static int check_event(struct elem_set_trial *trial, unsigned int mask,
unsigned int expected_count)
{
struct pollfd pfds;
int count;
unsigned short revents;
snd_ctl_event_t *event;
int err;
snd_ctl_event_alloca(&event);
if (snd_ctl_poll_descriptors_count(trial->handle) != 1)
return -ENXIO;
if (snd_ctl_poll_descriptors(trial->handle, &pfds, 1) != 1)
return -ENXIO;
while (expected_count > 0) {
count = poll(&pfds, 1, 1000);
if (count < 0)
return errno;
/* Some events are already supplied. */
if (count == 0)
return -ETIMEDOUT;
err = snd_ctl_poll_descriptors_revents(trial->handle, &pfds,
count, &revents);
if (err < 0)
return err;
if (revents & POLLERR)
return -EIO;
if (!(revents & POLLIN))
continue;
err = snd_ctl_read(trial->handle, event);
if (err < 0)
return err;
if (snd_ctl_event_get_type(event) != SND_CTL_EVENT_ELEM)
continue;
/*
* I expect each event is generated separately to the same
* element.
*/
if (!(snd_ctl_event_elem_get_mask(event) & mask))
continue;
--expected_count;
}
if (expected_count != 0)
return -EIO;
return 0;
}
/**
* \brief get count of poll descriptors for HCTL handle
* \param hctl HCTL handle
* \return count of poll descriptors
*/
int snd_hctl_poll_descriptors_count(snd_hctl_t *hctl)
{
assert(hctl);
return snd_ctl_poll_descriptors_count(hctl->ctl);
}
