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Revision 1.128 by root, Wed Sep 19 21:39:15 2007 UTC vs.
Revision 1.152 by root, Sun Oct 7 13:53:37 2007 UTC

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 };
15 print "1\n";
16 cede; # yield to coroutine
17 print "3\n";
18 cede; # and again
12 19
13 # alternatively create an async coroutine like this: 20 # use locking
21 my $lock = new Coro::Semaphore;
22 my $locked;
14 23
15 sub some_func : Coro { 24 $lock->down;
16 # some more async code 25 $locked = 1;
17 } 26 $lock->up;
18
19 cede;
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 $VERSION = '4.1';
56 63
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 64our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 65our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 66 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 67);
113reasons. If performance is not essential you are encouraged to use the 120reasons. If performance is not essential you are encouraged to use the
114C<Coro::current> function instead. 121C<Coro::current> function instead.
115 122
116=cut 123=cut
117 124
125$main->{desc} = "[main::]";
126
118# maybe some other module used Coro::Specific before... 127# maybe some other module used Coro::Specific before...
119$main->{specific} = $current->{specific} 128$main->{_specific} = $current->{_specific}
120 if $current; 129 if $current;
121 130
122_set_current $main; 131_set_current $main;
123 132
124sub current() { $current } 133sub current() { $current }
132This hook is overwritten by modules such as C<Coro::Timer> and 141This hook is overwritten by modules such as C<Coro::Timer> and
133C<Coro::Event> to wait on an external event that hopefully wake up a 142C<Coro::Event> to wait on an external event that hopefully wake up a
134coroutine so the scheduler can run it. 143coroutine so the scheduler can run it.
135 144
136Please note that if your callback recursively invokes perl (e.g. for event 145Please note that if your callback recursively invokes perl (e.g. for event
137handlers), then it must be prepared to be called recursively. 146handlers), then it must be prepared to be called recursively itself.
138 147
139=cut 148=cut
140 149
141$idle = sub { 150$idle = sub {
142 require Carp; 151 require Carp;
149 # free coroutine data and mark as destructed 158 # free coroutine data and mark as destructed
150 $self->_destroy 159 $self->_destroy
151 or return; 160 or return;
152 161
153 # call all destruction callbacks 162 # call all destruction callbacks
154 $_->(@{$self->{status}}) 163 $_->(@{$self->{_status}})
155 for @{(delete $self->{destroy_cb}) || []}; 164 for @{(delete $self->{_on_destroy}) || []};
156} 165}
157 166
158# this coroutine is necessary because a coroutine 167# this coroutine is necessary because a coroutine
159# cannot destroy itself. 168# cannot destroy itself.
160my @destroy; 169my @destroy;
166 while @destroy; 175 while @destroy;
167 176
168 &schedule; 177 &schedule;
169 } 178 }
170}; 179};
171 180$manager->desc ("[coro manager]");
172$manager->prio (PRIO_MAX); 181$manager->prio (PRIO_MAX);
173 182
174# static methods. not really. 183# static methods. not really.
175 184
176=back 185=back
184=item async { ... } [@args...] 193=item async { ... } [@args...]
185 194
186Create a new asynchronous coroutine and return it's coroutine object 195Create a new asynchronous coroutine and return it's coroutine object
187(usually unused). When the sub returns the new coroutine is automatically 196(usually unused). When the sub returns the new coroutine is automatically
188terminated. 197terminated.
198
199See the C<Coro::State::new> constructor for info about the coroutine
200environment in which coroutines run.
189 201
190Calling C<exit> in a coroutine will do the same as calling exit outside 202Calling C<exit> in a coroutine will do the same as calling exit outside
191the coroutine. Likewise, when the coroutine dies, the program will exit, 203the coroutine. Likewise, when the coroutine dies, the program will exit,
192just as it would in the main program. 204just as it would in the main program.
193 205
214issued in case of an exception instead of terminating the program, as 226issued in case of an exception instead of terminating the program, as
215C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 227C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
216will not work in the expected way, unless you call terminate or cancel, 228will not work in the expected way, unless you call terminate or cancel,
217which somehow defeats the purpose of pooling. 229which somehow defeats the purpose of pooling.
218 230
219The priority will be reset to C<0> after each job, otherwise the coroutine 231The priority will be reset to C<0> after each job, tracing will be
220will be re-used "as-is". 232disabled, the description will be reset and the default output filehandle
233gets restored, so you can change alkl these. Otherwise the coroutine will
234be re-used "as-is": most notably if you change other per-coroutine global
235stuff such as C<$/> you need to revert that change, which is most simply
236done by using local as in C< local $/ >.
221 237
222The pool size is limited to 8 idle coroutines (this can be adjusted by 238The pool size is limited to 8 idle coroutines (this can be adjusted by
223changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 239changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
224required. 240required.
