optimized memory used

src/test/java/com/alibaba/druid/stat/AtomicMemoryTest.java

@@ -0,0 +1,33 @@
+package com.alibaba.druid.stat;
+
+import java.lang.management.ManagementFactory;
+import java.text.NumberFormat;
+import java.util.concurrent.atomic.AtomicLong;
+
+import junit.framework.TestCase;
+
+public class AtomicMemoryTest extends TestCase {
+
+    public void test_0() throws Exception {
+        AtomicLong item = new AtomicLong();
+        gc();
+        long memoryStart = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        final int COUNT = 1024 * 1024;
+        AtomicLong[] items = new AtomicLong[COUNT];
+        for (int i = 0; i < COUNT; ++i) {
+            items[i] = new AtomicLong();
+            // items[i] = Histogram.makeHistogram(20);
+        }
+
+        long memoryEnd = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        System.out.println("memory used : " + NumberFormat.getInstance().format(memoryEnd - memoryStart));
+    }
+
+    private void gc() {
+        for (int i = 0; i < 10; ++i) {
+            System.gc();
+        }
+    }
+}

src/test/java/com/alibaba/druid/stat/HashMapMemoryTest.java

@@ -0,0 +1,34 @@
+package com.alibaba.druid.stat;
+
+import java.lang.management.ManagementFactory;
+import java.text.NumberFormat;
+import java.util.HashMap;
+import java.util.Map;
+
+import junit.framework.TestCase;
+
+public class HashMapMemoryTest extends TestCase {
+
+    public void test_0() throws Exception {
+        HashMap item = new HashMap();
+        gc();
+        long memoryStart = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        final int COUNT = 1024 * 1024;
+        Map[] items = new Map[COUNT];
+        for (int i = 0; i < COUNT; ++i) {
+            items[i] = new HashMap();
+            // items[i] = Histogram.makeHistogram(20);
+        }
+
+        long memoryEnd = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        System.out.println("memory used : " + NumberFormat.getInstance().format(memoryEnd - memoryStart));
+    }
+
+    private void gc() {
+        for (int i = 0; i < 10; ++i) {
+            System.gc();
+        }
+    }
+}

src/test/java/com/alibaba/druid/stat/MemoryTest.java

@@ -0,0 +1,38 @@
+package com.alibaba.druid.stat;
+
+import java.lang.management.ManagementFactory;
+import java.text.NumberFormat;
+import java.util.concurrent.atomic.AtomicLong;
+
+import junit.framework.TestCase;
+
+public class MemoryTest extends TestCase {
+
+    public void test_0() throws Exception {
+        A item = new A();
+        gc();
+        final int COUNT = 1024 * 1024;
+        A[] items = new A[COUNT];
+
+        long memoryStart = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        for (int i = 0; i < COUNT; ++i) {
+            items[i] = new A();
+            // items[i] = Histogram.makeHistogram(20);
+        }
+
+        long memoryEnd = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
+
+        System.out.println("memory used : " + NumberFormat.getInstance().format(memoryEnd - memoryStart));
+    }
+
+    private void gc() {
+        for (int i = 0; i < 10; ++i) {
+            System.gc();
+        }
+    }
+
+    public static class A {
+        private volatile long v;
+    }
+}

src/test/java/com/alibaba/druid/stat/PerfTest.java

@@ -0,0 +1,56 @@
+package com.alibaba.druid.stat;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicLongFieldUpdater;
+
+import junit.framework.TestCase;
+
+public class PerfTest extends TestCase {
+
+    public void test_0() throws Exception {
+        for (int i = 0; i < 3; ++i) {
+            long startMillis = System.currentTimeMillis();
+            a();
+            long millis = System.currentTimeMillis() - startMillis;
+            System.out.println("a : " + millis);
+        }
+    }
+
+    private void a() {
+        A a = new A();
+        for (int i = 0; i < 1000 * 1000 * 1000; ++i) {
+            a.incrementAndGet();
+        }
+    }
+
+    private void b() {
+        B b = new B();
+        for (int i = 0; i < 1000 * 1000 * 1000; ++i) {
+            b.incrementAndGet();
+        }
+    }
+
+    public static class A {
+
+        private volatile long                  value;
+
+        static final AtomicLongFieldUpdater<A> updater = AtomicLongFieldUpdater.newUpdater(A.class, "value");
+
+        public long incrementAndGet() {
+            return updater.incrementAndGet(this);
+        }
+
+        public long getValue() {
+            return value;
+        }
+    }
+
+    public static class B {
+
+        private final AtomicLong value = new AtomicLong();
+
+        public long incrementAndGet() {
+            return value.incrementAndGet();
+        }
+    }
+}

src/test/java/com/alibaba/druid/stat/WebSessionStatTest.java

@@ -10,7 +10,7 @@ import com.alibaba.druid.support.http.stat.WebSessionStat;
 public class WebSessionStatTest extends TestCase {
 
     public void test_0() throws Exception {
-        WebSessionStat item = new WebSessionStat("");
+        WebSessionStat item = new WebSessionStat("1b959a6db8489c4c7ef7bf0bd743ab52");
         gc();
         long memoryStart = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
 

src/test/java/com/alibaba/druid/stat/WebURIStatMemoryTest.java

@@ -18,6 +18,7 @@ public class WebURIStatMemoryTest extends TestCase {
         WebURIStat[] items = new WebURIStat[COUNT];
         for (int i = 0; i < COUNT; ++i) {
             items[i] = new WebURIStat("");
+            items[i].getProfiletat();
             // items[i] = Histogram.makeHistogram(20);
         }