import java.lang.Double;
public class STREAM {
static Object lock = new Object();
static Object lock2 = new Object();
static volatile int _barrier;
static void reach_barrier() { synchronized(lock2) { _barrier++; } }
static double total_bandwidth[] = new double[4];
static String[] label = { "Copy: ", "Scale: ", "Add: ", "Triad: " };
int N;
int M;
int NTIMES;
int OFFSET;
String HLINE ;
int precision;
double[] a ;
double[] b;
double[] c;
double[] avgtime;
double[] maxtime;
double[] mintime;
double[] bytes;
Double tmp;
double FLT_MAX;
long pr(long ticks, int pid, String msg) {
long t = System.currentTimeMillis();
System.out.println("PID "+pid+msg+" ("+((t-ticks)/1000)+" secs since last report)");
return t;
}
public void run(int pid) {
long ticks = pr(System.currentTimeMillis(),pid," begins to allocate");
N = 200000;
M = 20;
NTIMES=10;
OFFSET=0;
HLINE= "-------------------------------------------------------------";
precision = 8; // java uses 8bytes per DOUBLE PRECISION word
tmp= new Double(0);
FLT_MAX =tmp.longBitsToDouble(0x7fefffffffffffffL);
a = new double[N+OFFSET];
b = new double[N+OFFSET];
c = new double[N+OFFSET];
avgtime = new double[4];
maxtime = new double[4];
mintime = new double[4];
mintime[0] = FLT_MAX;
mintime[1] = FLT_MAX;
mintime[2] = FLT_MAX;
mintime[3] = FLT_MAX;
bytes= new double[4];
bytes[0] = 2 * precision * N;
bytes[1] = 2 * precision * N;
bytes[2] = 3 * precision * N;
bytes[3] = 3 * precision * N;
int BytesPerWord;
int j, k;
double scalar;
double[][] times = new double[4][NTIMES];
/* --- SETUP --- determine precision and check timing --- */
BytesPerWord = precision;
//System.out.println(HLINE);
//System.out.println("This system uses " + BytesPerWord+" bytes per DOUBLE PRECISION word." );
//System.out.println("Array size = "+ N+", Offset = "+OFFSET);
//System.out.println("Total memory required = "+ ((3.0 * BytesPerWord) * ( (double) N / 1048576.0)) + " MB." );
//System.out.println("Each test is run "+NTIMES+" times, but only the *best* time for each is used.");
/* Get initial value for system clock. */
for (j=0; j<N; j++) {
a[j] = 1.0;
b[j] = 2.0;
c[j] = 0.0;
}
ticks = pr(ticks,pid," checks time quanta");
final int quantum = checktick();
//System.out.println("Your clock granularity/precision appears to be " +quantum+ " microseconds.");
ticks = pr(ticks,pid," begins to init array");
double t = mysecond();
for (j = 0; j < N; j++)
a[j] = 2.0E0 * a[j];
t = 1.0E6 * (mysecond() - t);
//System.out.println("Each test below will take on the order of "+(int) t+" microseconds.");
//System.out.println(" (= "+(int) (t/quantum)+" clock ticks)" );
//System.out.println("Increase the size of the arrays if this shows that you are not getting at least 20 clock ticks per test.");
//System.out.println(HLINE);
reach_barrier();
ticks = pr(ticks,pid," waits on lock");
synchronized(lock) {} // block till all ready
ticks = pr(ticks,pid," starts main loop");
/* --- MAIN LOOP --- repeat test cases NTIMES times --- */
scalar = 3.0;
for (k=0; k<NTIMES; k++) {
times[0][k] = mysecond();
for (j=0; j<N; j++)
c[j] = a[j];
times[0][k] = mysecond() - times[0][k];
times[1][k] = mysecond();
for (j=0; j<N; j++)
b[j] = scalar*c[j];
times[1][k] = mysecond() - times[1][k];
