… | |
… | |
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 | use strict; |
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36 | no warnings "uninitialized"; |
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37 | |
37 | use Coro::State; |
38 | use Coro::State; |
38 | |
39 | |
39 | use base Exporter; |
40 | use base qw(Coro::State Exporter); |
40 | |
41 | |
41 | $VERSION = 0.49; |
42 | our $idle; # idle handler |
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43 | our $main; # main coroutine |
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44 | our $current; # current coroutine |
42 | |
45 | |
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46 | our $VERSION = '2.5'; |
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47 | |
43 | @EXPORT = qw(async cede schedule terminate current); |
48 | our @EXPORT = qw(async cede schedule terminate current); |
44 | %EXPORT_TAGS = ( |
49 | our %EXPORT_TAGS = ( |
45 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
46 | ); |
51 | ); |
47 | @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
48 | |
53 | |
49 | { |
54 | { |
50 | my @async; |
55 | my @async; |
51 | my $init; |
56 | my $init; |
52 | |
57 | |
53 | # this way of handling attributes simply is NOT scalable ;() |
58 | # this way of handling attributes simply is NOT scalable ;() |
54 | sub import { |
59 | sub import { |
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60 | no strict 'refs'; |
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61 | |
55 | Coro->export_to_level(1, @_); |
62 | Coro->export_to_level(1, @_); |
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63 | |
56 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
57 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
58 | my ($package, $ref) = (shift, shift); |
66 | my ($package, $ref) = (shift, shift); |
59 | my @attrs; |
67 | my @attrs; |
60 | for (@_) { |
68 | for (@_) { |
… | |
… | |
75 | }; |
83 | }; |
76 | } |
84 | } |
77 | |
85 | |
78 | } |
86 | } |
79 | |
87 | |
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88 | =over 4 |
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89 | |
80 | =item $main |
90 | =item $main |
81 | |
91 | |
82 | This coroutine represents the main program. |
92 | This coroutine represents the main program. |
83 | |
93 | |
84 | =cut |
94 | =cut |
85 | |
95 | |
86 | our $main = new Coro; |
96 | $main = new Coro; |
87 | |
97 | |
88 | =item $current (or as function: current) |
98 | =item $current (or as function: current) |
89 | |
99 | |
90 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
100 | The current coroutine (the last coroutine switched to). The initial value |
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101 | is C<$main> (of course). |
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102 | |
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103 | This variable is B<strictly> I<read-only>. It is provided for performance |
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104 | reasons. If performance is not essentiel you are encouraged to use the |
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105 | C<Coro::current> function instead. |
91 | |
106 | |
92 | =cut |
107 | =cut |
93 | |
108 | |
94 | # maybe some other module used Coro::Specific before... |
109 | # maybe some other module used Coro::Specific before... |
95 | if ($current) { |
110 | if ($current) { |
96 | $main->{specific} = $current->{specific}; |
111 | $main->{specific} = $current->{specific}; |
97 | } |
112 | } |
98 | |
113 | |
99 | our $current = $main; |
114 | $current = $main; |
100 | |
115 | |
101 | sub current() { $current } |
116 | sub current() { $current } |
102 | |
117 | |
103 | =item $idle |
118 | =item $idle |
104 | |
119 | |
105 | The coroutine to switch to when no other coroutine is running. The default |
120 | A callback that is called whenever the scheduler finds no ready coroutines |
106 | implementation prints "FATAL: deadlock detected" and exits. |
121 | to run. The default implementation prints "FATAL: deadlock detected" and |
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122 | exits. |
107 | |
123 | |
108 | =cut |
124 | This hook is overwritten by modules such as C<Coro::Timer> and |
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125 | C<Coro::Event> to wait on an external event that hopefully wakes up some |
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126 | coroutine. |
109 | |
127 | |
110 | # should be done using priorities :( |
128 | =cut |
111 | our $idle = new Coro sub { |
129 | |
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130 | $idle = sub { |
112 | print STDERR "FATAL: deadlock detected\n"; |
131 | print STDERR "FATAL: deadlock detected\n"; |
113 | exit(51); |
132 | exit (51); |
114 | }; |
133 | }; |
115 | |
134 | |
116 | # this coroutine is necessary because a coroutine |
135 | # this coroutine is necessary because a coroutine |
117 | # cannot destroy itself. |
136 | # cannot destroy itself. |
118 | my @destroy; |
137 | my @destroy; |
119 | my $manager = new Coro sub { |
138 | my $manager; $manager = new Coro sub { |
120 | while() { |
139 | while () { |
121 | delete ((pop @destroy)->{_coro_state}) while @destroy; |
140 | # by overwriting the state object with the manager we destroy it |
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141 | # while still being able to schedule this coroutine (in case it has |
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142 | # been readied multiple times. this is harmless since the manager |
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143 | # can be called as many times as neccessary and will always |
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144 | # remove itself from the runqueue |
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145 | while (@destroy) { |
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146 | my $coro = pop @destroy; |
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147 | $coro->{status} ||= []; |
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148 | $_->ready for @{delete $coro->{join} || []}; |
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149 | |
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150 | # the next line destroys the coro state, but keeps the |
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151 | # process itself intact (we basically make it a zombie |
