Introduction to Go WaitGroup and its application areas in Golang

Introduction to Go WaitGroup and its application areas in Golang

Introduction:
Go language (Golang), as an open source statically typed programming language, has been Officially released by Google in 2009. Its goal is to make development easier and more efficient, and is particularly good at handling high concurrency and distributed systems. In Golang, WaitGroup is a very practical concurrency control tool. It allows the main thread to wait for all child threads to complete execution before proceeding to the next step. This article will introduce Go WaitGroup, introduce its application areas in Golang, and give specific code examples.

1. Introduction to Go WaitGroup
Go WaitGroup (waiting group) is a concurrency control tool in Golang. By counting child threads, it realizes the function of continuing execution after the main thread waits for all child threads to complete execution. WaitGroup has three methods: Add(), Done() and Wait().

1. Add() method: used to set the number of child threads in the waiting group. Each child thread needs to call the Add() method once before starting execution. This method accepts a positive integer as a parameter, indicating the number of child threads.
2. Done() method: used to indicate the end of execution of a child thread. At the last line of code in each child thread, the Done() method needs to be called once. Each time the Done() method is called, the counter in the wait group will be decremented by 1.
3. Wait() method: Use this method in the main thread to wait for all sub-threads in the waiting group to complete execution. When the counter in the wait group reaches 0, the main thread continues execution.

2. Application fields of Go WaitGroup
Go WaitGroup is widely used in Golang in scenarios where you need to wait for a set of concurrent tasks to be completed before proceeding to the next step. Several specific application areas will be given below.

1. Concurrent crawler
   In a crawler program, it is usually necessary to start multiple crawling tasks at the same time to improve efficiency. Using WaitGroup, the main thread can wait for all crawling tasks to be completed before proceeding to the next step. Specific examples are as follows:

func crawl(url string, wg *sync.WaitGroup) {
    defer wg.Done()
    // 爬取逻辑
}

func main() {
    var wg sync.WaitGroup
    urls := []string{"url1", "url2", "url3"}

    for _, url := range urls {
        wg.Add(1)
        go crawl(url, &wg)
    }

    wg.Wait()
    // 其他操作
}

2. Concurrent file processing
   During the file processing process, using WaitGroup can make the main thread wait for all file processing tasks to be completed before proceeding to the next step. Specific examples are as follows:

func processFile(file string, wg *sync.WaitGroup) {
    defer wg.Done()
    // 文件处理逻辑
}

func main() {
    var wg sync.WaitGroup
    files := []string{"file1", "file2", "file3"}

    for _, file := range files {
        wg.Add(1)
        go processFile(file, &wg)
    }

    wg.Wait()
    // 其他操作
}

3. Concurrent task execution
   In some concurrent task execution scenarios, using WaitGroup can ensure that the main thread waits for all tasks to be executed before proceeding to the next step. Specific examples are as follows:

func executeTask(task func(), wg *sync.WaitGroup) {
    defer wg.Done()
    task() // 执行任务
}

func main() {
    var wg sync.WaitGroup
    tasks := []func(){task1, task2, task3}

    for _, task := range tasks {
        wg.Add(1)
        go executeTask(task, &wg)
    }

    wg.Wait()
    // 其他操作
}

Summary:
Go WaitGroup is a very practical concurrency control tool in Golang, which is used to implement the function of the main thread waiting for all child threads to complete execution before continuing. WaitGroup can work well in scenarios such as concurrent crawlers, concurrent file processing, and concurrent task execution. We hope that through the introduction and sample code of this article, readers can have a deeper understanding of the use of Go WaitGroup and use it flexibly in actual development.

The above is the detailed content of Introduction to Go WaitGroup and its application areas in Golang. For more information, please follow other related articles on the PHP Chinese website!