JVM各种内存溢出是否产生dump

叁歲伎倆 2022-08-22 01:29 190阅读 0赞

对于java的内存溢出，如果配置-XX:+HeapDumpOnOutOfMemoryError，很明确的知道堆内存溢出时会生成dump文件。但永久代内存溢出不明确是否会生成，今天来做一个实验：

**永久代内存溢出，有dump文件。**JVM的参数是-XX:PermSize=10m  -XX:MaxPermSize=10m   -XX:+HeapDumpOnOutOfMemoryError

import java.util.ArrayList;
    import java.util.List;
    public class PermPoolOOM{
        public static void main(String[] args){
            List  list = new ArrayList();
            int i = 0;
            while(true){
              list.add(String.valueOf(i++).intern());
            }
        }
    }

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)

**方法区溢出，有dump文件。**需要下载cglib-full-2.0.1.jar，JVM参数设置：\-XX:PermSize=10m  -XX:MaxPermSize=10m   -XX:+HeapDumpOnOutOfMemoryError

import java.lang.reflect.Method;
    import net.sf.cglib.proxy.Enhancer;
    import net.sf.cglib.proxy.MethodInterceptor;
    import net.sf.cglib.proxy.MethodProxy;
    
    public class JavaMethodAreaOOM {
    
        public static void main(String[] args) {
               while (true) {
                      Enhancer enhancer = new Enhancer();
                      enhancer.setSuperclass(OOMObject.class);
                      enhancer.setUseCache(false);
                      enhancer.setCallback(new MethodInterceptor() {
                             public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
                                    return proxy.invokeSuper(obj, args);
                             }
                      });
                      enhancer.create();
               }
        }
        static class OOMObject {
    
        }
    }

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

**直接内存溢出，没有dump文件。**JVM参数配置：-XX:PermSize=10m  -XX:MaxPermSize=10m   -XX:+HeapDumpOnOutOfMemoryError  -XX:MaxDirectMemorySize=10M

import java.lang.reflect.Field;
    import sun.misc.Unsafe;
    
    public class DirectMemoryOOM{
        private static final int _1MB = 1024* 1024 * 1024;
        public static void main(String[] args) throws Exception{
            Field unsafeField = Unsafe.class.getDeclaredFields()[0];
            unsafeField.setAccessible(true);
            Unsafe unsafe = (Unsafe) unsafeField.get(null);
            while(true){
                //unsafe直接想操作系统申请内存
                unsafe.allocateMemory(_1MB);
            }
        }
    }

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

**栈内存溢出，没有dump文件。**JVM参数设置:-Xss128k

public class JavaVMStackOF{
        int stackLength = 1;
        public void stackLeak(){
            stackLength++;
            stackLeak();
    }
    public static void main(String[] args){
        JavaVMStackOF oom = new JavaVMStackOF();
        oom.stackLeak();
    }
    }

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)