111

concurrent/src/test/java/concurrent/hashmap/HashMapTest.java

@@ -0,0 +1,25 @@
+package concurrent.hashmap;
+
+
+import org.junit.jupiter.api.Test;
+
+public class HashMapTest {
+    static final int MAXIMUM_CAPACITY = 1 << 30;
+
+    @Test
+    public void LinkedBlockingQueueModelTest() throws InterruptedException {
+        System.out.println(tableSizeFor(1000));
+    }
+
+    static final int tableSizeFor(int cap) {
+        int n = cap - 1;
+        n |= n >>> 1;
+        n |= n >>> 2;
+        n |= n >>> 4;
+        n |= n >>> 8;
+        n |= n >>> 16;
+        int t = (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
+        return t;
+    }
+
+}