… | |
… | |
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 to |
30 | This module collection manages coroutines. Coroutines are similar |
24 | threads but don't run in parallel. |
31 | to threads but don't run in parallel at the same time even on SMP |
|
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32 | machines. The specific flavor of coroutine used in this module also |
|
|
33 | guarantees you that it will not switch between coroutines unless |
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34 | necessary, at easily-identified points in your program, so locking and |
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35 | parallel access are rarely an issue, making coroutine programming much |
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36 | safer than threads programming. |
25 | |
37 | |
|
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38 | (Perl, however, does not natively support real threads but instead does a |
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39 | very slow and memory-intensive emulation of processes using threads. This |
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40 | is a performance win on Windows machines, and a loss everywhere else). |
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41 | |
26 | In this module, coroutines are defined as "callchain + lexical variables |
42 | In this module, coroutines are defined as "callchain + lexical variables + |
27 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
43 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
28 | callchain, it's own set of lexicals and it's own set of perl's most |
44 | its own set of lexicals and its own set of perls most important global |
29 | important global variables. |
45 | variables (see L<Coro::State> for more configuration). |
30 | |
46 | |
31 | =cut |
47 | =cut |
32 | |
48 | |
33 | package Coro; |
49 | package Coro; |
34 | |
50 | |
… | |
… | |
41 | |
57 | |
42 | our $idle; # idle handler |
58 | our $idle; # idle handler |
43 | our $main; # main coroutine |
59 | our $main; # main coroutine |
44 | our $current; # current coroutine |
60 | our $current; # current coroutine |
45 | |
61 | |
46 | our $VERSION = '3.0'; |
62 | our $VERSION = '4.33'; |
47 | |
63 | |
48 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
64 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
49 | our %EXPORT_TAGS = ( |
65 | our %EXPORT_TAGS = ( |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
66 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
51 | ); |
67 | ); |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
68 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
53 | |
69 | |
54 | { |
70 | { |
55 | my @async; |
71 | my @async; |
56 | my $init; |
72 | my $init; |
57 | |
73 | |
… | |
… | |
99 | |
115 | |
100 | The current coroutine (the last coroutine switched to). The initial value |
116 | The current coroutine (the last coroutine switched to). The initial value |
101 | is C<$main> (of course). |
117 | is C<$main> (of course). |
102 | |
118 | |
103 | 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 |
104 | 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 |
105 | C<Coro::current> function instead. |
121 | C<Coro::current> function instead. |
106 | |
122 | |
107 | =cut |
123 | =cut |
108 | |
124 | |
|
|
125 | $main->{desc} = "[main::]"; |
|
|
126 | |
109 | # maybe some other module used Coro::Specific before... |
127 | # maybe some other module used Coro::Specific before... |
110 | $main->{specific} = $current->{specific} |
128 | $main->{_specific} = $current->{_specific} |
111 | if $current; |
129 | if $current; |
112 | |
130 | |
113 | _set_current $main; |
131 | _set_current $main; |
114 | |
132 | |
115 | sub current() { $current } |
133 | sub current() { $current } |
… | |
… | |
123 | 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 |
124 | 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 |
125 | coroutine so the scheduler can run it. |
143 | coroutine so the scheduler can run it. |
126 | |
144 | |
127 | 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 |
128 | handlers), then it must be prepared to be called recursively. |
146 | handlers), then it must be prepared to be called recursively itself. |
129 | |
147 | |
130 | =cut |
148 | =cut |
131 | |
149 | |
132 | $idle = sub { |
150 | $idle = sub { |
133 | print STDERR "FATAL: deadlock detected\n"; |
151 | require Carp; |
134 | exit (51); |
152 | Carp::croak ("FATAL: deadlock detected"); |
135 | }; |
153 | }; |
|
|
154 | |
|
|
155 | sub _cancel { |
|
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156 | my ($self) = @_; |
|
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157 | |
|
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158 | # free coroutine data and mark as destructed |
|
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159 | $self->_destroy |
|
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160 | or return; |
|
|
161 | |
|
|
162 | # call all destruction callbacks |
|
|
163 | $_->(@{$self->{_status}}) |
|
|
164 | for @{(delete $self->{_on_destroy}) || []}; |
|
|
165 | } |
136 | |
166 | |
137 | # this coroutine is necessary because a coroutine |
167 | # this coroutine is necessary because a coroutine |
138 | # cannot destroy itself. |
168 | # cannot destroy itself. |
139 | my @destroy; |
169 | my @destroy; |
|
|
170 | my $manager; |
|
|
171 | |
