… | |
… | |
14 | |
14 | |
15 | sub some_func : Coro { |
15 | sub some_func : Coro { |
16 | # some more async code |
16 | # some more async code |
17 | } |
17 | } |
18 | |
18 | |
19 | yield; |
19 | cede; |
20 | |
20 | |
21 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
22 | |
22 | |
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23 | This module collection manages coroutines. Coroutines are similar to |
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24 | Threads but don't run in parallel. |
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25 | |
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26 | This module is still experimental, see the BUGS section below. |
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27 | |
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28 | In this module, coroutines are defined as "callchain + lexical variables |
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29 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
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30 | callchain, it's own set of lexicals and it's own set of perl's most |
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31 | important global variables. |
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32 | |
23 | =cut |
33 | =cut |
24 | |
34 | |
25 | package Coro; |
35 | package Coro; |
26 | |
36 | |
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37 | no warnings qw(uninitialized); |
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38 | |
27 | use Coro::State; |
39 | use Coro::State; |
28 | |
40 | |
29 | use base Exporter; |
41 | use base Exporter; |
30 | |
42 | |
31 | $VERSION = 0.04; |
43 | $VERSION = 0.5; |
32 | |
44 | |
33 | @EXPORT = qw(async yield schedule); |
45 | @EXPORT = qw(async cede schedule terminate current); |
34 | @EXPORT_OK = qw($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}}; |
35 | |
50 | |
36 | { |
51 | { |
37 | use subs 'async'; |
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38 | |
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39 | my @async; |
52 | my @async; |
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53 | my $init; |
40 | |
54 | |
41 | # this way of handling attributes simply is NOT scalable ;() |
55 | # this way of handling attributes simply is NOT scalable ;() |
42 | sub import { |
56 | sub import { |
43 | Coro->export_to_level(1, @_); |
57 | Coro->export_to_level(1, @_); |
44 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
58 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
… | |
… | |
46 | my ($package, $ref) = (shift, shift); |
60 | my ($package, $ref) = (shift, shift); |
47 | my @attrs; |
61 | my @attrs; |
48 | for (@_) { |
62 | for (@_) { |
49 | if ($_ eq "Coro") { |
63 | if ($_ eq "Coro") { |
50 | push @async, $ref; |
64 | push @async, $ref; |
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65 | unless ($init++) { |
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66 | eval q{ |
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67 | sub INIT { |
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68 | &async(pop @async) while @async; |
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69 | } |
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70 | }; |
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71 | } |
51 | } else { |
72 | } else { |
52 | push @attrs, @_; |
73 | push @attrs, $_; |
53 | } |
74 | } |
54 | } |
75 | } |
55 | return $old ? $old->($package, $name, @attrs) : @attrs; |
76 | return $old ? $old->($package, $ref, @attrs) : @attrs; |
56 | }; |
77 | }; |
57 | } |
78 | } |
58 | |
79 | |
59 | sub INIT { |
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60 | async pop @async while @async; |
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61 | } |
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62 | } |
80 | } |
63 | |
81 | |
64 | =item $main |
82 | =item $main |
65 | |
83 | |
66 | This coroutine represents the main program. |
84 | This coroutine represents the main program. |
67 | |
85 | |
68 | =cut |
86 | =cut |
69 | |
87 | |
70 | our $main = new Coro; |
88 | our $main = new Coro; |
71 | |
89 | |
72 | =item $current |
90 | =item $current (or as function: current) |
73 | |
91 | |
74 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
92 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
75 | |
93 | |
76 | =cut |
94 | =cut |
77 | |
95 | |
… | |
… | |
79 | if ($current) { |
97 | if ($current) { |
80 | $main->{specific} = $current->{specific}; |
98 | $main->{specific} = $current->{specific}; |
81 | } |
99 | } |
82 | |
100 | |
83 | our $current = $main; |
101 | our $current = $main; |
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102 | |
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103 | sub current() { $current } |
84 | |
104 | |
85 | =item $idle |
105 | =item $idle |
86 | |
106 | |
87 | The coroutine to switch to when no other coroutine is running. The default |
107 | The coroutine to switch to when no other coroutine is running. The default |
88 | implementation prints "FATAL: deadlock detected" and exits. |
108 | implementation prints "FATAL: deadlock detected" and exits. |
… | |
… | |
93 | our $idle = new Coro sub { |
113 | our $idle = new Coro sub { |
94 | print STDERR "FATAL: deadlock detected\n"; |
114 | print STDERR "FATAL: deadlock detected\n"; |
95 | exit(51); |
115 | exit(51); |
96 | }; |
116 | }; |
97 | |
117 | |
98 | # we really need priorities... |
118 | # this coroutine is necessary because a coroutine |
99 | my @ready = (); # the ready queue. hehe, rather broken ;) |
119 | # cannot destroy itself. |
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120 | my @destroy; |
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121 | my $manager = new Coro sub { |
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122 | while() { |
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123 | # by overwriting the state object with the manager we destroy it |
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124 | # while still being able to schedule this coroutine (in case it has |
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125 | # been readied multiple times. this is harmless since the manager |
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126 | # can be called as many times as neccessary and will always |
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127 | # remove itself from the runqueue |
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128 | (pop @destroy)->{_coro_state} = $manager->{_coro_state} while @destroy; |
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129 | &schedule; |
