… | |
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19 | cede; |
19 | cede; |
20 | |
20 | |
21 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
22 | |
22 | |
23 | This module collection manages coroutines. Coroutines are similar to |
23 | This module collection manages coroutines. Coroutines are similar to |
24 | Threads but don't run in parallel. |
24 | threads but don't run in parallel. |
25 | |
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26 | This module is still experimental, see the BUGS section below. |
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27 | |
25 | |
28 | In this module, coroutines are defined as "callchain + lexical variables |
26 | In this module, coroutines are defined as "callchain + lexical variables |
29 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
27 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
30 | callchain, it's own set of lexicals and it's own set of perl's most |
28 | callchain, it's own set of lexicals and it's own set of perl's most |
31 | important global variables. |
29 | important global variables. |
32 | |
30 | |
33 | =cut |
31 | =cut |
34 | |
32 | |
35 | package Coro; |
33 | package Coro; |
36 | |
34 | |
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35 | no warnings qw(uninitialized); |
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36 | |
37 | use Coro::State; |
37 | use Coro::State; |
38 | |
38 | |
39 | use base Exporter; |
39 | use base Exporter; |
40 | |
40 | |
41 | $VERSION = 0.45; |
41 | $VERSION = 0.6; |
42 | |
42 | |
43 | @EXPORT = qw(async cede schedule terminate current); |
43 | @EXPORT = qw(async cede schedule terminate current); |
44 | @EXPORT_OK = qw($current); |
44 | %EXPORT_TAGS = ( |
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45 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
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46 | ); |
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47 | @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
45 | |
48 | |
46 | { |
49 | { |
47 | my @async; |
50 | my @async; |
48 | my $init; |
51 | my $init; |
49 | |
52 | |
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72 | }; |
75 | }; |
73 | } |
76 | } |
74 | |
77 | |
75 | } |
78 | } |
76 | |
79 | |
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80 | =over 4 |
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81 | |
77 | =item $main |
82 | =item $main |
78 | |
83 | |
79 | This coroutine represents the main program. |
84 | This coroutine represents the main program. |
80 | |
85 | |
81 | =cut |
86 | =cut |
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111 | }; |
116 | }; |
112 | |
117 | |
113 | # this coroutine is necessary because a coroutine |
118 | # this coroutine is necessary because a coroutine |
114 | # cannot destroy itself. |
119 | # cannot destroy itself. |
115 | my @destroy; |
120 | my @destroy; |
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121 | my $manager; |
116 | my $manager = new Coro sub { |
122 | $manager = new Coro sub { |
117 | while() { |
123 | while() { |
118 | delete ((pop @destroy)->{_coro_state}) while @destroy; |
124 | # by overwriting the state object with the manager we destroy it |
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125 | # while still being able to schedule this coroutine (in case it has |
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126 | # been readied multiple times. this is harmless since the manager |
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127 | # can be called as many times as neccessary and will always |
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128 | # remove itself from the runqueue |
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129 | while (@destroy) { |
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130 | my $coro = pop @destroy; |
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131 | $coro->{status} ||= []; |
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132 | $_->ready for @{delete $coro->{join} || []}; |
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133 | $coro->{_coro_state} = $manager->{_coro_state}; |
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134 | } |
119 | &schedule; |
135 | &schedule; |
120 | } |
136 | } |
121 | }; |
137 | }; |
122 | |
138 | |
123 | # static methods. not really. |
139 | # static methods. not really. |
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140 | |
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141 | =back |
124 | |
142 | |
125 | =head2 STATIC METHODS |
143 | =head2 STATIC METHODS |
126 | |
144 | |
127 | Static methods are actually functions that operate on the current process only. |
145 | Static methods are actually functions that operate on the current process only. |
128 | |
146 | |
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165 | ready queue and calls C<schedule>, which has the effect of giving up the |
183 | ready queue and calls C<schedule>, which has the effect of giving up the |
166 | current "timeslice" to other coroutines of the same or higher priority. |
184 | current "timeslice" to other coroutines of the same or higher priority. |
167 | |
185 | |
168 | =cut |
186 | =cut |
169 | |
187 | |
170 | =item terminate |
188 | =item terminate [arg...] |
171 | |
189 | |
172 | Terminates the current process. |
190 | Terminates the current process. |
173 | |
191 | |
174 | Future versions of this function will allow result arguments. |
192 | Future versions of this function will allow result arguments. |
175 | |
193 | |
176 | =cut |
194 | =cut |
177 | |
195 | |
178 | sub terminate { |
196 | sub terminate { |
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197 | $current->{status} = [@_]; |
179 | $current->cancel; |
198 | $current->cancel; |
180 | &schedule; |
199 | &schedule; |
181 | die; # NORETURN |
200 | die; # NORETURN |
182 | } |
201 | } |
183 | |
202 | |
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192 | =over 4 |
211 | =over 4 |
193 | |
212 | |
194 | =item new Coro \&sub [, @args...] |
213 | =item new Coro \&sub [, @args...] |
195 | |
214 | |
196 | Create a new process and return it. When the sub returns the process |
215 | Create a new process and return it. When the sub returns the process |
197 | automatically terminates. To start the process you must first put it into |
216 | automatically terminates as if C<terminate> with the returned values were |
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217 | called. To make the process run you must first put it into the ready queue |
198 | the ready queue by calling the ready method. |
218 | by calling the ready method. |
199 | |
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200 | The coderef you submit MUST NOT be a closure that refers to variables |
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201 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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202 | |
219 | |
203 | =cut |
220 | =cut |
204 | |
221 | |
205 | sub _newcoro { |
222 | sub _newcoro { |
206 | terminate &{+shift}; |
223 | terminate &{+shift}; |
… | |
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213 | }, $class; |
230 | }, $class; |
214 | } |
231 | } |
215 | |
232 | |
216 | =item $process->ready |
233 | =item $process->ready |
217 | |
234 | |
218 | Put the current process into the ready queue. |
235 | Put the given process into the ready queue. |
219 | |
236 | |
220 | =cut |
237 | =cut |
221 | |
238 | |
222 | =item $process->cancel |
239 | =item $process->cancel |
223 | |
240 | |
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226 | =cut |
243 | =cut |
227 | |
244 | |
228 | sub cancel { |
245 | sub cancel { |
229 | push @destroy, $_[0]; |
246 | push @destroy, $_[0]; |
230 | $manager->ready; |
247 | $manager->ready; |