140 | my $manager; $manager = new Coro sub { |
172 | $manager = new Coro sub { |
141 | while () { |
173 | while () { |
142 | # by overwriting the state object with the manager we destroy it |
174 | (shift @destroy)->_cancel |
143 | # while still being able to schedule this coroutine (in case it has |
|
|
144 | # been readied multiple times. this is harmless since the manager |
|
|
145 | # can be called as many times as neccessary and will always |
|
|
146 | # remove itself from the runqueue |
|
|
147 | while (@destroy) { |
175 | while @destroy; |
148 | my $coro = pop @destroy; |
|
|
149 | $coro->{status} ||= []; |
|
|
150 | $_->ready for @{delete $coro->{join} || []}; |
|
|
151 | |
176 | |
152 | # the next line destroys the coro state, but keeps the |
|
|
153 | # coroutine itself intact (we basically make it a zombie |
|
|
154 | # coroutine that always runs the manager thread, so it's possible |
|
|
155 | # to transfer() to this coroutine). |
|
|
156 | $coro->_clone_state_from ($manager); |
|
|
157 | } |
|
|
158 | &schedule; |
177 | &schedule; |
159 | } |
178 | } |
160 | }; |
179 | }; |
|
|
180 | $manager->desc ("[coro manager]"); |
|
|
181 | $manager->prio (PRIO_MAX); |
161 | |
182 | |
162 | # static methods. not really. |
183 | # static methods. not really. |
163 | |
184 | |
164 | =back |
185 | =back |
165 | |
186 | |
… | |
… | |
173 | |
194 | |
174 | Create a new asynchronous coroutine and return it's coroutine object |
195 | Create a new asynchronous coroutine and return it's coroutine object |
175 | (usually unused). When the sub returns the new coroutine is automatically |
196 | (usually unused). When the sub returns the new coroutine is automatically |
176 | terminated. |
197 | terminated. |
177 | |
198 | |
178 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
199 | See the C<Coro::State::new> constructor for info about the coroutine |
|
|
200 | environment in which coroutines run. |
179 | |
201 | |
180 | When the coroutine dies, the program will exit, just as in the main |
202 | Calling C<exit> in a coroutine will do the same as calling exit outside |
181 | program. |
203 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
|
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204 | just as it would in the main program. |
182 | |
205 | |
183 | # create a new coroutine that just prints its arguments |
206 | # create a new coroutine that just prints its arguments |
184 | async { |
207 | async { |
185 | print "@_\n"; |
208 | print "@_\n"; |
186 | } 1,2,3,4; |
209 | } 1,2,3,4; |
187 | |
210 | |
188 | =cut |
211 | =cut |
189 | |
212 | |
190 | sub async(&@) { |
213 | sub async(&@) { |
191 | my $pid = new Coro @_; |
214 | my $coro = new Coro @_; |
192 | $pid->ready; |
215 | $coro->ready; |
193 | $pid |
216 | $coro |
|
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217 | } |
|
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218 | |
|
|
219 | =item async_pool { ... } [@args...] |
|
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220 | |
|
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221 | Similar to C<async>, but uses a coroutine pool, so you should not call |
|
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222 | terminate or join (although you are allowed to), and you get a coroutine |
|
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223 | that might have executed other code already (which can be good or bad :). |
|
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224 | |
|
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225 | Also, the block is executed in an C<eval> context and a warning will be |
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226 | issued in case of an exception instead of terminating the program, as |
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227 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
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228 | will not work in the expected way, unless you call terminate or cancel, |
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229 | which somehow defeats the purpose of pooling. |
|
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230 | |
|
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231 | The priority will be reset to C<0> after each job, tracing will be |
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232 | disabled, the description will be reset and the default output filehandle |
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233 | gets restored, so you can change alkl these. Otherwise the coroutine will |
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234 | be re-used "as-is": most notably if you change other per-coroutine global |
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235 | stuff such as C<$/> you need to revert that change, which is most simply |
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236 | done by using local as in C< local $/ >. |
|
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237 | |
|
|
238 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
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239 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
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240 | required. |
|
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241 | |
|
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242 | If you are concerned about pooled coroutines growing a lot because a |
