… | |
… | |
8 | |
8 | |
9 | async { |
9 | async { |
10 | # some asynchronous thread of execution |
10 | # some asynchronous thread of execution |
11 | }; |
11 | }; |
12 | |
12 | |
13 | # alternatively create an async process like this: |
13 | # alternatively create an async coroutine like this: |
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 | |
… | |
… | |
30 | |
30 | |
31 | =cut |
31 | =cut |
32 | |
32 | |
33 | package Coro; |
33 | package Coro; |
34 | |
34 | |
35 | BEGIN { eval { require warnings } && warnings->unimport ("uninitialized") } |
35 | use strict; |
|
|
36 | no warnings "uninitialized"; |
36 | |
37 | |
37 | use Coro::State; |
38 | use Coro::State; |
38 | |
39 | |
39 | use vars qw($idle $main $current); |
40 | use base qw(Coro::State Exporter); |
40 | |
41 | |
41 | use base Exporter; |
42 | our $idle; # idle handler |
|
|
43 | our $main; # main coroutine |
|
|
44 | our $current; # current coroutine |
42 | |
45 | |
43 | $VERSION = 0.95; |
46 | our $VERSION = '3.01'; |
44 | |
47 | |
45 | @EXPORT = qw(async cede schedule terminate current); |
48 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
46 | %EXPORT_TAGS = ( |
49 | our %EXPORT_TAGS = ( |
47 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
48 | ); |
51 | ); |
49 | @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
52 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
50 | |
53 | |
51 | { |
54 | { |
52 | my @async; |
55 | my @async; |
53 | my $init; |
56 | my $init; |
54 | |
57 | |
55 | # this way of handling attributes simply is NOT scalable ;() |
58 | # this way of handling attributes simply is NOT scalable ;() |
56 | sub import { |
59 | sub import { |
|
|
60 | no strict 'refs'; |
|
|
61 | |
57 | Coro->export_to_level(1, @_); |
62 | Coro->export_to_level (1, @_); |
|
|
63 | |
58 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
59 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
60 | my ($package, $ref) = (shift, shift); |
66 | my ($package, $ref) = (shift, shift); |
61 | my @attrs; |
67 | my @attrs; |
62 | for (@_) { |
68 | for (@_) { |
… | |
… | |
89 | |
95 | |
90 | $main = new Coro; |
96 | $main = new Coro; |
91 | |
97 | |
92 | =item $current (or as function: current) |
98 | =item $current (or as function: current) |
93 | |
99 | |
94 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
100 | The current coroutine (the last coroutine switched to). The initial value |
|
|
101 | is C<$main> (of course). |
|
|
102 | |
|
|
103 | This variable is B<strictly> I<read-only>. It is provided for performance |
|
|
104 | reasons. If performance is not essentiel you are encouraged to use the |
|
|
105 | C<Coro::current> function instead. |
95 | |
106 | |
96 | =cut |
107 | =cut |
97 | |
108 | |
98 | # maybe some other module used Coro::Specific before... |
109 | # maybe some other module used Coro::Specific before... |
99 | if ($current) { |
|
|
100 | $main->{specific} = $current->{specific}; |
110 | $main->{specific} = $current->{specific} |
101 | } |
111 | if $current; |
102 | |
112 | |
103 | $current = $main; |
113 | _set_current $main; |
104 | |
114 | |
105 | sub current() { $current } |
115 | sub current() { $current } |
106 | |
116 | |
107 | =item $idle |
117 | =item $idle |
108 | |
118 | |
109 | The coroutine to switch to when no other coroutine is running. The default |
119 | A callback that is called whenever the scheduler finds no ready coroutines |
110 | implementation prints "FATAL: deadlock detected" and exits. |
120 | to run. The default implementation prints "FATAL: deadlock detected" and |
|
|
121 | exits, because the program has no other way to continue. |
111 | |
122 | |
112 | =cut |
123 | This hook is overwritten by modules such as C<Coro::Timer> and |
|
|
124 | C<Coro::Event> to wait on an external event that hopefully wake up a |
|
|
125 | coroutine so the scheduler can run it. |
113 | |
126 | |
114 | # should be done using priorities :( |
127 | Please note that if your callback recursively invokes perl (e.g. for event |
115 | $idle = new Coro sub { |
128 | handlers), then it must be prepared to be called recursively. |
116 | print STDERR "FATAL: deadlock detected\n"; |
129 | |
