1 |
root |
1.1 |
=head1 NAME |
2 |
|
|
|
3 |
root |
1.8 |
Coro - coroutine process abstraction |
4 |
root |
1.1 |
|
5 |
|
|
=head1 SYNOPSIS |
6 |
|
|
|
7 |
|
|
use Coro; |
8 |
|
|
|
9 |
root |
1.8 |
async { |
10 |
|
|
# some asynchronous thread of execution |
11 |
root |
1.2 |
}; |
12 |
|
|
|
13 |
root |
1.8 |
# alternatively create an async process like this: |
14 |
root |
1.6 |
|
15 |
root |
1.8 |
sub some_func : Coro { |
16 |
|
|
# some more async code |
17 |
|
|
} |
18 |
|
|
|
19 |
root |
1.22 |
cede; |
20 |
root |
1.2 |
|
21 |
root |
1.1 |
=head1 DESCRIPTION |
22 |
|
|
|
23 |
root |
1.14 |
This module collection manages coroutines. Coroutines are similar to |
24 |
root |
1.42 |
threads but don't run in parallel. |
25 |
root |
1.14 |
|
26 |
root |
1.20 |
In this module, coroutines are defined as "callchain + lexical variables |
27 |
root |
1.23 |
+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
28 |
|
|
callchain, it's own set of lexicals and it's own set of perl's most |
29 |
|
|
important global variables. |
30 |
root |
1.22 |
|
31 |
root |
1.8 |
=cut |
32 |
|
|
|
33 |
|
|
package Coro; |
34 |
|
|
|
35 |
pcg |
1.55 |
BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") } |
36 |
root |
1.36 |
|
37 |
root |
1.8 |
use Coro::State; |
38 |
|
|
|
39 |
pcg |
1.55 |
use vars qw($idle $main $current); |
40 |
|
|
|
41 |
root |
1.8 |
use base Exporter; |
42 |
|
|
|
43 |
pcg |
1.61 |
$VERSION = 0.97; |
44 |
root |
1.8 |
|
45 |
root |
1.22 |
@EXPORT = qw(async cede schedule terminate current); |
46 |
root |
1.31 |
%EXPORT_TAGS = ( |
47 |
|
|
prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
48 |
|
|
); |
49 |
|
|
@EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
50 |
root |
1.8 |
|
51 |
|
|
{ |
52 |
|
|
my @async; |
53 |
root |
1.26 |
my $init; |
54 |
root |
1.8 |
|
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, $ref; |
65 |
root |
1.26 |
unless ($init++) { |
66 |
|
|
eval q{ |
67 |
|
|
sub INIT { |
68 |
|
|
&async(pop @async) while @async; |
69 |
|
|
} |
70 |
|
|
}; |
71 |
|
|
} |
72 |
root |
1.8 |
} else { |
73 |
root |
1.17 |
push @attrs, $_; |
74 |
root |
1.8 |
} |
75 |
|
|
} |
76 |
root |
1.17 |
return $old ? $old->($package, $ref, @attrs) : @attrs; |
77 |
root |
1.8 |
}; |
78 |
|
|
} |
79 |
|
|
|
80 |
|
|
} |
81 |
|
|
|
82 |
root |
1.43 |
=over 4 |
83 |
|
|
|
84 |
root |
1.8 |
=item $main |
85 |
root |
1.2 |
|
86 |
root |
1.8 |
This coroutine represents the main program. |
87 |
root |
1.1 |
|
88 |
|
|
=cut |
89 |
|
|
|
90 |
pcg |
1.55 |
$main = new Coro; |
91 |
root |
1.8 |
|
92 |
root |
1.19 |
=item $current (or as function: current) |
93 |
root |
1.1 |
|
94 |
root |
1.8 |
The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
95 |
root |
1.1 |
|
96 |
root |
1.8 |
=cut |
97 |
|
|
|
98 |
|
|
# maybe some other module used Coro::Specific before... |
99 |
|
|
if ($current) { |
100 |
|
|
$main->{specific} = $current->{specific}; |
101 |
root |
1.1 |
} |
102 |
|
|
|
103 |
pcg |
1.55 |
$current = $main; |
104 |
root |
1.19 |
|
105 |
|
|
sub current() { $current } |
106 |
root |
1.9 |
|
107 |
|
|
=item $idle |