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243 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
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244 | { terminate }> once per second or so to slowly replenish the pool. In |
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245 | addition to that, when the stacks used by a handler grows larger than 16kb |
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246 | (adjustable with $Coro::POOL_RSS) it will also exit. |
|
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247 | |
|
|
248 | =cut |
|
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249 | |
|
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250 | our $POOL_SIZE = 8; |
|
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251 | our $POOL_RSS = 16 * 1024; |
|
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252 | our @async_pool; |
|
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253 | |
|
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254 | sub pool_handler { |
|
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255 | my $cb; |
|
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256 | |
|
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257 | while () { |
|
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258 | eval { |
|
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259 | while () { |
|
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260 | _pool_1 $cb; |
|
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261 | &$cb; |
|
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262 | _pool_2 $cb; |
|
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263 | &schedule; |
|
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264 | } |
|
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265 | }; |
|
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266 | |
|
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267 | last if $@ eq "\3async_pool terminate\2\n"; |
|
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268 | warn $@ if $@; |
|
|
269 | } |
|
|
270 | } |
|
|
271 | |
|
|
272 | sub async_pool(&@) { |
|
|
273 | # this is also inlined into the unlock_scheduler |
|
|
274 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
|
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275 | |
|
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276 | $coro->{_invoke} = [@_]; |
|
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277 | $coro->ready; |
|
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278 | |
|
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279 | $coro |
194 | } |
280 | } |
195 | |
281 | |
196 | =item schedule |
282 | =item schedule |
197 | |
283 | |
198 | Calls the scheduler. Please note that the current coroutine will not be put |
284 | Calls the scheduler. Please note that the current coroutine will not be put |
… | |
… | |
211 | # wake up sleeping coroutine |
297 | # wake up sleeping coroutine |
212 | $current->ready; |
298 | $current->ready; |
213 | undef $current; |
299 | undef $current; |
214 | }; |
300 | }; |
215 | |
301 | |
216 | # call schedule until event occured. |
302 | # call schedule until event occurred. |
217 | # in case we are woken up for other reasons |
303 | # in case we are woken up for other reasons |
218 | # (current still defined), loop. |
304 | # (current still defined), loop. |
219 | Coro::schedule while $current; |
305 | Coro::schedule while $current; |
220 | } |
306 | } |
221 | |
307 | |
… | |
… | |
223 | |
309 | |
224 | "Cede" to other coroutines. This function puts the current coroutine into the |
310 | "Cede" to other coroutines. This function puts the current coroutine into the |
225 | ready queue and calls C<schedule>, which has the effect of giving up the |
311 | ready queue and calls C<schedule>, which has the effect of giving up the |
226 | current "timeslice" to other coroutines of the same or higher priority. |
312 | current "timeslice" to other coroutines of the same or higher priority. |
227 | |
313 | |
|
|
314 | =item Coro::cede_notself |
|
|
315 | |
|
|
316 | Works like cede, but is not exported by default and will cede to any |
|
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317 | coroutine, regardless of priority, once. |
|
|
318 | |
228 | =item terminate [arg...] |
319 | =item terminate [arg...] |
229 | |
320 | |
230 | Terminates the current coroutine with the given status values (see L<cancel>). |
321 | Terminates the current coroutine with the given status values (see L<cancel>). |
|
|
322 | |
|
|
323 | =item killall |
|
|
324 | |
|
|
325 | Kills/terminates/cancels all coroutines except the currently running |
|
|
326 | one. This is useful after a fork, either in the child or the parent, as |
|
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327 | usually only one of them should inherit the running coroutines. |
231 | |
328 | |
232 | =cut |
329 | =cut |
233 | |
330 | |
234 | sub terminate { |
331 | sub terminate { |
235 | $current->cancel (@_); |
332 | $current->cancel (@_); |
|
|
333 | } |
|
|
334 | |
|
|
335 | sub killall { |
|
|
336 | for (Coro::State::list) { |
|
|
337 | $_->cancel |
|
|
338 | if $_ != $current && UNIVERSAL::isa $_, "Coro"; |
|
|
339 | } |
236 | } |
340 | } |
237 | |
341 | |
238 | =back |
342 | =back |
239 | |
343 | |
240 | # dynamic methods |
344 | # dynamic methods |
… | |
… | |
