Question

我在perl脚本中遇到了一些内存泄漏问题，我正在运行很长一段时间，其中perl占用的内存量正在不断增长。因此，我尝试使用Devel::Leak来追踪泄漏。我发现每当我调用DBI的prepare方法时，Devel::Leak返回的标量值的数量就会增加一个。下面是我编写的测试脚本，它正在完成我正在描述的内容：

#!/usr/bin/perl
use strict;
use Devel::Leak;
use DBI;

START:
my $handle; # apparently this doesn't need to be anything at all
my $leaveCount = 0;
my $enterCount = Devel::Leak::NoteSV($handle);
print "ENTER: $enterCount SVs\n";
{
    # CONFIG VARIABLES
    my $platform = "mysql";
    my $database = "db";
    my $host = "localhost";
    my $port = "3306";
    my $user = "user";
    my $pw = "pass";

    #DATA SOURCE NAME
    my $dsn = "dbi:mysql:$database:$host:3306";

    # PERL DBI CONNECT
    my $dbh = DBI->connect($dsn, $user, $pw);
    $dbh->prepare("SELECT * FROM table"); # The script seems to gain one SV without this
                                          # line here, but since this is my issue in my
                                          # main script I decided to leave it in
    # undef $dbh; I tried undef-ing this, but it made no difference
}
$leaveCount = Devel::Leak::CheckSV($handle);
print "\nLEAVE: $leaveCount SVs\n";
sleep(1);
goto START;

那么我在这里做错了什么，或者这是DBI模块中的内存泄漏？另外，我知道每次在循环中添加一个SV并不是一个大问题，并且我很可能在其他地方有更大的内存泄漏，导致perl占用服务器的大量内存。但是，如果可以的话，我还是想解决这个问题。编码器的好奇心:)）

更新：

第一次通过它似乎增加了大约3,000个SV，然后每次增加它一次增加1个。

Answer 1

有一个DBI :: dr（一个有福的哈希）的实例，它位于$ DBI :: lasth。查看ChildHandles密钥。

#!/usr/bin/perl

use strict;
use warnings;
use Devel::Leak;
use Data::Dumper;
use Symbol::Table;
use DBI;

START:
{
    my $handle;
    my $enterCount = Devel::Leak::NoteSV($handle);

    DB:
    {
        my $platform = "mysql";
        my $database = "db";
        my $host     = "localhost";
        my $port     = "3306";
        my $user     = "user";
        my $pw       = "pass";

        my $dsn = "dbi:mysql:$database:$host:3306";

        my $dbh = DBI->connect( $dsn, $user, $pw );

        $dbh->prepare("SELECT * FROM table");

        $dbh->disconnect();
    }

    my $st = Symbol::Table->New( 'SCALAR', 'DBI' );

    for my $subpkg ( keys %{ $st } ) {

        my $val;
        {
            my $var = "DBI::${subpkg}";
            no strict 'refs';
            $val = ${$var};
        }

        print "scalar '$subpkg' => '$val'\n";
    }

    print Dumper( $DBI::lasth );

    $DBI::lasth->{ChildHandles} = []; # <-- reset leaking data structure

    my $leaveCount = Devel::Leak::CheckSV($handle);

    print "\nCOUNT: $enterCount to $leaveCount SVs\n";

    sleep(1);

    redo START;
}

perl DBI内存泄漏

1 个答案: