int poll(FAR struct pollfd *fds, nfds_t nfds, int timeout)
{
WDOG_ID wdog;
sem_t sem;
int count = 0;
int ret;
sem_init(&sem, 0, 0);
ret = poll_setup(fds, nfds, &sem);
if (ret >= 0)
{
if (timeout >= 0)
{
/* Wait for the poll event with a timeout. Note that the
* millisecond timeout has to be converted to system clock
* ticks for wd_start
*/
wdog = wd_create();
wd_start(wdog, MSEC2TICK(timeout), poll_timeout, 1, (uint32_t)&sem);
poll_semtake(&sem);
wd_delete(wdog);
}
else
{
/* Wait for the poll event with no timeout */
poll_semtake(&sem);
}
/* Teardown the poll operation and get the count of events */
ret = poll_teardown(fds, nfds, &count);
}
sem_destroy(&sem);
/* Check for errors */
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return count;
}
int poll(FAR struct pollfd *fds, nfds_t nfds, int timeout)
{
struct timespec abstime;
irqstate_t flags;
sem_t sem;
int count = 0;
int ret;
sem_init(&sem, 0, 0);
ret = poll_setup(fds, nfds, &sem);
if (ret >= 0)
{
if (timeout == 0)
{
/* Poll returns immediately whether we have a poll event or not. */
}
else if (timeout > 0)
{
time_t sec;
uint32_t nsec;
/* Either wait for either a poll event(s) to occur or for the
* specified timeout to elapse with no event.
*
* NOTE: If a poll event is pending (i.e., the semaphore has already
* been incremented), sem_timedwait() will not wait, but will return
* immediately.
*/
sec = timeout / MSEC_PER_SEC;
nsec = (timeout - MSEC_PER_SEC * sec) * NSEC_PER_MSEC;
/* Make sure that the following are atomic by disabling interrupts.
* Interrupts will be re-enabled while we are waiting.
*/
flags = irqsave();
(void)clock_gettime(CLOCK_REALTIME, &abstime);
abstime.tv_sec += sec;
abstime.tv_nsec += nsec;
if (abstime.tv_nsec > NSEC_PER_SEC)
{
abstime.tv_sec++;
abstime.tv_nsec -= NSEC_PER_SEC;
}
(void)sem_timedwait(&sem, &abstime);
irqrestore(flags);
}
else
{
/* Wait for the poll event with no timeout */
poll_semtake(&sem);
}
/* Teardown the poll operation and get the count of events. Zero will be
* returned in the case of a timeout.
*/
ret = poll_teardown(fds, nfds, &count);
}
sem_destroy(&sem);
/* Check for errors */
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return count;
}
