… | |
… | |
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 | In this module, coroutines are defined as "callchain + lexical variables |
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27 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
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28 | callchain, it's own set of lexicals and it's own set of perl's most |
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29 | important global variables. |
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30 | |
23 | =cut |
31 | =cut |
24 | |
32 | |
25 | package Coro; |
33 | package Coro; |
26 | |
34 | |
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35 | use strict; |
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36 | no warnings "uninitialized"; |
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37 | |
27 | use Coro::State; |
38 | use Coro::State; |
28 | |
39 | |
29 | use base Exporter; |
40 | use base qw(Coro::State Exporter); |
30 | |
41 | |
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42 | our $idle; # idle handler |
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43 | our $main; # main coroutine |
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44 | our $current; # current coroutine |
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45 | |
31 | $VERSION = 0.04; |
46 | our $VERSION = '3.0'; |
32 | |
47 | |
33 | @EXPORT = qw(async yield schedule); |
48 | our @EXPORT = qw(async cede schedule terminate current); |
34 | @EXPORT_OK = qw($current); |
49 | our %EXPORT_TAGS = ( |
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50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
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51 | ); |
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52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
35 | |
53 | |
36 | { |
54 | { |
37 | use subs 'async'; |
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38 | |
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39 | my @async; |
55 | my @async; |
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56 | my $init; |
40 | |
57 | |
41 | # this way of handling attributes simply is NOT scalable ;() |
58 | # this way of handling attributes simply is NOT scalable ;() |
42 | sub import { |
59 | sub import { |
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60 | no strict 'refs'; |
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61 | |
43 | Coro->export_to_level(1, @_); |
62 | Coro->export_to_level(1, @_); |
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63 | |
44 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
45 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
46 | my ($package, $ref) = (shift, shift); |
66 | my ($package, $ref) = (shift, shift); |
47 | my @attrs; |
67 | my @attrs; |
48 | for (@_) { |
68 | for (@_) { |
49 | if ($_ eq "Coro") { |
69 | if ($_ eq "Coro") { |
50 | push @async, $ref; |
70 | push @async, $ref; |
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71 | unless ($init++) { |
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72 | eval q{ |
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73 | sub INIT { |
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74 | &async(pop @async) while @async; |
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75 | } |
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76 | }; |
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77 | } |
51 | } else { |
78 | } else { |
52 | push @attrs, @_; |
79 | push @attrs, $_; |
53 | } |
80 | } |
54 | } |
81 | } |
55 | return $old ? $old->($package, $name, @attrs) : @attrs; |
82 | return $old ? $old->($package, $ref, @attrs) : @attrs; |
56 | }; |
83 | }; |
57 | } |
84 | } |
58 | |
85 | |
59 | sub INIT { |
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60 | async pop @async while @async; |
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61 | } |
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62 | } |
86 | } |
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87 | |
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88 | =over 4 |
63 | |
89 | |
64 | =item $main |
90 | =item $main |
65 | |
91 | |
66 | This coroutine represents the main program. |
92 | This coroutine represents the main program. |
67 | |
93 | |
68 | =cut |
94 | =cut |
69 | |
95 | |
70 | our $main = new Coro; |
96 | $main = new Coro; |
71 | |
97 | |
72 | =item $current |
98 | =item $current (or as function: current) |
73 | |
99 | |
74 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
100 | The current coroutine (the last coroutine switched to). The initial value |
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101 | is C<$main> (of course). |
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102 | |
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103 | This variable is B<strictly> I<read-only>. It is provided for performance |
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104 | reasons. If performance is not essentiel you are encouraged to use the |
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105 | C<Coro::current> function instead. |
75 | |
106 | |
76 | =cut |
107 | =cut |
77 | |
108 | |
78 | # maybe some other module used Coro::Specific before... |
109 | # maybe some other module used Coro::Specific before... |
79 | if ($current) { |
110 | if ($current) { |
80 | $main->{specific} = $current->{specific}; |
111 | $main->{specific} = $current->{specific}; |
81 | } |
112 | } |
82 | |
113 | |
83 | our $current = $main; |
114 | $current = $main; |
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115 | |
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116 | sub current() { $current } |
84 | |
117 | |
85 | =item $idle |
118 | =item $idle |
86 | |
119 | |
87 | 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 |
88 | implementation prints "FATAL: deadlock detected" and exits. |
121 | to run. The default implementation prints "FATAL: deadlock detected" and |
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122 | exits. |
89 | |
123 | |
90 | =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. |
91 | |
127 | |
92 | # should be done using priorities :( |
128 | =cut |
93 | our $idle = new Coro sub { |
129 | |
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130 | $idle = sub { |
94 | print STDERR "FATAL: deadlock detected\n"; |
131 | print STDERR "FATAL: deadlock detected\n"; |
95 | exit(51); |
132 | exit (51); |
96 | }; |
133 | }; |
97 | |
134 | |
98 | # we really need priorities... |
135 | # this coroutine is necessary because a coroutine |
99 | my @ready = (); # the ready queue. hehe, rather broken ;) |
136 | # cannot destroy itself. |
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137 | my @destroy; |
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138 | my $manager; $manager = new Coro sub { |
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139 | while () { |
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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 | } |
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156 | &schedule; |
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157 | } |
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158 | }; |
100 | |
159 | |
101 | # static methods. not really. |
