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Singleton mode The common writing methods of single case mode include lazy mode, hungry mode, double check mode, etc. Lazy mode is to create objects when you use them.Hungry man mode is a static object that has been loaded in advance.Double check mode is to check twice before and after locking to prevent multiple threads from creating multipl ...

From the overall logic of the JVM in the previous article, this article will talk about the class loading mechanism Review some working models: one we wrote ourselves java file, compiled and generated Class file, will The class file is loaded into the JVM according to The different data information of the class binary file is allocated to ...

You will know why interviewers like to ask such questions! One day, Zhang San went to an interview and was asked a question by the interviewer: What is multithreading? Zhang San: multithreading means that multiple threads execute on the CPU, seize CPU resources and improve CPU execution efficiency Interviewer: what are you talking about? W ...

1. Objects are allocated in Eden first In most cases, objects are allocated in the Cenozoic Eden district. When the Eden area does not have enough space for allocation, the virtual machine will initiate a Minor GC Parameters: -verbose:gc -Xms20M -Xmx20M -Xmn10M -XX:+PrintGCDetails -XX:SurvivorRatio=8 Indicates that the Java heap is 20MB, 10 ...

catalogue Guarantee mechanism Case 1: the new generation is unable to allocate memory, is promoted to the old age, and guarantees success Result 1: use the Serial collector Result 2: use the ParallelScavenge collector Case 2: Parallel Scavenge promotion condition: when the memory to be allocated is less than or equal to half of the memory ...

catalogue Reference articles Three JVM s 1.Sun        HotSpot         2.BEA        JRockit 3.IBM        J9 VM Heap Partition of heap memory Evolution of permanent generation Method area and permanent generation / meta space Trigger conditions for Minor GC and Full GC OOM(Out Of Memory) Common configuration parameters of JVM heap ...

1, Background During the development process, we encountered the problem of out of heap memory leakage - the service will fake death (it seems that the service process is still running, but there is no business response). Check the error log of logback and record the following information: [location-center:192.168.5.14:8017] [,] 2021-07-2 ...

JIT just in time compiler JIT (Just In Time) Just In Time compiler server compiler and layered compilation should be used for all applicationsAs long as the code cache is large enough, the compiler can provide perfect performance Code cache Generally, you only need to set the maximum value of the code cache: - XX: reservedcodachesize. The J ...

1, Foreword How to learn if you can't use it? Without scenes and demands, it seems that there is no need to learn these knowledge points. In fact, the best way is to summarize, sort out, practice and output. After a set of combination boxing, you will master this series of knowledge. However, it may not be used at the current stage. The ...

1, General flow of java command execution code: The loadClass class loading process includes the following steps: Load = > verify = > prepare = > parse = > initialize = > use = > unload Load: find and read bytecode files on the hard disk through IO. The class used will be loaded. In the loading phase, a Java. Net file r ...