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

Comparing cvsroot/Coro/Coro.pm (file contents):
Revision 1.196 by root, Sat Aug 30 03:07:46 2008 UTC vs.
Revision 1.220 by root, Sun Nov 16 11:12:57 2008 UTC

16 cede; # yield to coroutine 16 cede; # yield to coroutine
17 print "3\n"; 17 print "3\n";
18 cede; # and again 18 cede; # and again
19 19
20 # use locking 20 # use locking
21 use Coro::Semaphore;
21 my $lock = new Coro::Semaphore; 22 my $lock = new Coro::Semaphore;
22 my $locked; 23 my $locked;
23 24
24 $lock->down; 25 $lock->down;
25 $locked = 1; 26 $locked = 1;
55 56
56=cut 57=cut
57 58
58package Coro; 59package Coro;
59 60
60use strict; 61use strict qw(vars subs);
61no warnings "uninitialized"; 62no warnings "uninitialized";
62 63
63use Coro::State; 64use Coro::State;
64 65
65use base qw(Coro::State Exporter); 66use base qw(Coro::State Exporter);
66 67
67our $idle; # idle handler 68our $idle; # idle handler
68our $main; # main coroutine 69our $main; # main coroutine
69our $current; # current coroutine 70our $current; # current coroutine
70 71
71our $VERSION = 4.745; 72our $VERSION = 5.0;
72 73
73our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); 74our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub);
74our %EXPORT_TAGS = ( 75our %EXPORT_TAGS = (
75 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 76 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
76); 77);
85coroutines, it is mainly useful to compare again C<$Coro::current>, to see 86coroutines, it is mainly useful to compare again C<$Coro::current>, to see
86whether you are running in the main program or not. 87whether you are running in the main program or not.
87 88
88=cut 89=cut
89 90
90$main = new Coro; 91# $main is now being initialised by Coro::State
91 92
92=item $Coro::current 93=item $Coro::current
93 94
94The coroutine object representing the current coroutine (the last 95The coroutine object representing the current coroutine (the last
95coroutine that the Coro scheduler switched to). The initial value is 96coroutine that the Coro scheduler switched to). The initial value is
96C<$main> (of course). 97C<$Coro::main> (of course).
97 98
98This variable is B<strictly> I<read-only>. You can take copies of the 99This variable is B<strictly> I<read-only>. You can take copies of the
99value stored in it and use it as any other coroutine object, but you must 100value stored in it and use it as any other coroutine object, but you must
100not otherwise modify the variable itself. 101not otherwise modify the variable itself.
101 102
102=cut 103=cut
103
104$main->{desc} = "[main::]";
105
106# maybe some other module used Coro::Specific before...
107$main->{_specific} = $current->{_specific}
108 if $current;
109
110_set_current $main;
111 104
112sub current() { $current } # [DEPRECATED] 105sub current() { $current } # [DEPRECATED]
113 106
114=item $Coro::idle 107=item $Coro::idle
115 108
151 $self->_destroy 144 $self->_destroy
152 or return; 145 or return;
153 146
154 # call all destruction callbacks 147 # call all destruction callbacks
155 $_->(@{$self->{_status}}) 148 $_->(@{$self->{_status}})
156 for @{(delete $self->{_on_destroy}) || []}; 149 for @{ delete $self->{_on_destroy} || [] };
157} 150}
158 151
159# this coroutine is necessary because a coroutine 152# this coroutine is necessary because a coroutine
160# cannot destroy itself. 153# cannot destroy itself.
161my @destroy; 154my @destroy;
167 while @destroy; 160 while @destroy;
168 161
169 &schedule; 162 &schedule;
170 } 163 }
171}; 164};
172$manager->desc ("[coro manager]"); 165$manager->{desc} = "[coro manager]";
173$manager->prio (PRIO_MAX); 166$manager->prio (PRIO_MAX);
174 167
175=back 168=back
176 169
177=head2 SIMPLE COROUTINE CREATION 170=head2 SIMPLE COROUTINE CREATION
220terminate or join on it (although you are allowed to), and you get a 213terminate or join on it (although you are allowed to), and you get a
221coroutine that might have executed other code already (which can be good 214coroutine that might have executed other code already (which can be good
222or bad :). 215or bad :).
223 216
224On the plus side, this function is faster than creating (and destroying) 217On the plus side, this function is faster than creating (and destroying)
225a completely new coroutine, so if you need a lot of generic coroutines in 218a completly new coroutine, so if you need a lot of generic coroutines in
226quick successsion, use C<async_pool>, not C<async>. 219quick successsion, use C<async_pool>, not C<async>.
227 220
228The code block is executed in an C<eval> context and a warning will be 221The code block is executed in an C<eval> context and a warning will be
229issued in case of an exception instead of terminating the program, as 222issued in case of an exception instead of terminating the program, as
230C<async> does. As the coroutine is being reused, stuff like C<on_destroy> 223C<async> does. As the coroutine is being reused, stuff like C<on_destroy>
234 227
235The priority will be reset to C<0> after each run, tracing will be 228The priority will be reset to C<0> after each run, tracing will be
236disabled, the description will be reset and the default output filehandle 229disabled, the description will be reset and the default output filehandle
237gets restored, so you can change all these. Otherwise the coroutine will 230gets restored, so you can change all these. Otherwise the coroutine will
238be re-used "as-is": most notably if you change other per-coroutine global 231be re-used "as-is": most notably if you change other per-coroutine global
239stuff such as C<$/> 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
240simply done by using local as in: C< local $/ >. 233simply done by using local as in: C<< local $/ >>.
241 234
242The 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
243changing $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
244required. 237coros as required.
245 238
246If you are concerned about pooled coroutines growing a lot because a 239If you are concerned about pooled coroutines growing a lot because a
