space cati dump final list height pac unknown 永久

對於java的內存溢出，如果配置-XX:+HeapDumpOnOutOfMemoryError，很明確的知道堆內存溢出時會生成dump文件。但永久代內存溢出不明確是否會生成，今天來做一個實驗：

永久代內存溢出，有dump文件。JVM的參數是-XX:PermSize=10m -XX:MaxPermSize=10m -XX:+HeapDumpOnOutOfMemoryError

1. import java.util.ArrayList;
2. import java.util.List;
3. public class PermPoolOOM{
4. public static void main(String[] args){
5. List list = new ArrayList();
6. int i = 0;
7. while(true){
8. list.add(String.valueOf(i++).intern());
9. }
10. }
11. }

java.lang.OutOfMemoryError: PermGen space
Dumping heap to java_pid8900.hprof ...
Heap dump file created [17009938 bytes in 0.336 secs]
Exception in thread "main" java.lang.OutOfMemoryError: PermGen space
at java.lang.String.intern(Native Method)
at PermPoolOOM.main(PermPoolOOM.java:8)

方法區溢出，有dump文件。需要下載cglib-full-2.0.1.jar，JVM參數設置：-XX:PermSize=10m -XX:MaxPermSize=10m -XX:+HeapDumpOnOutOfMemoryError

1. import java.lang.reflect.Method;
2. import net.sf.cglib.proxy.Enhancer;
3. import net.sf.cglib.proxy.MethodInterceptor;
4. import net.sf.cglib.proxy.MethodProxy;
6. public class JavaMethodAreaOOM {
8. public static void main(String[] args) {
9. while (true) {
10. Enhancer enhancer = new Enhancer();
11. enhancer.setSuperclass(OOMObject.class);
12. enhancer.setUseCache(false);
13. enhancer.setCallback(new MethodInterceptor() {
14. public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
15. return proxy.invokeSuper(obj, args);
16. }
17. });
18. enhancer.create();
19. }
20. }
21. static class OOMObject {
23. }
24. }

java.lang.OutOfMemoryError: PermGen space
Dumping heap to java_pid11000.hprof ...
Heap dump file created [6752989 bytes in 0.075 secs]
Exception in thread "main" net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:208)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:406)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:318)
at JavaMethodAreaOOM.main(JavaMethodAreaOOM.java:21)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:411)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:195)
... 3 more
Caused by: java.lang.OutOfMemoryError: PermGen space
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
... 8 more

直接內存溢出，沒有dump文件。JVM參數配置：-XX:PermSize=10m -XX:MaxPermSize=10m -XX:+HeapDumpOnOutOfMemoryError -XX:MaxDirectMemorySize=10M

1. import java.lang.reflect.Field;
2. import sun.misc.Unsafe;
4. public class DirectMemoryOOM{
5. private static final int _1MB = 1024* 1024 * 1024;
6. public static void main(String[] args) throws Exception{
7. Field unsafeField = Unsafe.class.getDeclaredFields()[0];
8. unsafeField.setAccessible(true);
9. Unsafe unsafe = (Unsafe) unsafeField.get(null);
10. while(true){
11. //unsafe直接想操作系統申請內存
12. unsafe.allocateMemory(_1MB);
13. }
14. }
15. }

Exception in thread "main" java.lang.OutOfMemoryError
at sun.misc.Unsafe.allocateMemory(Native Method)
at com.comtop.DirectMemoryOOM.main(DirectMemoryOOM.java:15)

棧內存溢出，沒有dump文件。JVM參數設置:-Xss128k

1. public class JavaVMStackOF{
2. int stackLength = 1;
3. public void stackLeak(){
4. stackLength++;
5. stackLeak();
6. }
7. public static void main(String[] args){
8. JavaVMStackOF oom = new JavaVMStackOF();
9. oom.stackLeak();
10. }
11. }

Exception in thread "main" java.lang.StackOverflowError
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:6)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)
at JavaVMStackOF.stackLeak(JavaVMStackOF.java:7)

（轉）JVM各種內存溢出是否產生dump