(PHP 5 >= 5.4.0)
SessionHandlerInterface::destroy — Destroy a session
$session_id
)
Destroys a session. Called by session_regenerate_id() (with $destroy = TRUE),
session_destroy() and when session_decode() fails.
session_id
The session ID being destroyed.
会话存储的返回值（通常成功返回 0，失败返回 1）。