160 | # static methods. not really. |
102 | |
161 | |
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162 | =back |
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163 | |
103 | =head2 STATIC METHODS |
164 | =head2 STATIC METHODS |
104 | |
165 | |
105 | 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. |
106 | |
167 | |
107 | =over 4 |
168 | =over 4 |
108 | |
169 | |
109 | =item async { ... }; |
170 | =item async { ... } [@args...] |
110 | |
171 | |
111 | Create a new asynchronous process and return it's process object |
172 | Create a new asynchronous process and return it's process object |
112 | (usually unused). When the sub returns the new process is automatically |
173 | (usually unused). When the sub returns the new process is automatically |
113 | terminated. |
174 | terminated. |
114 | |
175 | |
115 | =cut |
176 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
116 | |
177 | |
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178 | When the coroutine dies, the program will exit, just as in the main |
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179 | program. |
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180 | |
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181 | # create a new coroutine that just prints its arguments |
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182 | async { |
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183 | print "@_\n"; |
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184 | } 1,2,3,4; |
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185 | |
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186 | =cut |
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187 | |
117 | sub async(&) { |
188 | sub async(&@) { |
118 | (new Coro $_[0])->ready; |
189 | my $pid = new Coro @_; |
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190 | $pid->ready; |
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191 | $pid |
119 | } |
192 | } |
120 | |
193 | |
121 | =item schedule |
194 | =item schedule |
122 | |
195 | |
123 | Calls the scheduler. Please note that the current process will not be put |
196 | 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 |
197 | into the ready queue, so calling this function usually means you will |
125 | never be called again. |
198 | never be called again. |
126 | |
199 | |
127 | =cut |
200 | =cut |
128 | |
201 | |
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 |
202 | =item cede |
138 | |
203 | |
139 | Yield to other processes. This function puts the current process into the |
204 | "Cede" to other processes. This function puts the current process into the |
140 | ready queue and calls C<schedule>. |
205 | ready queue and calls C<schedule>, which has the effect of giving up the |
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206 | current "timeslice" to other coroutines of the same or higher priority. |
141 | |
207 | |
142 | =cut |
208 | =cut |
143 | |
209 | |
144 | sub yield { |
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145 | $current->ready; |
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146 | &schedule; |
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147 | } |
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148 | |
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149 | =item terminate |
210 | =item terminate [arg...] |
150 | |
211 | |
151 | Terminates the current process. |
212 | Terminates the current process with the given status values (see L<cancel>). |
152 | |
213 | |
153 | =cut |
214 | =cut |
154 | |
215 | |
155 | sub terminate { |
216 | sub terminate { |
156 | &schedule; |
217 | $current->cancel (@_); |
157 | } |
218 | } |
158 | |
219 | |
159 | =back |
220 | =back |
160 | |
221 | |
161 | # dynamic methods |
222 | # dynamic methods |
… | |
… | |
164 | |
225 | |
165 | These are the methods you can call on process objects. |
226 | These are the methods you can call on process objects. |
166 | |
227 | |
167 | =over 4 |
228 | =over 4 |
168 | |
229 | |
169 | =item new Coro \⊂ |
230 | =item new Coro \&sub [, @args...] |
170 | |
231 | |
171 | Create a new process and return it. When the sub returns the process |
232 | 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 |
233 | automatically terminates as if C<terminate> with the returned values were |
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234 | called. To make the process run you must first put it into the ready queue |
173 | the ready queue by calling the ready method. |
235 | by calling the ready method. |
174 | |
236 | |
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237 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
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238 | |
175 | =cut |
239 | =cut |
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240 | |
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241 | sub _new_coro { |
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242 | terminate &{+shift}; |
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243 | } |
176 | |
244 | |
177 | sub new { |
245 | sub new { |
178 | my $class = shift; |
246 | my $class = shift; |
179 | my $proc = $_[0]; |
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180 | bless { |
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181 | _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), |
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182 | }, $class; |
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183 | } |
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184 | |
247 | |
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248 | $class->SUPER::new (\&_new_coro, @_) |
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249 | } |
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250 | |
185 | =item $process->ready |
251 | =item $success = $process->ready |
186 | |
252 | |
187 | Put the current process into the ready queue. |
253 | Put the given process into the ready queue (according to it's priority) |
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254 | and return true. If the process is already in the ready queue, do nothing |
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255 | and return false. |
188 | |
256 | |
189 | =cut |
257 | =item $is_ready = $process->is_ready |
190 | |
258 | |
191 | sub ready { |
259 | Return wether the process is currently the ready queue or not, |
192 | push @ready, $_[0]; |
260 | |
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261 | =item $process->cancel (arg...) |
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262 | |
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263 | Terminates the given process and makes it return the given arguments as |
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264 | status (default: the empty list). |
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265 | |
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266 | =cut |
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267 | |
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268 | sub cancel { |
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269 | my $self = shift; |
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270 | $self->{status} = [@_]; |
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271 | push @destroy, $self; |
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272 | $manager->ready; |
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273 | &schedule if $current == $self; |
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274 | } |
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275 | |
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276 | =item $process->join |
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277 | |
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278 | Wait until the coroutine terminates and return any values given to the |
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279 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
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280 | from multiple processes. |
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281 | |
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282 | =cut |
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283 | |
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284 | sub join { |
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285 | my $self = shift; |
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286 | unless ($self->{status}) { |
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287 | push @{$self->{join}}, $current; |
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288 | &schedule; |
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289 | } |
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290 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
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291 | } |
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292 | |
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293 | =item $oldprio = $process->prio ($newprio) |
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294 | |
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295 | Sets (or gets, if the argument is missing) the priority of the |
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296 | process. Higher priority processes get run before lower priority |
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297 | processes. Priorities are small signed integers (currently -4 .. +3), |
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298 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
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299 | to get then): |
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300 | |
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301 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
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302 | 3 > 1 > 0 > -1 > -3 > -4 |
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303 | |
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304 | # set priority to HIGH |
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305 | current->prio(PRIO_HIGH); |
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306 | |
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307 | The idle coroutine ($Coro::idle) always has a lower priority than any |
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308 | existing coroutine. |
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309 | |
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310 | Changing the priority of the current process will take effect immediately, |
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311 | but changing the priority of processes in the ready queue (but not |
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312 | running) will only take effect after the next schedule (of that |
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313 | process). This is a bug that will be fixed in some future version. |
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314 | |
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315 | =item $newprio = $process->nice ($change) |
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316 | |
|
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317 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
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318 | higher values mean lower priority, just as in unix). |
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319 | |
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320 | =item $olddesc = $process->desc ($newdesc) |
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321 | |
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322 | Sets (or gets in case the argument is missing) the description for this |
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323 | process. This is just a free-form string you can associate with a process. |
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324 | |
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325 | =cut |
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326 | |
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327 | sub desc { |
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328 | my $old = $_[0]{desc}; |
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329 | $_[0]{desc} = $_[1] if @_ > 1; |
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330 | $old; |
193 | } |
331 | } |
194 | |
332 | |
195 | =back |
333 | =back |
196 | |
334 | |
197 | =cut |
335 | =cut |
198 | |
336 | |
199 | 1; |
337 | 1; |
200 | |
338 | |
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339 | =head1 BUGS/LIMITATIONS |
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340 | |
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341 | - you must make very sure that no coro is still active on global |
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342 | destruction. very bad things might happen otherwise (usually segfaults). |
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343 | |
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344 | - this module is not thread-safe. You should only ever use this module |
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345 | from the same thread (this requirement might be losened in the future |
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346 | to allow per-thread schedulers, but Coro::State does not yet allow |
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347 | this). |
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348 | |
201 | =head1 SEE ALSO |
349 | =head1 SEE ALSO |
202 | |
350 | |
203 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
351 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
204 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. |
352 | |
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353 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
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354 | |
|
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355 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
|
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356 | |
|
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357 | Embedding: L<Coro:MakeMaker> |
205 | |
358 | |
206 | =head1 AUTHOR |
359 | =head1 AUTHOR |
207 | |
360 | |
208 | Marc Lehmann <pcg@goof.com> |
361 | Marc Lehmann <schmorp@schmorp.de> |
209 | http://www.goof.com/pcg/marc/ |
362 | http://home.schmorp.de/ |
210 | |
363 | |
211 | =cut |
364 | =cut |
212 | |
365 | |