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130 | } |
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131 | }; |
100 | |
132 | |
101 | # static methods. not really. |
133 | # static methods. not really. |
102 | |
134 | |
103 | =head2 STATIC METHODS |
135 | =head2 STATIC METHODS |
104 | |
136 | |
105 | Static methods are actually functions that operate on the current process only. |
137 | Static methods are actually functions that operate on the current process only. |
106 | |
138 | |
107 | =over 4 |
139 | =over 4 |
108 | |
140 | |
109 | =item async { ... }; |
141 | =item async { ... } [@args...] |
110 | |
142 | |
111 | Create a new asynchronous process and return it's process object |
143 | Create a new asynchronous process and return it's process object |
112 | (usually unused). When the sub returns the new process is automatically |
144 | (usually unused). When the sub returns the new process is automatically |
113 | terminated. |
145 | terminated. |
114 | |
146 | |
115 | =cut |
147 | # create a new coroutine that just prints its arguments |
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148 | async { |
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149 | print "@_\n"; |
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150 | } 1,2,3,4; |
116 | |
151 | |
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152 | The coderef you submit MUST NOT be a closure that refers to variables |
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153 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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154 | |
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155 | =cut |
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156 | |
117 | sub async(&) { |
157 | sub async(&@) { |
118 | (new Coro $_[0])->ready; |
158 | my $pid = new Coro @_; |
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159 | $manager->ready; # this ensures that the stack is cloned from the manager |
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160 | $pid->ready; |
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161 | $pid; |
119 | } |
162 | } |
120 | |
163 | |
121 | =item schedule |
164 | =item schedule |
122 | |
165 | |
123 | Calls the scheduler. Please note that the current process will not be put |
166 | Calls the scheduler. Please note that the current process will not be put |
124 | into the ready queue, so calling this function usually means you will |
167 | into the ready queue, so calling this function usually means you will |
125 | never be called again. |
168 | never be called again. |
126 | |
169 | |
127 | =cut |
170 | =cut |
128 | |
171 | |
129 | my $prev; |
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130 | |
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131 | sub schedule { |
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132 | # should be done using priorities :( |
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133 | ($prev, $current) = ($current, shift @ready || $idle); |
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134 | Coro::State::transfer($prev, $current); |
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135 | } |
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136 | |
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137 | =item yield |
172 | =item cede |
138 | |
173 | |
139 | Yield to other processes. This function puts the current process into the |
174 | "Cede" to other processes. This function puts the current process into the |
140 | ready queue and calls C<schedule>. |
175 | ready queue and calls C<schedule>, which has the effect of giving up the |
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176 | current "timeslice" to other coroutines of the same or higher priority. |
141 | |
177 | |
142 | =cut |
178 | =cut |
143 | |
179 | |
144 | sub yield { |
180 | =item terminate |
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181 | |
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182 | Terminates the current process. |
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183 | |
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184 | Future versions of this function will allow result arguments. |
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185 | |
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186 | =cut |
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187 | |
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188 | sub terminate { |
145 | $current->ready; |
189 | $current->cancel; |
146 | &schedule; |
190 | &schedule; |
147 | } |
191 | die; # NORETURN |
148 | |
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149 | =item terminate |
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150 | |
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151 | Terminates the current process. |
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152 | |
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153 | =cut |
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154 | |
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155 | sub terminate { |
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156 | &schedule; |
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157 | } |
192 | } |
158 | |
193 | |
159 | =back |
194 | =back |
160 | |
195 | |
161 | # dynamic methods |
196 | # dynamic methods |
… | |
… | |
164 | |
199 | |
165 | These are the methods you can call on process objects. |
200 | These are the methods you can call on process objects. |
166 | |
201 | |
167 | =over 4 |
202 | =over 4 |
168 | |
203 | |
169 | =item new Coro \⊂ |
204 | =item new Coro \&sub [, @args...] |
170 | |
205 | |
171 | Create a new process and return it. When the sub returns the process |
206 | Create a new process and return it. When the sub returns the process |
172 | automatically terminates. To start the process you must first put it into |
207 | automatically terminates. To start the process you must first put it into |
173 | the ready queue by calling the ready method. |
208 | the ready queue by calling the ready method. |
174 | |
209 | |
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210 | The coderef you submit MUST NOT be a closure that refers to variables |
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211 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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212 | |
175 | =cut |
213 | =cut |
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214 | |
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215 | sub _newcoro { |
