Replay Java Memoir (12): Use of Java 12 thread, Java 12

Replay Java Memoir (12): Use of Java 12 thread, Java 12

Processes and threads

Process: A sub-Program executed in an operating system, including virtual cpu, code, and Data DOS

Multi-process: Multiple subprograms executed in one operating system improve cpu usage

Thread: subprogram stream that is executed simultaneously in a process

Multithreading: Several subprogram streams that are executed simultaneously in a process

Differences between processes and threads:

Processes have independent process space (data storage) and are independent of each other.

The thread heap space is shared, the stack space is independent, and the resources occupied by the thread are relatively small, which can affect each other.

How to use processes in Java

Class that calls the local program

Runtime: The current running environment exec returns the result of process

Process: Process

Java program running

Jvm running: Process-level running. Once the JVM ends, the threads above the JVM are destroyed.

Java code is interpreted (run) in Jvm, and every executable Java program should be treated as a thread

A -- main thread

-- Enable other threads through the main thread and end the main method --> end of the main thread

-- The thread opened by main is still being executed

B -- main

 

Features of threads:

1. Mutual influence between threads

2. Priority exists between threads

How to write threads in java

Thread running

New -------> start -- Automatic --> run <-----> pause (wait/sleep)

--------> Destroy (distory)

 

Main method: It is a special thread with the highest priority

 

The essence of the thread: run: is an execution method run ()

 

-- Extends

Thread class: Thread: requires sub-classes to implement the run method (rewrite)

 

-- Implementation method implements

Thread running mode: Runnable: run Method