| 1 | =head1 NAME |
1 | =head1 NAME |
| 2 | |
2 | |
| 3 | Coro - create an manage coroutines |
3 | Coro - coroutine process abstraction |
| 4 | |
4 | |
| 5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
| 6 | |
6 | |
| 7 | use Coro; |
7 | use Coro; |
| 8 | |
8 | |
|
|
9 | async { |
|
|
10 | # some asynchronous thread of execution |
|
|
11 | }; |
|
|
12 | |
|
|
13 | # alternatively create an async process like this: |
|
|
14 | |
|
|
15 | sub some_func : Coro { |
|
|
16 | # some more async code |
|
|
17 | } |
|
|
18 | |
|
|
19 | cede; |
|
|
20 | |
| 9 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
| 10 | |
22 | |
|
|
23 | This module collection manages coroutines. Coroutines are similar to |
|
|
24 | Threads but don't run in parallel. |
|
|
25 | |
|
|
26 | This module is still experimental, see the BUGS section below. |
|
|
27 | |
|
|
28 | In this module, coroutines are defined as "callchain + lexical variables |
|
|
29 | + @_ + $_ + $@ + $^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 |
|
|
31 | important global variables. |
|
|
32 | |
|
|
33 | =cut |
|
|
34 | |
|
|
35 | package Coro; |
|
|
36 | |
|
|
37 | no warnings qw(uninitialized); |
|
|
38 | |
|
|
39 | use Coro::State; |
|
|
40 | |
|
|
41 | use base Exporter; |
|
|
42 | |
|
|
43 | $VERSION = 0.52; |
|
|
44 | |
|
|
45 | @EXPORT = qw(async cede schedule terminate current); |
|
|
46 | %EXPORT_TAGS = ( |
|
|
47 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
|
|
48 | ); |
|
|
49 | @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
|
|
50 | |
|
|
51 | { |
|
|
52 | my @async; |
|
|
53 | my $init; |
|
|
54 | |
|
|
55 | # this way of handling attributes simply is NOT scalable ;() |
|
|
56 | sub import { |
|
|
57 | Coro->export_to_level(1, @_); |
|
|
58 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
|
|
59 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
|
|
60 | my ($package, $ref) = (shift, shift); |
|
|
61 | my @attrs; |
|
|
62 | for (@_) { |
|
|
63 | if ($_ eq "Coro") { |
|
|
64 | push @async, $ref; |
|
|
65 | unless ($init++) { |
|
|
66 | eval q{ |
|
|
67 | sub INIT { |
|
|
68 | &async(pop @async) while @async; |
|
|
69 | } |
|
|
70 | }; |
|
|
71 | } |
|
|
72 | } else { |
|
|
73 | push @attrs, $_; |
|
|
74 | } |
|
|
75 | } |
|
|
76 | return $old ? $old->($package, $ref, @attrs) : @attrs; |
|
|
77 | }; |
|
|
78 | } |
|
|
79 | |
|
|
80 | } |
|
|
81 | |
|
|
82 | =item $main |
|
|
83 | |
|
|
84 | This coroutine represents the main program. |
|
|
85 | |
|
|
86 | =cut |
|
|
87 | |
|
|
88 | our $main = new Coro; |
|
|
89 | |
|
|
90 | =item $current (or as function: current) |
|
|
91 | |
|
|
92 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
|
|
93 | |
|
|
94 | =cut |
|
|
95 | |
|
|
96 | # maybe some other module used Coro::Specific before... |
|
|
97 | if ($current) { |
|
|
98 | $main->{specific} = $current->{specific}; |
|
|
99 | } |
|
|
100 | |
|
|
101 | our $current = $main; |
|
|
102 | |
|
|
103 | sub current() { $current } |
|
|
104 | |
|
|
105 | =item $idle |
|
|
106 | |
|
|
107 | The coroutine to switch to when no other coroutine is running. The default |
|
|
108 | implementation prints "FATAL: deadlock detected" and exits. |
|
|
109 | |
|
|
110 | =cut |
|
|
111 | |
|
|
112 | # should be done using priorities :( |
|
|
113 | our $idle = new Coro sub { |