225 241
226If you are concerned about pooled coroutines growing a lot because a 242If you are concerned about pooled coroutines growing a lot because a
227single C<async_pool> used a lot of stackspace you can e.g. C<async_pool { 243single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
228terminate }> once per second or so to slowly replenish the pool. 244{ terminate }> once per second or so to slowly replenish the pool. In
245addition to that, when the stacks used by a handler grows larger than 16kb
246(adjustable with $Coro::POOL_RSS) it will also exit.
229 247
230=cut 248=cut
231 249
232our $POOL_SIZE = 8; 250our $POOL_SIZE = 8;
251our $POOL_RSS = 16 * 1024;
233our @pool; 252our @async_pool;
234 253
235sub pool_handler { 254sub pool_handler {
255 my $cb;
256
236 while () { 257 while () {
237 eval { 258 eval {
238 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 259 while () {
239 $cb->(@arg); 260 _pool_1 $cb;
261 &$cb;
262 _pool_2 $cb;
263 &schedule;
264 }
240 }; 265 };
266
267 last if $@ eq "\3async_pool terminate\2\n";
241 warn $@ if $@; 268 warn $@ if $@;
242
243 last if @pool >= $POOL_SIZE;
244 push @pool, $current;
245
246 $current->save (Coro::State::SAVE_DEF);
247 $current->prio (0);
248 schedule;
249 } 269 }
250} 270}
251 271
252sub async_pool(&@) { 272sub async_pool(&@) {
253 # this is also inlined into the unlock_scheduler 273 # this is also inlined into the unlock_scheduler
254 my $coro = (pop @pool) || do {
255 my $coro = new Coro \&pool_handler; 274 my $coro = (pop @async_pool) || new Coro \&pool_handler;
256 $coro->{desc} = "async_pool";
257 $coro
258 };
259 275
260 $coro->{_invoke} = [@_]; 276 $coro->{_invoke} = [@_];
261 $coro->ready; 277 $coro->ready;
262 278
263 $coro 279 $coro
306 322
307=item terminate [arg...] 323=item terminate [arg...]
308 324
309Terminates the current coroutine with the given status values (see L<cancel>). 325Terminates the current coroutine with the given status values (see L<cancel>).
310 326
327=item killall
328
329Kills/terminates/cancels all coroutines except the currently running
330one. This is useful after a fork, either in the child or the parent, as
331usually only one of them should inherit the running coroutines.
332
311=cut 333=cut
312 334
313sub terminate { 335sub terminate {
314 $current->cancel (@_); 336 $current->cancel (@_);
337}
338
339sub killall {
340 for (Coro::State::list) {
341 $_->cancel
342 if $_ != $current && UNIVERSAL::isa $_, "Coro";
343 }
315} 344}
316 345
317=back 346=back
318 347
319# dynamic methods 348# dynamic methods
329Create a new coroutine and return it. When the sub returns the coroutine 358Create a new coroutine and return it. When the sub returns the coroutine
330automatically terminates as if C<terminate> with the returned values were 359automatically terminates as if C<terminate> with the returned values were
331called. To make the coroutine run you must first put it into the ready queue 360called. To make the coroutine run you must first put it into the ready queue
332by calling the ready method. 361by calling the ready method.
333 362
334See C<async> for additional discussion. 363See C<async> and C<Coro::State::new> for additional info about the
364coroutine environment.
335 365
336=cut 366=cut
337 367
338sub _run_coro { 368sub _run_coro {
339 terminate &{+shift}; 369 terminate &{+shift};
363 393
364=cut 394=cut
365 395
366sub cancel { 396sub cancel {
367 my $self = shift; 397 my $self = shift;
368 $self->{status} = [@_]; 398 $self->{_status} = [@_];
369 399
370 if ($current == $self) { 400 if ($current == $self) {
371 push @destroy, $self; 401 push @destroy, $self;
372 $manager->ready; 402 $manager->ready;
373 &schedule while 1; 403 &schedule while 1;
377} 407}
378 408
379=item $coroutine->join 409=item $coroutine->join
380 410
381Wait until the coroutine terminates and return any values given to the 411Wait until the coroutine terminates and return any values given to the
382C<terminate> or C<cancel> functions. C<join> can be called multiple times 412C<terminate> or C<cancel> functions. C<join> can be called concurrently
383from multiple coroutine. 413from multiple coroutines.
