^25 processes and threads

1、 process ： An execution of a program , It has a unique memory space ( Can pass window Task manager Check the process )

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2、 Threads ：

- An independent unit within a process

- A complete process of program execution

- CPU Minimum scheduling unit of

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3、 Related content ：

- The application must run on a process of a process

- There is at least one running thread in a process ： The main thread , Automatically created after the process starts

- Multiple threads can be run simultaneously in a process , We would say that programs are multithreaded

- Data in a process can be shared by multiple threads

- Data between multiple processes cannot be shared directly

- Thread pool ： A container that holds multiple thread objects , Realize the reuse of Thread objects

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4、 Related issues ：

- What is multiprocessing and multithreading ？

                    many process ： A program can start multiple instances to run at the same time

                    many Threads ： In a process , There are multiple threads running at the same time

- Compare single and multithreaded ？

                    single Threads ：( advantage ： Sequential programming is easy to understand )( shortcoming ： Low efficiency )

                    many Threads ：( advantage ： Can effectively improve CPU Utilization ratio )( shortcoming ： Creating multithreading overhead 、 Switching overhead between threads 、 Deadlock and state synchronization )

- JS Single thread or multi thread ？

                    JS It's single threaded

                    But use HTML5 Medium Web Worker It can be multithreaded

- Is the browser running single threaded or multi-threaded ？

                    All are many Thread running

- Is the browser running in a single process or multiple processes ？

                    There are plenty of them single process , There are plenty of them many process

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