|
|
114 | print STDERR "FATAL: deadlock detected\n"; |
|
|
115 | exit(51); |
|
|
116 | }; |
|
|
117 | |
|
|
118 | # this coroutine is necessary because a coroutine |
|
|
119 | # cannot destroy itself. |
|
|
120 | my @destroy; |
|
|
121 | my $manager; |
|
|
122 | $manager = new Coro sub { |
|
|
123 | while() { |
|
|
124 | # by overwriting the state object with the manager we destroy it |
|
|
125 | # while still being able to schedule this coroutine (in case it has |
|
|
126 | # been readied multiple times. this is harmless since the manager |
|
|
127 | # can be called as many times as neccessary and will always |
|
|
128 | # remove itself from the runqueue |
|
|
129 | while (@destroy) { |
|
|
130 | my $coro = pop @destroy; |
|
|
131 | $coro->{status} ||= []; |
|
|
132 | $_->ready for @{delete $coro->{join} || []}; |
|
|
133 | $coro->{_coro_state} = $manager->{_coro_state}; |
|
|
134 | } |
|
|
135 | &schedule; |
|
|
136 | } |
|
|
137 | }; |
|
|
138 | |
|
|
139 | # static methods. not really. |
|
|
140 | |
|
|
141 | =head2 STATIC METHODS |
|
|
142 | |
|
|
143 | Static methods are actually functions that operate on the current process only. |
|
|
144 | |
| 11 | =over 4 |
145 | =over 4 |
| 12 | |
146 | |
| 13 | =cut |
147 | =item async { ... } [@args...] |
| 14 | |
148 | |
| 15 | package Coro; |
149 | Create a new asynchronous process and return it's process object |
|
|
150 | (usually unused). When the sub returns the new process is automatically |
|
|
151 | terminated. |
| 16 | |
152 | |
| 17 | BEGIN { |
153 | # create a new coroutine that just prints its arguments |
| 18 | $VERSION = 0.01; |
154 | async { |
|
|
155 | print "@_\n"; |
|
|
156 | } 1,2,3,4; |
| 19 | |
157 | |
| 20 | require XSLoader; |
158 | The coderef you submit MUST NOT be a closure that refers to variables |
| 21 | XSLoader::load Coro, $VERSION; |
159 | in an outer scope. This does NOT work. Pass arguments into it instead. |
| 22 | } |
|
|
| 23 | |
160 | |
| 24 | =item $main |
|
|
| 25 | |
|
|
| 26 | This coroutine represents the main program. |
|
|
| 27 | |
|
|
| 28 | =item $current |
|
|
| 29 | |
|
|
| 30 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
|
|
| 31 | |
|
|
| 32 | =cut |
161 | =cut |
| 33 | |
162 | |
| 34 | $main = $current = _newprocess { |
163 | sub async(&@) { |
| 35 | # never being called |
164 | my $pid = new Coro @_; |
| 36 | }; |
165 | $manager->ready; # this ensures that the stack is cloned from the manager |
|
|
166 | $pid->ready; |
|
|
167 | $pid; |
|
|
168 | } |
| 37 | |
169 | |
| 38 | =item $error, $error_msg, $error_coro |
170 | =item schedule |
| 39 | |
171 | |
| 40 | This coroutine will be called on fatal errors. C<$error_msg> and |
172 | Calls the scheduler. Please note that the current process will not be put |
| 41 | C<$error_coro> return the error message and the error-causing coroutine, |
173 | into the ready queue, so calling this function usually means you will |
| 42 | respectively. |
174 | never be called again. |
| 43 | |
175 | |
| 44 | =cut |
176 | =cut |
| 45 | |
177 | |
| 46 | $error_msg = |
178 | =item cede |
| 47 | $error_coro = undef; |
|
|
| 48 | |
179 | |
| 49 | $error = _newprocess { |
180 | "Cede" to other processes. This function puts the current process into the |
| 50 | print STDERR "FATAL: $error_msg, program aborted\n"; |
