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Revision 1.132 by root, Thu Sep 20 22:53:23 2007 UTC vs.
Revision 1.179 by root, Sat Apr 19 19:06:02 2008 UTC

2 2
3Coro - coroutine process abstraction 3Coro - coroutine process abstraction
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use Coro; 7 use Coro;
8 8
9 async { 9 async {
10 # some asynchronous thread of execution 10 # some asynchronous thread of execution
11 print "2\n";
12 cede; # yield back to main
13 print "4\n";
11 }; 14 };
12 15 print "1\n";
13 # alternatively create an async coroutine like this: 16 cede; # yield to coroutine
14 17 print "3\n";
15 sub some_func : Coro { 18 cede; # and again
16 # some more async code 19
17 } 20 # use locking
18 21 my $lock = new Coro::Semaphore;
19 cede; 22 my $locked;
23
24 $lock->down;
25 $locked = 1;
26 $lock->up;
20 27
21=head1 DESCRIPTION 28=head1 DESCRIPTION
22 29
23This module collection manages coroutines. Coroutines are similar 30This module collection manages coroutines. Coroutines are similar
24to threads but don't run in parallel at the same time even on SMP 31to threads but don't run in parallel at the same time even on SMP
33is a performance win on Windows machines, and a loss everywhere else). 40is a performance win on Windows machines, and a loss everywhere else).
34 41
35In this module, coroutines are defined as "callchain + lexical variables + 42In this module, coroutines are defined as "callchain + lexical variables +
36@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, 43@_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain,
37its own set of lexicals and its own set of perls most important global 44its own set of lexicals and its own set of perls most important global
38variables. 45variables (see L<Coro::State> for more configuration).
39 46
40=cut 47=cut
41 48
42package Coro; 49package Coro;
43 50
50 57
51our $idle; # idle handler 58our $idle; # idle handler
52our $main; # main coroutine 59our $main; # main coroutine
53our $current; # current coroutine 60our $current; # current coroutine
54 61
55our $VERSION = '3.7'; 62our $VERSION = '4.51';
56 63
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 64our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 65our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 66 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 67);
61our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); 68our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready));
62 69
63{
64 my @async;
65 my $init;
66
67 # this way of handling attributes simply is NOT scalable ;()
68 sub import {
69 no strict 'refs';
70
71 Coro->export_to_level (1, @_);
72
73 my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
74 *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
75 my ($package, $ref) = (shift, shift);
76 my @attrs;
77 for (@_) {
78 if ($_ eq "Coro") {
79 push @async, $ref;
80 unless ($init++) {
81 eval q{
82 sub INIT {
83 &async(pop @async) while @async;
84 }
85 };
86 }
87 } else {
88 push @attrs, $_;
89 }
90 }
91 return $old ? $old->($package, $ref, @attrs) : @attrs;
92 };
93 }
94
95}
96
97=over 4 70=over 4
98 71
99=item $main 72=item $main
100 73
101This coroutine represents the main program. 74This coroutine represents the main program.
116=cut 89=cut
117 90
118$main->{desc} = "[main::]"; 91$main->{desc} = "[main::]";
119 92
120# maybe some other module used Coro::Specific before... 93# maybe some other module used Coro::Specific before...
121$main->{specific} = $current->{specific} 94$main->{_specific} = $current->{_specific}
122 if $current; 95 if $current;
123 96
124_set_current $main; 97_set_current $main;
125 98
126sub current() { $current } 99sub current() { $current }
134This hook is overwritten by modules such as C<Coro::Timer> and 107This hook is overwritten by modules such as C<Coro::Timer> and
135C<Coro::Event> to wait on an external event that hopefully wake up a 108C<Coro::Event> to wait on an external event that hopefully wake up a
136coroutine so the scheduler can run it. 109coroutine so the scheduler can run it.
137 110
138Please note that if your callback recursively invokes perl (e.g. for event 111Please note that if your callback recursively invokes perl (e.g. for event
139handlers), then it must be prepared to be called recursively. 112handlers), then it must be prepared to be called recursively itself.
