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This article mainly introduces "Jvm memory in Java is divided into several parts". In daily operation, I believe that many people have doubts about the problem of dividing Jvm memory into several parts in Java. Xiaobian consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubt that "Jvm memory in Java is divided into several parts". Next, please follow the editor to study!

We don't have to worry about memory management in Java development because Jvm does a lot of work for us. Jvm roughly divides memory into the following sections for different purposes. As shown below:

Let's describe the specific functions of each piece in detail below.

Program counter: a line number indicator of the bytecode executed by the current thread. In other words, its function is to select which bytecode instructions to execute through the value of this counter. We know that although many programs can be run at the same time in a multitasking system, the nature of running is determined by the fact that CPU allocates execution time to different programs. If we start a Java program if it is single-threaded, although the program starts, CPU may execute other programs at this time, then when CPU re-executes the Java program, be sure to know where the program was last executed, and then continue to execute this assignment, this counter records the execution line number of the program. The only difference is that this counter is not for the program, but for the thread, because the logic that each thread may execute is different, so Jvm needs to know where each thread was last executed. So the program counter, each thread is independent. If the thread is executing a Java method, this counter records the bytecode instruction address of the virtual machine being executed. If the method executed is the Native method, then the value of this counter is empty.

Stack: mainly stores local variable table, dynamic link, method exit and other information. And the stack also exists independently of each thread.

Heap: the largest place in Jvm to manage memory. Its function is to store an instance of the object. We can control the heap size by setting-Xmx and-Xms. The heap is also the main place where garbage collectors are recycled in Jvm. And heap memory is an area shared by all threads.

Method area: like the heap, it is also a memory area shared by all threads, except that it mainly stores class information, constants, static variables and other information loaded by the virtual machine.

Run-time pool: the constant pool is stored in the method area, mainly saving literals and symbolic references generated at compile time. Because the constant pool is stored in the method area, the constant pool is also shared by all threads.

At this point, the study on "Jvm memory in Java is divided into several parts" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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