117 | exit(51); |
130 | =cut |
|
|
131 | |
|
|
132 | $idle = sub { |
|
|
133 | require Carp; |
|
|
134 | Carp::croak ("FATAL: deadlock detected"); |
118 | }; |
135 | }; |
119 | |
136 | |
120 | # this coroutine is necessary because a coroutine |
137 | # this coroutine is necessary because a coroutine |
121 | # cannot destroy itself. |
138 | # cannot destroy itself. |
122 | my @destroy; |
139 | my @destroy; |
123 | my $manager; |
|
|
124 | $manager = new Coro sub { |
140 | my $manager; $manager = new Coro sub { |
125 | while () { |
141 | while () { |
126 | # by overwriting the state object with the manager we destroy it |
142 | # by overwriting the state object with the manager we destroy it |
127 | # while still being able to schedule this coroutine (in case it has |
143 | # while still being able to schedule this coroutine (in case it has |
128 | # been readied multiple times. this is harmless since the manager |
144 | # been readied multiple times. this is harmless since the manager |
129 | # can be called as many times as neccessary and will always |
145 | # can be called as many times as neccessary and will always |
… | |
… | |
131 | while (@destroy) { |
147 | while (@destroy) { |
132 | my $coro = pop @destroy; |
148 | my $coro = pop @destroy; |
133 | $coro->{status} ||= []; |
149 | $coro->{status} ||= []; |
134 | $_->ready for @{delete $coro->{join} || []}; |
150 | $_->ready for @{delete $coro->{join} || []}; |
135 | |
151 | |
136 | # the next line destroys the _coro_state, but keeps the |
152 | # the next line destroys the coro state, but keeps the |
137 | # process itself intact (we basically make it a zombie |
153 | # coroutine itself intact (we basically make it a zombie |
138 | # process that always runs the manager thread, so it's possible |
154 | # coroutine that always runs the manager thread, so it's possible |
139 | # to transfer() to this process). |
155 | # to transfer() to this coroutine). |
140 | $coro->{_coro_state} = $manager->{_coro_state}; |
156 | $coro->_clone_state_from ($manager); |
141 | } |
157 | } |
142 | &schedule; |
158 | &schedule; |
143 | } |
159 | } |
144 | }; |
160 | }; |
145 | |
161 | |
… | |
… | |
147 | |
163 | |
148 | =back |
164 | =back |
149 | |
165 | |
150 | =head2 STATIC METHODS |
166 | =head2 STATIC METHODS |
151 | |
167 | |
152 | Static methods are actually functions that operate on the current process only. |
168 | Static methods are actually functions that operate on the current coroutine only. |
153 | |
169 | |
154 | =over 4 |
170 | =over 4 |
155 | |
171 | |
156 | =item async { ... } [@args...] |
172 | =item async { ... } [@args...] |
157 | |
173 | |
158 | Create a new asynchronous process and return it's process object |
174 | Create a new asynchronous coroutine and return it's coroutine object |
159 | (usually unused). When the sub returns the new process is automatically |
175 | (usually unused). When the sub returns the new coroutine is automatically |
160 | terminated. |
176 | terminated. |
|
|
177 | |
|
|
178 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
|
|
179 | |
|
|
180 | When the coroutine dies, the program will exit, just as in the main |
|
|
181 | program. |
161 | |
182 | |
162 | # create a new coroutine that just prints its arguments |
183 | # create a new coroutine that just prints its arguments |
163 | async { |
184 | async { |
164 | print "@_\n"; |
185 | print "@_\n"; |
165 | } 1,2,3,4; |
186 | } 1,2,3,4; |
166 | |
187 | |
167 | =cut |
188 | =cut |
168 | |
189 | |
169 | sub async(&@) { |
190 | sub async(&@) { |
170 | my $pid = new Coro @_; |
191 | my $pid = new Coro @_; |
171 | $manager->ready; # this ensures that the stack is cloned from the manager |
|
|
172 | $pid->ready; |
192 | $pid->ready; |
173 | $pid; |
193 | $pid |
174 | } |
194 | } |
175 | |
195 | |
176 | =item schedule |
196 | =item schedule |
177 | |
197 | |
178 | Calls the scheduler. Please note that the current process will not be put |
198 | Calls the scheduler. Please note that the current coroutine will not be put |
179 | into the ready queue, so calling this function usually means you will |
199 | into the ready queue, so calling this function usually means you will |
