &schedule if $current == $self; |
291 | &schedule if $current == $self; |
260 | } |
292 | } |
261 | |
293 | |
262 | =item $process->join |
294 | =item $coroutine->join |
263 | |
295 | |
264 | Wait until the coroutine terminates and return any values given to the |
296 | Wait until the coroutine terminates and return any values given to the |
265 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
297 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
266 | from multiple processes. |
298 | from multiple coroutine. |
267 | |
299 | |
268 | =cut |
300 | =cut |
269 | |
301 | |
270 | sub join { |
302 | sub join { |
271 | my $self = shift; |
303 | my $self = shift; |
… | |
… | |
274 | &schedule; |
306 | &schedule; |
275 | } |
307 | } |
276 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
308 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
277 | } |
309 | } |
278 | |
310 | |
279 | =item $oldprio = $process->prio($newprio) |
311 | =item $oldprio = $coroutine->prio ($newprio) |
280 | |
312 | |
281 | Sets (or gets, if the argument is missing) the priority of the |
313 | Sets (or gets, if the argument is missing) the priority of the |
282 | process. Higher priority processes get run before lower priority |
314 | coroutine. Higher priority coroutines get run before lower priority |
283 | processes. Priorities are small signed integers (currently -4 .. +3), |
315 | coroutines. Priorities are small signed integers (currently -4 .. +3), |
284 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
316 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
285 | to get then): |
317 | to get then): |
286 | |
318 | |
287 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
319 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
288 | 3 > 1 > 0 > -1 > -3 > -4 |
320 | 3 > 1 > 0 > -1 > -3 > -4 |
… | |
… | |
291 | current->prio(PRIO_HIGH); |
323 | current->prio(PRIO_HIGH); |
292 | |
324 | |
293 | The idle coroutine ($Coro::idle) always has a lower priority than any |
325 | The idle coroutine ($Coro::idle) always has a lower priority than any |
294 | existing coroutine. |
326 | existing coroutine. |
295 | |
327 | |
296 | Changing the priority of the current process will take effect immediately, |
328 | Changing the priority of the current coroutine will take effect immediately, |
297 | but changing the priority of processes in the ready queue (but not |
329 | but changing the priority of coroutines in the ready queue (but not |
298 | running) will only take effect after the next schedule (of that |
330 | running) will only take effect after the next schedule (of that |
299 | process). This is a bug that will be fixed in some future version. |
331 | coroutine). This is a bug that will be fixed in some future version. |
300 | |
332 | |
301 | =cut |
|
|
302 | |
|
|
303 | sub prio { |
|
|
304 | my $old = $_[0]{prio}; |
|
|
305 | $_[0]{prio} = $_[1] if @_ > 1; |
|
|
306 | $old; |
|
|
307 | } |
|
|
308 | |
|
|
309 | =item $newprio = $process->nice($change) |
333 | =item $newprio = $coroutine->nice ($change) |
310 | |
334 | |
311 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
335 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
312 | higher values mean lower priority, just as in unix). |
336 | higher values mean lower priority, just as in unix). |
313 | |
337 | |
314 | =cut |
|
|
315 | |
|
|
316 | sub nice { |
|
|
317 | $_[0]{prio} -= $_[1]; |
|
|
318 | } |
|
|
319 | |
|
|
320 | =item $olddesc = $process->desc($newdesc) |
338 | =item $olddesc = $coroutine->desc ($newdesc) |
321 | |
339 | |
322 | Sets (or gets in case the argument is missing) the description for this |
340 | Sets (or gets in case the argument is missing) the description for this |
323 | process. This is just a free-form string you can associate with a process. |
341 | coroutine. This is just a free-form string you can associate with a coroutine. |
324 | |
342 | |
325 | =cut |
343 | =cut |
326 | |
344 | |
327 | sub desc { |
345 | sub desc { |
328 | my $old = $_[0]{desc}; |
346 | my $old = $_[0]{desc}; |
… | |
… | |
330 | $old; |
348 | $old; |
331 | } |
349 | } |
332 | |
350 | |
333 | =back |
351 | =back |
334 | |
352 | |
|
|
353 | =head2 UTILITY FUNCTIONS |
|
|
354 | |
|
|
355 | =over 4 |
|
|
356 | |
|
|
357 | =item unblock_sub { ... } |
|
|
358 | |
|
|
359 | This utility function takes a BLOCK or code reference and "unblocks" it, |
|
|
360 | returning the new coderef. This means that the new coderef will return |
|
|
361 | immediately without blocking, returning nothing, while the original code |
|
|
362 | ref will be called (with parameters) from within its own coroutine. |
|
|
363 | |
|
|
364 | The reason this fucntion exists is that many event libraries (such as the |
|
|
365 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
|
|
366 | of thread-safety). This means you must not block within event callbacks, |
|
|
367 | otherwise you might suffer from crashes or worse. |
|
|
368 | |
|
|
369 | This function allows your callbacks to block by executing them in another |
|
|
370 | coroutine where it is safe to block. One example where blocking is handy |
|
|
371 | is when you use the L<Coro::AIO|Coro::AIO> functions to save results to |
|
|
372 | disk. |
|
|
373 | |
|
|
374 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
|
|
375 | creating event callbacks that want to block. |
|
|
376 | |
|
|
377 | =cut |
|
|
378 | |
|
|
379 | our @unblock_pool; |
|
|
380 | our @unblock_queue; |
|
|
381 | our $UNBLOCK_POOL_SIZE = 2; |
|
|
382 | |
|
|
383 | sub unblock_handler_ { |
|
|
384 | while () { |
|
|
385 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
|
|
386 | $cb->(@arg); |
|
|
387 | |
|
|
388 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
|
|
389 | push @unblock_pool, $Coro::current; |
|
|
390 | schedule; |
|
|
391 | } |
|
|
392 | } |
|
|
393 | |
|
|
394 | our $unblock_scheduler = async { |
|
|
395 | while () { |
|
|
396 | while (my $cb = pop @unblock_queue) { |
|
|
397 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
|
|
398 | $handler->{arg} = $cb; |
|
|
399 | $handler->ready; |
|
|
400 | cede; |
|
|
401 | } |
|
|
402 | |
|
|
403 | schedule; |
|
|
404 | } |
|
|
405 | }; |
|
|
406 | |
|
|
407 | sub unblock_sub(&) { |
|
|
408 | my $cb = shift; |
|
|
409 | |
|
|
410 | sub { |
|
|
411 | push @unblock_queue, [$cb, @_]; |
|
|
412 | $unblock_scheduler->ready; |
|
|
413 | } |
|
|
414 | } |
|
|
415 | |
|
|
416 | =back |
|
|
417 | |
335 | =cut |
418 | =cut |
336 | |
419 | |
337 | 1; |
420 | 1; |
338 | |
421 | |
339 | =head1 BUGS/LIMITATIONS |
422 | =head1 BUGS/LIMITATIONS |