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Comparing AnyEvent-Fork-Pool/Pool.pm (file contents):
Revision 1.8 by root, Sun Apr 21 12:28:34 2013 UTC vs.
Revision 1.9 by root, Thu Apr 25 00:27:22 2013 UTC

… …
89 89
90use Guard (); 90use Guard ();
91use Array::Heap (); 91use Array::Heap ();
92 92
93use AnyEvent; 93use AnyEvent;
94# explicit version on next line, as some cpan-testers test with the 0.1 version,
95# ignoring dependencies, and this line will at least give a clear indication of that.
94use AnyEvent::Fork; # we don't actually depend on it, this is for convenience 96use AnyEvent::Fork 0.6; # we don't actually depend on it, this is for convenience
95use AnyEvent::Fork::RPC; 97use AnyEvent::Fork::RPC;
96 98
97# these are used for the first and last argument of events 99# these are used for the first and last argument of events
98# in the hope of not colliding. yes, I don't like it either, 100# in the hope of not colliding. yes, I don't like it either,
99# but didn't come up with an obviously better alternative. 101# but didn't come up with an obviously better alternative.
… …
446to this function are effectively read-only - modifying them after the call 448to this function are effectively read-only - modifying them after the call
447and before the callback is invoked causes undefined behaviour. 449and before the callback is invoked causes undefined behaviour.
448 450
449=cut 451=cut
450 452
453=item $cpus = AnyEvent::Fork::Pool::ncpu [$default_cpus]
454
455=item ($cpus, $eus) = AnyEvent::Fork::Pool::ncpu [$default_cpus]
456
457Tries to detect the number of CPUs (C<$cpus> often called cpu cores
458nowadays) and execution units (C<$eus>) which include e.g. extra
459hyperthreaded units). When C<$cpus> cannot be determined reliably,
460C<$default_cpus> is returned for both values, or C<1> if it is missing.
461
462For normal CPU bound uses, it is wise to have as many worker processes
463as CPUs in the system (C<$cpus>), if nothing else uses the CPU. Using
464hyperthreading is usually detrimental to performance, but in those rare
465cases where that really helps it might be beneficial to use more workers
466(C<$eus>).
467
468Currently, F</proc/cpuinfo> is parsed on GNU/Linux systems for both
469C<$cpus> and C<$eu>, and on {Free,Net,Open}BSD, F<sysctl -n hw.ncpu> is
470used for C<$cpus>.
471
472Example: create a worker pool with as many workers as cpu cores, or C<2>,
473if the actual number could not be determined.
474
475 $fork->AnyEvent::Fork::Pool::run ("myworker::function",
476 max => (scalar AnyEvent::Fork::Pool::ncpu 2),
477 );
478
479=cut
480
481BEGIN {
482 if ($^O eq "linux") {
483 *ncpu = sub(;$) {
484 my ($cpus, $eus);
485
486 if (open my $fh, "<", "/proc/cpuinfo") {
487 my %id;
488
489 while (<$fh>) {
490 if (/^core id\s*:\s*(\d+)/) {
491 ++$eus;
492 undef $id{$1};
493 }
494 }
495
496 $cpus = scalar keys %id;
497 } else {
498 $cpus = $eus = @_ ? shift : 1;
499 }
500 wantarray ? ($cpus, $eus) : $cpus
501 };
502 } elsif ($^O eq "freebsd" || $^O eq "netbsd" || $^O eq "openbsd") {
503 *ncpu = sub(;$) {
504 my $cpus = qx<sysctl -n hw.ncpu> * 1
505 || (@_ ? shift : 1);
506 wantarray ? ($cpus, $cpus) : $cpus
507 };
508 } else {
509 *ncpu = sub(;$) {
510 my $cpus = @_ ? shift : 1;
511 wantarray ? ($cpus, $cpus) : $cpus
512 };
513 }
514}
515
451=back 516=back
452 517
453=head1 CHILD USAGE 518=head1 CHILD USAGE
454 519
455In addition to the L<AnyEvent::Fork::RPC> API, this module implements one 520In addition to the L<AnyEvent::Fork::RPC> API, this module implements one

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