… | |
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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 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
30 | callchain, it's own set of lexicals and it's own set of perl's most |
28 | callchain, it's own set of lexicals and it's own set of perl's most |
31 | important global variables. |
29 | important global variables. |
32 | |
30 | |
33 | =cut |
31 | =cut |
34 | |
32 | |
35 | package Coro; |
33 | package Coro; |
36 | |
34 | |
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35 | BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") } |
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36 | |
37 | use Coro::State; |
37 | use Coro::State; |
38 | |
38 | |
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39 | use vars qw($idle $main $current); |
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40 | |
39 | use base Exporter; |
41 | use base Exporter; |
40 | |
42 | |
41 | $VERSION = 0.45; |
43 | $VERSION = "0.9"; |
42 | |
44 | |
43 | @EXPORT = qw(async cede schedule terminate current); |
45 | @EXPORT = qw(async cede schedule terminate current); |
44 | @EXPORT_OK = qw($current); |
46 | %EXPORT_TAGS = ( |
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47 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
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48 | ); |
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49 | @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
45 | |
50 | |
46 | { |
51 | { |
47 | my @async; |
52 | my @async; |
48 | my $init; |
53 | my $init; |
49 | |
54 | |
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72 | }; |
77 | }; |
73 | } |
78 | } |
74 | |
79 | |
75 | } |
80 | } |
76 | |
81 | |
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82 | =over 4 |
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83 | |
77 | =item $main |
84 | =item $main |
78 | |
85 | |
79 | This coroutine represents the main program. |
86 | This coroutine represents the main program. |
80 | |
87 | |
81 | =cut |
88 | =cut |
82 | |
89 | |
83 | our $main = new Coro; |
90 | $main = new Coro; |
84 | |
91 | |
85 | =item $current (or as function: current) |
92 | =item $current (or as function: current) |
86 | |
93 | |
87 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
94 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
88 | |
95 | |
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91 | # maybe some other module used Coro::Specific before... |
98 | # maybe some other module used Coro::Specific before... |
92 | if ($current) { |
99 | if ($current) { |
93 | $main->{specific} = $current->{specific}; |
100 | $main->{specific} = $current->{specific}; |
94 | } |
101 | } |
95 | |
102 | |
96 | our $current = $main; |
103 | $current = $main; |
97 | |
104 | |
98 | sub current() { $current } |
105 | sub current() { $current } |
99 | |
106 | |
100 | =item $idle |
107 | =item $idle |
101 | |
108 | |
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103 | implementation prints "FATAL: deadlock detected" and exits. |
110 | implementation prints "FATAL: deadlock detected" and exits. |
104 | |
111 | |
105 | =cut |
112 | =cut |
106 | |
113 | |
107 | # should be done using priorities :( |
114 | # should be done using priorities :( |
108 | our $idle = new Coro sub { |
115 | $idle = new Coro sub { |
109 | print STDERR "FATAL: deadlock detected\n"; |
116 | print STDERR "FATAL: deadlock detected\n"; |
110 | exit(51); |
117 | exit(51); |
111 | }; |
118 | }; |
112 | |
119 | |
113 | # this coroutine is necessary because a coroutine |
120 | # this coroutine is necessary because a coroutine |
114 | # cannot destroy itself. |
121 | # cannot destroy itself. |
115 | my @destroy; |
122 | my @destroy; |
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123 | my $manager; |
116 | my $manager = new Coro sub { |
124 | $manager = new Coro sub { |
117 | while() { |
125 | while() { |
118 | delete ((pop @destroy)->{_coro_state}) while @destroy; |
126 | # by overwriting the state object with the manager we destroy it |
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127 | # while still being able to schedule this coroutine (in case it has |
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128 | # been readied multiple times. this is harmless since the manager |
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129 | # can be called as many times as neccessary and will always |
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130 | # remove itself from the runqueue |
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131 | while (@destroy) { |
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132 | my $coro = pop @destroy; |
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133 | $coro->{status} ||= []; |
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134 | $_->ready for @{delete $coro->{join} || []}; |
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135 | $coro->{_coro_state} = $manager->{_coro_state}; |
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136 | } |
119 | &schedule; |
137 | &schedule; |
120 | } |
138 | } |
121 | }; |
139 | }; |
122 | |
140 | |
123 | # we really need priorities... |
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124 | my @ready; # the ready queue. hehe, rather broken ;) |
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125 | |
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126 | # static methods. not really. |
141 | # static methods. not really. |
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142 | |
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143 | =back |
127 | |
144 | |
128 | =head2 STATIC METHODS |
145 | =head2 STATIC METHODS |
129 | |
146 | |
130 | Static methods are actually functions that operate on the current process only. |
147 | Static methods are actually functions that operate on the current process only. |
131 | |
148 | |
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160 | into the ready queue, so calling this function usually means you will |
177 | into the ready queue, so calling this function usually means you will |
161 | never be called again. |
178 | never be called again. |
162 | |
179 | |
163 | =cut |
180 | =cut |
164 | |
181 | |
165 | my $prev; |
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166 | |
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167 | sub schedule { |
