/** Get a MMAL_BUFFER_HEADER_T from a QUEUE. */
MMAL_BUFFER_HEADER_T *mmal_queue_get(MMAL_QUEUE_T *queue)
{
vcos_assert(queue);
if(!queue) return 0;
if(vcos_semaphore_trywait(&queue->semaphore) != VCOS_SUCCESS)
return NULL;
return mmal_queue_get_core(queue);
}
/**
* <DFN>vc_hdcp2_service_wait_for_reply</DFN> blocks until a response comes back
* from Videocore.
*
* @param client_handle is the vchi client handle
*
* @param sema is the signalling semaphore indicating a reply
*
* @param response is the reponse buffer
*
* @param max_length is the maximum length of the buffer
*
* @param actual_length will be set to the actual length of the buffer (or zero if error)
*
* @return zero if successful, vchi error code otherwise
*/
int32_t vc_hdcp2_service_wait_for_reply(VCHI_SERVICE_HANDLE_T client_handle,
VCOS_SEMAPHORE_T *sema,
void *response, uint32_t max_length, uint32_t *actual_length) {
int32_t success = 0;
VCOS_STATUS_T status;
uint32_t length_read = 0;
vcos_assert(sema);
vcos_assert(response && max_length);
do {
//TODO : we need to deal with messages coming through on more than one connections properly
//At the moment it will always try to read the first connection if there is something there
//Check if there is something in the queue, if so return immediately
//otherwise wait for the semaphore and read again
success = vchi_msg_dequeue( client_handle, response, max_length, &length_read, VCHI_FLAGS_NONE );
} while( length_read == 0 || (status = vcos_semaphore_trywait(sema)) != VCOS_SUCCESS);
if(vcos_verify(*actual_length)) {
*actual_length = (success == 0)? length_read : 0;
}
return success;
}
