use strict;
use warnings;
use base qw(PublicInbox::Lock);
+use 5.010_001;
use PublicInbox::SearchIdxShard;
use PublicInbox::MIME;
use PublicInbox::Git;
# to increase Xapian shards
our $NPROC_MAX_DEFAULT = 4;
+sub detect_nproc () {
+ for my $nproc (qw(nproc gnproc)) { # GNU coreutils nproc
+ `$nproc 2>/dev/null` =~ /^(\d+)$/ and return $1;
+ }
+
+ # getconf(1) is POSIX, but *NPROCESSORS* vars are not
+ for (qw(_NPROCESSORS_ONLN NPROCESSORS_ONLN)) {
+ `getconf $_ 2>/dev/null` =~ /^(\d+)$/ and return $1;
+ }
+
+ # should we bother with `sysctl hw.ncpu`? Those only give
+ # us total processor count, not online processor count.
+ undef
+}
+
sub nproc_shards ($) {
my ($creat_opt) = @_;
my $n = $creat_opt->{nproc} if ref($creat_opt) eq 'HASH';
$n //= $ENV{NPROC};
if (!$n) {
- chomp($n = `nproc 2>/dev/null`);
- # assume 2 cores if GNU nproc(1) is not available
- $n = 2 if !$n;
+ # assume 2 cores if not detectable or zero
+ state $NPROC_DETECTED = detect_nproc() || 2;
+ $n = $NPROC_DETECTED;
$n = $NPROC_MAX_DEFAULT if $n > $NPROC_MAX_DEFAULT;
}