php – 有人可以解释一下这个关于mysqli close函数的陈述吗？

You should always use mysqli_kill()
function before mysqli_close() to
actually close and free up the tcp
socket being used by PHP. Garbage
collection after script execution nor
mysqli_close() do not kill the tcp
socket on their own. The socket would
otherwise remain in ‘wait’ state for
approximately 30 seconds,and any
additional page loads/connection
attempts would only add to the total
number of open tcp connections. This
wait time does not appear to be
configurable via PHP settings.

Also as of this version,mysqli
created links cannot be “deactivated”,
and will continue to accumulate in
process memory until the PHP server or
process is restarted,essentially
making mysqli.max_links = -1 required.

有人可以解释这意味着什么,如果应该设置mysqli.max_links,怎么做,如果我应该使用mysqli_kill();