使用多线程两个线程返回相同的值与不同的输入?

时间:2012-12-20 22:00:46

标签: .net multithreading

您好我是多线程并尝试将其合并到我的程序中,以便使特定计算更快地收敛。但是当我创建下面的两个线程时

        Thread firstThread = new Thread(() => { p0 = f(changePoint, result); });
        Thread secondThread = new Thread(() => { p1 = f(changePoint + 1, result); });
        firstThread.Start();
        secondThread.Start();
        firstThread.Join();
        secondThread.Join();

p0和p1中的值相同(p0与p1的值相同)。现在,如果我拿走多线程并只是这样称呼它们:

        p0 = f(changePoint, result);
        p1 = f(changePoint + 1, result);

返回不同的值,一切正常。

我缺少什么?

代码f(x,y)

public double f(double x,double result)
    {

        double temp = PCAcont.Future2Yrs(x).Last().FirstOrDefault().StatNetWorthToAssets.GetValueOrDefault();
        return temp - result;

    }

主要方法

public double SecantMethod(double prec, int stepsCutoff, double changePoint, double result)
    {
        double p2, p1 = 0, p0 = 0;
        int i;

        Thread firstThread = new Thread(() => { p0 = f(changePoint, result); });
        Thread secondThread = new Thread(() => { p1 = f(changePoint + 1, result); });
        firstThread.Start();
        secondThread.Start();
        firstThread.Join();
        secondThread.Join();

        //p0 = f(changePoint, result);
        //p1 = f(changePoint + 1, result);
        p2 = p1 - f(p1, result) * (p1 - p0) / (f(p1, result) - f(p0, result));

        for (i = 0; System.Math.Abs(p2 - p1) > prec && i < stepsCutoff; i++)
        {
            p0 = p1;
            p1 = p2;
            p2 = p1 - f(p1, result) * (p1 - p0) / (f(p1, result) - f(p0,result));
        }
        if (i < stepsCutoff)
            return p2;
        else
        {
            System.Diagnostics.Debug.WriteLine("{0}.The method did not converge", p2);
            return double.NaN;
        }

    }

1 个答案:

答案 0 :(得分:0)

基于你的评论只采取第二个。

看看这个

PCAcont.Future2Yrs(X)。去年()FirstOrDefault()StatNetWorthToAssets.GetValueOrDefault()。;

PCAcont未锁定,您将获得第二个X的结果 你需要锁定。
并锁定了返回,因为linq可能会被推迟。