250 | Create a new coroutine and return it. When the sub returns the coroutine |
354 | Create a new coroutine and return it. When the sub returns the coroutine |
251 | automatically terminates as if C<terminate> with the returned values were |
355 | automatically terminates as if C<terminate> with the returned values were |
252 | called. To make the coroutine run you must first put it into the ready queue |
356 | called. To make the coroutine run you must first put it into the ready queue |
253 | by calling the ready method. |
357 | by calling the ready method. |
254 | |
358 | |
255 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
359 | See C<async> and C<Coro::State::new> for additional info about the |
|
|
360 | coroutine environment. |
256 | |
361 | |
257 | =cut |
362 | =cut |
258 | |
363 | |
259 | sub _new_coro { |
364 | sub _run_coro { |
260 | terminate &{+shift}; |
365 | terminate &{+shift}; |
261 | } |
366 | } |
262 | |
367 | |
263 | sub new { |
368 | sub new { |
264 | my $class = shift; |
369 | my $class = shift; |
265 | |
370 | |
266 | $class->SUPER::new (\&_new_coro, @_) |
371 | $class->SUPER::new (\&_run_coro, @_) |
267 | } |
372 | } |
268 | |
373 | |
269 | =item $success = $coroutine->ready |
374 | =item $success = $coroutine->ready |
270 | |
375 | |
271 | Put the given coroutine into the ready queue (according to it's priority) |
376 | Put the given coroutine into the ready queue (according to it's priority) |
… | |
… | |
277 | Return wether the coroutine is currently the ready queue or not, |
382 | Return wether the coroutine is currently the ready queue or not, |
278 | |
383 | |
279 | =item $coroutine->cancel (arg...) |
384 | =item $coroutine->cancel (arg...) |
280 | |
385 | |
281 | Terminates the given coroutine and makes it return the given arguments as |
386 | Terminates the given coroutine and makes it return the given arguments as |
282 | status (default: the empty list). |
387 | status (default: the empty list). Never returns if the coroutine is the |
|
|
388 | current coroutine. |
283 | |
389 | |
284 | =cut |
390 | =cut |
285 | |
391 | |
286 | sub cancel { |
392 | sub cancel { |
287 | my $self = shift; |
393 | my $self = shift; |
288 | $self->{status} = [@_]; |
394 | $self->{_status} = [@_]; |
|
|
395 | |
|
|
396 | if ($current == $self) { |
289 | push @destroy, $self; |
397 | push @destroy, $self; |
290 | $manager->ready; |
398 | $manager->ready; |
291 | &schedule if $current == $self; |
399 | &schedule while 1; |
|
|
400 | } else { |
|
|
401 | $self->_cancel; |
|
|
402 | } |
292 | } |
403 | } |
293 | |
404 | |
294 | =item $coroutine->join |
405 | =item $coroutine->join |
295 | |
406 | |
296 | Wait until the coroutine terminates and return any values given to the |
407 | Wait until the coroutine terminates and return any values given to the |
297 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
408 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
298 | from multiple coroutine. |
409 | from multiple coroutines. |
299 | |
410 | |
300 | =cut |
411 | =cut |
301 | |
412 | |
302 | sub join { |
413 | sub join { |
303 | my $self = shift; |
414 | my $self = shift; |
|
|
415 | |
304 | unless ($self->{status}) { |
416 | unless ($self->{_status}) { |
305 | push @{$self->{join}}, $current; |
417 | my $current = $current; |
306 | &schedule; |
418 | |
|
|
419 | push @{$self->{_on_destroy}}, sub { |
|
|
420 | $current->ready; |
|
|
421 | undef $current; |
|
|
422 | }; |
|
|
423 | |
|
|
424 | &schedule while $current; |
307 | } |
425 | } |
|
|
426 | |
308 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
427 | wantarray ? @{$self->{_status}} : $self->{_status}[0]; |
|
|
428 | } |
|
|
429 | |
|
|
430 | =item $coroutine->on_destroy (\&cb) |
|
|
431 | |
|
|
432 | Registers a callback that is called when this coroutine gets destroyed, |
|
|
433 | but before it is joined. The callback gets passed the terminate arguments, |
|
|
434 | if any. |
|
|
435 | |
|
|
436 | =cut |
|
|
437 | |
|
|
438 | sub on_destroy { |
|
|
439 | my ($self, $cb) = @_; |
|
|
440 | |
|
|
441 | push @{ $self->{_on_destroy} }, $cb; |
309 | } |
442 | } |
310 | |
443 | |
311 | =item $oldprio = $coroutine->prio ($newprio) |
444 | =item $oldprio = $coroutine->prio ($newprio) |
312 | |
445 | |
313 | Sets (or gets, if the argument is missing) the priority of the |
446 | Sets (or gets, if the argument is missing) the priority of the |
… | |
… | |
338 | =item $olddesc = $coroutine->desc ($newdesc) |
471 | =item $olddesc = $coroutine->desc ($newdesc) |
339 | |
472 | |
340 | Sets (or gets in case the argument is missing) the description for this |
473 | Sets (or gets in case the argument is missing) the description for this |
341 | coroutine. This is just a free-form string you can associate with a coroutine. |
474 | coroutine. This is just a free-form string you can associate with a coroutine. |
342 | |
475 | |
|
|
476 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
|
|
477 | can modify this member directly if you wish. |
|
|
478 | |
|
|
479 | =item $coroutine->throw ([$scalar]) |
|
|
480 | |
|
|
481 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
482 | inside the coroutine at the next convinient point in time (usually after |
|
|
483 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
484 | exception object. |
|
|
485 | |
|
|
486 | The exception object will be thrown "as is" with the specified scalar in |
|
|