181 | ready queue and calls C<schedule>, which has the effect of giving up the |
| 51 | exit 250; |
182 | current "timeslice" to other coroutines of the same or higher priority. |
| 52 | }; |
|
|
| 53 | |
183 | |
| 54 | =item $coro = new $coderef [, @args] |
|
|
| 55 | |
|
|
| 56 | Create a new coroutine and return it. The first C<resume> call to this |
|
|
| 57 | coroutine will start execution at the given coderef. If it returns it |
|
|
| 58 | should return a coroutine to switch to. If, after returning, the coroutine |
|
|
| 59 | is C<resume>d again it starts execution again at the givne coderef. |
|
|
| 60 | |
|
|
| 61 | =cut |
184 | =cut |
|
|
185 | |
|
|
186 | =item terminate [arg...] |
|
|
187 | |
|
|
188 | Terminates the current process. |
|
|
189 | |
|
|
190 | Future versions of this function will allow result arguments. |
|
|
191 | |
|
|
192 | =cut |
|
|
193 | |
|
|
194 | sub terminate { |
|
|
195 | $current->{status} = [@_]; |
|
|
196 | $current->cancel; |
|
|
197 | &schedule; |
|
|
198 | die; # NORETURN |
|
|
199 | } |
|
|
200 | |
|
|
201 | =back |
|
|
202 | |
|
|
203 | # dynamic methods |
|
|
204 | |
|
|
205 | =head2 PROCESS METHODS |
|
|
206 | |
|
|
207 | These are the methods you can call on process objects. |
|
|
208 | |
|
|
209 | =over 4 |
|
|
210 | |
|
|
211 | =item new Coro \&sub [, @args...] |
|
|
212 | |
|
|
213 | Create a new process and return it. When the sub returns the process |
|
|
214 | automatically terminates as if C<terminate> with the returned values were |
|
|
215 | called. To make the process run you must first put it into the ready queue |
|
|
216 | by calling the ready method. |
|
|
217 | |
|
|
218 | =cut |
|
|
219 | |
|
|
220 | sub _newcoro { |
|
|
221 | terminate &{+shift}; |
|
|
222 | } |
| 62 | |
223 | |
| 63 | sub new { |
224 | sub new { |
| 64 | my $class = $_[0]; |
225 | my $class = shift; |
| 65 | my $proc = $_[1]; |
226 | bless { |
| 66 | bless _newprocess { |
227 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
| 67 | do { |
|
|
| 68 | eval { &$proc->resume }; |
|
|
| 69 | if ($@) { |
|
|
| 70 | ($error_msg, $error_coro) = ($@, $current); |
|
|
| 71 | $error->resume; |
|
|
| 72 | } |
|
|
| 73 | } while (); |
|
|
| 74 | }, $class; |
228 | }, $class; |
| 75 | } |
229 | } |
| 76 | |
230 | |
| 77 | =item $coro->resume |
231 | =item $process->ready |
| 78 | |
232 | |
| 79 | Resume execution at the given coroutine. |
233 | Put the given process into the ready queue. |
| 80 | |
234 | |
| 81 | =cut |
235 | =cut |
| 82 | |
236 | |
| 83 | my $prev; |
237 | =item $process->cancel |
| 84 | |
238 | |
| 85 | sub resume { |
239 | Like C<terminate>, but terminates the specified process instead. |
| 86 | $prev = $current; $current = $_[0]; |
240 | |
| 87 | _transfer($prev, $current); |
241 | =cut |
|
|
242 | |
|
|
243 | sub cancel { |
|
|
244 | push @destroy, $_[0]; |
|
|
245 | $manager->ready; |
|
|
246 | &schedule if $current == $_[0]; |
| 88 | } |
247 | } |
|
|
248 | |
|
|
249 | =item $process->join |
|
|
250 | |
|
|
251 | Wait until the coroutine terminates and return any values given to the |
|
|
252 | C<terminate> function. C<join> can be called multiple times from multiple |
|
|
253 | processes. |
|
|
254 | |
|
|
255 | =cut |
|
|
256 | |
|
|
257 | sub join { |
|
|
258 | my $self = shift; |
