sysclose

static VALUE
ossl_ssl_close(VALUE self)
{
    SSL *ssl;

    Data_Get_Struct(self, SSL, ssl);
    ossl_ssl_shutdown(ssl);
    if (RTEST(ossl_ssl_get_sync_close(self)))
        rb_funcall(ossl_ssl_get_io(self), rb_intern("close"), 0);

    return Qnil;
}