108 |
|
|
|
109 |
|
|
The coroutine to switch to when no other coroutine is running. The default |
110 |
|
|
implementation prints "FATAL: deadlock detected" and exits. |
111 |
|
|
|
112 |
|
|
=cut |
113 |
|
|
|
114 |
|
|
# should be done using priorities :( |
115 |
pcg |
1.55 |
$idle = new Coro sub { |
116 |
root |
1.9 |
print STDERR "FATAL: deadlock detected\n"; |
117 |
|
|
exit(51); |
118 |
|
|
}; |
119 |
root |
1.8 |
|
120 |
root |
1.24 |
# this coroutine is necessary because a coroutine |
121 |
|
|
# cannot destroy itself. |
122 |
|
|
my @destroy; |
123 |
root |
1.38 |
my $manager; |
124 |
|
|
$manager = new Coro sub { |
125 |
pcg |
1.57 |
while () { |
126 |
root |
1.37 |
# by overwriting the state object with the manager we destroy it |
127 |
|
|
# while still being able to schedule this coroutine (in case it has |
128 |
|
|
# been readied multiple times. this is harmless since the manager |
129 |
|
|
# can be called as many times as neccessary and will always |
130 |
|
|
# remove itself from the runqueue |
131 |
root |
1.40 |
while (@destroy) { |
132 |
|
|
my $coro = pop @destroy; |
133 |
|
|
$coro->{status} ||= []; |
134 |
|
|
$_->ready for @{delete $coro->{join} || []}; |
135 |
pcg |
1.59 |
|
136 |
|
|
# the next line destroys the _coro_state, but keeps the |
137 |
|
|
# process itself intact (we basically make it a zombie |
138 |
|
|
# process that always runs the manager thread, so it's possible |
139 |
|
|
# to transfer() to this process). |
140 |
root |
1.40 |
$coro->{_coro_state} = $manager->{_coro_state}; |
141 |
|
|
} |
142 |
root |
1.24 |
&schedule; |
143 |
|
|
} |
144 |
|
|
}; |
145 |
|
|
|
146 |
root |
1.8 |
# static methods. not really. |
147 |
root |
1.43 |
|
148 |
|
|
=back |
149 |
root |
1.8 |
|
150 |
|
|
=head2 STATIC METHODS |
151 |
|
|
|
152 |
|
|
Static methods are actually functions that operate on the current process only. |
153 |
|
|
|
154 |
|
|
=over 4 |
155 |
|
|
|
156 |
root |
1.13 |
=item async { ... } [@args...] |
157 |
root |
1.8 |
|
158 |
|
|
Create a new asynchronous process and return it's process object |
159 |
|
|
(usually unused). When the sub returns the new process is automatically |
160 |
|
|
terminated. |
161 |
|
|
|
162 |
root |
1.13 |
# create a new coroutine that just prints its arguments |
163 |
|
|
async { |
164 |
|
|
print "@_\n"; |
165 |
|
|
} 1,2,3,4; |
166 |
|
|
|
167 |
root |
1.8 |
=cut |
168 |
|
|
|
169 |
root |
1.13 |
sub async(&@) { |
170 |
|
|
my $pid = new Coro @_; |
171 |
root |
1.24 |
$manager->ready; # this ensures that the stack is cloned from the manager |
172 |
root |
1.11 |
$pid->ready; |
173 |
|
|
$pid; |
174 |
root |
1.8 |
} |
175 |
root |
1.1 |
|
176 |
root |
1.8 |
=item schedule |
177 |
root |
1.6 |
|
178 |
root |
1.8 |
Calls the scheduler. Please note that the current process will not be put |
179 |
|
|
into the ready queue, so calling this function usually means you will |
180 |
|
|
never be called again. |
181 |
root |
1.1 |
|
182 |
|
|
=cut |
183 |
|
|
|
184 |
root |
1.22 |
=item cede |
185 |
root |
1.1 |
|
186 |
root |
1.22 |