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152 | # process that always runs the manager thread, so it's possible |
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153 | # to transfer() to this process). |
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154 | $coro->_clone_state_from ($manager); |
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155 | } |
122 | &schedule; |
156 | &schedule; |
123 | } |
157 | } |
124 | }; |
158 | }; |
125 | |
159 | |
126 | # static methods. not really. |
160 | # static methods. not really. |
127 | |
161 | |
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162 | =back |
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163 | |
128 | =head2 STATIC METHODS |
164 | =head2 STATIC METHODS |
129 | |
165 | |
130 | Static methods are actually functions that operate on the current process only. |
166 | Static methods are actually functions that operate on the current process only. |
131 | |
167 | |
132 | =over 4 |
168 | =over 4 |
… | |
… | |
134 | =item async { ... } [@args...] |
170 | =item async { ... } [@args...] |
135 | |
171 | |
136 | Create a new asynchronous process and return it's process object |
172 | Create a new asynchronous process and return it's process object |
137 | (usually unused). When the sub returns the new process is automatically |
173 | (usually unused). When the sub returns the new process is automatically |
138 | terminated. |
174 | terminated. |
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175 | |
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176 | When the coroutine dies, the program will exit, just as in the main |
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177 | program. |
139 | |
178 | |
140 | # create a new coroutine that just prints its arguments |
179 | # create a new coroutine that just prints its arguments |
141 | async { |
180 | async { |
142 | print "@_\n"; |
181 | print "@_\n"; |
143 | } 1,2,3,4; |
182 | } 1,2,3,4; |
144 | |
183 | |
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 | |
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148 | =cut |
184 | =cut |
149 | |
185 | |
150 | sub async(&@) { |
186 | sub async(&@) { |
151 | my $pid = new Coro @_; |
187 | my $pid = new Coro @_; |
152 | $manager->ready; # this ensures that the stack is cloned from the manager |
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153 | $pid->ready; |
188 | $pid->ready; |
154 | $pid; |
189 | $pid |
155 | } |
190 | } |
156 | |
191 | |
157 | =item schedule |
192 | =item schedule |
158 | |
193 | |
159 | Calls the scheduler. Please note that the current process will not be put |
194 | Calls the scheduler. Please note that the current process will not be put |
… | |
… | |
168 | ready queue and calls C<schedule>, which has the effect of giving up the |
203 | 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. |
204 | current "timeslice" to other coroutines of the same or higher priority. |
170 | |
205 | |
171 | =cut |
206 | =cut |
172 | |
207 | |
173 | =item terminate |
208 | =item terminate [arg...] |
174 | |
209 | |
175 | Terminates the current process. |
210 | 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 | |
211 | |
179 | =cut |
212 | =cut |
180 | |
213 | |
181 | sub terminate { |
214 | sub terminate { |
182 | $current->cancel; |
215 | $current->cancel (@_); |
183 | &schedule; |
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184 | die; # NORETURN |
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185 | } |
216 | } |
186 | |
217 | |
187 | =back |
218 | =back |
188 | |
219 | |
189 | # dynamic methods |
220 | # dynamic methods |
… | |
… | |
195 | =over 4 |
226 | =over 4 |
196 | |
227 | |
197 | =item new Coro \&sub [, @args...] |
228 | =item new Coro \&sub [, @args...] |
198 | |
229 | |
199 | Create a new process and return it. When the sub returns the process |
230 | 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 |
231 | automatically terminates as if C<terminate> with the returned values were |
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232 | called. To make the process run you must first put it into the ready queue |
201 | the ready queue by calling the ready method. |
233 | by calling the ready method. |
202 | |
234 | |
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 | |
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206 | =cut |
235 | =cut |
207 | |
236 | |
208 | sub _newcoro { |
237 | sub _new_coro { |
209 | terminate &{+shift}; |
238 | terminate &{+shift}; |
210 | } |
239 | } |
211 | |
240 | |
212 | sub new { |
241 | sub new { |
213 | my $class = shift; |
242 | my $class = shift; |
214 | bless { |
243 | |
215 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
244 | $class->SUPER::new (\&_new_coro, @_) |
216 | }, $class; |
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217 | } |
245 | } |
218 | |
246 | |
219 | =item $process->ready |
247 | =item $process->ready |
220 | |
248 | |
221 | Put the current process into the ready queue. |
249 | Put the given process into the ready queue. |
222 | |
250 | |
223 | =cut |
251 | =cut |
224 | |
252 | |
225 | =item $process->cancel |
253 | =item $process->cancel (arg...) |
226 | |
254 | |
227 | Like C<terminate>, but terminates the specified process instead. |
255 | Terminates the given process and makes it return the given arguments as |
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256 | status (default: the empty list). |
228 | |
257 | |
229 | =cut |
258 | =cut |
230 | |
259 | |
231 | sub cancel { |
260 | sub cancel { |
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261 | my $self = shift; |
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262 | $self->{status} = [@_]; |
232 | push @destroy, $_[0]; |
263 | push @destroy, $self; |
233 | $manager->ready; |
264 | $manager->ready; |
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265 | &schedule if $current == $self; |
234 | } |
266 | } |
235 | |
267 | |
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268 | =item $process->join |
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269 | |
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270 | Wait until the coroutine terminates and return any values given to the |
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271 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
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272 | from multiple processes. |