140 113
141=cut 114=cut
142 115
143$idle = sub { 116$idle = sub {
144 require Carp; 117 require Carp;
151 # free coroutine data and mark as destructed 124 # free coroutine data and mark as destructed
152 $self->_destroy 125 $self->_destroy
153 or return; 126 or return;
154 127
155 # call all destruction callbacks 128 # call all destruction callbacks
156 $_->(@{$self->{status}}) 129 $_->(@{$self->{_status}})
157 for @{(delete $self->{destroy_cb}) || []}; 130 for @{(delete $self->{_on_destroy}) || []};
158} 131}
159 132
160# this coroutine is necessary because a coroutine 133# this coroutine is necessary because a coroutine
161# cannot destroy itself. 134# cannot destroy itself.
162my @destroy; 135my @destroy;
171 } 144 }
172}; 145};
173$manager->desc ("[coro manager]"); 146$manager->desc ("[coro manager]");
174$manager->prio (PRIO_MAX); 147$manager->prio (PRIO_MAX);
175 148
176# static methods. not really.
177
178=back 149=back
179 150
180=head2 STATIC METHODS 151=head2 STATIC METHODS
181 152
182Static methods are actually functions that operate on the current coroutine only. 153Static methods are actually functions that operate on the current coroutine only.
186=item async { ... } [@args...] 157=item async { ... } [@args...]
187 158
188Create a new asynchronous coroutine and return it's coroutine object 159Create a new asynchronous coroutine and return it's coroutine object
189(usually unused). When the sub returns the new coroutine is automatically 160(usually unused). When the sub returns the new coroutine is automatically
190terminated. 161terminated.
162
163See the C<Coro::State::new> constructor for info about the coroutine
164environment in which coroutines run.
191 165
192Calling C<exit> in a coroutine will do the same as calling exit outside 166Calling C<exit> in a coroutine will do the same as calling exit outside
193the coroutine. Likewise, when the coroutine dies, the program will exit, 167the coroutine. Likewise, when the coroutine dies, the program will exit,
194just as it would in the main program. 168just as it would in the main program.
195 169
216issued in case of an exception instead of terminating the program, as 190issued in case of an exception instead of terminating the program, as
217C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 191C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
218will not work in the expected way, unless you call terminate or cancel, 192will not work in the expected way, unless you call terminate or cancel,
219which somehow defeats the purpose of pooling. 193which somehow defeats the purpose of pooling.
220 194
221The priority will be reset to C<0> after each job, otherwise the coroutine 195The priority will be reset to C<0> after each job, tracing will be
222will be re-used "as-is". 196disabled, the description will be reset and the default output filehandle
197gets restored, so you can change alkl these. Otherwise the coroutine will
198be re-used "as-is": most notably if you change other per-coroutine global
199stuff such as C<$/> you need to revert that change, which is most simply
200done by using local as in C< local $/ >.
223 201
224The pool size is limited to 8 idle coroutines (this can be adjusted by 202The pool size is limited to 8 idle coroutines (this can be adjusted by
225changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 203changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
226required. 204required.
227 205
228If you are concerned about pooled coroutines growing a lot because a 206If you are concerned about pooled coroutines growing a lot because a
229single C<async_pool> used a lot of stackspace you can e.g. C<async_pool { 207single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
230terminate }> once per second or so to slowly replenish the pool. 208{ terminate }> once per second or so to slowly replenish the pool. In
209addition to that, when the stacks used by a handler grows larger than 16kb
210(adjustable with $Coro::POOL_RSS) it will also exit.
