Perl threads::shared for nested data structure

Question

# thread::shared only allws a single level of shared structure
# needs a explicit hash creation for nested data structures
my %counts     : shared = ();
foreach my $state (%known_states) {
    # COUNTS
    unless (exists $counts{build}) {
        my %cb : shared;
        $counts{build} = %cb;
    }
    $counts{build}{$state} = 0;
}

现在，我必须

做类似上面的事情，我必须为每个子级哈希显式创建一个哈希引用。

有没有更好的方法？

附言如果我不创建哈希引用，那么我会收到"共享标量值无效"错误，因为我试图将其用作哈希。

Answer 1

自活化使

$counts{build}{$state} = 0;

表现得像

( $counts{build} //= {} )->{$state} = 0;

为了可读性，让我们把它变成两行

$counts{build} //= {};
$counts{build}{$state} = 0;

但就像你说的，我们需要一个共享哈希。

$counts{build} //= &share({});
$counts{build}{$state} = 0;

您可以添加以下内容以确保不会意外地激活未共享的变量：

no autovivification qw( fetch store exists delete );