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168 | # should be done using priorities :( |
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169 | ($prev, $current) = ($current, shift @ready || $idle); |
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170 | Coro::State::transfer($prev, $current); |
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171 | } |
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172 | |
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173 | =item cede |
182 | =item cede |
174 | |
183 | |
175 | "Cede" to other processes. This function puts the current process into the |
184 | "Cede" to other processes. This function puts the current process into the |
176 | ready queue and calls C<schedule>, which has the effect of giving up the |
185 | ready queue and calls C<schedule>, which has the effect of giving up the |
177 | current "timeslice" to other coroutines of the same or higher priority. |
186 | current "timeslice" to other coroutines of the same or higher priority. |
178 | |
187 | |
179 | =cut |
188 | =cut |
180 | |
189 | |
181 | sub cede { |
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182 | $current->ready; |
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183 | &schedule; |
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184 | } |
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185 | |
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186 | =item terminate |
190 | =item terminate [arg...] |
187 | |
191 | |
188 | Terminates the current process. |
192 | Terminates the current process. |
189 | |
193 | |
190 | Future versions of this function will allow result arguments. |
194 | Future versions of this function will allow result arguments. |
191 | |
195 | |
192 | =cut |
196 | =cut |
193 | |
197 | |
194 | sub terminate { |
198 | sub terminate { |
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199 | $current->{status} = [@_]; |
195 | $current->cancel; |
200 | $current->cancel; |
196 | &schedule; |
201 | &schedule; |
197 | die; # NORETURN |
202 | die; # NORETURN |
198 | } |
203 | } |
199 | |
204 | |
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208 | =over 4 |
213 | =over 4 |
209 | |
214 | |
210 | =item new Coro \&sub [, @args...] |
215 | =item new Coro \&sub [, @args...] |
211 | |
216 | |
212 | Create a new process and return it. When the sub returns the process |
217 | Create a new process and return it. When the sub returns the process |
213 | automatically terminates. To start the process you must first put it into |
218 | automatically terminates as if C<terminate> with the returned values were |
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219 | called. To make the process run you must first put it into the ready queue |
214 | the ready queue by calling the ready method. |
220 | by calling the ready method. |
215 | |
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216 | The coderef you submit MUST NOT be a closure that refers to variables |
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217 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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218 | |
221 | |
219 | =cut |
222 | =cut |
220 | |
223 | |
221 | sub _newcoro { |
224 | sub _newcoro { |
222 | terminate &{+shift}; |
225 | terminate &{+shift}; |
… | |
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229 | }, $class; |
232 | }, $class; |
230 | } |
233 | } |
231 | |
234 | |
232 | =item $process->ready |
235 | =item $process->ready |
233 | |
236 | |
234 | Put the current process into the ready queue. |
237 | Put the given process into the ready queue. |
235 | |
238 | |
236 | =cut |
239 | =cut |
237 | |
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238 | sub ready { |
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239 | push @ready, $_[0]; |
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240 | } |
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241 | |
240 | |
242 | =item $process->cancel |
241 | =item $process->cancel |
243 | |
242 | |
244 | Like C<terminate>, but terminates the specified process instead. |
243 | Like C<terminate>, but terminates the specified process instead. |
245 | |
244 | |
246 | =cut |
245 | =cut |
247 | |
246 | |
248 | sub cancel { |
247 | sub cancel { |
249 | push @destroy, $_[0]; |
248 | push @destroy, $_[0]; |
250 | $manager->ready; |
249 | $manager->ready; |
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250 | &schedule if $current == $_[0]; |
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251 | } |
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252 | |
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253 | =item $process->join |
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254 | |
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255 | Wait until the coroutine terminates and return any values given to the |
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256 | C<terminate> function. C<join> can be called multiple times from multiple |
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257 | processes. |
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258 | |
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259 | =cut |
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260 | |
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261 | sub join { |
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262 | my $self = shift; |
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263 | unless ($self->{status}) { |
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264 | push @{$self->{join}}, $current; |
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265 | &schedule; |
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266 | } |
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267 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
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268 | } |
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269 | |
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270 | =item $oldprio = $process->prio($newprio) |
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271 | |
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272 | Sets (or gets, if the argument is missing) the priority of the |
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273 | process. Higher priority processes get run before lower priority |