180 | never be called again. |
200 | never be called again unless something else (e.g. an event handler) calls |
|
|
201 | ready. |
181 | |
202 | |
182 | =cut |
203 | The canonical way to wait on external events is this: |
|
|
204 | |
|
|
205 | { |
|
|
206 | # remember current coroutine |
|
|
207 | my $current = $Coro::current; |
|
|
208 | |
|
|
209 | # register a hypothetical event handler |
|
|
210 | on_event_invoke sub { |
|
|
211 | # wake up sleeping coroutine |
|
|
212 | $current->ready; |
|
|
213 | undef $current; |
|
|
214 | }; |
|
|
215 | |
|
|
216 | # call schedule until event occured. |
|
|
217 | # in case we are woken up for other reasons |
|
|
218 | # (current still defined), loop. |
|
|
219 | Coro::schedule while $current; |
|
|
220 | } |
183 | |
221 | |
184 | =item cede |
222 | =item cede |
185 | |
223 | |
186 | "Cede" to other processes. This function puts the current process into the |
224 | "Cede" to other coroutines. This function puts the current coroutine into the |
187 | ready queue and calls C<schedule>, which has the effect of giving up the |
225 | 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. |
226 | current "timeslice" to other coroutines of the same or higher priority. |
189 | |
227 | |
190 | =cut |
|
|
191 | |
|
|
192 | =item terminate [arg...] |
228 | =item terminate [arg...] |
193 | |
229 | |
194 | Terminates the current process with the given status values (see L<cancel>). |
230 | Terminates the current coroutine with the given status values (see L<cancel>). |
195 | |
231 | |
196 | =cut |
232 | =cut |
197 | |
233 | |
198 | sub terminate { |
234 | sub terminate { |
199 | $current->cancel (@_); |
235 | $current->cancel (@_); |
… | |
… | |
201 | |
237 | |
202 | =back |
238 | =back |
203 | |
239 | |
204 | # dynamic methods |
240 | # dynamic methods |
205 | |
241 | |
206 | =head2 PROCESS METHODS |
242 | =head2 COROUTINE METHODS |
207 | |
243 | |
208 | These are the methods you can call on process objects. |
244 | These are the methods you can call on coroutine objects. |
209 | |
245 | |
210 | =over 4 |
246 | =over 4 |
211 | |
247 | |
212 | =item new Coro \&sub [, @args...] |
248 | =item new Coro \&sub [, @args...] |
213 | |
249 | |
214 | Create a new process and return it. When the sub returns the process |
250 | Create a new coroutine and return it. When the sub returns the coroutine |
215 | automatically terminates as if C<terminate> with the returned values were |
251 | automatically terminates as if C<terminate> with the returned values were |
216 | called. To make the process run you must first put it into the ready queue |
252 | called. To make the coroutine run you must first put it into the ready queue |
217 | by calling the ready method. |
253 | by calling the ready method. |
218 | |
254 | |
219 | =cut |
255 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
220 | |
256 | |
|
|
257 | =cut |
|
|
258 | |
221 | sub _newcoro { |
259 | sub _run_coro { |
222 | terminate &{+shift}; |
260 | terminate &{+shift}; |
223 | } |
261 | } |
224 | |
262 | |
225 | sub new { |
263 | sub new { |
226 | my $class = shift; |
264 | my $class = shift; |
227 | bless { |
|
|
228 | _coro_state => (new Coro::State $_[0] && \&_newcoro, @_), |
|
|
229 | }, $class; |
|
|
230 | } |
|
|
231 | |
265 | |
232 | =item $process->ready |
266 | $class->SUPER::new (\&_run_coro, @_) |
|
|
267 | } |
233 | |
268 | |
234 | Put the given process into the ready queue. |
269 | =item $success = $coroutine->ready |
235 | |
270 | |
236 | =cut |
271 | Put the given coroutine into the ready queue (according to it's priority) |
|
|
272 | and return true. If the coroutine is already in the ready queue, do nothing |
|
|
273 | and return false. |
237 | |
274 | |
|
|
275 | =item $is_ready = $coroutine->is_ready |
|
|
276 | |
|
|
277 | Return wether the coroutine is currently the ready queue or not, |
|
|
278 | |
238 | =item $process->cancel (arg...) |
279 | =item $coroutine->cancel (arg...) |
239 | |
280 | |
240 | Temrinates the given process and makes it return the given arguments as |
281 | Terminates the given coroutine and makes it return the given arguments as |
241 | status (default: the empty list). |