247single 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
248{ 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
249addition 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
274 } 267 }
275 } 268 }
276} 269}
277 270
278sub async_pool(&@) { 271sub async_pool(&@) {
279 # this is also inlined into the unlock_scheduler 272 # this is also inlined into the unblock_scheduler
280 my $coro = (pop @async_pool) || new Coro \&pool_handler; 273 my $coro = (pop @async_pool) || new Coro \&pool_handler;
281 274
282 $coro->{_invoke} = [@_]; 275 $coro->{_invoke} = [@_];
283 $coro->ready; 276 $coro->ready;
284 277
440 } else { 433 } else {
441 $self->_cancel; 434 $self->_cancel;
442 } 435 }
443} 436}
444 437
438=item $coroutine->throw ([$scalar])
439
440If C<$throw> is specified and defined, it will be thrown as an exception
441inside the coroutine at the next convenient point in time (usually after
442it gains control at the next schedule/transfer/cede). Otherwise clears the
443exception object.
444
445The exception object will be thrown "as is" with the specified scalar in
446C<$@>, i.e. if it is a string, no line number or newline will be appended
447(unlike with C<die>).
448
449This can be used as a softer means than C<cancel> to ask a coroutine to
450end itself, although there is no guarantee that the exception will lead to
451termination, and if the exception isn't caught it might well end the whole
452program.
453
454You might also think of C<throw> as being the moral equivalent of
455C<kill>ing a coroutine with a signal (in this case, a scalar).
456
445=item $coroutine->join 457=item $coroutine->join
446 458
447Wait until the coroutine terminates and return any values given to the 459Wait until the coroutine terminates and return any values given to the
448C<terminate> or C<cancel> functions. C<join> can be called concurrently 460C<terminate> or C<cancel> functions. C<join> can be called concurrently
449from multiple coroutines, and all will be resumed and given the status 461from multiple coroutines, and all will be resumed and given the status
510higher values mean lower priority, just as in unix). 522higher values mean lower priority, just as in unix).
511 523
512=item $olddesc = $coroutine->desc ($newdesc) 524=item $olddesc = $coroutine->desc ($newdesc)
513 525
514Sets (or gets in case the argument is missing) the description for this 526Sets (or gets in case the argument is missing) the description for this
515coroutine. This is just a free-form string you can associate with a coroutine. 527coroutine. This is just a free-form string you can associate with a
528coroutine.
516 529
517This method simply sets the C<< $coroutine->{desc} >> member to the given string. You 530This method simply sets the C<< $coroutine->{desc} >> member to the given
518can modify this member directly if you wish. 531string. You can modify this member directly if you wish.
519
520=item $coroutine->throw ([$scalar])
521
522If C<$throw> is specified and defined, it will be thrown as an exception
523inside the coroutine at the next convinient point in time (usually after
524it gains control at the next schedule/transfer/cede). Otherwise clears the
525exception object.
526
527The exception object will be thrown "as is" with the specified scalar in
528C<$@>, i.e. if it is a string, no line number or newline will be appended
529(unlike with C<die>).
530
531This can be used as a softer means than C<cancel> to ask a coroutine to
532end itself, although there is no guarentee that the exception will lead to
533termination, and if the exception isn't caught it might well end the whole
534program.
535 532
536=cut 533=cut
537 534
538sub desc { 535sub desc {
539 my $old = $_[0]{desc}; 536 my $old = $_[0]{desc};
641 cede; # for short-lived callbacks, this reduces pressure on the coro pool 638 cede; # for short-lived callbacks, this reduces pressure on the coro pool
642 } 639 }
643 schedule; # sleep well 640 schedule; # sleep well
644 } 641 }
645}; 642};
646$unblock_scheduler->desc ("[unblock_sub scheduler]"); 643$unblock_scheduler->{desc} = "[unblock_sub scheduler]";
647 644
648sub unblock_sub(&) { 645sub unblock_sub(&) {
649 my $cb = shift; 646 my $cb = shift;
650 647
651 sub { 648 sub {
660 657
6611; 6581;
662 659
663=head1 BUGS/LIMITATIONS 660=head1 BUGS/LIMITATIONS
664 661
662=over 4
663
664=item fork with pthread backend
665
666When Coro is compiled using the pthread backend (which isn't recommended
667but required on many BSDs as their libcs are completely broken), then
668coroutines will not survive a fork. There is no known workaround except to
669fix your libc and use a saner backend.
670
671=item perl process emulation ("threads")
672
665This module is not perl-pseudo-thread-safe. You should only ever use this 673This module is not perl-pseudo-thread-safe. You should only ever use this
666module from the same thread (this requirement might be removed in the 674module from the same thread (this requirement might be removed in the
667future to allow per-thread schedulers, but Coro::State does not yet allow 675future to allow per-thread schedulers, but Coro::State does not yet allow
668this). I recommend disabling thread support and using processes, as this 676this). I recommend disabling thread support and using processes, as having
669is much faster and uses less memory. 677the windows process emulation enabled under unix roughly halves perl
678performance, even when not used.
679
680=item coroutine switching not signal safe
681
682You must not switch to another coroutine from within a signal handler
683(only relevant with %SIG - most event libraries provide safe signals).
684
685That means you I<MUST NOT> call any fucntion that might "block" the
686current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or
687anything that calls those. Everything else, including calling C<ready>,
688works.
689
690=back
691
670 692
671=head1 SEE ALSO 693=head1 SEE ALSO
672 694
673Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. 695Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
674 696

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines