Re: [心得] 比較陣列的相減後取絕對值速度

[DearKurt ("小朋友"會自己找出路...)]

小弟只針對一維的程式去修改成多執行緒

static void Main(string[] args)
{
    ushort[] myArray1 = new ushort[2452 * 2054];
    ushort[] myArray2 = new ushort[2452 * 2054];
    ushort[] myArray3 = new ushort[2452 * 2054];

    //視核心數量 雙核就2個AutoResetEvent
    AutoResetEvent[] aREs = new AutoResetEvent[2];
    Random myRnd = new Random();
    TimeSpan clock01 = new TimeSpan();
    int cycleTimes = 10;

    for (int i = 0; i < cycleTimes; i++)
    {
        //AutoResetEvent初始化
        for (int j = 0; j < aREs.Length; j++)
        {
            aREs[j] = new AutoResetEvent(false);
        }

        for (int j = 0; j < myArray1.Length; j++)
        {
            //NextDouble()取整數後是0 改成這樣可能比較適當
            myArray1[j] = (ushort)myRnd.Next(256*256);
            myArray2[j] = (ushort)myRnd.Next(256*256);
        }

        System.DateTime startTime = DateTime.Now;

        //把原本for loop拆成多個執行緒去執行
        for (int k = 0; k < aREs.Length; k++)
        {
            int y = k;
            ThreadPool.QueueUserWorkItem(new WaitCallback(delegate(object o)
            {
                for (int j = y; j < myArray1.Length; j += aREs.Length)
                {

                    myArray3[j] = (ushort)Math.Abs(myArray1[j] - myArray2[j]);

                }
                aREs[y].Set();
            }));
        }

        WaitHandle.WaitAll(aREs);

        clock01 = (DateTime.Now - startTime) + clock01;
    }
    Console.WriteLine((clock01.TotalMilliseconds / cycleTimes).ToString());
    Console.ReadLine();
}

cpu是AthlonIIx2 240超到3.5G
用build完的執行檔跑
單執行緒平均45ms 雙執行緒平均26ms
如果是四核心的i7 每秒超過30張應該是沒問題了XD

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※ 編輯: DearKurt        來自: 124.11.129.161       (01/17 00:56)