… | |
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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), that is, a coroutine has it's own callchain, it's |
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30 | own set of lexicals and it's own set of perl's most important global |
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31 | variables. |
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32 | |
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33 | WARNING: When using this module, make sure that, at program end, no |
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34 | coroutines are still running OR just call exit before falling off the |
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35 | end. The reason for this is that some coroutine of yours might have called |
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36 | into a C function, and falling off the end of main:: results in returning |
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37 | to that C function instead if to the main C interpreter. |
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38 | |
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39 | WARNING: Unless you really know what you are doing, do NOT do context |
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40 | switches inside callbacks from the XS level. The reason for this is |
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41 | similar to the reason above: A callback calls a perl function, this |
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42 | perl function does a context switch, some other callback is called, the |
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43 | original function returns from it - to what? To the wrong XS function, |
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44 | with totally different return values. Unfortunately, this includes |
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45 | callbacks done by perl itself (tie'd variables!). |
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46 | |
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47 | The only workaround for this is to do coroutines on C level. |
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48 | |
23 | =cut |
49 | =cut |
24 | |
50 | |
25 | package Coro; |
51 | package Coro; |
26 | |
52 | |
27 | use Coro::State; |
53 | use Coro::State; |
28 | |
54 | |
29 | use base Exporter; |
55 | use base Exporter; |
30 | |
56 | |
31 | $VERSION = 0.04; |
57 | $VERSION = 0.10; |
32 | |
58 | |
33 | @EXPORT = qw(async yield schedule); |
59 | @EXPORT = qw(async cede schedule terminate current); |
34 | @EXPORT_OK = qw($current); |
60 | @EXPORT_OK = qw($current); |
35 | |
61 | |
36 | { |
62 | { |
37 | use subs 'async'; |
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38 | |
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39 | my @async; |
63 | my @async; |
40 | |
64 | |
41 | # this way of handling attributes simply is NOT scalable ;() |
65 | # this way of handling attributes simply is NOT scalable ;() |
42 | sub import { |
66 | sub import { |
43 | Coro->export_to_level(1, @_); |
67 | Coro->export_to_level(1, @_); |
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47 | my @attrs; |
71 | my @attrs; |
48 | for (@_) { |
72 | for (@_) { |
49 | if ($_ eq "Coro") { |
73 | if ($_ eq "Coro") { |
50 | push @async, $ref; |
74 | push @async, $ref; |
51 | } else { |
75 | } else { |
52 | push @attrs, @_; |
76 | push @attrs, $_; |
53 | } |
77 | } |
54 | } |
78 | } |
55 | return $old ? $old->($package, $name, @attrs) : @attrs; |
79 | return $old ? $old->($package, $ref, @attrs) : @attrs; |
56 | }; |
80 | }; |
57 | } |
81 | } |
58 | |
82 | |
59 | sub INIT { |
83 | sub INIT { |
60 | async pop @async while @async; |
84 | &async(pop @async) while @async; |
61 | } |
85 | } |
62 | } |
86 | } |
63 | |
87 | |
64 | =item $main |
88 | =item $main |
65 | |
89 | |
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67 | |
91 | |
68 | =cut |
92 | =cut |
69 | |
93 | |
70 | our $main = new Coro; |
94 | our $main = new Coro; |
71 | |
95 | |
72 | =item $current |
96 | =item $current (or as function: current) |
73 | |
97 | |
74 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
98 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
75 | |
99 | |
76 | =cut |
100 | =cut |
77 | |
101 | |
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79 | if ($current) { |
103 | if ($current) { |
80 | $main->{specific} = $current->{specific}; |
104 | $main->{specific} = $current->{specific}; |
81 | } |
105 | } |
82 | |
106 | |
83 | our $current = $main; |
107 | our $current = $main; |
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108 | |
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109 | sub current() { $current } |
84 | |
110 | |
85 | =item $idle |
111 | =item $idle |
86 | |
112 | |
87 | The coroutine to switch to when no other coroutine is running. The default |
113 | The coroutine to switch to when no other coroutine is running. The default |
88 | implementation prints "FATAL: deadlock detected" and exits. |
114 | implementation prints "FATAL: deadlock detected" and exits. |
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94 | print STDERR "FATAL: deadlock detected\n"; |
120 | print STDERR "FATAL: deadlock detected\n"; |
95 | exit(51); |
121 | exit(51); |
96 | }; |
122 | }; |
97 | |
123 | |
98 | # we really need priorities... |
124 | # we really need priorities... |
99 | my @ready = (); # the ready queue. hehe, rather broken ;) |
125 | my @ready; # the ready queue. hehe, rather broken ;) |
100 | |
126 | |
101 | # static methods. not really. |
127 | # static methods. not really. |
102 | |
128 | |
103 | =head2 STATIC METHODS |
129 | =head2 STATIC METHODS |
104 | |
130 | |
105 | Static methods are actually functions that operate on the current process only. |
131 | Static methods are actually functions that operate on the current process only. |
106 | |
132 | |
107 | =over 4 |
133 | =over 4 |
108 | |
134 | |
109 | =item async { ... }; |
135 | =item async { ... } [@args...] |
110 | |
136 | |
111 | Create a new asynchronous process and return it's process object |
137 | Create a new asynchronous process and return it's process object |
112 | (usually unused). When the sub returns the new process is automatically |
138 | (usually unused). When the sub returns the new process is automatically |
113 | terminated. |
139 | terminated. |
114 | |
140 | |
115 | =cut |
141 | # create a new coroutine that just prints its arguments |
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142 | async { |
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143 | print "@_\n"; |
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144 | } 1,2,3,4; |
116 | |
145 | |
