Working draft of understandingcollections/jmh

understandingcollections/CountedString.java

@@ -14,7 +14,7 @@ public class CountedString {
     s = str;
     created.add(s);
     // id is the total number of instances
-    // of this String in use by CountedString:
+    // of this String used by CountedString:
     for(String s2 : created)
       if(s2.equals(s))
         id++;

understandingcollections/SuppliersCollectionTest.java

@@ -29,7 +29,7 @@ public class SuppliersCollectionTest {
     Suppliers.fill(list, new Government(), 15);
     System.out.println(list);
 
-    // Or we could just use Streams:
+    // Or we can use Streams:
     set = Arrays.stream(Government.foundation).collect(
       Collectors.toSet());
     System.out.println(set);

understandingcollections/ToDoList.java

@@ -36,15 +36,15 @@ class ToDoList extends PriorityQueue<ToDoList.ToDoItem> {
     super.add(new ToDoItem(td, pri, sec));
   }
   public static void main(String[] args) {
-    ToDoList toDoList = new ToDoList();
+    ToDoList toDo = new ToDoList();
-    toDoList.add("Empty trash", 'C', 4);
+    toDo.add("Empty trash", 'C', 4);
-    toDoList.add("Feed dog", 'A', 2);
+    toDo.add("Feed dog", 'A', 2);
-    toDoList.add("Feed bird", 'B', 7);
+    toDo.add("Feed bird", 'B', 7);
-    toDoList.add("Mow lawn", 'C', 3);
+    toDo.add("Mow lawn", 'C', 3);
-    toDoList.add("Water lawn", 'A', 1);
+    toDo.add("Water lawn", 'A', 1);
-    toDoList.add("Feed cat", 'B', 1);
+    toDo.add("Feed cat", 'B', 1);
-    while(!toDoList.isEmpty())
+    while(!toDo.isEmpty())
-      System.out.println(toDoList.remove());
+      System.out.println(toDo.remove());
   }
 }
 /* Output:

understandingcollections/jmh/Deques.java

@@ -0,0 +1,70 @@
+// understandingcollections/jmh/Deques.java
+// (c)2016 MindView LLC: see Copyright.txt
+// We make no guarantees that this code is fit for any purpose.
+// Visit http://OnJava8.com for more book information.
+// Performance differences between Deques
+package understandingcollections.jmh;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+import java.util.concurrent.TimeUnit;
+import java.util.*;
+
+@State(Scope.Thread)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Warmup(iterations = 5, batchSize = 5000)
+@Measurement(iterations = 5, batchSize = 5000)
+@BenchmarkMode(Mode.SingleShotTime)
+@Fork(1)
+public class Deques {
+  private Deque<String> deque;
+
+  @Param({
+    "java.util.LinkedList",
+    "java.util.ArrayDeque",
+    "java.util.concurrent.ConcurrentLinkedDeque",
+    "java.util.concurrent.LinkedBlockingDeque",
+  })
+  private String type;
+
+  @Param({
+    "1",
+    "10",
+    "100",
+    "1000",
+    "10000",
+    "100000"
+  })
+  private int size;
+
+  @Setup
+  public void setup() {
+    try {
+      deque = (Deque<String>)
+        Class.forName(type).newInstance();
+    } catch(Exception e) {
+      System.err.println(
+        "-> Cannot create: " + type);
+      System.exit(99);
+    }
+    for(int i = 0; i < size; i++)
+      deque.add(Integer.toString(i));
+  }
+  @Benchmark
+  public Deque<String> addFirst() {
+    deque.addFirst("test");
+    return deque;
+  }
+  @Benchmark
+  public Deque<String> addLast() {
+    deque.addLast("test");
+    return deque;
+  }
+  @Benchmark
+  public void pollFirst(Blackhole bh) {
+    bh.consume(deque.pollFirst());
+  }
+  @Benchmark
+  public void pollLast(Blackhole bh) {
+    bh.consume(deque.pollLast());
+  }
+}

understandingcollections/jmh/Lists.java

@@ -2,80 +2,90 @@
 // (c)2016 MindView LLC: see Copyright.txt
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://OnJava8.com for more book information.
-// Demonstrates performance differences in Lists
+// Performance differences between Lists
 package understandingcollections.jmh;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
 import java.util.*;
-import static java.util.concurrent.TimeUnit.*;
+import java.util.concurrent.*;
 
