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Comparing Coro/Coro.pm (file contents):
Revision 1.202 by root, Tue Sep 30 17:12:34 2008 UTC vs.
Revision 1.223 by root, Tue Nov 18 10:44:07 2008 UTC

56 56
57=cut 57=cut
58 58
59package Coro; 59package Coro;
60 60
61use strict; 61use strict qw(vars subs);
62no warnings "uninitialized"; 62no warnings "uninitialized";
63 63
64use Coro::State; 64use Coro::State;
65 65
66use base qw(Coro::State Exporter); 66use base qw(Coro::State Exporter);
67 67
68our $idle; # idle handler 68our $idle; # idle handler
69our $main; # main coroutine 69our $main; # main coroutine
70our $current; # current coroutine 70our $current; # current coroutine
71 71
72our $VERSION = 4.8; 72our $VERSION = 5.0;
73 73
74our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 74our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
75our %EXPORT_TAGS = ( 75our %EXPORT_TAGS = (
76 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 76 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
77); 77);
86coroutines, it is mainly useful to compare again C<$Coro::current>, to see 86coroutines, it is mainly useful to compare again C<$Coro::current>, to see
87whether you are running in the main program or not. 87whether you are running in the main program or not.
88 88
89=cut 89=cut
90 90
91$main = new Coro; 91# $main is now being initialised by Coro::State
92 92
93=item $Coro::current 93=item $Coro::current
94 94
95The coroutine object representing the current coroutine (the last 95The coroutine object representing the current coroutine (the last
96coroutine that the Coro scheduler switched to). The initial value is 96coroutine that the Coro scheduler switched to). The initial value is
97C<$main> (of course). 97C<$Coro::main> (of course).
98 98
99This variable is B<strictly> I<read-only>. You can take copies of the 99This variable is B<strictly> I<read-only>. You can take copies of the
100value stored in it and use it as any other coroutine object, but you must 100value stored in it and use it as any other coroutine object, but you must
101not otherwise modify the variable itself. 101not otherwise modify the variable itself.
102 102
103=cut 103=cut
104
105$main->{desc} = "[main::]";
106
107# maybe some other module used Coro::Specific before...
108$main->{_specific} = $current->{_specific}
109 if $current;
110
111_set_current $main;
112 104
113sub current() { $current } # [DEPRECATED] 105sub current() { $current } # [DEPRECATED]
114 106
115=item $Coro::idle 107=item $Coro::idle
116 108
152 $self->_destroy 144 $self->_destroy
153 or return; 145 or return;
154 146
155 # call all destruction callbacks 147 # call all destruction callbacks
156 $_->(@{$self->{_status}}) 148 $_->(@{$self->{_status}})
157 for @{(delete $self->{_on_destroy}) || []}; 149 for @{ delete $self->{_on_destroy} || [] };
158} 150}
159 151
160# this coroutine is necessary because a coroutine 152# this coroutine is necessary because a coroutine
161# cannot destroy itself. 153# cannot destroy itself.
162my @destroy; 154my @destroy;
168 while @destroy; 160 while @destroy;
169 161
170 &schedule; 162 &schedule;
171 } 163 }
172}; 164};
173$manager->desc ("[coro manager]"); 165$manager->{desc} = "[coro manager]";
174$manager->prio (PRIO_MAX); 166$manager->prio (PRIO_MAX);
175 167
176=back 168=back
177 169
178=head2 SIMPLE COROUTINE CREATION 170=head2 SIMPLE COROUTINE CREATION
221terminate or join on it (although you are allowed to), and you get a 213terminate or join on it (although you are allowed to), and you get a
222coroutine that might have executed other code already (which can be good 214coroutine that might have executed other code already (which can be good
223or bad :). 215or bad :).
224 216
225On the plus side, this function is faster than creating (and destroying) 217On the plus side, this function is faster than creating (and destroying)
226a completely new coroutine, so if you need a lot of generic coroutines in 218a completly new coroutine, so if you need a lot of generic coroutines in
227quick successsion, use C<async_pool>, not C<async>. 219quick successsion, use C<async_pool>, not C<async>.
228 220
229The code block is executed in an C<eval> context and a warning will be 221The code block is executed in an C<eval> context and a warning will be
230issued in case of an exception instead of terminating the program, as 222issued in case of an exception instead of terminating the program, as
231C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 223C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
235 227
236The priority will be reset to C<0> after each run, tracing will be 228The priority will be reset to C<0> after each run, tracing will be
237disabled, the description will be reset and the default output filehandle 229disabled, the description will be reset and the default output filehandle
238gets restored, so you can change all these. Otherwise the coroutine will 230gets restored, so you can change all these. Otherwise the coroutine will
239be re-used "as-is": most notably if you change other per-coroutine global 231be re-used "as-is": most notably if you change other per-coroutine global
240stuff such as C<$/> you I<must needs> to revert that change, which is most 232stuff such as C<$/> you I<must needs> revert that change, which is most
241simply done by using local as in: C< local $/ >. 233simply done by using local as in: C<< local $/ >>.
242 234
243The pool size is limited to C<8> idle coroutines (this can be adjusted by 235The idle pool size is limited to C<8> idle coroutines (this can be
244changing $Coro::POOL_SIZE), and there can be as many non-idle coros as 236adjusted by changing $Coro::POOL_SIZE), but there can be as many non-idle
245required. 237coros as required.
