markword to synchronized 1

assets/synchronized/JOLSample_01_Age.java

@@ -0,0 +1,68 @@
+package jol;
+
+import org.openjdk.jol.info.ClassLayout;
+import org.openjdk.jol.vm.VM;
+
+import static java.lang.System.out;
+
+/**
+ * @author Aleksey Shipilev
+ */
+public class JOLSample_01_Age {
+
+    public static void main(String[] args) {
+        A a = new A();
+        for (int i = 0; i < 500; i++) {
+            var bytes = new byte[1024 * 1024];
+        }
+        out.println(ClassLayout.parseInstance(a).toPrintable());
+        long markword = VM.current().getLong(a, 0);
+        printAgeBit(markword);
+    }
+
+    public static class A {
+        boolean f;
+    }
+
+    public static void printMarkWordBin(long markword) {
+        out.printf("markword bit: %s\n", toBinaryWithSpaces(markword));
+    }
+
+    public static void printMarkBit(long markword) {
+        out.printf("mark bit: %s\n", toBinaryWithSpaces(markword & 0b11));
+    }
+
+    public static void printbiasBit(long markword) {
+        out.printf("bias bit: %s\n", toBinaryWithSpaces(markword >> 2 & 0b1));
+    }
+
+    public static void printAgeBit(long markword) {
+        out.printf("age bit: %s\n", toBinaryWithSpaces(markword >> 3 & 0b1111));
+    }
+
+    public static void printHashcodeBit(long markword) {
+        out.printf("hash code bit: %s\n", toBinaryWithSpaces((markword >>> 8)));
+    }
+
+
+    public static String toHexWithSpaces(long number) {
+        String hex = Long.toHexString(number);
+        // 如果长度是奇数，在前面补零
+        if (hex.length() % 2 != 0) {
+            hex = "0" + hex;
+        }
+        // 每两位分隔开
+        return hex.replaceAll("(?<=..)(..)", " $1").toUpperCase();
+    }
+
+    public static String toBinaryWithSpaces(long number) {
+        String binary = Long.toBinaryString(number);
+        // 如果长度不是8的倍数，前面补零
+        while (binary.length() % 8 != 0) {
+            binary = "0" + binary;
+        }
+        // 每8位分隔开
+        return binary.replaceAll("(.{8})", "$1 ");
+    }
+
+}

assets/synchronized/JOLSample_01_Basic.java

@@ -0,0 +1,70 @@
+package jol;
+
+import org.openjdk.jol.info.ClassLayout;
+import org.openjdk.jol.vm.VM;
+
+import static java.lang.System.out;
+
+/**
+ * @author Aleksey Shipilev
+ */
+public class JOLSample_01_Basic {
+
+    public static void main(String[] args) {
+        A a = new A();
+        out.println(ClassLayout.parseInstance(a).toPrintable());
+
+        long markword = VM.current().getLong(a,0);
+        printMarkWordBin(markword);
+        printMarkBit(markword);
+        printbiasBit(markword);
+        printAgeBit(markword);
+    }
+
+    public static class A {
+        boolean f;
+    }
+
+    public static void printMarkWordBin(long markword) {
+        out.printf("markword bit: %s\n", toBinaryWithSpaces(markword));
+    }
+
+    public static  void  printMarkBit(long markword) {
+        out.printf("mark bit: %s\n", toBinaryWithSpaces(markword & 0b11));
+    }
+
+    public static  void  printbiasBit(long markword) {
+        out.printf("bias bit: %s\n", toBinaryWithSpaces(markword>>2 & 0b1));
+    }
+
+    public static  void  printAgeBit(long markword) {
+        out.printf("age bit: %s\n", toBinaryWithSpaces(markword >> 3 & 0b1111));
+    }
+
+    public static  void  printHashcodeBit(long markword) {
+        out.printf("hash code bit: %s\n", toBinaryWithSpaces((markword >>> 8)));
+    }
+
+
+
+    public static String toHexWithSpaces(long number) {
+        String hex = Long.toHexString(number);
+        // 如果长度是奇数，在前面补零
+        if (hex.length() % 2 != 0) {
+            hex = "0" + hex;
+        }
+        // 每两位分隔开
+        return hex.replaceAll("(?<=..)(..)", " $1").toUpperCase();
+    }
+
+    public static String toBinaryWithSpaces(long number) {
+        String binary = Long.toBinaryString(number);
+        // 如果长度不是8的倍数，前面补零
+        while (binary.length() % 8 != 0) {
+            binary = "0" + binary;
+        }
+        // 每8位分隔开
+        return binary.replaceAll("(.{8})", "$1 ");
+    }
+
+}