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146 | The coderef you submit MUST NOT be a closure that refers to variables |
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147 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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148 | |
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149 | =cut |
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150 | |
117 | sub async(&) { |
151 | sub async(&@) { |
118 | (new Coro $_[0])->ready; |
152 | my $pid = new Coro @_; |
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153 | $pid->ready; |
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154 | $pid; |
119 | } |
155 | } |
120 | |
156 | |
121 | =item schedule |
157 | =item schedule |
122 | |
158 | |
123 | Calls the scheduler. Please note that the current process will not be put |
159 | Calls the scheduler. Please note that the current process will not be put |
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132 | # should be done using priorities :( |
168 | # should be done using priorities :( |
133 | ($prev, $current) = ($current, shift @ready || $idle); |
169 | ($prev, $current) = ($current, shift @ready || $idle); |
134 | Coro::State::transfer($prev, $current); |
170 | Coro::State::transfer($prev, $current); |
135 | } |
171 | } |
136 | |
172 | |
137 | =item yield |
173 | =item cede |
138 | |
174 | |
139 | Yield to other processes. This function puts the current process into the |
175 | "Cede" to other processes. This function puts the current process into the |
140 | ready queue and calls C<schedule>. |
176 | ready queue and calls C<schedule>, which has the effect of giving up the |
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177 | current "timeslice" to other coroutines of the same or higher priority. |
141 | |
178 | |
142 | =cut |
179 | =cut |
143 | |
180 | |
144 | sub yield { |
181 | sub cede { |
145 | $current->ready; |
182 | $current->ready; |
146 | &schedule; |
183 | &schedule; |
147 | } |
184 | } |
148 | |
185 | |
149 | =item terminate |
186 | =item terminate |
150 | |
187 | |
151 | Terminates the current process. |
188 | Terminates the current process. |
152 | |
189 | |
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190 | Future versions of this function will allow result arguments. |
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191 | |
153 | =cut |
192 | =cut |
154 | |
193 | |
155 | sub terminate { |
194 | sub terminate { |
156 | &schedule; |
195 | my $self = $current; |
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196 | $self->{_results} = [@_]; |
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197 | $current = shift @ready || $idle; |
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198 | Coro::State::transfer(delete $self->{_coro_state}, $current); |
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199 | # cannot return |
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200 | die; |
157 | } |
201 | } |
158 | |
202 | |
159 | =back |
203 | =back |
160 | |
204 | |
161 | # dynamic methods |
205 | # dynamic methods |
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164 | |
208 | |
165 | These are the methods you can call on process objects. |
209 | These are the methods you can call on process objects. |
166 | |
210 | |
167 | =over 4 |
211 | =over 4 |
168 | |
212 | |
169 | =item new Coro \⊂ |
213 | =item new Coro \&sub [, @args...] |
170 | |
214 | |
171 | Create a new process and return it. When the sub returns the process |
215 | 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 |
216 | automatically terminates. To start the process you must first put it into |
173 | the ready queue by calling the ready method. |
217 | the ready queue by calling the ready method. |
174 | |
218 | |
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219 | The coderef you submit MUST NOT be a closure that refers to variables |
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220 | in an outer scope. This does NOT work. Pass arguments into it instead. |
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221 | |
175 | =cut |
222 | =cut |
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223 | |
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224 | sub _newcoro { |
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225 | terminate &{+shift}; |
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226 | } |
176 | |
227 | |
177 | sub new { |
228 | sub new { |
178 | my $class = shift; |
229 | my $class = shift; |
179 | my $proc = $_[0]; |
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180 | bless { |
230 | bless { |
181 | _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), |
231 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
182 | }, $class; |
232 | }, $class; |
183 | } |
233 | } |
184 | |
234 | |
185 | =item $process->ready |
235 | =item $process->ready |
186 | |
236 | |
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196 | |
246 | |
197 | =cut |
247 | =cut |
198 | |
248 | |
199 | 1; |
249 | 1; |
200 | |
250 | |
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251 | =head1 BUGS/LIMITATIONS |
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252 | |
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253 | - could be faster, especially when the core would introduce special |
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254 | support for coroutines (like it does for threads). |
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255 | - there is still a memleak on coroutine termination that I could not |
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256 | identify. Could be as small as a single SV. |
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257 | - this module is not well-tested. |
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258 | - if variables or arguments "disappear" (become undef) or become |
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259 | corrupted please contact the author so he cen iron out the |
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260 | remaining bugs. |
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261 | - this module is not thread-safe. You must only ever use this module from |
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262 | the same thread (this requirement might be loosened in the future to |
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263 | allow per-thread schedulers, but Coro::State does not yet allow this). |
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264 | |
201 | =head1 SEE ALSO |
265 | =head1 SEE ALSO |
202 | |
266 | |
203 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
267 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
204 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. |
268 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>. |
205 | |
269 | |