487 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
488 | (unlike with C<die>). |
|
|
489 | |
|
|
490 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
491 | end itself, although there is no guarentee that the exception will lead to |
|
|
492 | termination, and if the exception isn't caught it might well end the whole |
|
|
493 | program. |
|
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494 | |
343 | =cut |
495 | =cut |
344 | |
496 | |
345 | sub desc { |
497 | sub desc { |
346 | my $old = $_[0]{desc}; |
498 | my $old = $_[0]{desc}; |
347 | $_[0]{desc} = $_[1] if @_ > 1; |
499 | $_[0]{desc} = $_[1] if @_ > 1; |
348 | $old; |
500 | $old; |
349 | } |
501 | } |
350 | |
502 | |
351 | =back |
503 | =back |
352 | |
504 | |
353 | =head2 UTILITY FUNCTIONS |
505 | =head2 GLOBAL FUNCTIONS |
354 | |
506 | |
355 | =over 4 |
507 | =over 4 |
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508 | |
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509 | =item Coro::nready |
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510 | |
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511 | Returns the number of coroutines that are currently in the ready state, |
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512 | i.e. that can be switched to. The value C<0> means that the only runnable |
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513 | coroutine is the currently running one, so C<cede> would have no effect, |
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514 | and C<schedule> would cause a deadlock unless there is an idle handler |
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515 | that wakes up some coroutines. |
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516 | |
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517 | =item my $guard = Coro::guard { ... } |
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518 | |
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519 | This creates and returns a guard object. Nothing happens until the object |
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520 | gets destroyed, in which case the codeblock given as argument will be |
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521 | executed. This is useful to free locks or other resources in case of a |
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522 | runtime error or when the coroutine gets canceled, as in both cases the |
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523 | guard block will be executed. The guard object supports only one method, |
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524 | C<< ->cancel >>, which will keep the codeblock from being executed. |
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525 | |
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526 | Example: set some flag and clear it again when the coroutine gets canceled |
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527 | or the function returns: |
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528 | |
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529 | sub do_something { |
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530 | my $guard = Coro::guard { $busy = 0 }; |
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531 | $busy = 1; |
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532 | |
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533 | # do something that requires $busy to be true |
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534 | } |
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535 | |
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536 | =cut |
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537 | |
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538 | sub guard(&) { |
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539 | bless \(my $cb = $_[0]), "Coro::guard" |
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540 | } |
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541 | |
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542 | sub Coro::guard::cancel { |
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543 | ${$_[0]} = sub { }; |
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544 | } |
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545 | |
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546 | sub Coro::guard::DESTROY { |
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547 | ${$_[0]}->(); |
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548 | } |
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549 | |
356 | |
550 | |
357 | =item unblock_sub { ... } |
551 | =item unblock_sub { ... } |
358 | |
552 | |
359 | This utility function takes a BLOCK or code reference and "unblocks" it, |
553 | 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 |
554 | returning the new coderef. This means that the new coderef will return |
361 | immediately without blocking, returning nothing, while the original code |
555 | immediately without blocking, returning nothing, while the original code |
362 | ref will be called (with parameters) from within its own coroutine. |
556 | ref will be called (with parameters) from within its own coroutine. |
363 | |
557 | |
364 | The reason this fucntion exists is that many event libraries (such as the |
558 | The reason this function exists is that many event libraries (such as the |
365 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
559 | 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, |
560 | of thread-safety). This means you must not block within event callbacks, |
367 | otherwise you might suffer from crashes or worse. |
561 | otherwise you might suffer from crashes or worse. |
368 | |
562 | |
369 | This function allows your callbacks to block by executing them in another |
563 | This function allows your callbacks to block by executing them in another |
… | |
… | |
374 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
568 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
375 | creating event callbacks that want to block. |
569 | creating event callbacks that want to block. |
376 | |
570 | |
377 | =cut |
571 | =cut |
378 | |
572 | |
379 | our @unblock_pool; |
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380 | our @unblock_queue; |
573 | our @unblock_queue; |
381 | our $UNBLOCK_POOL_SIZE = 2; |
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382 | |
574 | |
383 | sub unblock_handler_ { |
575 | # we create a special coro because we want to cede, |
384 | while () { |
576 | # to reduce pressure on the coro pool (because most callbacks |
385 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
577 | # return immediately and can be reused) and because we cannot cede |
386 | $cb->(@arg); |
578 | # inside an event callback. |
387 | |
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388 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
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389 | push @unblock_pool, $Coro::current; |
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390 | schedule; |
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391 | } |
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392 | } |
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393 | |
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394 | our $unblock_scheduler = async { |
579 | our $unblock_scheduler = new Coro sub { |
395 | while () { |
580 | while () { |
396 | while (my $cb = pop @unblock_queue) { |
581 | while (my $cb = pop @unblock_queue) { |
397 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
582 | # this is an inlined copy of async_pool |
398 | $handler->{arg} = $cb; |
583 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
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584 | |
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585 | $coro->{_invoke} = $cb; |
399 | $handler->ready; |
586 | $coro->ready; |
400 | cede; |
587 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
401 | } |
588 | } |
402 | |
589 | schedule; # sleep well |
403 | schedule; |
|
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404 | } |
590 | } |
405 | }; |
591 | }; |
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592 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
406 | |
593 | |
407 | sub unblock_sub(&) { |
594 | sub unblock_sub(&) { |
408 | my $cb = shift; |
595 | my $cb = shift; |
409 | |
596 | |
410 | sub { |
597 | sub { |
411 | push @unblock_queue, [$cb, @_]; |
598 | unshift @unblock_queue, [$cb, @_]; |
412 | $unblock_scheduler->ready; |
599 | $unblock_scheduler->ready; |
413 | } |
600 | } |
414 | } |
601 | } |
415 | |
602 | |
416 | =back |
603 | =back |
… | |
… | |
423 | |
610 | |
424 | - you must make very sure that no coro is still active on global |
611 | - you must make very sure that no coro is still active on global |
425 | destruction. very bad things might happen otherwise (usually segfaults). |
612 | destruction. very bad things might happen otherwise (usually segfaults). |
426 | |
613 | |
427 | - this module is not thread-safe. You should only ever use this module |
614 | - this module is not thread-safe. You should only ever use this module |
428 | from the same thread (this requirement might be losened in the future |
615 | from the same thread (this requirement might be loosened in the future |
429 | to allow per-thread schedulers, but Coro::State does not yet allow |
616 | to allow per-thread schedulers, but Coro::State does not yet allow |
430 | this). |
617 | this). |
431 | |
618 | |
432 | =head1 SEE ALSO |
619 | =head1 SEE ALSO |
433 | |
620 | |
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621 | Lower level Configuration, Coroutine Environment: L<Coro::State>. |
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622 | |
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623 | Debugging: L<Coro::Debug>. |
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624 | |
434 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
625 | Support/Utility: L<Coro::Specific>, L<Coro::Util>. |
435 | |
626 | |
436 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
627 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
437 | |
628 | |
438 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
629 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>. |
439 | |
630 | |
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631 | Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>. |
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632 | |
440 | Embedding: L<Coro:MakeMaker> |
633 | Embedding: L<Coro::MakeMaker>. |
441 | |
634 | |
442 | =head1 AUTHOR |
635 | =head1 AUTHOR |
443 | |
636 | |
444 | Marc Lehmann <schmorp@schmorp.de> |
637 | Marc Lehmann <schmorp@schmorp.de> |
445 | http://home.schmorp.de/ |
638 | http://home.schmorp.de/ |