| 10 |
|
* Estimates time per iteration of collection iterators. Preloads |
| 11 |
|
* most elements, but adds about 1/8 of them dynamically to preclude |
| 12 |
|
* overly clever optimizations. The array of collections has |
| 13 |
< |
* approximately exponentially different lengths, so chek both short |
| 13 |
> |
* approximately exponentially different lengths, so check both short |
| 14 |
|
* and long iterators. Reports include times for adds and other |
| 15 |
|
* checks, so overestimate times per iteration. |
| 16 |
|
*/ |
| 17 |
|
|
| 18 |
|
public final class IteratorLoops { |
| 19 |
|
static final int DEFAULT_SIZE = 16384; |
| 20 |
< |
static final int DEFAULT_TRIALS = 2; |
| 20 |
> |
static final int DEFAULT_TRIALS = 4; |
| 21 |
|
static final int NC = 16; // number of collections must be power of 2 |
| 22 |
|
static volatile long mismatches = 0; |
| 23 |
|
static int randomSeed = 3122688; |
| 24 |
|
|
| 25 |
|
public static void main(String[] args) throws Exception { |
| 26 |
|
Class klass = Class.forName(args[0]); |
| 27 |
< |
int n = (args.length <= 1)? DEFAULT_SIZE : Integer.parseInt(args[1]); |
| 28 |
< |
int t = (args.length <= 2)? DEFAULT_TRIALS : Integer.parseInt(args[2]); |
| 27 |
> |
int n = (args.length <= 1) ? DEFAULT_SIZE : Integer.parseInt(args[1]); |
| 28 |
> |
int t = (args.length <= 2) ? DEFAULT_TRIALS : Integer.parseInt(args[2]); |
| 29 |
|
|
| 30 |
|
System.out.print("Class: " + klass.getName()); |
| 31 |
< |
System.out.print(" ~iters: " + (long)n * (long)n); |
| 31 |
> |
System.out.print(" ~iters: " + (long) n * (long) n); |
| 32 |
|
System.out.print(" trials: " + t); |
| 33 |
|
System.out.println(); |
| 34 |
|
|
| 35 |
|
Collection<Integer>[] colls = |
| 36 |
|
(Collection<Integer>[])new Collection[NC]; |
| 37 |
|
|
| 38 |
< |
for (int k = 0; k < colls.length; ++k) |
| 39 |
< |
colls[k] = (Collection<Integer>)klass.newInstance(); |
| 38 |
> |
for (int k = 0; k < colls.length; ++k) { |
| 39 |
> |
Object x = klass.newInstance(); |
| 40 |
> |
if (x instanceof Collection) |
| 41 |
> |
colls[k] = (Collection<Integer>) x; |
| 42 |
> |
else if (x instanceof Map) |
| 43 |
> |
colls[k] = (Collection<Integer>) |
| 44 |
> |
Collections.newSetFromMap((Map) x); |
| 45 |
> |
else |
| 46 |
> |
throw new Error("bad class"); |
| 47 |
> |
} |
| 48 |
|
|
| 49 |
< |
for (int i = 0; i < t; ++i) |
| 49 |
> |
for (int i = 0; i < t; ++i) |
| 50 |
|
new IteratorLoops(colls).oneRun(n); |
| 51 |
|
|
| 52 |
< |
if (mismatches != 0) |
| 52 |
> |
if (mismatches != 0) |
| 53 |
|
throw new Error("Bad checksum :" + mismatches); |
| 54 |
|
} |
| 55 |
|
|
| 56 |
|
private int elementCount; |
| 57 |
|
private final Collection<Integer>[] cs; |
| 58 |
|
|
| 59 |
< |
IteratorLoops(Collection<Integer>[] colls) { |
| 60 |
< |
cs = colls; |
| 59 |
> |
IteratorLoops(Collection<Integer>[] colls) { |
| 60 |
> |
cs = colls; |
| 61 |
|
elementCount = 0; |
| 62 |
|
} |
| 63 |
|
|
| 65 |
|
preload(n); |
| 66 |
|
long startTime = System.nanoTime(); |
| 67 |
|
long count = traversals(n); |
| 68 |
< |
double elapsed = (double)(System.nanoTime() - startTime); |
| 68 |
> |
double elapsed = (double) (System.nanoTime() - startTime); |
| 69 |
|
double npi = elapsed / count; |
| 70 |
|
double secs = elapsed / 1000000000; |
| 71 |
|
System.out.printf("%7.1f ns/iter %8.3fs run time\n", npi, secs); |
| 93 |
|
} |
| 94 |
|
} |
| 95 |
|
return count; |
| 96 |
< |
} |
| 96 |
> |
} |
| 97 |
|
|
| 98 |
|
void maybeAdd() { |
| 99 |
|
int r = randomSeed; |
| 100 |
< |
r ^= r << 6; |
| 101 |
< |
r ^= r >>> 21; |
| 100 |
> |
r ^= r << 6; |
| 101 |
> |
r ^= r >>> 21; |
| 102 |
|
r ^= r << 7; |
| 103 |
|
randomSeed = r; |
| 104 |
< |
if ((r >>> 29) == 0) |
| 104 |
> |
if ((r >>> 29) == 0) |
| 105 |
|
cs[r & (cs.length-1)].add(new Integer(elementCount++)); |
| 106 |
< |
} |
| 106 |
> |
} |
| 107 |
|
|
| 108 |
|
void preload(int n) { |
| 109 |
< |
for (int i = 0; i < cs.length; ++i) |
| 109 |
> |
for (int i = 0; i < cs.length; ++i) |
| 110 |
|
cs[i].clear(); |
| 111 |
|
int k = (n - n / 8) / 2; |
| 112 |
|
ArrayList<Integer> al = new ArrayList<Integer>(k+1); |
| 113 |
|
for (int i = 0; i < cs.length; ++i) { |
| 114 |
|
if (k > 0) { |
| 115 |
< |
for (int j = 0; j < k; ++j) |
| 115 |
> |
for (int j = 0; j < k; ++j) |
| 116 |
|
al.add(new Integer(elementCount++)); |
| 117 |
|
cs[i].addAll(al); |
| 118 |
|
al.clear(); |
| 120 |
|
k >>>= 1; |
| 121 |
|
} |
| 122 |
|
// let GC settle down |
| 123 |
< |
try { Thread.sleep(500); } catch(Exception ex) { return; } |
| 124 |
< |
} |
| 123 |
> |
try { Thread.sleep(500); } |
| 124 |
> |
catch (Exception ex) { return; } |
| 125 |
> |
} |
| 126 |
|
|
| 127 |
|
|
| 128 |
|
} |
