CODEWITHSUNDEEP
c#threadpoolmatrix-multiplicationqueueuserworkitem
Twoengineers
Twoengineers

Reputation: 11

ThreadPool.QueueUserWorkItem, The Thread Exited has with code 0 (0x0)

    #region Parallel_Loop
    static void MultiplyMatricesParallel(int[,] matA, int[,] matB, int[,] result)
    {
        int matACols = matA.GetLength(1);
        int matBCols = matB.GetLength(1);
        int matARows = matA.GetLength(0);
        int count = 0;
        // A basic matrix multiplication.
        // Parallelize the outer loop to partition the source array by rows.
        Parallel.For(0, matARows, i =>
        {
            for (int j = 0; j < matBCols; j++)
            {
                int temp = 0;
                int numThreads = (commonFeatures.resultMatrix.GetLength(0)* commonFeatures.resultMatrix.GetLength(1));
                int toProcess = numThreads;
                var resetEvent = new ManualResetEvent(false);
                ThreadPool.QueueUserWorkItem(
    new WaitCallback(delegate (object state) {
        rowColCall(matACols, temp, matA, matB, i, j);
        if (Interlocked.Decrement(ref toProcess) == 0) resetEvent.Set();
    }), null);
                resetEvent.WaitOne();
            }
        }); // Parallel.For
    }
    #endregion


    public static int rowCol(int matACols, int temp, int [,] matA, int [,] matB, int i, int j) {
        for (int k = 0; k < matACols; k++)
        {
            temp += matA[i, k] * matB[k, j];
        }
        return temp;
    }

    public static void rowColCall(int matACols, int temp, int[,] matA, int[,] matB, int i, int j) {

        int a = rowCol(matACols, temp, matA, matB, i, j);
        Console.WriteLine(i + "," + j + " = " + a);
        Console.ReadLine();
    }

Hi,

I'm new on threadpool usage and doing matrix multiplication on c# by using thread pool(ThreadPool.QueueUserWorkItem.) on row*col multiplication. When I execute my code with Matrices {1 2 3 4; 0 0 2 4} and {1 4, 1 5, 3 6, 4,7} it returns me as output:

0,0 = 28 1,0 = 22 The thread 0x179c has exited with code 0 (0x0). The thread 0x1fd4 has exited with code 0 (0x0).

So it calculates first two threads and waits in infinite loop; I don't know why.

Upvotes: 0

Views: 240

Answers (0)

Related Questions