"Cede" to other processes. This function puts the current process into the |
187 |
|
|
ready queue and calls C<schedule>, which has the effect of giving up the |
188 |
|
|
current "timeslice" to other coroutines of the same or higher priority. |
189 |
root |
1.7 |
|
190 |
root |
1.8 |
=cut |
191 |
|
|
|
192 |
root |
1.40 |
=item terminate [arg...] |
193 |
root |
1.7 |
|
194 |
pcg |
1.59 |
Terminates the current process with the given status values (see L<cancel>). |
195 |
root |
1.13 |
|
196 |
root |
1.1 |
=cut |
197 |
|
|
|
198 |
root |
1.8 |
sub terminate { |
199 |
pcg |
1.59 |
$current->cancel (@_); |
200 |
root |
1.1 |
} |
201 |
root |
1.6 |
|
202 |
root |
1.8 |
=back |
203 |
|
|
|
204 |
|
|
# dynamic methods |
205 |
|
|
|
206 |
|
|
=head2 PROCESS METHODS |
207 |
|
|
|
208 |
|
|
These are the methods you can call on process objects. |
209 |
root |
1.6 |
|
210 |
root |
1.8 |
=over 4 |
211 |
|
|
|
212 |
root |
1.13 |
=item new Coro \&sub [, @args...] |
213 |
root |
1.8 |
|
214 |
|
|
Create a new process and return it. When the sub returns the process |
215 |
root |
1.40 |
automatically terminates as if C<terminate> with the returned values were |
216 |
root |
1.41 |
called. To make the process run you must first put it into the ready queue |
217 |
|
|
by calling the ready method. |
218 |
root |
1.13 |
|
219 |
root |
1.6 |
=cut |
220 |
|
|
|
221 |
root |
1.13 |
sub _newcoro { |
222 |
|
|
terminate &{+shift}; |
223 |
|
|
} |
224 |
|
|
|
225 |
root |
1.8 |
sub new { |
226 |
|
|
my $class = shift; |
227 |
|
|
bless { |
228 |
root |
1.13 |
_coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
229 |
root |
1.8 |
}, $class; |
230 |
|
|
} |
231 |
root |
1.6 |
|
232 |
root |
1.8 |
=item $process->ready |
233 |
root |
1.1 |
|
234 |
root |
1.39 |
Put the given process into the ready queue. |
235 |
root |
1.1 |
|
236 |
root |
1.8 |
=cut |
237 |
root |
1.28 |
|
238 |
pcg |
1.59 |
=item $process->cancel (arg...) |
239 |
root |
1.28 |
|
240 |
pcg |
1.59 |
Temrinates the given process and makes it return the given arguments as |
241 |
|
|
status (default: the empty list). |
242 |
root |
1.28 |
|
243 |
|
|
=cut |
244 |
|
|
|
245 |
|
|
sub cancel { |
246 |
pcg |
1.59 |
my $self = shift; |
247 |
|
|
$self->{status} = [@_]; |
248 |
|
|
push @destroy, $self; |
249 |
root |
1.28 |
$manager->ready; |
250 |
pcg |
1.59 |
&schedule if $current == $self; |
251 |
root |
1.40 |
} |
252 |
|
|
|
253 |
|
|
=item $process->join |
254 |
|
|
|
255 |
|
|
Wait until the coroutine terminates and return any values given to the |
256 |
pcg |
1.59 |
C<terminate> or C<cancel> functions. C<join> can be called multiple times |
257 |
|
|
from multiple processes. |
258 |
root |
1.40 |
|
259 |
|
|
=cut |
260 |
|
|
|
261 |
|
|
sub join { |
262 |
|
|
my $self = shift; |
263 |
|
|
unless ($self->{status}) { |
264 |
|
|
push @{$self->{join}}, $current; |
265 |
|
|
&schedule; |
266 |
|
|
} |
267 |
|
|
wantarray ? @{$self->{status}} : $self->{status}[0]; |
268 |
root |
1.31 |
} |
269 |
|
|
|
270 |
|
|
=item $oldprio = $process->prio($newprio) |
271 |
|
|
|
272 |
root |
1.41 |
Sets (or gets, if the argument is missing) the priority of the |
