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Comparing Coro/Coro.pm (file contents):
Revision 1.114 by root, Wed Jan 24 16:22:08 2007 UTC vs.
Revision 1.139 by root, Thu Sep 27 15:52:30 2007 UTC

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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
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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 = '3.5'; 55our $VERSION = '3.8';
56 56
57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 57our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
58our %EXPORT_TAGS = ( 58our %EXPORT_TAGS = (
59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 59 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
60); 60);
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108 108
109The current coroutine (the last coroutine switched to). The initial value 109The current coroutine (the last coroutine switched to). The initial value
110is C<$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
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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 $manager;
162 172
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166 while @destroy; 176 while @destroy;
167 177
168 &schedule; 178 &schedule;
169 } 179 }
170}; 180};
171 181$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
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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 not work correctly, so do not do that. 200Calling C<exit> in a coroutine will do the same as calling exit outside
191 201the coroutine. Likewise, when the coroutine dies, the program will exit,
192When the coroutine dies, the program will exit, just as in the main 202just as it would in the main program.
193program.
194 203
195 # create a new coroutine that just prints its arguments 204 # create a new coroutine that just prints its arguments
196 async { 205 async {
197 print "@_\n"; 206 print "@_\n";
198 } 1,2,3,4; 207 } 1,2,3,4;
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223The 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
224changing $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
225required. 234required.
226 235
227If you are concerned about pooled coroutines growing a lot because a 236If you are concerned about pooled coroutines growing a lot because a
228single 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
229terminate }> 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.
230 241
231=cut 242=cut
232 243
233our $POOL_SIZE = 8; 244our $POOL_SIZE = 8;
245our $POOL_RSS = 16 * 1024;
234our @pool; 246our @async_pool;
235 247
236sub pool_handler { 248sub pool_handler {
249 my $cb;
250
237 while () { 251 while () {
238 eval { 252 eval {
239 my ($cb, @arg) = @{ delete $current->{_invoke} or return }; 253 while () {
240 $cb->(@arg); 254 _pool_1 $cb;
255 &$cb;
256 _pool_2 $cb;
257 &schedule;
258 }
241 }; 259 };
260
261 last if $@ eq "\3terminate\2\n";
242 warn $@ if $@; 262 warn $@ if $@;
243
244 last if @pool >= $POOL_SIZE;
245 push @pool, $current;
246
247 $current->prio (0);
248 schedule;
249 } 263 }
250} 264}
251 265
252sub async_pool(&@) { 266sub async_pool(&@) {
253 # this is also inlined into the unlock_scheduler 267 # this is also inlined into the unlock_scheduler
254 my $coro = (pop @pool or new Coro \&pool_handler); 268 my $coro = (pop @async_pool) || new Coro \&pool_handler;
255 269
256 $coro->{_invoke} = [@_]; 270 $coro->{_invoke} = [@_];
257 $coro->ready; 271 $coro->ready;
258 272
259 $coro 273 $coro
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277 # wake up sleeping coroutine 291 # wake up sleeping coroutine
278 $current->ready; 292 $current->ready;
279 undef $current; 293 undef $current;
280 }; 294 };
281 295
282 # call schedule until event occured. 296 # call schedule until event occurred.
283 # in case we are woken up for other reasons 297 # in case we are woken up for other reasons
284 # (current still defined), loop. 298 # (current still defined), loop.
285 Coro::schedule while $current; 299 Coro::schedule while $current;
286 } 300 }
287 301
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325Create a new coroutine and return it. When the sub returns the coroutine 339Create a new coroutine and return it. When the sub returns the coroutine
326automatically terminates as if C<terminate> with the returned values were 340automatically terminates as if C<terminate> with the returned values were
327called. To make the coroutine run you must first put it into the ready queue 341called. To make the coroutine run you must first put it into the ready queue
328by calling the ready method. 342by calling the ready method.
329 343
330Calling C<exit> in a coroutine will not work correctly, so do not do that. 344See C<async> for additional discussion.