384 414
385=cut 415=cut
386 416
387sub join { 417sub join {
388 my $self = shift; 418 my $self = shift;
389 419
390 unless ($self->{status}) { 420 unless ($self->{_status}) {
391 my $current = $current; 421 my $current = $current;
392 422
393 push @{$self->{destroy_cb}}, sub { 423 push @{$self->{_on_destroy}}, sub {
394 $current->ready; 424 $current->ready;
395 undef $current; 425 undef $current;
396 }; 426 };
397 427
398 &schedule while $current; 428 &schedule while $current;
399 } 429 }
400 430
401 wantarray ? @{$self->{status}} : $self->{status}[0]; 431 wantarray ? @{$self->{_status}} : $self->{_status}[0];
402} 432}
403 433
404=item $coroutine->on_destroy (\&cb) 434=item $coroutine->on_destroy (\&cb)
405 435
406Registers a callback that is called when this coroutine gets destroyed, 436Registers a callback that is called when this coroutine gets destroyed,
410=cut 440=cut
411 441
412sub on_destroy { 442sub on_destroy {
413 my ($self, $cb) = @_; 443 my ($self, $cb) = @_;
414 444
415 push @{ $self->{destroy_cb} }, $cb; 445 push @{ $self->{_on_destroy} }, $cb;
416} 446}
417 447
418=item $oldprio = $coroutine->prio ($newprio) 448=item $oldprio = $coroutine->prio ($newprio)
419 449
420Sets (or gets, if the argument is missing) the priority of the 450Sets (or gets, if the argument is missing) the priority of the
444 474
445=item $olddesc = $coroutine->desc ($newdesc) 475=item $olddesc = $coroutine->desc ($newdesc)
446 476
447Sets (or gets in case the argument is missing) the description for this 477Sets (or gets in case the argument is missing) the description for this
448coroutine. This is just a free-form string you can associate with a coroutine. 478coroutine. This is just a free-form string you can associate with a coroutine.
479
480This method simply sets the C<< $coroutine->{desc} >> member to the given string. You
481can modify this member directly if you wish.
482
483=item $coroutine->throw ([$scalar])
484
485If C<$throw> is specified and defined, it will be thrown as an exception
486inside the coroutine at the next convinient point in time (usually after
487it gains control at the next schedule/transfer/cede). Otherwise clears the
488exception object.
489
490The exception object will be thrown "as is" with the specified scalar in
491C<$@>, i.e. if it is a string, no line number or newline will be appended
492(unlike with C<die>).
493
494This can be used as a softer means than C<cancel> to ask a coroutine to
495end itself, although there is no guarentee that the exception will lead to
496termination, and if the exception isn't caught it might well end the whole
497program.
449 498
450=cut 499=cut
451 500
452sub desc { 501sub desc {
453 my $old = $_[0]{desc}; 502 my $old = $_[0]{desc};
529 578
530# we create a special coro because we want to cede, 579# we create a special coro because we want to cede,
531# to reduce pressure on the coro pool (because most callbacks 580# to reduce pressure on the coro pool (because most callbacks
532# return immediately and can be reused) and because we cannot cede 581# return immediately and can be reused) and because we cannot cede
533# inside an event callback. 582# inside an event callback.
534our $unblock_scheduler = async { 583our $unblock_scheduler = new Coro sub {
535 while () { 584 while () {
536 while (my $cb = pop @unblock_queue) { 585 while (my $cb = pop @unblock_queue) {
537 # this is an inlined copy of async_pool 586 # this is an inlined copy of async_pool
538 my $coro = (pop @pool or new Coro \&pool_handler); 587 my $coro = (pop @async_pool) || new Coro \&pool_handler;
539 588
540 $coro->{_invoke} = $cb; 589 $coro->{_invoke} = $cb;
541 $coro->ready; 590 $coro->ready;
542 cede; # for short-lived callbacks, this reduces pressure on the coro pool 591 cede; # for short-lived callbacks, this reduces pressure on the coro pool
543 } 592 }
544 schedule; # sleep well 593 schedule; # sleep well
545 } 594 }
546}; 595};
596$unblock_scheduler->desc ("[unblock_sub scheduler]");
547 597
548sub unblock_sub(&) { 598sub unblock_sub(&) {
549 my $cb = shift; 599 my $cb = shift;
550 600
551 sub { 601 sub {
570 to allow per-thread schedulers, but Coro::State does not yet allow 620 to allow per-thread schedulers, but Coro::State does not yet allow
571 this). 621 this).
572 622
573=head1 SEE ALSO 623=head1 SEE ALSO
574 624
625Lower level Configuration, Coroutine Environment: L<Coro::State>.
626
627Debugging: L<Coro::Debug>.
628
575Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. 629Support/Utility: L<Coro::Specific>, L<Coro::Util>.
576 630
577Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. 631Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>.
578 632
579Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. 633Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>.
580 634
635Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>.
636
581Embedding: L<Coro:MakeMaker> 637Embedding: L<Coro:MakeMaker>.
582 638
583=head1 AUTHOR 639=head1 AUTHOR
584 640
585 Marc Lehmann <schmorp@schmorp.de> 641 Marc Lehmann <schmorp@schmorp.de>
586 http://home.schmorp.de/ 642 http://home.schmorp.de/

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