/* Must be called with nklock locked irqs off */
int __xnselect_signal(struct xnselect *select_block, unsigned state)
{
xnholder_t *holder;
int resched;
for(resched = 0, holder = getheadq(&select_block->bindings);
holder; holder = nextq(&select_block->bindings, holder)) {
struct xnselect_binding *binding;
struct xnselector *selector;
binding = link2binding(holder, link);
selector = binding->selector;
if (state) {
if (!__FD_ISSET(binding->bit_index,
&selector->fds[binding->type].pending)) {
__FD_SET(binding->bit_index,
&selector->fds[binding->type].pending);
if (xnselect_wakeup(selector))
resched = 1;
}
} else
__FD_CLR(binding->bit_index,
&selector->fds[binding->type].pending);
}
return resched;
}
/**
* Destroy the @a xnselect structure associated with a file descriptor.
*
* Any binding with a @a xnselector block is destroyed.
*
* @param select_block pointer to the @a xnselect structure associated with a file descriptor
*/
void xnselect_destroy(struct xnselect *select_block)
{
xnholder_t *holder;
int resched = 0;
spl_t s;
xnlock_get_irqsave(&nklock, s);
while ((holder = getq(&select_block->bindings))) {
struct xnselect_binding *binding;
struct xnselector *selector;
binding = link2binding(holder, link);
selector = binding->selector;
__FD_CLR(binding->bit_index,
&selector->fds[binding->type].expected);
if (!__FD_ISSET(binding->bit_index,
&selector->fds[binding->type].pending)) {
__FD_SET(binding->bit_index,
&selector->fds[binding->type].pending);
if (xnselect_wakeup(selector))
resched = 1;
}
removeq(&selector->bindings, &binding->slink);
xnlock_put_irqrestore(&nklock, s);
xnfree(binding);
xnlock_get_irqsave(&nklock, s);
}
if (resched)
xnpod_schedule();
xnlock_put_irqrestore(&nklock, s);
}
static int exa_select(struct exa_select *sel)
{
int i;
int one=0;
int ret = -EFAULT;
/* first phase register on each queue */
for (i = 0; i < __FD_SETSIZE; i++)
{
__FD_CLR(i, &sel->result);
if (__FD_ISSET(i, &sel->select))
{
sel->elt[i].socket = exa_getsock(i);
if (sel->elt[i].socket == NULL)
{
ret = -EINVAL;
continue;
}
set_callbacks(sel->elt[i].socket, &sel->elt[i]);
if (sel->operation == EXA_SELECT_IN)
{
if (sock_readable(sel->elt[i].socket) == 1)
one = 1;
}
if (sel->operation == EXA_SELECT_OUT)
if (sock_writable(sel->elt[i].socket) == 1)
one = 1;
}
}
/* second phase : check if nothing arrived and wait if nothing arrived */
if (one==0)
{
int timeout = SELECT_TIMEOUT ;
set_current_state(TASK_INTERRUPTIBLE);
for (i = 0; i < __FD_SETSIZE; i++)
{
if (__FD_ISSET(i, &sel->select) && (sel->elt[i].socket != NULL))
{
if (sel->operation == EXA_SELECT_IN)
{
if (sock_readable(sel->elt[i].socket) == 1)
one = 1;
}
if (sel->operation == EXA_SELECT_OUT)
{
if (sock_writable(sel->elt[i].socket) == 1)
one = 1;
}
}
}
if (one == 0) /* if some data already pending, we must not wait (or some race can occur)*/
timeout = schedule_timeout(timeout);
set_current_state(TASK_RUNNING);
}
/* third : find wich socket receive/sent something */
for (i = __FD_SETSIZE - 1; i >= 0; i--)
{
if (__FD_ISSET(i, &sel->select))
{
if (sel->elt[i].socket == NULL)
continue;
if (sel->operation == EXA_SELECT_IN)
{
if (sock_readable(sel->elt[i].socket) == 1)
__FD_SET(i, &sel->result);
}
if (sel->operation == EXA_SELECT_OUT)
{
if (sock_writable(sel->elt[i].socket) == 1)
__FD_SET(i, &sel->result);
}
if ((__FD_ISSET(i, &sel->result)) && (ret == -EFAULT))
ret = 0;
restore_callbacks(sel->elt[i].socket, &sel->elt[i]);
fput(sel->elt[i].socket->file);
sel->elt[i].socket = NULL;
}
}
/* XXX this is not an error, -EFAULT is used here as the timeout return
* value....
* FIXME use ETIME to have an explicit timeout. */
if (ret == -EFAULT)
__FD_ZERO(&sel->result);
return ret;
}