231 211
232=cut 212=cut
233 213
234our $POOL_SIZE = 8; 214our $POOL_SIZE = 8;
235our $MAX_POOL_RSS = 64 * 1024; 215our $POOL_RSS = 16 * 1024;
236our @pool; 216our @async_pool;
237 217
238sub pool_handler { 218sub pool_handler {
219 my $cb;
220
239 while () { 221 while () {
240 $current->{desc} = "[async_pool]";
241
242 eval { 222 eval {
243 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 223 while () {
244 $cb->(@arg); 224 _pool_1 $cb;
225 &$cb;
226 _pool_2 $cb;
227 &schedule;
228 }
245 }; 229 };
230
231 last if $@ eq "\3async_pool terminate\2\n";
246 warn $@ if $@; 232 warn $@ if $@;
247
248 last if @pool >= $POOL_SIZE || $current->rss >= $MAX_POOL_RSS;
249
250 push @pool, $current;
251 $current->{desc} = "[async_pool idle]";
252 $current->save (Coro::State::SAVE_DEF);
253 $current->prio (0);
254 schedule;
255 } 233 }
256} 234}
257 235
258sub async_pool(&@) { 236sub async_pool(&@) {
259 # this is also inlined into the unlock_scheduler 237 # this is also inlined into the unlock_scheduler
260 my $coro = (pop @pool) || new Coro \&pool_handler;; 238 my $coro = (pop @async_pool) || new Coro \&pool_handler;
261 239
262 $coro->{_invoke} = [@_]; 240 $coro->{_invoke} = [@_];
263 $coro->ready; 241 $coro->ready;
264 242
265 $coro 243 $coro
295 273
296"Cede" to other coroutines. This function puts the current coroutine into the 274"Cede" to other coroutines. This function puts the current coroutine into the
297ready queue and calls C<schedule>, which has the effect of giving up the 275ready queue and calls C<schedule>, which has the effect of giving up the
298current "timeslice" to other coroutines of the same or higher priority. 276current "timeslice" to other coroutines of the same or higher priority.
299 277
300Returns true if at least one coroutine switch has happened.
301
302=item Coro::cede_notself 278=item Coro::cede_notself
303 279
304Works like cede, but is not exported by default and will cede to any 280Works like cede, but is not exported by default and will cede to any
305coroutine, regardless of priority, once. 281coroutine, regardless of priority, once.
306 282
307Returns true if at least one coroutine switch has happened.
308
309=item terminate [arg...] 283=item terminate [arg...]
310 284
311Terminates the current coroutine with the given status values (see L<cancel>). 285Terminates the current coroutine with the given status values (see L<cancel>).
286
287=item killall
288
289Kills/terminates/cancels all coroutines except the currently running
290one. This is useful after a fork, either in the child or the parent, as
291usually only one of them should inherit the running coroutines.
312 292
313=cut 293=cut
314 294
315sub terminate { 295sub terminate {
316 $current->cancel (@_); 296 $current->cancel (@_);
317} 297}
318 298
299sub killall {
300 for (Coro::State::list) {
301 $_->cancel
302 if $_ != $current && UNIVERSAL::isa $_, "Coro";
303 }
304}
305
319=back 306=back
320
321# dynamic methods
322 307
323=head2 COROUTINE METHODS 308=head2 COROUTINE METHODS
324 309
325These are the methods you can call on coroutine objects. 310These are the methods you can call on coroutine objects.
326 311
331Create a new coroutine and return it. When the sub returns the coroutine 316Create a new coroutine and return it. When the sub returns the coroutine
332automatically terminates as if C<terminate> with the returned values were 317automatically terminates as if C<terminate> with the returned values were
333called. To make the coroutine run you must first put it into the ready queue 318called. To make the coroutine run you must first put it into the ready queue
334by calling the ready method. 319by calling the ready method.
335 320
336See C<async> for additional discussion. 321See C<async> and C<Coro::State::new> for additional info about the
322coroutine environment.
337 323
338=cut 324=cut
339 325
340sub _run_coro { 326sub _run_coro {
341 terminate &{+shift}; 327 terminate &{+shift};
365 351
366=cut 352=cut
367 353
368sub cancel { 354sub cancel {
369 my $self = shift; 355 my $self = shift;
370 $self->{status} = [@_]; 356 $self->{_status} = [@_];
371 357
372 if ($current == $self) { 358 if ($current == $self) {
373 push @destroy, $self; 359 push @destroy, $self;
374 $manager->ready; 360 $manager->ready;
375 &schedule while 1; 361 &schedule while 1;
379} 365}
380 366
381=item $coroutine->join 367=item $coroutine->join
382 368
383Wait until the coroutine terminates and return any values given to the 369Wait until the coroutine terminates and return any values given to the
384C<terminate> or C<cancel> functions. C<join> can be called multiple times 370C<terminate> or C<cancel> functions. C<join> can be called concurrently
385from multiple coroutine. 371from multiple coroutines.
