perl 通过信号控制执行超时

[oracle@yyjk tmp]$ cat check_oracle.pl
use DBI;   
use Crypt::RC4::XS;
use HTTP::Date qw(time2iso str2time time2iso time2isoz); 
use Net::SMTP;
use Encode;
use JSON;
use Sys::SigAction qw( set_sig_handler );
use Net::Ping;
use POSIX;
no warnings;
my $dbName = 'tlyy';   
my $dbUser = 'tlcbuser';
my $dbUserPass = 'xxxxx';   
my $XDATE = strftime("%Y%m%d%H%M%S",localtime());
my $dbip='192.168.137.1';
$dbh1 = DBI->connect( "dbi:Oracle://$dbip:1521/$dbname", $dbuser, $dbpass ) or die "Cannot conenct db: $DBI::errstr\n";
[oracle@yyjk tmp]$ time perl check_oracle.pl
DBI connect('//192.168.137.1:1521/','',...) failed: ORA-12170: TNS: 连接超时 (DBD ERROR: OCIServerAttach) at check_oracle.pl line 16.
Cannot conenct db: ORA-12170: TNS: 连接超时 (DBD ERROR: OCIServerAttach)