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248 | &schedule if $current == $_[0]; |
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249 | } |
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250 | |
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251 | =item $process->join |
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252 | |
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253 | Wait until the coroutine terminates and return any values given to the |
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254 | C<terminate> function. C<join> can be called multiple times from multiple |
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255 | processes. |
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256 | |
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257 | =cut |
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258 | |
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259 | sub join { |
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260 | my $self = shift; |
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261 | unless ($self->{status}) { |
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262 | push @{$self->{join}}, $current; |
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263 | &schedule; |
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264 | } |
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265 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
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266 | } |
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267 | |
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268 | =item $oldprio = $process->prio($newprio) |
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269 | |
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270 | Sets (or gets, if the argument is missing) the priority of the |
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271 | process. Higher priority processes get run before lower priority |
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272 | processes. Priorities are smalled signed integer (currently -4 .. +3), |
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273 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
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274 | to get then): |
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275 | |
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276 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
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277 | 3 > 1 > 0 > -1 > -3 > -4 |
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278 | |
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279 | # set priority to HIGH |
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280 | current->prio(PRIO_HIGH); |
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281 | |
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282 | The idle coroutine ($Coro::idle) always has a lower priority than any |
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283 | existing coroutine. |
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284 | |
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285 | Changing the priority of the current process will take effect immediately, |
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286 | but changing the priority of processes in the ready queue (but not |
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287 | running) will only take effect after the next schedule (of that |
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288 | process). This is a bug that will be fixed in some future version. |
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289 | |
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290 | =cut |
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291 | |
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292 | sub prio { |
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293 | my $old = $_[0]{prio}; |
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294 | $_[0]{prio} = $_[1] if @_ > 1; |
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295 | $old; |
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296 | } |
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297 | |
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298 | =item $newprio = $process->nice($change) |
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299 | |
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300 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
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301 | higher values mean lower priority, just as in unix). |
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302 | |
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303 | =cut |
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304 | |
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305 | sub nice { |
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306 | $_[0]{prio} -= $_[1]; |
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307 | } |
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308 | |
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309 | =item $olddesc = $process->desc($newdesc) |
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310 | |
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311 | Sets (or gets in case the argument is missing) the description for this |
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312 | process. This is just a free-form string you can associate with a process. |
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313 | |
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314 | =cut |
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315 | |
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316 | sub desc { |
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317 | my $old = $_[0]{desc}; |
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318 | $_[0]{desc} = $_[1] if @_ > 1; |
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319 | $old; |
231 | } |
320 | } |
232 | |
321 | |
233 | =back |
322 | =back |
234 | |
323 | |
235 | =cut |
324 | =cut |
236 | |
325 | |
237 | 1; |
326 | 1; |
238 | |
327 | |
239 | =head1 BUGS/LIMITATIONS |
328 | =head1 BUGS/LIMITATIONS |
240 | |
329 | |
241 | - could be faster, especially when the core would introduce special |
330 | - you must make very sure that no coro is still active on global destruction. |
242 | support for coroutines (like it does for threads). |
331 | very bad things might happen otherwise (usually segfaults). |
243 | - there is still a memleak on coroutine termination that I could not |
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244 | identify. Could be as small as a single SV. |
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245 | - this module is not well-tested. |
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246 | - if variables or arguments "disappear" (become undef) or become |
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247 | corrupted please contact the author so he cen iron out the |
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248 | remaining bugs. |
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249 | - this module is not thread-safe. You must only ever use this module from |
332 | - this module is not thread-safe. You should only ever use this module from |
250 | the same thread (this requirement might be loosened in the future to |
333 | the same thread (this requirement might be loosened in the future to |
251 | allow per-thread schedulers, but Coro::State does not yet allow this). |
334 | allow per-thread schedulers, but Coro::State does not yet allow this). |
252 | |
335 | |
253 | =head1 SEE ALSO |
336 | =head1 SEE ALSO |
254 | |
337 | |