386 372
387=cut 373=cut
388 374
389sub join { 375sub join {
390 my $self = shift; 376 my $self = shift;
391 377
392 unless ($self->{status}) { 378 unless ($self->{_status}) {
393 my $current = $current; 379 my $current = $current;
394 380
395 push @{$self->{destroy_cb}}, sub { 381 push @{$self->{_on_destroy}}, sub {
396 $current->ready; 382 $current->ready;
397 undef $current; 383 undef $current;
398 }; 384 };
399 385
400 &schedule while $current; 386 &schedule while $current;
401 } 387 }
402 388
403 wantarray ? @{$self->{status}} : $self->{status}[0]; 389 wantarray ? @{$self->{_status}} : $self->{_status}[0];
404} 390}
405 391
406=item $coroutine->on_destroy (\&cb) 392=item $coroutine->on_destroy (\&cb)
407 393
408Registers a callback that is called when this coroutine gets destroyed, 394Registers a callback that is called when this coroutine gets destroyed,
412=cut 398=cut
413 399
414sub on_destroy { 400sub on_destroy {
415 my ($self, $cb) = @_; 401 my ($self, $cb) = @_;
416 402
417 push @{ $self->{destroy_cb} }, $cb; 403 push @{ $self->{_on_destroy} }, $cb;
418} 404}
419 405
420=item $oldprio = $coroutine->prio ($newprio) 406=item $oldprio = $coroutine->prio ($newprio)
421 407
422Sets (or gets, if the argument is missing) the priority of the 408Sets (or gets, if the argument is missing) the priority of the
446 432
447=item $olddesc = $coroutine->desc ($newdesc) 433=item $olddesc = $coroutine->desc ($newdesc)
448 434
449Sets (or gets in case the argument is missing) the description for this 435Sets (or gets in case the argument is missing) the description for this
450coroutine. This is just a free-form string you can associate with a coroutine. 436coroutine. This is just a free-form string you can associate with a coroutine.
437
438This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
439can modify this member directly if you wish.
440
441=item $coroutine->throw ([$scalar])
442
443If C<$throw> is specified and defined, it will be thrown as an exception
444inside the coroutine at the next convinient point in time (usually after
445it gains control at the next schedule/transfer/cede). Otherwise clears the
446exception object.
447
448The exception object will be thrown "as is" with the specified scalar in
449C<$@>, i.e. if it is a string, no line number or newline will be appended
450(unlike with C<die>).
451
452This can be used as a softer means than C<cancel> to ask a coroutine to
453end itself, although there is no guarentee that the exception will lead to
454termination, and if the exception isn't caught it might well end the whole
455program.
451 456
452=cut 457=cut
453 458
454sub desc { 459sub desc {
455 my $old = $_[0]{desc}; 460 my $old = $_[0]{desc};
535# inside an event callback. 540# inside an event callback.
536our $unblock_scheduler = new Coro sub { 541our $unblock_scheduler = new Coro sub {
537 while () { 542 while () {
538 while (my $cb = pop @unblock_queue) { 543 while (my $cb = pop @unblock_queue) {
539 # this is an inlined copy of async_pool 544 # this is an inlined copy of async_pool
540 my $coro = (pop @pool or new Coro \&pool_handler); 545 my $coro = (pop @async_pool) || new Coro \&pool_handler;
541 546
542 $coro->{_invoke} = $cb; 547 $coro->{_invoke} = $cb;
543 $coro->ready; 548 $coro->ready;
544 cede; # for short-lived callbacks, this reduces pressure on the coro pool 549 cede; # for short-lived callbacks, this reduces pressure on the coro pool
545 } 550 }
573 to allow per-thread schedulers, but Coro::State does not yet allow 578 to allow per-thread schedulers, but Coro::State does not yet allow
574 this). 579 this).
575 580
576=head1 SEE ALSO 581=head1 SEE ALSO
577 582
583Lower level Configuration, Coroutine Environment: L<Coro::State>.
584
585Debugging: L<Coro::Debug>.
586
578Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. 587Support/Utility: L<Coro::Specific>, L<Coro::Util>.
579 588
580Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. 589Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
581 590
582Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. 591Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
583 592
593Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
594
584Embedding: L<Coro:MakeMaker> 595Embedding: L<Coro::MakeMaker>.
585 596
586=head1 AUTHOR 597=head1 AUTHOR
587 598
588 Marc Lehmann <schmorp@schmorp.de> 599 Marc Lehmann <schmorp@schmorp.de>
589 http://home.schmorp.de/ 600 http://home.schmorp.de/

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