 @State(Scope.Thread)
-@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
-@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
+@Warmup(iterations = 5, batchSize = 5000)
+@Measurement(iterations = 5, batchSize = 5000)
+@BenchmarkMode(Mode.SingleShotTime)
 @Fork(1)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(MICROSECONDS)
 public class Lists {
-  private List<Integer> list;
+  private List<String> list;
 
-  @Param({"ArrayList", "LinkedList", "Vector"})
+  @Param({
+    "java.util.ArrayList",
+    "java.util.Vector",
+    "java.util.LinkedList",
+    "java.util.concurrent.CopyOnWriteArrayList"
+  })
   private String type;
 
-  private int begin;
+  @Param({
-  private int end;
+    "1",
+    "10",
+    "100",
+    "1000",
+    "10000",
+    "100000"
+  })
+  private int size;
 
   @Setup
   public void setup() {
-    switch(type) {
+    try {
-      case "ArrayList":
+      list = (List<String>)
-        list = new ArrayList<>();
+        Class.forName(type).newInstance();
-        break;
+    } catch(Exception e) {
-      case "LinkedList":
+      System.err.println(
-        list = new LinkedList<>();
+        "-> Cannot create: " + type);
-        break;
+      System.exit(99);
-      case "Vector":
-        list = new Vector<>();
-        break;
-      default:
-        throw new IllegalStateException("Unknown " + type);
-    }
-    begin = 0;
-    end = 256;
-    for(int i = begin; i < end; i++) {
-      list.add(i);
     }
+    for(int i = 0; i < size; i++)
+      list.add(Integer.toString(i));
   }
   @Benchmark
-  public void add() {
+  public List<String> add() {
-    for(int i = begin; i < end; i++)
+    list.add(list.size() / 2, "test");
-      list.add(i);
+    return list;
   }
   @Benchmark
   public void get(Blackhole bh) {
-    for(int i = begin; i < end; i++)
+    bh.consume(list.get(list.size() / 2));
-      bh.consume(list.get(i));
   }
   @Benchmark
-  public void set() {
+  public List<String> set() {
-    for(int i = begin; i < end; i++)
+    list.set(list.size() / 2, "test");
-      list.set(i, 47);
+    return list;
   }
   @Benchmark
-  public void iteradd() {
+  public List<String> iteradd() {
-    int half = list.size() / 2;
+    ListIterator<String> it =
-    ListIterator<Integer> it =
+      list.listIterator(list.size() / 2);
-      list.listIterator(half);
+    try {
-    for(int i = begin; i < end; i++)
+      it.add("test");
-      it.add(47);
+    } catch(UnsupportedOperationException e) {
+      System.err.println(
+        "-> Unsupported: listIterator.add() in " +
+        list.getClass().getSimpleName());
+    }
+    return list;
   }
   @Benchmark
-  public void insert() {
+  public List<String> insert() {
-    for(int i = begin; i < end; i++)
+    list.add(list.size() / 2, "test");
-      list.add(5, 47);
+    return list;
   }
   @Benchmark
-  public void remove() {
+  public List<String> remove() {
-    while(list.size() > 5)
+    int index = list.size() / 2;
-      list.remove(5);
+    if(index > 0)
+      list.remove(index);
+    return list;
   }
 }

understandingcollections/jmh/Maps.java

@@ -7,65 +7,60 @@ package understandingcollections.jmh;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
 import java.util.*;
-import static java.util.concurrent.TimeUnit.*;
+import java.util.concurrent.*;
 
 @State(Scope.Thread)
-@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
-@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
+@Warmup(iterations = 5, batchSize = 5000)
+@Measurement(iterations = 5, batchSize = 5000)
+@BenchmarkMode(Mode.SingleShotTime)
 @Fork(1)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(MICROSECONDS)
 public class Maps {
-  private Map<Integer, Integer> map;
+  private Map<String,String> map;
 
