public static void main(String[] args) throws Exception {
int n = 1 << 18;
int reps = 1 << 8;
Rand[] array = new Rand[n];
for (int i = 0; i < n; ++i) array[i] = new Rand(i + 1);
ForkJoinPool fjp = new ForkJoinPool(1);
ParallelArray<Rand> pa = ParallelArray.createUsingHandoff(array, fjp);
final GetNext getNext = new GetNext();
final Accum accum = new Accum();
final Long zero = Long.valueOf(0);
long last, now;
double elapsed;
for (int j = 0; j < 2; ++j) {
long rseed = rng.nextLong();
resetSeeds(array, rseed);
long seqsum = 0;
last = System.nanoTime();
for (int k = 0; k < reps; ++k) {
seqsum += seqMapReduce(array, getNext, accum, zero);
Rand tmp = array[k];
array[k] = array[n - k - 1];
array[n - k - 1] = tmp;
}
now = System.nanoTime();
elapsed = (double) (now - last) / NPS;
last = now;
System.out.printf("sequential: %7.3f\n", elapsed);
for (int i = 2; i <= NCPU; i <<= 1) {
resetSeeds(array, rseed);
long sum = 0;
fjp.setPoolSize(i);
last = System.nanoTime();
for (int k = 0; k < reps; ++k) {
sum += pa.withMapping(getNext).reduce(accum, zero);
Rand tmp = array[k];
array[k] = array[n - k - 1];
array[n - k - 1] = tmp;
}
now = System.nanoTime();
elapsed = (double) (now - last) / NPS;
last = now;
System.out.printf("poolSize %3d: %7.3f\n", i, elapsed);
if (sum != seqsum) throw new Error("checksum");
}
for (int i = NCPU; i >= 1; i >>>= 1) {
resetSeeds(array, rseed);
long sum = 0;
fjp.setPoolSize(i);
last = System.nanoTime();
for (int k = 0; k < reps; ++k) {
sum += pa.withMapping(getNext).reduce(accum, zero);
Rand tmp = array[k];
array[k] = array[n - k - 1];
array[n - k - 1] = tmp;
}
now = System.nanoTime();
elapsed = (double) (now - last) / NPS;
last = now;
System.out.printf("poolSize %3d: %7.3f\n", i, elapsed);
if (sum != seqsum) throw new Error("checksum");
}
}
fjp.shutdownNow();
fjp.awaitTermination(1, TimeUnit.SECONDS);
Thread.sleep(100);
}
/** new list contains all elements of initializing array */
public void testConstructor2() {
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE - 1; ++i) ints[i] = new Integer(i);
List a = ParallelArray.createUsingHandoff(ints, ParallelArray.defaultExecutor()).asList();
for (int i = 0; i < SIZE; ++i) assertEquals(ints[i], a.get(i));
}