… | |
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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 = 0.5; |
43 | $VERSION = 0.97; |
42 | |
44 | |
43 | @EXPORT = qw(async cede schedule terminate current); |
45 | @EXPORT = qw(async cede schedule terminate current); |
44 | %EXPORT_TAGS = ( |
46 | %EXPORT_TAGS = ( |
45 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
47 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
46 | ); |
48 | ); |
… | |
… | |
75 | }; |
77 | }; |
76 | } |
78 | } |
77 | |
79 | |
78 | } |
80 | } |
79 | |
81 | |
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82 | =over 4 |
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83 | |
80 | =item $main |
84 | =item $main |
81 | |
85 | |
82 | This coroutine represents the main program. |
86 | This coroutine represents the main program. |
83 | |
87 | |
84 | =cut |
88 | =cut |
85 | |
89 | |
86 | our $main = new Coro; |
90 | $main = new Coro; |
87 | |
91 | |
88 | =item $current (or as function: current) |
92 | =item $current (or as function: current) |
89 | |
93 | |
90 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
94 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
91 | |
95 | |
… | |
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94 | # maybe some other module used Coro::Specific before... |
98 | # maybe some other module used Coro::Specific before... |
95 | if ($current) { |
99 | if ($current) { |
96 | $main->{specific} = $current->{specific}; |
100 | $main->{specific} = $current->{specific}; |
97 | } |
101 | } |
98 | |
102 | |
99 | our $current = $main; |
103 | $current = $main; |
100 | |
104 | |
101 | sub current() { $current } |
105 | sub current() { $current } |
102 | |
106 | |
103 | =item $idle |
107 | =item $idle |
104 | |
108 | |
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106 | implementation prints "FATAL: deadlock detected" and exits. |
110 | implementation prints "FATAL: deadlock detected" and exits. |
107 | |
111 | |
108 | =cut |
112 | =cut |
109 | |
113 | |
110 | # should be done using priorities :( |
114 | # should be done using priorities :( |
111 | our $idle = new Coro sub { |
115 | $idle = new Coro sub { |
112 | print STDERR "FATAL: deadlock detected\n"; |
116 | print STDERR "FATAL: deadlock detected\n"; |
113 | exit(51); |
117 | exit(51); |
114 | }; |
118 | }; |
115 | |
119 | |
116 | # this coroutine is necessary because a coroutine |
120 | # this coroutine is necessary because a coroutine |
117 | # cannot destroy itself. |
121 | # cannot destroy itself. |
118 | my @destroy; |
122 | my @destroy; |
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123 | my $manager; |
119 | my $manager = new Coro sub { |
124 | $manager = new Coro sub { |
120 | while() { |
125 | while () { |
121 | 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 | |
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136 | # the next line destroys the _coro_state, but keeps the |
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137 | # process itself intact (we basically make it a zombie |
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138 | # process that always runs the manager thread, so it's possible |
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139 | # to transfer() to this process). |
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140 | $coro->{_coro_state} = $manager->{_coro_state}; |
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141 | } |
122 | &schedule; |
142 | &schedule; |
123 | } |
143 | } |
124 | }; |
144 | }; |
125 | |
145 | |
126 | # static methods. not really. |
146 | # static methods. not really. |
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147 | |
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148 | =back |
127 | |
149 | |
128 | =head2 STATIC METHODS |
150 | =head2 STATIC METHODS |
129 | |
151 | |
130 | Static methods are actually functions that operate on the current process only. |
152 | Static methods are actually functions that operate on the current process only. |
131 | |
153 | |
… | |
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139 | |
161 | |
140 | # create a new coroutine that just prints its arguments |
162 | # create a new coroutine that just prints its arguments |
141 | async { |
163 | async { |
142 | print "@_\n"; |
164 | print "@_\n"; |
143 | } 1,2,3,4; |
165 | } 1,2,3,4; |
144 | |
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145 | The coderef you submit MUST NOT be a closure that refers to variables |
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146 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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147 | |
166 | |
148 | =cut |
167 | =cut |
149 | |
168 | |
150 | sub async(&@) { |
169 | sub async(&@) { |
151 | my $pid = new Coro @_; |
170 | my $pid = new Coro @_; |
… | |
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168 | ready queue and calls C<schedule>, which has the effect of giving up the |
187 | ready queue and calls C<schedule>, which has the effect of giving up the |
169 | current "timeslice" to other coroutines of the same or higher priority. |
188 | current "timeslice" to other coroutines of the same or higher priority. |
170 | |
189 | |
171 | =cut |
190 | =cut |
172 | |
191 | |
173 | =item terminate |
192 | =item terminate [arg...] |
174 | |
193 | |
175 | Terminates the current process. |
194 | Terminates the current process with the given status values (see L<cancel>). |
176 | |
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177 | Future versions of this function will allow result arguments. |
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178 | |
195 | |
