ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/Coro/Coro.pm
(Generate patch)

Comparing Coro/Coro.pm (file contents):
Revision 1.121 by root, Fri Apr 13 12:56:55 2007 UTC vs.
Revision 1.139 by root, Thu Sep 27 15:52:30 2007 UTC

… …
20 20
21=head1 DESCRIPTION 21=head1 DESCRIPTION
22 22
23This module collection manages coroutines. Coroutines are similar 23This module collection manages coroutines. Coroutines are similar
24to threads but don't run in parallel at the same time even on SMP 24to threads but don't run in parallel at the same time even on SMP
25machines. The specific flavor of coroutine use din this module also 25machines. The specific flavor of coroutine used in this module also
26guarentees you that it will not switch between coroutines unless 26guarantees you that it will not switch between coroutines unless
27necessary, at easily-identified points in your program, so locking and 27necessary, at easily-identified points in your program, so locking and
28parallel access are rarely an issue, making coroutine programming much 28parallel access are rarely an issue, making coroutine programming much
29safer than threads programming. 29safer than threads programming.
30 30
31(Perl, however, does not natively support real threads but instead does a 31(Perl, however, does not natively support real threads but instead does a
… …
50 50
51our $idle; # idle handler 51our $idle; # idle handler
52our $main; # main coroutine 52our $main; # main coroutine
53our $current; # current coroutine 53our $current; # current coroutine
54 54
55our $VERSION = '3.56'; 55our $VERSION = '3.8';
56 56
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 58our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 60);
… …
108 108
109The current coroutine (the last coroutine switched to). The initial value 109The current coroutine (the last coroutine switched to). The initial value
110is C<$main> (of course). 110is C<$main> (of course).
111 111
112This variable is B<strictly> I<read-only>. It is provided for performance 112This variable is B<strictly> I<read-only>. It is provided for performance
113reasons. If performance is not essentiel you are encouraged to use the 113reasons. If performance is not essential you are encouraged to use the
114C<Coro::current> function instead. 114C<Coro::current> function instead.
115 115
116=cut 116=cut
117
118$main->{desc} = "[main::]";
117 119
118# maybe some other module used Coro::Specific before... 120# maybe some other module used Coro::Specific before...
119$main->{specific} = $current->{specific} 121$main->{specific} = $current->{specific}
120 if $current; 122 if $current;
121 123
… …
153 # call all destruction callbacks 155 # call all destruction callbacks
154 $_->(@{$self->{status}}) 156 $_->(@{$self->{status}})
155 for @{(delete $self->{destroy_cb}) || []}; 157 for @{(delete $self->{destroy_cb}) || []};
156} 158}
157 159
160sub _do_trace_sub {
161 &{$current->{_trace_sub_cb}}
162}
163
164sub _do_trace_line {
165 &{$current->{_trace_line_cb}}
166}
167
158# this coroutine is necessary because a coroutine 168# this coroutine is necessary because a coroutine
159# cannot destroy itself. 169# cannot destroy itself.
160my @destroy; 170my @destroy;
161my $manager; 171my $manager;
162 172
… …
166 while @destroy; 176 while @destroy;
167 177
168 &schedule; 178 &schedule;
169 } 179 }
170}; 180};
171 181$manager->desc ("[coro manager]");
172$manager->prio (PRIO_MAX); 182$manager->prio (PRIO_MAX);
173 183
174# static methods. not really. 184# static methods. not really.
175 185
176=back 186=back
… …
185 195
186Create a new asynchronous coroutine and return it's coroutine object 196Create a new asynchronous coroutine and return it's coroutine object
187(usually unused). When the sub returns the new coroutine is automatically 197(usually unused). When the sub returns the new coroutine is automatically
188terminated. 198terminated.
189 199
190Calling C<exit> in a coroutine will try to do the same as calling exit 200Calling C<exit> in a coroutine will do the same as calling exit outside
191outside the coroutine, but this is experimental. It is best not to rely on 201the coroutine. Likewise, when the coroutine dies, the program will exit,
192exit doing any cleanups or even not crashing. 202just as it would in the main program.
193
194When the coroutine dies, the program will exit, just as in the main
195program.
196 203
197 # create a new coroutine that just prints its arguments 204 # create a new coroutine that just prints its arguments
198 async { 205 async {
199 print "@_\n"; 206 print "@_\n";
200 } 1,2,3,4; 207 } 1,2,3,4;
… …
225The pool size is limited to 8 idle coroutines (this can be adjusted by 232The pool size is limited to 8 idle coroutines (this can be adjusted by
226changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 233changing $Coro::POOL_SIZE), and there can be as many non-idle coros as
227required. 234required.
228 235
229If you are concerned about pooled coroutines growing a lot because a 236If you are concerned about pooled coroutines growing a lot because a
230single C<async_pool> used a lot of stackspace you can e.g. C<async_pool { 237single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
231terminate }> once per second or so to slowly replenish the pool. 238{ terminate }> once per second or so to slowly replenish the pool. In
239addition to that, when the stacks used by a handler grows larger than 16kb
240(adjustable with $Coro::POOL_RSS) it will also exit.
232 241
233=cut 242=cut
234 243
235our $POOL_SIZE = 8; 244our $POOL_SIZE = 8;
245our $POOL_RSS = 16 * 1024;
236our @pool; 246our @async_pool;
237 247
238sub pool_handler { 248sub pool_handler {
249 my $cb;
250
239 while () { 251 while () {
240 eval { 252 eval {
