Golang function concurrency and coroutine usage guide

Go language achieves concurrency through goroutine. Coroutines are lightweight threads that communicate through channels. The key points are as follows: coroutines are created using the go keyword and executed in parallel. Coroutines share process memory and communicate through channels. In the concurrent web server example, the handler function uses goroutine to process requests in parallel.

Go function concurrency and coroutine usage guide

Concurrency and coroutine overview

Concurrency is the execution of multiple tasks at the same time capabilities, and coroutines are lightweight threads that enable concurrency. Coroutines are more lightweight and consume fewer resources than threads.

Concurrency in Go

The Go language implements concurrency through the built-in goroutine, which is a function that executes in parallel. Create goroutine using the go keyword:

func main() {
    go incrementCounter()
}

func incrementCounter() {
    // 并发地更新计数器
}

Coroutine in Go

Coroutine is a user space thread that shares the memory space of the process . In Go, coroutines can communicate through channel.

Practical Case: Concurrent Web Server

Let us write a concurrent Web server that uses coroutines to handle incoming requests:

package main

import (
    "fmt"
    "log"
    "net/http"
)

func main() {
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    go func() {
        // 在协程中处理请求
        fmt.Fprintf(w, "Hello from a goroutine!\n")
    }()
}

In the above code, handler The function uses the go keyword to create a coroutine to handle incoming requests. Coroutines run in parallel and do not block the main thread.

Notes

• Data competition: Concurrent access to shared data will cause data competition, resulting in unpredictable results. Use locks or atomic variables from the sync package to protect shared data.
• Pipe blocking: Pipe capacity is limited. If the pipe is full, the send operation blocks until space is available on the pipe. Use a buffered pipe or check if the pipe is full.
• Context cancellation: When a coroutine needs to be canceled, use context.Context to propagate the cancellation request.

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