Go language programming practice: execution and waiting of the main function

[Title]Go language programming practice: execution and waiting of the main function

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As a concurrent programming language, Go language has the execution and waiting of the main function. Waiting is a very important topic. In Go, the main function is usually the main function, which is the entry point of the program and is responsible for starting the program and executing related logic. However, when it comes to concurrent programming, the way the main function executes and waits may differ. This article will explore the execution and waiting process of the main function through specific code examples.

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Execution of the main function

In the Go language, the execution of the main function is completed through the main function. We can show how the main function is executed by writing a simple example program:

package main

import "fmt"

func main() {
    fmt.Println("Hello, Go!")
}

In the above example, the main function prints a simple message "Hello, Go!". When we run this program, the main function will be executed and this message will be output. In this case, the execution of the main function is sequential. Once the main function is executed, the entire program ends.

Waiting in the main function

However, in actual applications, we may encounter situations where we need to wait for other goroutines to finish executing before ending the program. In the Go language, we can implement waiting in the main function by using WaitGroup in the sync package.

Let's look at a specific example. Suppose we have a requirement to start multiple goroutines at the same time. Each goroutine will handle some tasks, and after all goroutines have been executed, the main function will end the program. The following is a sample code:

package main

import (
    "fmt"
    "sync"
)

func worker(id int, wg *sync.WaitGroup) {
    defer wg.Done()
    fmt.Printf("Worker %d is working
", id)
}

func main() {
    var wg sync.WaitGroup

    for i := 1; i <= 5; i++ {
        wg.Add(1)
        go worker(i, &wg)
    }

    wg.Wait()
    
    fmt.Println("All workers have finished, exiting main function")
}

In the above example, we defined a worker function to simulate the work of goroutine, and then started 5 goroutines in the main function to execute the worker function. Use sync.WaitGroup to wait for all goroutines to finish executing before outputting a message.

Summary

Through the above code example, we understand how to handle the execution and waiting issues of the main function in the Go language. The execution of the main function is usually sequential, but when it comes to concurrent programming, we may need to wait for some goroutines to finish executing before ending the program. By using the WaitGroup in the sync package, we can simply implement the waiting function of the main function to ensure the correct execution of the program.

In actual development, we may encounter more complex concurrency scenarios, but after mastering the execution and waiting principles of the main function, we can better handle problems in concurrent programming. I hope this article can help readers gain a deeper understanding of the execution and waiting mechanism of the main function in the Go language and apply it flexibly in practice.

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