times[2][k] = mysecond();
for (j=0; j<N; j++)
c[j] = a[j]+b[j];
times[2][k] = mysecond() - times[2][k];
times[3][k] = mysecond();
for (j=0; j<N; j++)
a[j] = b[j]+scalar*c[j];
times[3][k] = mysecond() - times[3][k];
}
/* --- SUMMARY --- */
for (k=1; k<NTIMES; k++) { /* note -- skip first iteration */
for (j=0; j<4; j++) {
avgtime[j] = avgtime[j]+ times[j][k];
mintime[j] = MIN(mintime[j], times[j][k]);
maxtime[j] = MAX(maxtime[j], times[j][k]);
}
}
//System.out.println("Function Rate (MB/s) Avg time Min time Max time");
synchronized(lock2) {
System.out.print("PID: "+pid+" ");
for (j=0; j<4; j++) {
avgtime[j] = avgtime[j]/(double)(NTIMES-1);
double bandwidth = 1.0E-06 * bytes[j]/mintime[j];
System.out.print(label[j]+bandwidth+ "MB/sec ");
total_bandwidth[j] += bandwidth;
}
System.out.println();
}
/* --- Check Results --- */
//checkSTREAMresults();
ticks = pr(ticks,pid," exits");
//System.out.println(HLINE);
}
public double MIN(double x, double y) {
if(x<y)
return x;
else
return y;
}
public double MAX(double x, double y) {
if(x>y)
return x;
else
return y;
}
public static void main(String args[]) {
int num_threads = Integer.parseInt(args[0]);
System.out.println("=== Warmup 0");
new STREAM().run(0);
System.out.println("=== Warmup 1");
new STREAM().run(1);
System.out.println("=== Warmup 2");
new STREAM().run(2);
System.out.println("=== Warmup 3");
new STREAM().run(3);
_barrier = 0; // Reset barrier
for( int i=0; i<4; i++ ) total_bandwidth[i] = 0.0;
Thread ts[] = new Thread[num_threads];
synchronized(lock) {
for( int i=0; i<ts.length; i++ ) {
final int num = i;
(ts[i] = new Thread() {
public void run() {
new STREAM().run(num);
}
}
).start();
}
int i=0;
while( _barrier < num_threads ) {
System.out.println("=== main waits "+i+" secs, seen "+_barrier+"/"+num_threads+" reach barrier");
i++;
try { Thread.sleep(1000); }
catch( Exception e ) { }
}
System.out.println("=== Go!");
} // Release lock
for( int i=0; i<ts.length; i++ ) {
try { ts[i].join(); }
catch( Exception e ) { }
}
System.out.println("=== Caught the last thread.");
synchronized(lock2) {
System.out.print("Average cpu bandwidth: ");
for (int j=0; j<4; j++) System.out.print(label[j]+(long)(total_bandwidth[j]/num_threads )+ "MB/sec/cpu ");
System.out.println();
System.out.print("Total system bandwidth: ");
for (int j=0; j<4; j++) System.out.print(label[j]+(long)(total_bandwidth[j] )+ "MB/sec ");
System.out.println();
}
}
private int checktick() {
int i, minDelta, Delta;
double t1, t2;
double[] timesfound = new double[M];
/* Collect a sequence of M unique time values from the system. */
for (i = 0; i < M; i++) {
t1 = mysecond();
while( ((t2=mysecond()) - t1) < 1.0E-6 ) {}
timesfound[i] = t1 = t2;
}
/*
* Determine the minimum difference between these M values.
* This result will be our estimate (in microseconds) for the
* clock granularity.
*/
minDelta = 1000000;
for (i = 1; i < M; i++) {
Delta = (int)( 1.0E6 * (timesfound[i]-timesfound[i-1]));
minDelta =(int) MIN(minDelta, MAX(Delta,0));
}
return(minDelta);
}
/** A gettimeofday routine to give access to the wall
clock timer on most UNIX-like systems. */
private double mysecond() {
//need to return microseconds not milliseconds -- big big problem!
return System.nanoTime()/1e9;
}
}