273 |
|
|
process. Higher priority processes get run before lower priority |
274 |
root |
1.52 |
processes. Priorities are small signed integers (currently -4 .. +3), |
275 |
root |
1.41 |
that you can refer to using PRIO_xxx constants (use the import tag :prio |
276 |
|
|
to get then): |
277 |
root |
1.31 |
|
278 |
|
|
PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
279 |
|
|
3 > 1 > 0 > -1 > -3 > -4 |
280 |
|
|
|
281 |
|
|
# set priority to HIGH |
282 |
|
|
current->prio(PRIO_HIGH); |
283 |
|
|
|
284 |
|
|
The idle coroutine ($Coro::idle) always has a lower priority than any |
285 |
|
|
existing coroutine. |
286 |
|
|
|
287 |
|
|
Changing the priority of the current process will take effect immediately, |
288 |
|
|
but changing the priority of processes in the ready queue (but not |
289 |
|
|
running) will only take effect after the next schedule (of that |
290 |
|
|
process). This is a bug that will be fixed in some future version. |
291 |
|
|
|
292 |
|
|
=cut |
293 |
|
|
|
294 |
|
|
sub prio { |
295 |
|
|
my $old = $_[0]{prio}; |
296 |
|
|
$_[0]{prio} = $_[1] if @_ > 1; |
297 |
|
|
$old; |
298 |
|
|
} |
299 |
|
|
|
300 |
|
|
=item $newprio = $process->nice($change) |
301 |
|
|
|
302 |
|
|
Similar to C<prio>, but subtract the given value from the priority (i.e. |
303 |
|
|
higher values mean lower priority, just as in unix). |
304 |
|
|
|
305 |
|
|
=cut |
306 |
|
|
|
307 |
|
|
sub nice { |
308 |
|
|
$_[0]{prio} -= $_[1]; |
309 |
root |
1.41 |
} |
310 |
|
|
|
311 |
|
|
=item $olddesc = $process->desc($newdesc) |
312 |
|
|
|
313 |
|
|
Sets (or gets in case the argument is missing) the description for this |
314 |
|
|
process. This is just a free-form string you can associate with a process. |
315 |
|
|
|
316 |
|
|
=cut |
317 |
|
|
|
318 |
|
|
sub desc { |
319 |
|
|
my $old = $_[0]{desc}; |
320 |
|
|
$_[0]{desc} = $_[1] if @_ > 1; |
321 |
|
|
$old; |
322 |
root |
1.8 |
} |
323 |
root |
1.1 |
|
324 |
root |
1.8 |
=back |
325 |
root |
1.2 |
|
326 |
root |
1.8 |
=cut |
327 |
root |
1.2 |
|
328 |
root |
1.8 |
1; |
329 |
root |
1.14 |
|
330 |
root |
1.17 |
=head1 BUGS/LIMITATIONS |
331 |
root |
1.14 |
|
332 |
root |
1.52 |
- you must make very sure that no coro is still active on global |
333 |
root |
1.53 |
destruction. very bad things might happen otherwise (usually segfaults). |
334 |
root |
1.52 |
|
335 |
|
|
- this module is not thread-safe. You should only ever use this module |
336 |
|
|
from the same thread (this requirement might be losened in the future |
337 |
|
|
to allow per-thread schedulers, but Coro::State does not yet allow |
338 |
|
|
this). |
339 |
root |
1.9 |
|
340 |
|
|
=head1 SEE ALSO |
341 |
|
|
|
342 |
|
|
L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
343 |
pcg |
1.54 |
L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>, |
344 |
root |
1.62 |
L<Coro::Handle>, L<Coro::RWLock>, L<Coro::Socket>. |
345 |
root |
1.1 |
|
346 |
|
|
=head1 AUTHOR |
347 |
|
|
|
348 |
|
|
Marc Lehmann <pcg@goof.com> |
349 |
|
|
http://www.goof.com/pcg/marc/ |
350 |
|
|
|
351 |
|
|
=cut |
352 |
|
|
|