garbage collection in java interview questions

Java garbage Collection (i)In Java, its memory management consists of two aspects: memory allocation and memory recycling , both of which are done automatically by the JVM, reducing the learning difficulty of Java programmers and avoiding the danger of direct manipulation of

Java garbage collection mechanism concepts This article is an example of the Garbage Collection Handbook that will be published in a few weeks. At the same time, you can be familiar with the basic knowledge of garbage

Problem? Java garbage collection mechanism1. Sorting of fragmentsKnow that Java objects, after recycling, will form fragments, and then how is it recycled and organized?Then the next write operation becomes more time consuming, because finding the next available free block is no longer a simple operation.When the JVM c

Document directory Spam memory judgment Algorithm Garbage collection Algorithm This series of Reading Notes for deep understanding of Java Virtual Machine (by Zhou Zhiming) There are three core issues of garbage collection: (1) memory to be recycled (2) when to recycle

Notes, in-depth understanding of Java virtual machines Java run-time memory area program counter , thread exclusive, the line number indicator of the byte code that the current thread executes, each thread needs to record where it is executed, and the next time it is scheduled to continue, this area is the only one that will not happen to Oom. stack , thread exclusive, containing a virtual machine stack or

The first thing to clarify is that the garbage collection (GC) history is far older than Java, and when we realize the trouble of manually managing memory, lazy instincts drive pioneers to find simpler, easier-to-use, and key-to-fool memory management techniques. The emergence of GC technology from the Lisp language of MIT in the 1960 shows that the smarter the m

the activity resumes when the B callback is completed. Reference variable: The reference variable is the same as a local variable and can be referenced only when it is in scope, referencing a local variable Instance variable: The scope of the instance variable is the class to which it belongs, and if the object is alive, the instance variable is also alive, and if the object is freed, it is freed (the instance variable and the object live on the heap)three ways to dispose of objects:1. Place t

Java's memory allocations and recoveries are all automatically completed by the JVM garbage collection process. Unlike the C language, Java developers do not need to write their own code to implement garbage collection. This is one of the many popular features of

Garbage collection policy in JavaGarbage collection problems Who needs to be recycled When to recycle How to recycle who needs to be recycledIf an object is no longer used, it can be recycled. The key is how to know that an object is no longer used.Reference countWhen an object is referenced, the reference count plus 1. When the reference fails, the Count min

1. Common algorithms:A. Reference counting method: Configure an shaping counter for each object, when there is a reference, counter +1, when the reference fails, counter-1. Counter 0 for garbage collectionProblem: A object reference b,b object reference A. Circular reference, cannot be purged, causes memory leakThe Java garbage collector does not use the algorith

Java 9 wishing list: Please give us a better garbage collection mechanism Oracle said that the low pause of the G1 garbage collection mechanism will replace Parallel GC to improve system execution efficiency. Currently, Oracle is planning to use the G1 server

I. Overview Java is much more convenient than recovering memory from C and C + +, because the JVM automatically allocates memory and reclaims memory for us. In previous JVM storage management, we introduced several areas of JVM memory management where program counters and virtual machine stacks were thread-private and were out of the thread, so it was not considered garbage

In this Java GC Series tutorial, let's learn about tools for garbage collection monitoring and analysis. Then, choose a tool to monitor the garbage collection process for a Java sample program. If you are a beginner, you'd better

The garbage collection mechanism algorithm is an important factor to limit the efficiency of the JVM.There are many kinds of algorithms to implement garbage collection, the use of separate is always mixed, so the actual garbage collectio