|
|
259 | unless ($self->{status}) { |
|
|
260 | push @{$self->{join}}, $current; |
|
|
261 | &schedule; |
|
|
262 | } |
|
|
263 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
|
|
264 | } |
|
|
265 | |
|
|
266 | =item $oldprio = $process->prio($newprio) |
|
|
267 | |
|
|
268 | Sets (or gets, if the argument is missing) the priority of the |
|
|
269 | process. Higher priority processes get run before lower priority |
|
|
270 | processes. Priorities are smalled signed integer (currently -4 .. +3), |
|
|
271 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
|
|
272 | to get then): |
|
|
273 | |
|
|
274 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
|
|
275 | 3 > 1 > 0 > -1 > -3 > -4 |
|
|
276 | |
|
|
277 | # set priority to HIGH |
|
|
278 | current->prio(PRIO_HIGH); |
|
|
279 | |
|
|
280 | The idle coroutine ($Coro::idle) always has a lower priority than any |
|
|
281 | existing coroutine. |
|
|
282 | |
|
|
283 | Changing the priority of the current process will take effect immediately, |
|
|
284 | but changing the priority of processes in the ready queue (but not |
|
|
285 | running) will only take effect after the next schedule (of that |
|
|
286 | process). This is a bug that will be fixed in some future version. |
|
|
287 | |
|
|
288 | =cut |
|
|
289 | |
|
|
290 | sub prio { |
|
|
291 | my $old = $_[0]{prio}; |
|
|
292 | $_[0]{prio} = $_[1] if @_ > 1; |
|
|
293 | $old; |
|
|
294 | } |
|
|
295 | |
|
|
296 | =item $newprio = $process->nice($change) |
|
|
297 | |
|
|
298 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
|
|
299 | higher values mean lower priority, just as in unix). |
|
|
300 | |
|
|
301 | =cut |
|
|
302 | |
|
|
303 | sub nice { |
|
|
304 | $_[0]{prio} -= $_[1]; |
|
|
305 | } |
|
|
306 | |
|
|
307 | =item $olddesc = $process->desc($newdesc) |
|
|
308 | |
|
|
309 | Sets (or gets in case the argument is missing) the description for this |
|
|
310 | process. This is just a free-form string you can associate with a process. |
|
|
311 | |
|
|
312 | =cut |
|
|
313 | |
|
|
314 | sub desc { |
|
|
315 | my $old = $_[0]{desc}; |
|
|
316 | $_[0]{desc} = $_[1] if @_ > 1; |
|
|
317 | $old; |
|
|
318 | } |
|
|
319 | |
|
|
320 | =back |
|
|
321 | |
|
|
322 | =cut |
| 89 | |
323 | |
| 90 | 1; |
324 | 1; |
| 91 | |
325 | |
| 92 | =back |
326 | =head1 BUGS/LIMITATIONS |
| 93 | |
327 | |
| 94 | =head1 BUGS |
328 | - you must make very sure that no coro is still active on global destruction. |
|
|
329 | very bad things might happen otherwise (usually segfaults). |
|
|
330 | - this module is not thread-safe. You must only ever use this module from |
|
|
331 | the same thread (this requirement might be loosened in the future to |
|
|
332 | allow per-thread schedulers, but Coro::State does not yet allow this). |
| 95 | |
333 | |
| 96 | This module has not yet been extensively tested. |
334 | =head1 SEE ALSO |
|
|
335 | |
|
|
336 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
|
|
337 | L<Coro::Signal>, L<Coro::State>, L<Coro::Event>, L<Coro::RWLock>, |
|
|
338 | L<Coro::Handle>, L<Coro::Socket>. |
| 97 | |
339 | |
| 98 | =head1 AUTHOR |
340 | =head1 AUTHOR |
| 99 | |
341 | |
| 100 | Marc Lehmann <pcg@goof.com> |
342 | Marc Lehmann <pcg@goof.com> |
| 101 | http://www.goof.com/pcg/marc/ |
343 | http://www.goof.com/pcg/marc/ |