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274 | processes. Priorities are small signed integers (currently -4 .. +3), |
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275 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
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276 | to get then): |
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277 | |
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278 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
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279 | 3 > 1 > 0 > -1 > -3 > -4 |
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280 | |
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281 | # set priority to HIGH |
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282 | current->prio(PRIO_HIGH); |
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283 | |
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284 | The idle coroutine ($Coro::idle) always has a lower priority than any |
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285 | existing coroutine. |
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286 | |
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287 | Changing the priority of the current process will take effect immediately, |
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288 | but changing the priority of processes in the ready queue (but not |
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289 | running) will only take effect after the next schedule (of that |
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290 | process). This is a bug that will be fixed in some future version. |
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291 | |
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292 | =cut |
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293 | |
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294 | sub prio { |
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295 | my $old = $_[0]{prio}; |
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296 | $_[0]{prio} = $_[1] if @_ > 1; |
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297 | $old; |
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298 | } |
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299 | |
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300 | =item $newprio = $process->nice($change) |
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301 | |
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302 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
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303 | higher values mean lower priority, just as in unix). |
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304 | |
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305 | =cut |
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306 | |
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307 | sub nice { |
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308 | $_[0]{prio} -= $_[1]; |
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309 | } |
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310 | |
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311 | =item $olddesc = $process->desc($newdesc) |
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312 | |
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313 | Sets (or gets in case the argument is missing) the description for this |
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314 | process. This is just a free-form string you can associate with a process. |
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315 | |
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316 | =cut |
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317 | |
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318 | sub desc { |
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319 | my $old = $_[0]{desc}; |
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320 | $_[0]{desc} = $_[1] if @_ > 1; |
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321 | $old; |
251 | } |
322 | } |
252 | |
323 | |
253 | =back |
324 | =back |
254 | |
325 | |
255 | =cut |
326 | =cut |
256 | |
327 | |
257 | 1; |
328 | 1; |
258 | |
329 | |
259 | =head1 BUGS/LIMITATIONS |
330 | =head1 BUGS/LIMITATIONS |
260 | |
331 | |
261 | - could be faster, especially when the core would introduce special |
332 | - you must make very sure that no coro is still active on global |
262 | support for coroutines (like it does for threads). |
333 | destruction. very bad things might happen otherwise (usually segfaults). |
263 | - there is still a memleak on coroutine termination that I could not |
334 | |
264 | identify. Could be as small as a single SV. |
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265 | - this module is not well-tested. |
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266 | - if variables or arguments "disappear" (become undef) or become |
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267 | corrupted please contact the author so he cen iron out the |
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268 | remaining bugs. |
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269 | - this module is not thread-safe. You must only ever use this module from |
335 | - this module is not thread-safe. You should only ever use this module |
270 | the same thread (this requirement might be loosened in the future to |
336 | from the same thread (this requirement might be losened in the future |
271 | allow per-thread schedulers, but Coro::State does not yet allow this). |
337 | to allow per-thread schedulers, but Coro::State does not yet allow |
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338 | this). |
272 | |
339 | |
273 | =head1 SEE ALSO |
340 | =head1 SEE ALSO |
274 | |
341 | |
275 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
342 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
276 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, |
343 | L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>, |
277 | L<Coro::Handle>, L<Coro::Socket>. |
344 | L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>. |
278 | |
345 | |
279 | =head1 AUTHOR |
346 | =head1 AUTHOR |
280 | |
347 | |
281 | Marc Lehmann <pcg@goof.com> |
348 | Marc Lehmann <pcg@goof.com> |
282 | http://www.goof.com/pcg/marc/ |
349 | http://www.goof.com/pcg/marc/ |