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216 | terminate &{+shift}; |
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217 | } |
176 | |
218 | |
177 | sub new { |
219 | sub new { |
178 | my $class = shift; |
220 | my $class = shift; |
179 | my $proc = $_[0]; |
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180 | bless { |
221 | bless { |
181 | _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), |
222 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
182 | }, $class; |
223 | }, $class; |
183 | } |
224 | } |
184 | |
225 | |
185 | =item $process->ready |
226 | =item $process->ready |
186 | |
227 | |
187 | Put the current process into the ready queue. |
228 | Put the current process into the ready queue. |
188 | |
229 | |
189 | =cut |
230 | =cut |
190 | |
231 | |
191 | sub ready { |
232 | =item $process->cancel |
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233 | |
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234 | Like C<terminate>, but terminates the specified process instead. |
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235 | |
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236 | =cut |
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237 | |
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238 | sub cancel { |
192 | push @ready, $_[0]; |
239 | push @destroy, $_[0]; |
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240 | $manager->ready; |
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241 | &schedule if $current == $_[0]; |
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242 | } |
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243 | |
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244 | =item $oldprio = $process->prio($newprio) |
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245 | |
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246 | Sets the priority of the process. Higher priority processes get run before |
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247 | lower priority processes. Priorities are smalled signed integer (currently |
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248 | -4 .. +3), that you can refer to using PRIO_xxx constants (use the import |
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249 | tag :prio to get then): |
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250 | |
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251 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
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252 | 3 > 1 > 0 > -1 > -3 > -4 |
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253 | |
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254 | # set priority to HIGH |
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255 | current->prio(PRIO_HIGH); |
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256 | |
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257 | The idle coroutine ($Coro::idle) always has a lower priority than any |
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258 | existing coroutine. |
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259 | |
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260 | Changing the priority of the current process will take effect immediately, |
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261 | but changing the priority of processes in the ready queue (but not |
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262 | running) will only take effect after the next schedule (of that |
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263 | process). This is a bug that will be fixed in some future version. |
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264 | |
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265 | =cut |
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266 | |
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267 | sub prio { |
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268 | my $old = $_[0]{prio}; |
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269 | $_[0]{prio} = $_[1] if @_ > 1; |
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270 | $old; |
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271 | } |
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272 | |
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273 | =item $newprio = $process->nice($change) |
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274 | |
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275 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
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276 | higher values mean lower priority, just as in unix). |
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277 | |
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278 | =cut |
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279 | |
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280 | sub nice { |
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281 | $_[0]{prio} -= $_[1]; |
193 | } |
282 | } |
194 | |
283 | |
195 | =back |
284 | =back |
196 | |
285 | |
197 | =cut |
286 | =cut |
198 | |
287 | |
199 | 1; |
288 | 1; |
200 | |
289 | |
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290 | =head1 BUGS/LIMITATIONS |
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291 | |
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292 | - you must make very sure that no coro is still active on global destruction. |
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293 | very bad things might happen otherwise (usually segfaults). |
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294 | - this module is not thread-safe. You must only ever use this module from |
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295 | the same thread (this requirement might be loosened in the future to |
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296 | allow per-thread schedulers, but Coro::State does not yet allow this). |
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297 | |
201 | =head1 SEE ALSO |
298 | =head1 SEE ALSO |
202 | |
299 | |
203 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
300 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
204 | L<Coro::Signal>, L<Coro::State>. |
301 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, |
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302 | L<Coro::Handle>, L<Coro::Socket>. |
205 | |
303 | |
206 | =head1 AUTHOR |
304 | =head1 AUTHOR |
207 | |
305 | |
208 | Marc Lehmann <pcg@goof.com> |
306 | Marc Lehmann <pcg@goof.com> |
209 | http://www.goof.com/pcg/marc/ |
307 | http://www.goof.com/pcg/marc/ |