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273 | |
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274 | =cut |
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275 | |
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276 | sub join { |
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277 | my $self = shift; |
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278 | unless ($self->{status}) { |
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279 | push @{$self->{join}}, $current; |
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280 | &schedule; |
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281 | } |
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282 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
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283 | } |
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284 | |
236 | =item $oldprio = $process->prio($newprio) |
285 | =item $oldprio = $process->prio ($newprio) |
237 | |
286 | |
238 | Sets the priority of the process. Higher priority processes get run before |
287 | Sets (or gets, if the argument is missing) the priority of the |
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288 | process. Higher priority processes get run before lower priority |
239 | lower priority processes. Priorities are smalled signed integer (currently |
289 | processes. Priorities are small signed integers (currently -4 .. +3), |
240 | -4 .. +3), that you can refer to using PRIO_xxx constants (use the import |
290 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
241 | tag :prio to get then): |
291 | to get then): |
242 | |
292 | |
243 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
293 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
244 | 3 > 1 > 0 > -1 > -3 > -4 |
294 | 3 > 1 > 0 > -1 > -3 > -4 |
245 | |
295 | |
246 | # set priority to HIGH |
296 | # set priority to HIGH |
… | |
… | |
252 | Changing the priority of the current process will take effect immediately, |
302 | Changing the priority of the current process will take effect immediately, |
253 | but changing the priority of processes in the ready queue (but not |
303 | but changing the priority of processes in the ready queue (but not |
254 | running) will only take effect after the next schedule (of that |
304 | running) will only take effect after the next schedule (of that |
255 | process). This is a bug that will be fixed in some future version. |
305 | process). This is a bug that will be fixed in some future version. |
256 | |
306 | |
257 | =cut |
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258 | |
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259 | sub prio { |
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260 | my $old = $_[0]{prio}; |
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261 | $_[0]{prio} = $_[1] if @_ > 1; |
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262 | $old; |
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263 | } |
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264 | |
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265 | =item $newprio = $process->nice($change) |
307 | =item $newprio = $process->nice ($change) |
266 | |
308 | |
267 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
309 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
268 | higher values mean lower priority, just as in unix). |
310 | higher values mean lower priority, just as in unix). |
269 | |
311 | |
270 | =cut |
312 | =item $olddesc = $process->desc ($newdesc) |
271 | |
313 | |
272 | sub nice { |
314 | Sets (or gets in case the argument is missing) the description for this |
273 | $_[0]{prio} -= $_[1]; |
315 | process. This is just a free-form string you can associate with a process. |
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316 | |
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317 | =cut |
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318 | |
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319 | sub desc { |
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320 | my $old = $_[0]{desc}; |
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321 | $_[0]{desc} = $_[1] if @_ > 1; |
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322 | $old; |
274 | } |
323 | } |
275 | |
324 | |
276 | =back |
325 | =back |
277 | |
326 | |
278 | =cut |
327 | =cut |
279 | |
328 | |
280 | 1; |
329 | 1; |
281 | |
330 | |
282 | =head1 BUGS/LIMITATIONS |
331 | =head1 BUGS/LIMITATIONS |
283 | |
332 | |
284 | - you must make very sure that no coro is still active on global destruction. |
333 | - you must make very sure that no coro is still active on global |
285 | very bad things might happen otherwise (usually segfaults). |
334 | destruction. very bad things might happen otherwise (usually segfaults). |
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335 | |
286 | - this module is not thread-safe. You must only ever use this module from |
336 | - this module is not thread-safe. You should only ever use this module |
287 | the same thread (this requirement might be loosened in the future to |
337 | from the same thread (this requirement might be losened in the future |
288 | allow per-thread schedulers, but Coro::State does not yet allow this). |
338 | to allow per-thread schedulers, but Coro::State does not yet allow |
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339 | this). |
289 | |
340 | |
290 | =head1 SEE ALSO |
341 | =head1 SEE ALSO |
291 | |
342 | |
292 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
343 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
293 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, |
344 | |
294 | L<Coro::Handle>, L<Coro::Socket>. |
345 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
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346 | |
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347 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
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348 | |
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349 | Embedding: L<Coro:MakeMaker> |
295 | |
350 | |
296 | =head1 AUTHOR |
351 | =head1 AUTHOR |
297 | |
352 | |
298 | Marc Lehmann <pcg@goof.com> |
353 | Marc Lehmann <schmorp@schmorp.de> |
299 | http://www.goof.com/pcg/marc/ |
354 | http://home.schmorp.de/ |
300 | |
355 | |
301 | =cut |
356 | =cut |
302 | |
357 | |