-  @Param({"HashMap", "TreeMap", "LinkedHashMap",
+  @Param({
-    "IdentityHashMap", "WeakHashMap", "Hashtable",})
+    "java.util.HashMap",
+    "java.util.Hashtable",
+    "java.util.TreeMap",
+    "java.util.LinkedHashMap",
+    "java.util.IdentityHashMap",
+    "java.util.WeakHashMap",
+    "java.util.concurrent.ConcurrentHashMap",
+    "java.util.concurrent.ConcurrentSkipListMap",
+  })
   private String type;
 
-  private int begin;
+  @Param({
-  private int end;
+    "1",
+    "10",
+    "100",
+    "1000",
+    "10000",
+  })
+  private int size;
 
   @Setup
   public void setup() {
-    switch(type) {
+    try {
-      case "HashMap":
+      map = (Map<String,String>)
-        map = new HashMap<>();
+        Class.forName(type).newInstance();
-        break;
+    } catch(Exception e) {
-      case "TreeMap":
+      System.err.println(
-        map = new TreeMap<>();
+        "-> Cannot create: " + type);
-        break;
+      System.exit(99);
-      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);
     }
+    for(int i = 0; i < size; i++)
+      map.put(Integer.toString(i), Integer.toString(i));
   }
   @Benchmark
   public void get(Blackhole bh) {
-    for (int i = begin; i < end; i++) {
+    String key = Integer.toString(size / 2);
-      bh.consume(map.get(i));
+    bh.consume(map.get(key));
-    }
   }
   @Benchmark
-  public void put() {
+  public Map<String,String> put() {
-    for (int i = begin; i < end; i++) {
+    map.put("test", "test");
-      map.put(i, i);
+    return map;
-    }
   }
   @Benchmark
   public void iterate(Blackhole bh) {

understandingcollections/jmh/Queues.java

@@ -2,61 +2,68 @@
 // (c)2016 MindView LLC: see Copyright.txt
 // We make no guarantees that this code is fit for any purpose.
 // Visit http://OnJava8.com for more book information.
-// Demonstrates performance differences in Queues
+// Performance differences between Queues
 package understandingcollections.jmh;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
 import java.util.*;
-import static java.util.concurrent.TimeUnit.*;
+import java.util.concurrent.*;
 
 @State(Scope.Thread)
-@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
-@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
+@Warmup(iterations = 5, batchSize = 5000)
+@Measurement(iterations = 5, batchSize = 5000)
+@BenchmarkMode(Mode.SingleShotTime)
 @Fork(1)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(MICROSECONDS)
 public class Queues {
-  private LinkedList<Integer> queue;
+  private Queue<String> queue;
 
-  @Param({"LinkedList"})
+  @Param({
+    "java.util.LinkedList",
+    "java.util.concurrent.ConcurrentLinkedQueue",
+    "java.util.concurrent.LinkedBlockingQueue",
+    "java.util.concurrent.LinkedTransferQueue",
+    "java.util.concurrent.PriorityBlockingQueue",
+    "java.util.PriorityQueue",
+    // Requires a size for construction:
+    //"java.util.concurrent.ArrayBlockingQueue",
+    // Won't accept more than one element:
+    //"java.util.concurrent.SynchronousQueue",
+    // Requires "Delayed" elements:
+    //"java.util.concurrent.DelayQueue",
+  })
   private String type;
 
-  private int begin;
+  @Param({
-  private int end;
+    "1",
+    "10",
+    "100",
+    "1000",
+    "10000",
+    "100000"
+  })
+  private int size;
 