331 345
332=cut 346=cut
333 347
334sub _run_coro { 348sub _run_coro {
335 terminate &{+shift}; 349 terminate &{+shift};
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458=over 4 472=over 4
459 473
460=item Coro::nready 474=item Coro::nready
461 475
462Returns the number of coroutines that are currently in the ready state, 476Returns the number of coroutines that are currently in the ready state,
463i.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
464coroutine 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,
465and 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
466that wakes up some coroutines. 480that wakes up some coroutines.
467 481
468=item my $guard = Coro::guard { ... } 482=item my $guard = Coro::guard { ... }
469 483
470This creates and returns a guard object. Nothing happens until the objetc 484This creates and returns a guard object. Nothing happens until the object
471gets destroyed, in which case the codeblock given as argument will be 485gets destroyed, in which case the codeblock given as argument will be
472executed. This is useful to free locks or other resources in case of a 486executed. This is useful to free locks or other resources in case of a
473runtime error or when the coroutine gets canceled, as in both cases the 487runtime error or when the coroutine gets canceled, as in both cases the
474guard block will be executed. The guard object supports only one method, 488guard block will be executed. The guard object supports only one method,
475C<< ->cancel >>, which will keep the codeblock from being executed. 489C<< ->cancel >>, which will keep the codeblock from being executed.
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504This utility function takes a BLOCK or code reference and "unblocks" it, 518This utility function takes a BLOCK or code reference and "unblocks" it,
505returning the new coderef. This means that the new coderef will return 519returning the new coderef. This means that the new coderef will return
506immediately without blocking, returning nothing, while the original code 520immediately without blocking, returning nothing, while the original code
507ref will be called (with parameters) from within its own coroutine. 521ref will be called (with parameters) from within its own coroutine.
508 522
509The 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
510venerable L<Event|Event> module) are not coroutine-safe (a weaker form 524venerable L<Event|Event> module) are not coroutine-safe (a weaker form
511of thread-safety). This means you must not block within event callbacks, 525of thread-safety). This means you must not block within event callbacks,
512otherwise you might suffer from crashes or worse. 526otherwise you might suffer from crashes or worse.
513 527
514This function allows your callbacks to block by executing them in another 528This function allows your callbacks to block by executing them in another
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525 539
526# we create a special coro because we want to cede, 540# we create a special coro because we want to cede,
527# to reduce pressure on the coro pool (because most callbacks 541# to reduce pressure on the coro pool (because most callbacks
528# return immediately and can be reused) and because we cannot cede 542# return immediately and can be reused) and because we cannot cede
529# inside an event callback. 543# inside an event callback.
530our $unblock_scheduler = async { 544our $unblock_scheduler = new Coro sub {
531 while () { 545 while () {
532 while (my $cb = pop @unblock_queue) { 546 while (my $cb = pop @unblock_queue) {
533 # this is an inlined copy of async_pool 547 # this is an inlined copy of async_pool
534 my $coro = (pop @pool or new Coro \&pool_handler); 548 my $coro = (pop @async_pool) || new Coro \&pool_handler;
535 549
536 $coro->{_invoke} = $cb; 550 $coro->{_invoke} = $cb;
537 $coro->ready; 551 $coro->ready;
538 cede; # for short-lived callbacks, this reduces pressure on the coro pool 552 cede; # for short-lived callbacks, this reduces pressure on the coro pool
539 } 553 }
540 schedule; # sleep well 554 schedule; # sleep well
541 } 555 }
542}; 556};
557$unblock_scheduler->desc ("[unblock_sub scheduler]");
543 558
544sub unblock_sub(&) { 559sub unblock_sub(&) {
545 my $cb = shift; 560 my $cb = shift;
546 561
547 sub { 562 sub {
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560 575
561 - 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
562 destruction. very bad things might happen otherwise (usually segfaults). 577 destruction. very bad things might happen otherwise (usually segfaults).
563 578
564 - 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
565 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
566 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
567 this). 582 this).
568 583
569=head1 SEE ALSO 584=head1 SEE ALSO
570 585

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