CPU使用率DLL使う側(Unity)

CPUUsage.cs

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System.Runtime.InteropServices;

public class CPUUsage : MonoBehaviour {
    [DllImport("CPUUsage")]
    private static extern void StartCPUUsage(uint usage);
    [DllImport("CPUUsage")]
    private static extern long GetCPUUsage();

    // Use this for initialization
    void Start () {
        // CPU測定開始(1000m秒毎)
        StartCPUUsage(1000);
    }

    // Update is called once per frame
    void Update () {
        // 測定結果取得
        long usage = GetCPUUsage();
        this.GetComponent<Text>().text = string.Format("CPU {0,3}%", usage.ToString());
    }
}