241 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 253 while () {
242 $cb->(@arg); 254 _pool_1 $cb;
255 &$cb;
256 _pool_2 $cb;
257 &schedule;
258 }
243 }; 259 };
260
261 last if $@ eq "\3terminate\2\n";
244 warn $@ if $@; 262 warn $@ if $@;
245
246 last if @pool >= $POOL_SIZE;
247 push @pool, $current;
248
249 $current->save (Coro::State::SAVE_DEF);
250 $current->prio (0);
251 schedule;
252 } 263 }
253} 264}
254 265
255sub async_pool(&@) { 266sub async_pool(&@) {
256 # this is also inlined into the unlock_scheduler 267 # this is also inlined into the unlock_scheduler
257 my $coro = (pop @pool or new Coro \&pool_handler); 268 my $coro = (pop @async_pool) || new Coro \&pool_handler;
258 269
259 $coro->{_invoke} = [@_]; 270 $coro->{_invoke} = [@_];
260 $coro->ready; 271 $coro->ready;
261 272
262 $coro 273 $coro
… …
280 # wake up sleeping coroutine 291 # wake up sleeping coroutine
281 $current->ready; 292 $current->ready;
282 undef $current; 293 undef $current;
283 }; 294 };
284 295
285 # call schedule until event occured. 296 # call schedule until event occurred.
286 # in case we are woken up for other reasons 297 # in case we are woken up for other reasons
287 # (current still defined), loop. 298 # (current still defined), loop.
288 Coro::schedule while $current; 299 Coro::schedule while $current;
289 } 300 }
290 301
… …
461=over 4 472=over 4
462 473
463=item Coro::nready 474=item Coro::nready
464 475
465Returns the number of coroutines that are currently in the ready state, 476Returns the number of coroutines that are currently in the ready state,
466i.e. that can be swicthed to. The value C<0> means that the only runnable 477i.e. that can be switched to. The value C<0> means that the only runnable
467coroutine is the currently running one, so C<cede> would have no effect, 478coroutine is the currently running one, so C<cede> would have no effect,
468and C<schedule> would cause a deadlock unless there is an idle handler 479and C<schedule> would cause a deadlock unless there is an idle handler
469that wakes up some coroutines. 480that wakes up some coroutines.
470 481
471=item my $guard = Coro::guard { ... } 482=item my $guard = Coro::guard { ... }
… …
507This utility function takes a BLOCK or code reference and "unblocks" it, 518This utility function takes a BLOCK or code reference and "unblocks" it,
508returning the new coderef. This means that the new coderef will return 519returning the new coderef. This means that the new coderef will return
509immediately without blocking, returning nothing, while the original code 520immediately without blocking, returning nothing, while the original code
510ref will be called (with parameters) from within its own coroutine. 521ref will be called (with parameters) from within its own coroutine.
511 522
512The reason this fucntion exists is that many event libraries (such as the 523The reason this function exists is that many event libraries (such as the
513venerable L<Event|Event> module) are not coroutine-safe (a weaker form 524venerable L<Event|Event> module) are not coroutine-safe (a weaker form
514of thread-safety). This means you must not block within event callbacks, 525of thread-safety). This means you must not block within event callbacks,
515otherwise you might suffer from crashes or worse. 526otherwise you might suffer from crashes or worse.
516 527
517This function allows your callbacks to block by executing them in another 528This function allows your callbacks to block by executing them in another
… …
528 539
529# we create a special coro because we want to cede, 540# we create a special coro because we want to cede,
530# to reduce pressure on the coro pool (because most callbacks 541# to reduce pressure on the coro pool (because most callbacks
531# return immediately and can be reused) and because we cannot cede 542# return immediately and can be reused) and because we cannot cede
532# inside an event callback. 543# inside an event callback.
533our $unblock_scheduler = async { 544our $unblock_scheduler = new Coro sub {
534 while () { 545 while () {
535 while (my $cb = pop @unblock_queue) { 546 while (my $cb = pop @unblock_queue) {
536 # this is an inlined copy of async_pool 547 # this is an inlined copy of async_pool
537 my $coro = (pop @pool or new Coro \&pool_handler); 548 my $coro = (pop @async_pool) || new Coro \&pool_handler;
538 549
539 $coro->{_invoke} = $cb; 550 $coro->{_invoke} = $cb;
540 $coro->ready; 551 $coro->ready;
541 cede; # for short-lived callbacks, this reduces pressure on the coro pool 552 cede; # for short-lived callbacks, this reduces pressure on the coro pool
542 } 553 }
543 schedule; # sleep well 554 schedule; # sleep well
544 } 555 }
545}; 556};
557$unblock_scheduler->desc ("[unblock_sub scheduler]");
546 558
547sub unblock_sub(&) { 559sub unblock_sub(&) {
548 my $cb = shift; 560 my $cb = shift;
549 561
550 sub { 562 sub {
… …
563 575
564 - you must make very sure that no coro is still active on global 576 - you must make very sure that no coro is still active on global
565 destruction. very bad things might happen otherwise (usually segfaults). 577 destruction. very bad things might happen otherwise (usually segfaults).
566 578
567 - this module is not thread-safe. You should only ever use this module 579 - this module is not thread-safe. You should only ever use this module
568 from the same thread (this requirement might be losened in the future 580 from the same thread (this requirement might be loosened in the future
569 to allow per-thread schedulers, but Coro::State does not yet allow 581 to allow per-thread schedulers, but Coro::State does not yet allow
570 this). 582 this).
571 583
572=head1 SEE ALSO 584=head1 SEE ALSO
573 585

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines