阅读了这个问题后，我决定改编我的程序。我的新程序无需同步即可运行良好。谢谢您的想法，彼得。
新代码：
package algorithms;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.Future;import java.util.concurrent.FutureTask;public class Java6MatrixMultiply implements Algorithm { private static final int SIZE = 2048; private static final int THRESHOLD = 64; private static final int MAX_THREADS = Runtime.getRuntime().availableProcessors(); private final ExecutorService executor = Executors.newFixedThreadPool(MAX_THREADS); private float[][] a = new float[SIZE][SIZE]; private float[][] b = new float[SIZE][SIZE]; private float[][] c = new float[SIZE][SIZE]; @Override public void initialize() { init(a, b, SIZE); } @Override public void execute() { MatrixMultiplyTask mainTask = new MatrixMultiplyTask(a, 0, 0, b, 0, 0, c, 0, 0, SIZE); Future future = executor.submit(mainTask); try { future.get(); } catch (Exception e) { System.out.println("Error: " + e.getMessage()); } } @Override public void printResult() { check(c, SIZE); for (int i = 0; i < SIZE && i <= 10; i++) { for (int j = 0; j < SIZE && j <= 10; j++) { if(j == 10) { System.out.print("..."); } else { System.out.print(c[i][j] + " "); } } if(i == 10) { System.out.println(); for(int k = 0; k < 10; k++) System.out.print(" ... "); } System.out.println(); } System.out.println(); } // To simplify checking, fill with all 1's. Answer should be all n's. static void init(float[][] a, float[][] b, int n) { for (int i = 0; i < n; ++i) { for (int j = 0; j < n; ++j) { a[i][j] = 1.0F; b[i][j] = 1.0F; } } } static void check(float[][] c, int n) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (c[i][j] != n) { throw new Error("Check Failed at [" + i + "][" + j + "]: " + c[i][j]); //System.out.println("Check Failed at [" + i + "][" + j + "]: " + c[i][j]); } } }} public class Seq implements Runnable { private final MatrixMultiplyTask a; private final MatrixMultiplyTask b; public Seq(MatrixMultiplyTask a, MatrixMultiplyTask b) { this.a = a; this.b = b; } public void run() { a.run(); b.run(); } } private class MatrixMultiplyTask implements Runnable { private final float[][] A; // Matrix A private final int aRow; // first row of current quadrant of A private final int aCol; // first column of current quadrant of A private final float[][] B; // Similarly for B private final int bRow; private final int bCol; private final float[][] C; // Similarly for result matrix C private final int cRow; private final int cCol; private final int size; public MatrixMultiplyTask(float[][] A, int aRow, int aCol, float[][] B, int bRow, int bCol, float[][] C, int cRow, int cCol, int size) { this.A = A; this.aRow = aRow; this.aCol = aCol; this.B = B; this.bRow = bRow; this.bCol = bCol; this.C = C; this.cRow = cRow; this.cCol = cCol; this.size = size; } public void run() { //System.out.println("Thread: " + Thread.currentThread().getName()); if (size <= THRESHOLD) { multiplyStride2(); } else { int h = size / 2; Seq seq1 = new Seq(new MatrixMultiplyTask(A, aRow, aCol, // A11 B, bRow, bCol, // B11 C, cRow, cCol, // C11 h), new MatrixMultiplyTask(A, aRow, aCol + h, // A12 B, bRow + h, bCol, // B21 C, cRow, cCol, // C11 h)); Seq seq2 = new Seq(new MatrixMultiplyTask(A, aRow, aCol, // A11 B, bRow, bCol + h, // B12 C, cRow, cCol + h, // C12 h), new MatrixMultiplyTask(A, aRow, aCol + h, // A12 B, bRow + h, bCol + h, // B22 C, cRow, cCol + h, // C12 h)); Seq seq3 = new Seq(new MatrixMultiplyTask(A, aRow + h, aCol, // A21 B, bRow, bCol, // B11 C, cRow + h, cCol, // C21 h), new MatrixMultiplyTask(A, aRow + h, aCol + h, // A22 B, bRow + h, bCol, // B21 C, cRow + h, cCol, // C21 h)); Seq seq4 = new Seq(new MatrixMultiplyTask(A, aRow + h, aCol, // A21 B, bRow, bCol + h, // B12 C, cRow + h, cCol + h, // C22 h), new MatrixMultiplyTask(A, aRow + h, aCol + h, // A22 B, bRow + h, bCol + h, // B22 C, cRow + h, cCol + h, // C22 h)); final FutureTask s1Task = new FutureTask(seq2, null); final FutureTask s2Task = new FutureTask(seq3, null); final FutureTask s3Task = new FutureTask(seq4, null); executor.execute(s1Task); executor.execute(s2Task); executor.execute(s3Task); seq1.run(); s1Task.run(); s2Task.run(); s3Task.run(); try { s1Task.get(); s2Task.get(); s3Task.get(); } catch (Exception e) { System.out.println("Error: " + e.getMessage()); executor.shutdownNow(); } } } public void multiplyStride2() { for (int j = 0; j < size; j += 2) { for (int i = 0; i < size; i += 2) { float[] a0 = A[aRow + i]; float[] a1 = A[aRow + i + 1]; float s00 = 0.0F; float s01 = 0.0F; float s10 = 0.0F; float s11 = 0.0F; for (int k = 0; k < size; k += 2) { float[] b0 = B[bRow + k]; s00 += a0[aCol + k] * b0[bCol + j]; s10 += a1[aCol + k] * b0[bCol + j]; s01 += a0[aCol + k] * b0[bCol + j + 1]; s11 += a1[aCol + k] * b0[bCol + j + 1]; float[] b1 = B[bRow + k + 1]; s00 += a0[aCol + k + 1] * b1[bCol + j]; s10 += a1[aCol + k + 1] * b1[bCol + j]; s01 += a0[aCol + k + 1] * b1[bCol + j + 1]; s11 += a1[aCol + k + 1] * b1[bCol + j + 1]; } C[cRow + i][cCol + j] += s00; C[cRow + i][cCol + j + 1] += s01; C[cRow + i + 1][cCol + j] += s10; C[cRow + i + 1][cCol + j + 1] += s11; } } } }}
