Is perl DBD::mysql thread safe under RHEL6.5?

Issue

• On RHEL 6.5, are "_r" libraries thread safe versions?

# ldd /usr/lib64/perl5/vendor_perl/auto/DBD/mysql/mysql.so | grep mysql
  libmysqlclient.so.16 => /usr/lib64/mysql/libmysqlclient.so.16 (0x00007fa564515000)

# ls -l /usr/lib64/mysql/libmysqlclient*
lrwxrwxrwx. 1 root root      26 Jan 25 09:15 /usr/lib64/mysql/libmysqlclient_r.so.16 -> libmysqlclient_r.so.16.0.0
-rwxr-xr-x  1 root root 1598280 Feb  4  2014 /usr/lib64/mysql/libmysqlclient_r.so.16.0.0
lrwxrwxrwx. 1 root root      24 Jan 25 09:15 /usr/lib64/mysql/libmysqlclient.so.16 -> libmysqlclient.so.16.0.0
-rwxr-xr-x  1 root root 1587712 Feb  4  2014 /usr/lib64/mysql/libmysqlclient.so.16.0.0