282 | status (default: the empty list). |
242 | |
283 | |
243 | =cut |
284 | =cut |
244 | |
285 | |
245 | sub cancel { |
286 | sub cancel { |
… | |
… | |
248 | push @destroy, $self; |
289 | push @destroy, $self; |
249 | $manager->ready; |
290 | $manager->ready; |
250 | &schedule if $current == $self; |
291 | &schedule if $current == $self; |
251 | } |
292 | } |
252 | |
293 | |
253 | =item $process->join |
294 | =item $coroutine->join |
254 | |
295 | |
255 | Wait until the coroutine terminates and return any values given to the |
296 | Wait until the coroutine terminates and return any values given to the |
256 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
297 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
257 | from multiple processes. |
298 | from multiple coroutine. |
258 | |
299 | |
259 | =cut |
300 | =cut |
260 | |
301 | |
261 | sub join { |
302 | sub join { |
262 | my $self = shift; |
303 | my $self = shift; |
… | |
… | |
265 | &schedule; |
306 | &schedule; |
266 | } |
307 | } |
267 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
308 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
268 | } |
309 | } |
269 | |
310 | |
270 | =item $oldprio = $process->prio($newprio) |
311 | =item $oldprio = $coroutine->prio ($newprio) |
271 | |
312 | |
272 | Sets (or gets, if the argument is missing) the priority of the |
313 | Sets (or gets, if the argument is missing) the priority of the |
273 | process. Higher priority processes get run before lower priority |
314 | coroutine. Higher priority coroutines get run before lower priority |
274 | processes. Priorities are small signed integers (currently -4 .. +3), |
315 | coroutines. Priorities are small signed integers (currently -4 .. +3), |
275 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
316 | that you can refer to using PRIO_xxx constants (use the import tag :prio |
276 | to get then): |
317 | to get then): |
277 | |
318 | |
278 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
319 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
279 | 3 > 1 > 0 > -1 > -3 > -4 |
320 | 3 > 1 > 0 > -1 > -3 > -4 |
… | |
… | |
282 | current->prio(PRIO_HIGH); |
323 | current->prio(PRIO_HIGH); |
283 | |
324 | |
284 | The idle coroutine ($Coro::idle) always has a lower priority than any |
325 | The idle coroutine ($Coro::idle) always has a lower priority than any |
285 | existing coroutine. |
326 | existing coroutine. |
286 | |
327 | |
287 | Changing the priority of the current process will take effect immediately, |
328 | Changing the priority of the current coroutine will take effect immediately, |
288 | but changing the priority of processes in the ready queue (but not |
329 | but changing the priority of coroutines in the ready queue (but not |
289 | running) will only take effect after the next schedule (of that |
330 | 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. |
331 | coroutine). This is a bug that will be fixed in some future version. |
291 | |
332 | |
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) |
333 | =item $newprio = $coroutine->nice ($change) |
301 | |
334 | |
302 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
335 | Similar to C<prio>, but subtract the given value from the priority (i.e. |
303 | higher values mean lower priority, just as in unix). |
336 | higher values mean lower priority, just as in unix). |
304 | |
337 | |
305 | =cut |
|
|
306 | |
|
|
307 | sub nice { |
|
|
308 | $_[0]{prio} -= $_[1]; |
|
|
309 | } |
|
|
310 | |
|
|
311 | =item $olddesc = $process->desc($newdesc) |
338 | =item $olddesc = $coroutine->desc ($newdesc) |
312 | |
339 | |
313 | Sets (or gets in case the argument is missing) the description for this |
340 | 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. |
341 | coroutine. This is just a free-form string you can associate with a coroutine. |
315 | |
342 | |
316 | =cut |
343 | =cut |
317 | |
344 | |
318 | sub desc { |
345 | sub desc { |
319 | my $old = $_[0]{desc}; |
346 | my $old = $_[0]{desc}; |
… | |
… | |
321 | $old; |
348 | $old; |
322 | } |
349 | } |
323 | |
350 | |
324 | =back |
351 | =back |
325 | |
352 | |
|
|
353 | =head2 GLOBAL FUNCTIONS |
|
|
354 | |
|
|
355 | =over 4 |
|
|
356 | |
|
|
357 | =item Coro::nready |
|
|
358 | |
|
|
359 | Returns the number of coroutines that are currently in the ready state, |
|
|
360 | i.e. that can be swicthed to. The value C<0> means that the only runnable |
|
|
361 | coroutine is the currently running one, so C<cede> would have no effect, |
|
|
362 | and C<schedule> would cause a deadlock unless there is an idle handler |
|
|
363 | that wakes up some coroutines. |
|
|
364 | |
|
|
365 | =item unblock_sub { ... } |
|
|
366 | |
|
|
367 | This utility function takes a BLOCK or code reference and "unblocks" it, |
|
|
368 | returning the new coderef. This means that the new coderef will return |
|
|
369 | immediately without blocking, returning nothing, while the original code |
|
|
370 | ref will be called (with parameters) from within its own coroutine. |
|
|
371 | |
|
|
372 | The reason this fucntion exists is that many event libraries (such as the |
|
|
373 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
|
|
374 | of thread-safety). This means you must not block within event callbacks, |
|
|
375 | otherwise you might suffer from crashes or worse. |
|
|
376 | |
|
|
377 | This function allows your callbacks to block by executing them in another |
|
|
378 | coroutine where it is safe to block. One example where blocking is handy |
|
|
379 | is when you use the L<Coro::AIO|Coro::AIO> functions to save results to |
|
|
380 | disk. |
|
|
381 | |
|
|
382 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
|
|
383 | creating event callbacks that want to block. |
|
|
384 | |
|
|
385 | =cut |
|
|
386 | |
|
|
387 | our @unblock_pool; |
|
|
388 | our @unblock_queue; |
|
|
389 | our $UNBLOCK_POOL_SIZE = 2; |
|
|
390 | |
|
|
391 | sub unblock_handler_ { |
|
|
392 | while () { |
|
|
393 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
|
|
394 | $cb->(@arg); |
|
|
395 | |
|
|
396 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
|
|
397 | push @unblock_pool, $Coro::current; |
|
|
398 | schedule; |
|
|
399 | } |
|
|
400 | } |
|
|
401 | |
|
|
402 | our $unblock_scheduler = async { |
|
|
403 | while () { |
|
|
404 | while (my $cb = pop @unblock_queue) { |
|
|
405 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
|
|
406 | $handler->{arg} = $cb; |
|
|
407 | $handler->ready; |
|
|
408 | cede; |
|
|
409 | } |
|
|
410 | |
|
|
411 | schedule; |
|
|
412 | } |
|
|
413 | }; |
|
|
414 | |
|
|
415 | sub unblock_sub(&) { |
|
|
416 | my $cb = shift; |
|
|
417 | |
|
|
418 | sub { |
|
|
419 | push @unblock_queue, [$cb, @_]; |
|
|
420 | $unblock_scheduler->ready; |
|
|
421 | } |
|
|
422 | } |
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423 | |
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424 | =back |
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425 | |
326 | =cut |
426 | =cut |
327 | |
427 | |
328 | 1; |
428 | 1; |
329 | |
429 | |
330 | =head1 BUGS/LIMITATIONS |
430 | =head1 BUGS/LIMITATIONS |
… | |
… | |
337 | to allow per-thread schedulers, but Coro::State does not yet allow |
437 | to allow per-thread schedulers, but Coro::State does not yet allow |
338 | this). |
438 | this). |
339 | |
439 | |
340 | =head1 SEE ALSO |
440 | =head1 SEE ALSO |
341 | |
441 | |
342 | L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>, |
442 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
343 | L<Coro::Signal>, L<Coro::State>, L<Coro::Timer>, L<Coro::Event>, |
443 | |
344 | L<Coro::L<Coro::RWLock>, Handle>, L<Coro::Socket>. |
444 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
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445 | |
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446 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
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447 | |
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448 | Embedding: L<Coro:MakeMaker> |
345 | |
449 | |
346 | =head1 AUTHOR |
450 | =head1 AUTHOR |
347 | |
451 | |
348 | Marc Lehmann <pcg@goof.com> |
452 | Marc Lehmann <schmorp@schmorp.de> |
349 | http://www.goof.com/pcg/marc/ |
453 | http://home.schmorp.de/ |
350 | |
454 | |
351 | =cut |
455 | =cut |
352 | |
456 | |