udev_new, udev_ref, udev_unref - Create, acquire and release a udev context object
struct udev *udev_new(void);
struct udev *udev_ref(struct udev *udev);
struct udev *udev_unref(struct udev *udev);
udev_new() allocates a new udev context object and returns a pointer to it. This object is opaque and must not be accessed by the caller via different means than functions provided by libudev. Initially, the reference count of the context is 1. You can acquire further references, and drop gained references via udev_ref() and udev_unref(). Once the reference count hits 0, the context object is destroyed and freed.
On success, udev_new() returns a pointer to the allocated udev context. On failure, NULL is returned. udev_ref() returns the argument that it was passed, unmodified. udev_unref() always returns NULL.