Function magma_enumerate_devices 

pub unsafe extern "C" fn magma_enumerate_devices(
    device_namespace: *const c_char,
    device_directory_channel: magma_handle_t,
    device_count_inout: *mut u32,
    device_path_size: u32,
    device_paths_out: *mut c_char,
) -> magma_status_t

\brief Returns information describing the magma devices that are available. NOTE - this is appropriate for use only if devices are guaranteed to be present at the time the call is made. On Fuchsia, this guarantee is provided by the loader design for Vulkan ICDs. Other asynchronous environments may require a directory watcher mechanism to handle racy startup conditions. Returns: MAGMA_STATUS_MEMORY_ERROR if |device_count_inout| is insufficient; MAGMA_STATUS_INVALID_ARGS if |device_path_size| is insufficient. \param device_namespace Namespace corresponding to the |device_directory_channel|; this should be MAGMA_DEVICE_NAMESPACE. Used only on Fuchsia. \param device_directory_channel Channel used for reading devices from |device_namespace|. Used only on Fuchsia. \param device_count_inout The number of array elements in |device_paths_out|. On success, will be set to the number of elements written. \param device_path_size Size of each entry in |device_paths_out|. PATH_MAX should be sufficient. \param device_paths_out Pointer to storage for magma device paths. The buffer’s size in bytes should be |*device_count_inout| * |device_path_size|.