golang asynchronous implementation

With the continuous development of Internet technology, computer programming languages ​​are also constantly updated and improved. As a relatively young programming language, Go language (golang for short) is favored by more and more developers because of its high concurrency and excellent memory management. In golang, implementing asynchronous calls is a very common requirement. In this article, we will explore the implementation of asynchronous calls in golang in detail.

1. The concept of golang asynchronous calling

We all know that computer programs are generally executed in sequence according to the code sequence, but in actual application processes, multiple tasks often need to be executed at the same time. This When we do this, we will introduce the concept of asynchronous calls. Asynchronous calling is a method of concurrent execution, which means that the program executes multiple tasks at the same time without waiting for each task to end before executing the next task. In an asynchronous call, each task will start a separate thread and return to the main thread after completing the task, so it will not affect the normal execution of other tasks.

In golang, the implementation of asynchronous calls is different from other programming languages. Golang uses goroutine (coroutine) to implement asynchronous calls. Goroutine is a lightweight thread that can create multiple coroutines in a program. Each coroutine is independent and can be executed concurrently.

2. How to implement asynchronous calls in golang

In golang, we can use goroutine and channel to implement the function of asynchronous calls.

1. Use goroutine to implement asynchronous calls

In golang, it is very simple to open a goroutine. You only need to add the go keyword in front of the function, for example:

go func() {
    // 执行任务的代码
}()

The above code is to execute a task in the new goroutine. Let’s take a look at a complete sample code:

package main

import (
    "fmt"
    "time"
)

func main() {
    // 开启一个goroutine执行任务
    go func() {
        for i := 0; i < 10; i++ {
            fmt.Println("goroutine执行...", i)
            time.Sleep(1 * time.Second)
        }
    }()

    // 主线程执行任务
    for i := 0; i < 5; i++ {
        fmt.Println("主线程执行...", i)
        time.Sleep(1 * time.Second)
    }

    // 等待一段时间，保证goroutine执行完毕
    time.Sleep(15 * time.Second)
    fmt.Println("程序结束...")
}

Through the above code, we can see that the program starts a goroutine execution task, and the main thread is also executing another task at the same time. During the running of the program, the main thread and goroutine can run at the same time without affecting each other.

2. Use channels to implement asynchronous calls

In golang, channel is a way of communication between goroutines. We can use channels to implement asynchronous calls. We can create a channel with a buffer, then execute the task in the goroutine and pass the result to the main thread through the channel, as shown below:

package main

import (
    "fmt"
    "time"
)

func main() {
    // 创建一个带缓冲区的channel
    ch := make(chan int, 10)

    // 在goroutine中执行任务，并将结果通过channel传递给主线程
    go func() {
        for i := 0; i < 10; i++ {
            ch <- i
        }
    }()

    // 主线程读取channel中的数据
    for {
        num, ok := <-ch
        if ok {
            fmt.Println("收到数据：", num)
        } else {
            break
        }
    }

    fmt.Println("程序结束...")
}

In the above code, we create a channel with The channel of the buffer and executes a task in the goroutine, and the result of the task is passed to the main thread through the channel. The main thread reads the data in the channel through a loop. When the channel is closed, it uses the ok variable to determine whether the loop ends, thereby ensuring that the program can exit normally.

3. Application scenarios of golang asynchronous calls

In actual applications, asynchronous calls are often used in the following scenarios:

1. Network requests

In network communication, due to the uncertainty of network conditions, the response time of the request may be very long. If synchronous calling is used, the program will be blocked for a long time and affect the user experience. Therefore, we can use asynchronous calling. We do not have to wait for the response after the request, but continue to perform other tasks and wait until the response arrives before processing.

2. File operations

For some file operations, a large number of I/O operations may be required, such as reading file contents, writing files, etc. These I/O operations are time-consuming. If synchronous calls are used, the program may be blocked and inefficient. Therefore, we can use asynchronous calling to use goroutine to perform tasks when file operations take a lot of time, without affecting the normal operation of the main thread.

3. Scheduled tasks

In some scheduled tasks, you may need to perform some time-consuming operations. If synchronous calling is used, the time accuracy and stability of the program may be affected. Therefore, we can use asynchronous calling to enable goroutine to perform specific operation tasks while the main thread performs scheduled tasks, without affecting the accuracy and stability of the program.

4. Conclusion

Asynchronous calling is a very common programming technique in modern programming languages, which can make the program more efficient and stable. As a programming language with strong concurrency, golang supports asynchronous calls through goroutine and channel, which is very convenient and practical. In practical applications, we need to choose the appropriate asynchronous calling method based on specific scenarios to improve program performance and user experience.

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