Programowanie współbieżne w języku Java

final double[][] c) {
// check(a,b,c);
final int m = a.length;
final int n = b.length;
final int p = b[0].length;
}
final double[] Bcolj = new double[n];
for (int j = 0; j < p; j++) {
for (int k = 0; k < n; k++) {
Bcolj[k] = b[k][j];
}
for (int i = 0; i < m; i++) {
final double[] Arowi = a[i];
double s = 0;
for (int k = 0; k < n; k++) {
s += Arowi[k] * Bcolj[k];
}
c[i][j] = s;
}
}
// Jama type method which uses several threads
static void threadedMatrixMultiply(final double[][] a, final double[][] b,
final double[][] c, final int numTasks) {
// check(a,b,c);
final int m = a.length;
final int n = b.length;
final int p = b[0].length;
final ExecutorService executor = Executors.newFixedThreadPool(numTasks);
for (int interval = numTasks, end = p, size = (int) Math.ceil(p * 1.0 /
numTasks);
interval > 0; interval--, end -= size) {
final int to = end;
final int from = Math.max(0, end - size);
final Runnable runnable = new Runnable() {
public void run() {
final double[] Bcolj = new double[n];
for (int j = from; j < to; j++) {
for (int k = 0; k < n; k++) {
Bcolj[k] = b[k][j];
}
for (int i = 0; i < m; i++) {
final double[] Arowi = a[i];
double s = 0;
for (int k = 0; k < n; k++) {
s += Arowi[k] * Bcolj[k];
}
c[i][j] = s;
}
}
}
};
executor.execute(runnable);
}
try {
executor.shutdown();
executor.awaitTermination(2, TimeUnit.DAYS); // O(n^3) can take a
while!
} catch (final InterruptedException e) {
System.out.println("Interrupted.");
// empty(c);
}
}
public static void printMatrix(double[][] A, int aRow, int aCol, String
str) {
System.out.println("Matrix " + str + " nRows = " + aRow + " nCols = " +
aCol);
Lab. „Programowanie współbieżne w języku Java”
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