Functions to create, destroy and control sensors on the device.
This file defines the sensor service, which provides functions for creating, deleting, and controlling sensors on the device. Controlling a sensor includes assigning which sigevent will be used as a notification for the sensor, sending sigevents to the sensor, setting the delays between events, enabling/disable event queues, background mode and reduced reporting. This file also contains functions for retrieving the latest event from a sensor, and a function that blocks a thread until data is available or a timeout has occurred.