Initial Reasonable JMH example working

This commit is contained in:
Bruce Eckel 2016-08-05 16:07:30 -06:00
parent b72a223d07
commit 71a6aa7e71
2 changed files with 81 additions and 66 deletions

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// understandingcollections/jmhtests/MapPerformance.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Performance differences between Maps
package understandingcollections.jmhtests;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;
import java.util.*;
import static java.util.concurrent.TimeUnit.*;
@State(Scope.Thread)
@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
@Fork(1)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(NANOSECONDS)
public class MapPerformance {
private Map<Integer, Integer> map;
@Param({"hashmap", "treemap", "linkedhashmap",
"identityhashmap", "weakhashmap", "hashtable"})
private String type;
private int begin;
private int end;
@Setup
public void setup() {
switch(type) {
case "hashmap":
map = new HashMap<>();
break;
case "treemap":
map = new TreeMap<>();
break;
case "linkedhashmap":
map = new LinkedHashMap<>();
break;
case "identityhashmap":
map = new IdentityHashMap<>();
break;
case "weakhashmap":
map = new WeakHashMap<>();
break;
case "hashtable":
map = new Hashtable<>();
break;
default:
throw new IllegalStateException("Unknown " + type);
}
begin = 1;
end = 256;
for (int i = begin; i < end; i++) {
map.put(i, i);
}
}
@Benchmark
public void get(Blackhole bh) {
for (int i = begin; i < end; i++) {
bh.consume(map.get(i));
}
}
@Benchmark
public void put(Blackhole bh) {
for (int i = begin; i < end; i++) {
bh.consume(map.put(i, i));
}
}
@Benchmark
public void iterate(Blackhole bh) {
Iterator it = map.entrySet().iterator();
while(it.hasNext())
bh.consume(it.next());
}
}

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// understandingcollections/jmhtests/MapPerformanceJMH.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Demonstrates performance differences in Maps
package understandingcollections.jmhtests;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;
import java.util.*;
@State(Scope.Thread)
public class MapPerformanceJMH {
private Map<Integer, Integer> map;
@Param({"hashmap", "treemap"})
private String type;
private int begin;
private int end;
@Setup
public void setup() {
if (type.equals("hashmap")) {
map = new HashMap<Integer, Integer>();
} else if (type.equals("treemap")) {
map = new TreeMap<Integer, Integer>();
} else {
throw new IllegalStateException("Unknown type: " + type);
}
begin = 1;
end = 256;
for (int i = begin; i < end; i++) {
map.put(i, i);
}
}
@Benchmark
public void get(Blackhole bh) {
for (int i = begin; i < end; i++) {
bh.consume(map.get(i));
}
}
// These are incomplete placeholders from the
// original MapPerformance.jaava:
/* @Benchmark
int put() {
for(int i = 0; i < loops; i++) {
map.clear();
for(int j = 0; j < size; j++)
map.put(j, j);
}
return loops * size;
}*/
/* @Benchmark
int iterate() {
for(int i = 0; i < loops; i ++) {
Iterator it = map.entrySet().iterator();
while(it.hasNext())
it.next();
}
}*/
}