assets/synchronized/JOLSample_01_Hashcode.java

@@ -0,0 +1,70 @@
+package jol;
+
+import org.openjdk.jol.info.ClassLayout;
+import org.openjdk.jol.vm.VM;
+
+import static java.lang.System.out;
+
+/**
+ * @author Aleksey Shipilev
+ */
+public class JOLSample_01_Hashcode {
+
+    public static void main(String[] args) {
+        A a = new A();
+
+        int hashcode = a.hashCode();
+        out.println(ClassLayout.parseInstance(a).toPrintable());
+        out.println("a.hashCode() : " + toBinaryWithSpaces(hashcode));
+        long markword = VM.current().getLong(a,0);
+        printHashcodeBit(markword);//(markword >>> 8)
+        printMarkWordBin(markword);
+    }
+
+    public static class A {
+        boolean f;
+    }
+
+    public static void printMarkWordBin(long markword) {
+        out.printf("markword bit: %s\n", toBinaryWithSpaces(markword));
+    }
+
+    public static  void  printMarkBit(long markword) {
+        out.printf("mark bit: %s\n", toBinaryWithSpaces(markword & 0b11));
+    }
+
+    public static  void  printbiasBit(long markword) {
+        out.printf("bias bit: %s\n", toBinaryWithSpaces(markword>>2 & 0b1));
+    }
+
+    public static  void  printAgeBit(long markword) {
+        out.printf("age bit: %s\n", toBinaryWithSpaces(markword >> 3 & 0b1111));
+    }
+
+    public static  void  printHashcodeBit(long markword) {
+        out.printf("hash code bit: %s\n", toBinaryWithSpaces((markword >>> 8)));
+    }
+
+
+
+    public static String toHexWithSpaces(long number) {
+        String hex = Long.toHexString(number);
+        // 如果长度是奇数，在前面补零
+        if (hex.length() % 2 != 0) {
+            hex = "0" + hex;
+        }
+        // 每两位分隔开
+        return hex.replaceAll("(?<=..)(..)", " $1").toUpperCase();
+    }
+
+    public static String toBinaryWithSpaces(long number) {
+        String binary = Long.toBinaryString(number);
+        // 如果长度不是8的倍数，前面补零
+        while (binary.length() % 8 != 0) {
+            binary = "0" + binary;
+        }
+        // 每8位分隔开
+        return binary.replaceAll("(.{8})", "$1 ");
+    }
+
+}

assets/synchronized/SyncTest.java

@@ -0,0 +1,36 @@
+import java.util.ArrayList;
+
+public class SyncTest {
+    private Object lock = new Object();
+    private Object lock1 = new Object();
+
+    public static void main(String[] args) {
+        new Thread(()->{
+                new SyncTest().testCountMonitorInMethod();
+            }).start();
+        smallObj();
+    }
+
+    public void testCountMonitorInMethod() {
+       synchronized (lock) {
+           synchronized (lock1) {
+             sleep();
+           }
+       }
+    }
+
+    public static void smallObj() {
+        ArrayList<byte[]> list = new ArrayList<byte[]>();
+        for (int i = 0; i < 100000; i++) {
+            list.add(new byte[1024*1024/2]);
+        }
+    }
+
+    public void sleep(){
+        try {
+                Thread.sleep(1000_1000);
+            } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+        }
+    }
+}