179 | =cut |
196 | =cut |
180 | |
197 | |
181 | sub terminate { |
198 | sub terminate { |
182 | $current->cancel; |
199 | $current->cancel (@_); |
183 | &schedule; |
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184 | die; # NORETURN |
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185 | } |
200 | } |
186 | |
201 | |
187 | =back |
202 | =back |
188 | |
203 | |
189 | # dynamic methods |
204 | # dynamic methods |
… | |
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195 | =over 4 |
210 | =over 4 |
196 | |
211 | |
197 | =item new Coro \&sub [, @args...] |
212 | =item new Coro \&sub [, @args...] |
198 | |
213 | |
199 | Create a new process and return it. When the sub returns the process |
214 | Create a new process and return it. When the sub returns the process |
200 | automatically terminates. To start the process you must first put it into |
215 | automatically terminates as if C<terminate> with the returned values were |
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216 | called. To make the process run you must first put it into the ready queue |
201 | the ready queue by calling the ready method. |
217 | by calling the ready method. |
202 | |
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203 | The coderef you submit MUST NOT be a closure that refers to variables |
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204 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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205 | |
218 | |
206 | =cut |
219 | =cut |
207 | |
220 | |
208 | sub _newcoro { |
221 | sub _newcoro { |
209 | terminate &{+shift}; |
222 | terminate &{+shift}; |
… | |
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216 | }, $class; |
229 | }, $class; |
217 | } |
230 | } |
218 | |
231 | |
219 | =item $process->ready |
232 | =item $process->ready |
220 | |
233 | |
221 | Put the current process into the ready queue. |
234 | Put the given process into the ready queue. |
222 | |
235 | |
223 | =cut |
236 | =cut |
224 | |
237 | |
225 | =item $process->cancel |
238 | =item $process->cancel (arg...) |
226 | |
239 | |
227 | Like C<terminate>, but terminates the specified process instead. |
240 | Temrinates the given process and makes it return the given arguments as |
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241 | status (default: the empty list). |
228 | |
242 | |
229 | =cut |
243 | =cut |
230 | |
244 | |
231 | sub cancel { |
245 | sub cancel { |
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246 | my $self = shift; |
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247 | $self->{status} = [@_]; |
232 | push @destroy, $_[0]; |
248 | push @destroy, $self; |
233 | $manager->ready; |
249 | $manager->ready; |
234 | &schedule if $current == $_[0]; |
250 | &schedule if $current == $self; |
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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> or C<cancel> functions. C<join> can be called multiple times |
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257 | from multiple 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]; |
235 | } |
268 | } |
236 | |
269 | |
237 | =item $oldprio = $process->prio($newprio) |
270 | =item $oldprio = $process->prio($newprio) |
238 | |
271 | |
239 | Sets the priority of the process. Higher priority processes get run before |
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 |
240 | lower priority processes. Priorities are smalled signed integer (currently |
274 | processes. Priorities are small signed integers (currently -4 .. +3), |
241 | -4 .. +3), that you can refer to using PRIO_xxx constants (use the import |
275 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
242 | tag :prio to get then): |
276 | to get then): |
243 | |
277 | |
244 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
278 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
245 | 3 > 1 > 0 > -1 > -3 > -4 |
279 | 3 > 1 > 0 > -1 > -3 > -4 |
246 | |
280 | |
247 | # set priority to HIGH |
281 | # set priority to HIGH |
… | |
… | |
272 | |
306 | |
273 | sub nice { |
307 | sub nice { |
274 | $_[0]{prio} -= $_[1]; |
308 | $_[0]{prio} -= $_[1]; |
275 | } |
309 | } |
276 | |
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; |
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322 | } |
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323 | |
277 | =back |
324 | =back |
278 | |
325 | |
279 | =cut |
326 | =cut |
280 | |
327 | |
281 | 1; |
328 | 1; |
282 | |
329 | |
283 | =head1 BUGS/LIMITATIONS |
330 | =head1 BUGS/LIMITATIONS |
284 | |
331 | |
285 | - you must make very sure that no coro is still active on global destruction. |
332 | - you must make very sure that no coro is still active on global |
286 | very bad things might happen otherwise (usually segfaults). |
333 | destruction. very bad things might happen otherwise (usually segfaults). |
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334 | |
287 | - 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 |
288 | 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 |
289 | 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). |
290 | |
339 | |
291 | =head1 SEE ALSO |
340 | =head1 SEE ALSO |
292 | |
341 | |
293 | 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>, |
294 | 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>, |
295 | L<Coro::Handle>, L<Coro::Socket>. |
344 | L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>. |
296 | |
345 | |
297 | =head1 AUTHOR |
346 | =head1 AUTHOR |
298 | |
347 | |
299 | Marc Lehmann <pcg@goof.com> |
348 | Marc Lehmann <pcg@goof.com> |
300 | http://www.goof.com/pcg/marc/ |
349 | http://www.goof.com/pcg/marc/ |