246 238
247If you are concerned about pooled coroutines growing a lot because a 239If you are concerned about pooled coroutines growing a lot because a
248single C<async_pool> used a lot of stackspace you can e.g. C<async_pool 240single C<async_pool> used a lot of stackspace you can e.g. C<async_pool
249{ terminate }> once per second or so to slowly replenish the pool. In 241{ terminate }> once per second or so to slowly replenish the pool. In
250addition to that, when the stacks used by a handler grows larger than 16kb 242addition to that, when the stacks used by a handler grows larger than 16kb
275 } 267 }
276 } 268 }
277} 269}
278 270
279sub async_pool(&@) { 271sub async_pool(&@) {
280 # this is also inlined into the unlock_scheduler 272 # this is also inlined into the unblock_scheduler
281 my $coro = (pop @async_pool) || new Coro \&pool_handler; 273 my $coro = (pop @async_pool) || new Coro \&pool_handler;
282 274
283 $coro->{_invoke} = [@_]; 275 $coro->{_invoke} = [@_];
284 $coro->ready; 276 $coro->ready;
285 277
441 } else { 433 } else {
442 $self->_cancel; 434 $self->_cancel;
443 } 435 }
444} 436}
445 437
438=item $coroutine->throw ([$scalar])
439
440If C<$throw> is specified and defined, it will be thrown as an exception
441inside the coroutine at the next convenient point in time. Otherwise
442clears the exception object.
443
444Coro will check for the exception each time a schedule-like-function
445returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down
446>>, C<< Coro::Handle->readable >> and so on. Most of these functions
447detect this case and return early in case an exception is pending.
448
449The exception object will be thrown "as is" with the specified scalar in
450C<$@>, i.e. if it is a string, no line number or newline will be appended
451(unlike with C<die>).
452
453This can be used as a softer means than C<cancel> to ask a coroutine to
454end itself, although there is no guarantee that the exception will lead to
455termination, and if the exception isn't caught it might well end the whole
456program.
457
458You might also think of C<throw> as being the moral equivalent of
459C<kill>ing a coroutine with a signal (in this case, a scalar).
460
446=item $coroutine->join 461=item $coroutine->join
447 462
448Wait until the coroutine terminates and return any values given to the 463Wait until the coroutine terminates and return any values given to the
449C<terminate> or C<cancel> functions. C<join> can be called concurrently 464C<terminate> or C<cancel> functions. C<join> can be called concurrently
450from multiple coroutines, and all will be resumed and given the status 465from multiple coroutines, and all will be resumed and given the status
511higher values mean lower priority, just as in unix). 526higher values mean lower priority, just as in unix).
512 527
513=item $olddesc = $coroutine->desc ($newdesc) 528=item $olddesc = $coroutine->desc ($newdesc)
514 529
515Sets (or gets in case the argument is missing) the description for this 530Sets (or gets in case the argument is missing) the description for this
516coroutine. This is just a free-form string you can associate with a coroutine. 531coroutine. This is just a free-form string you can associate with a
532coroutine.
517 533
518This method simply sets the C<< $coroutine->{desc} >> member to the given string. You 534This method simply sets the C<< $coroutine->{desc} >> member to the given
519can modify this member directly if you wish. 535string. You can modify this member directly if you wish.
520
521=item $coroutine->throw ([$scalar])
522
523If C<$throw> is specified and defined, it will be thrown as an exception
524inside the coroutine at the next convinient point in time (usually after
525it gains control at the next schedule/transfer/cede). Otherwise clears the
526exception object.
527
528The exception object will be thrown "as is" with the specified scalar in
529C<$@>, i.e. if it is a string, no line number or newline will be appended
530(unlike with C<die>).
531
532This can be used as a softer means than C<cancel> to ask a coroutine to
533end itself, although there is no guarentee that the exception will lead to
534termination, and if the exception isn't caught it might well end the whole
535program.
536 536
537=cut 537=cut
538 538
539sub desc { 539sub desc {
540 my $old = $_[0]{desc}; 540 my $old = $_[0]{desc};
642 cede; # for short-lived callbacks, this reduces pressure on the coro pool 642 cede; # for short-lived callbacks, this reduces pressure on the coro pool
643 } 643 }
644 schedule; # sleep well 644 schedule; # sleep well
645 } 645 }
646}; 646};
647$unblock_scheduler->desc ("[unblock_sub scheduler]"); 647$unblock_scheduler->{desc} = "[unblock_sub scheduler]";
648 648
649sub unblock_sub(&) { 649sub unblock_sub(&) {
650 my $cb = shift; 650 my $cb = shift;
651 651
652 sub { 652 sub {
661 661
6621; 6621;
663 663
664=head1 BUGS/LIMITATIONS 664=head1 BUGS/LIMITATIONS
665 665
666=over 4
667
668=item fork with pthread backend
669
670When Coro is compiled using the pthread backend (which isn't recommended
671but required on many BSDs as their libcs are completely broken), then
672coroutines will not survive a fork. There is no known workaround except to
673fix your libc and use a saner backend.
674
675=item perl process emulation ("threads")
676
666This module is not perl-pseudo-thread-safe. You should only ever use this 677This module is not perl-pseudo-thread-safe. You should only ever use this
667module from the same thread (this requirement might be removed in the 678module from the same thread (this requirement might be removed in the
668future to allow per-thread schedulers, but Coro::State does not yet allow 679future to allow per-thread schedulers, but Coro::State does not yet allow
669this). I recommend disabling thread support and using processes, as this 680this). I recommend disabling thread support and using processes, as having
670is much faster and uses less memory. 681the windows process emulation enabled under unix roughly halves perl
682performance, even when not used.
683
684=item coroutine switching not signal safe
685
686You must not switch to another coroutine from within a signal handler
687(only relevant with %SIG - most event libraries provide safe signals).
688
689That means you I<MUST NOT> call any function that might "block" the
690current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or
691anything that calls those. Everything else, including calling C<ready>,
692works.
693
694=back
695
671 696
672=head1 SEE ALSO 697=head1 SEE ALSO
673 698
674Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. 699Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
675 700

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