   @Setup
   public void setup() {
-    switch(type) {
+    try {
-      case "LinkedList":
+      queue = (Queue<String>)
-        queue = new LinkedList<>();
+        Class.forName(type).newInstance();
-        break;
+    } catch(Exception e) {
-      default:
+      System.err.println(
-        throw new IllegalStateException("Unknown " + type);
+        "-> Cannot create: " + type);
-    }
+      System.exit(99);
-    begin = 1;
-    end = 256;
-    for(int i = begin; i < end; i++) {
-      queue.add(i);
     }
+    for(int i = 0; i < size; i++)
+      queue.add(Integer.toString(i));
   }
   @Benchmark
-  public void queue_addFirst() {
+  public Queue<String> add() {
-    for(int i = begin; i < end; i++)
+    queue.add("test");
-      queue.addFirst(47);
+    return queue;
   }
   @Benchmark
-  public void queue_addLast() {
+  public void poll(Blackhole bh) {
-    for(int i = begin; i < end; i++)
+    bh.consume(queue.poll());
-      queue.addLast(47);
-  }
-  @Benchmark
-  public void queue_removeFirst(Blackhole bh) {
-    while(queue.size() > 0)
-      bh.consume(queue.removeFirst());
-  }
-  @Benchmark
-  public void queue_removeLast(Blackhole bh) {
-    while(queue.size() > 0)
-      bh.consume(queue.removeLast());
   }
 }

understandingcollections/jmh/Sets.java

@@ -7,56 +7,61 @@ package understandingcollections.jmh;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
 import java.util.*;
-import static java.util.concurrent.TimeUnit.*;
+import java.util.concurrent.*;
 
 @State(Scope.Thread)
-@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
-@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
+@Warmup(iterations = 5, batchSize = 5000)
+@Measurement(iterations = 5, batchSize = 5000)
+@BenchmarkMode(Mode.SingleShotTime)
 @Fork(1)
-@BenchmarkMode(Mode.AverageTime)
-@OutputTimeUnit(MICROSECONDS)
 public class Sets {
-  private Set<Integer> set;
+  private Set<String> set;
 
-  @Param({"HashSet", "TreeSet", "LinkedHashSet"})
+  @Param({
+    "java.util.HashSet",
+    "java.util.TreeSet",
+    "java.util.LinkedHashSet",
+    "java.util.concurrent.ConcurrentSkipListSet",
+    "java.util.concurrent.CopyOnWriteArraySet",
+  })
   private String type;
 
-  private int begin;
+  @Param({
-  private int end;
+    "1",
+    "10",
+    "100",
+    "1000",
+    "10000",
+  })
+  private int size;
 
   @Setup
   public void setup() {
-    switch(type) {
+    try {
-      case "HashSet":
+      set = (Set<String>)
-        set = new HashSet<>();
+        Class.forName(type).newInstance();
-        break;
+    } catch(Exception e) {
-      case "TreeSet":
+      System.err.println(
-        set = new TreeSet<>();
+        "-> Cannot create: " + type);
-        break;
+      System.exit(99);
-      case "LinkedHashSet":
-        set = new LinkedHashSet<>();
-        break;
-      default:
-        throw new IllegalStateException("Unknown " + type);
     }
-    begin = 1;
+    for(int i = 0; i < size; i++)
-    end = 256;
+      set.add(Integer.toString(i));
-    for (int i = begin; i < end; i++)
-      set.add(i);
   }
   @Benchmark
-  public void add() {
+  public Set<String> add() {
-    for(int i = begin; i < end; i++)
+    set.add("test");
-      set.add(i);
+    return set;
   }
   @Benchmark
   public void contains(Blackhole bh) {
-    for(int i = begin; i < end; i++)
+    String key = Integer.toString(size/2);
-      bh.consume(set.contains(i));
+    bh.consume(set.contains(key));
   }
   @Benchmark
   public void iterate(Blackhole bh) {
-    Iterator<Integer> it = set.iterator();
+    Iterator<String> it = set.iterator();
     while(it.hasNext())
       bh.consume(it.next());
   }

validating/jmh/JMH3.java

@@ -34,8 +34,8 @@ public class JMH3 {
     la = new long[size];
   }
   public static long f(long x) {
-    long divisor = x % 25 + 1;
+    long quadratic = 42 * x * x + 19 * x + 47;
-    return Long.divideUnsigned(x, divisor);
+    return Long.divideUnsigned(quadratic, x + 1);
   }
   @Benchmark
   public void setAll() {