/*
* Wait for a DCCP event.
*
* Note that we don't need to lock the socket, as the upper poll layers
* take care of normal races (between the test and the event) and we don't
* go look at any of the socket buffers directly.
*/
unsigned int dccp_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
unsigned int mask;
struct sock *sk = sock->sk;
sock_poll_wait(file, sk_sleep(sk), wait);
if (sk->sk_state == DCCP_LISTEN)
return inet_csk_listen_poll(sk);
/* Socket is not locked. We are protected from async events
by poll logic and correct handling of state changes
made by another threads is impossible in any case.
*/
mask = 0;
if (sk->sk_err)
mask = POLLERR;
if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
mask |= POLLIN | POLLRDNORM | POLLRDHUP;
/* Connected? */
if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
if (atomic_read(&sk->sk_rmem_alloc) > 0)
mask |= POLLIN | POLLRDNORM;
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
if (sk_stream_is_writeable(sk)) {
mask |= POLLOUT | POLLWRNORM;
} else { /* send SIGIO later */
set_bit(SOCK_ASYNC_NOSPACE,
&sk->sk_socket->flags);
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
/* Race breaker. If space is freed after
* wspace test but before the flags are set,
* IO signal will be lost.
*/
if (sk_stream_is_writeable(sk))
mask |= POLLOUT | POLLWRNORM;
}
}
}
return mask;
}
unsigned int dccp_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
unsigned int mask;
struct sock *sk = sock->sk;
sock_poll_wait(file, sk->sk_sleep, wait);
if (sk->sk_state == DCCP_LISTEN)
return inet_csk_listen_poll(sk);
mask = 0;
if (sk->sk_err)
mask = POLLERR;
if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
mask |= POLLIN | POLLRDNORM | POLLRDHUP;
if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
if (atomic_read(&sk->sk_rmem_alloc) > 0)
mask |= POLLIN | POLLRDNORM;
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
mask |= POLLOUT | POLLWRNORM;
} else {
set_bit(SOCK_ASYNC_NOSPACE,
&sk->sk_socket->flags);
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
mask |= POLLOUT | POLLWRNORM;
}
}
}
return mask;
}
