Detailed explanation of Golang coroutine blocking mechanism

Go coroutine blocking occurs when the coroutine continues execution after waiting for an event to complete, such as waiting for pipeline data, system call completion, or lock release. Solutions include: 1. Use non-blocking I/O; 2. Use Select to listen to multiple events; 3. Set operation timeout; 4. Create a coroutine pool.

Detailed explanation of Go coroutine blocking mechanism

The coroutine (goroutine) in Go is a lightweight thread. to execute code in parallel. Unlike threads, coroutines are less expensive to create and switch, making them ideal for building high-performance concurrent applications.

Blocking coroutine

Coroutine blocking occurs when the coroutine waits for an event to complete before continuing execution. This can happen when:

• Waiting for data on a pipe or channel
• Waiting for a system call to complete (for example, file I/O or a network connection)
• Waiting for lock or mutex release

Solution to blocking coroutine

Go provides several mechanisms to deal with blocking coroutine:

• Non-blocking I/O: Use libraries such as net/http, io/ioutil and os Non-blocking I/O functions avoid blocking.
• Select: The select statement allows a coroutine to listen to multiple events at the same time and automatically switch coroutines when one of the events is ready.
• Timeout operation: Use the context.Context and time.After functions to set the operation timeout to prevent the coroutine from blocking indefinitely.
• Coroutine Pool: Create a coroutine pool to manage the use of coroutines and prevent overload.

Practical Case

Consider the following example where one coroutine reads data from a file and sends data to another coroutine:

package main

import (
    "context"
    "fmt"
    "io/ioutil"
    "time"
)

func main() {
    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    defer cancel()

    // 创建一个管道来缓冲数据
    ch := make(chan []byte)

    // 启动一个 goroutine 从文件中读取数据
    go func() {
        defer close(ch)
        data, err := ioutil.ReadFile("data.txt")
        if err != nil {
            fmt.Println(err)
            return
        }
        ch <- data
    }()

    select {
    case data := <-ch:
        fmt.Println(string(data))
    case <-ctx.Done():
        fmt.Println("Timeout while reading file")
    }
}

In this example:

• We use the select statement to listen to both the pipe and the timeout.
• If the file is read successfully, the coroutine will send the data to the pipe.
• If the file reading times out, the program will print a timeout message.

Conclusion

Understanding the blocking mechanism of coroutines in Go is crucial to building efficient and robust concurrent applications. By applying non-blocking techniques, using select and timeout operations, and managing coroutine pools, you can effectively handle coroutine blocking and ensure the reliable operation of concurrent code.

The above is the detailed content of Detailed explanation of Golang coroutine blocking mechanism. For more information, please follow other related articles on the PHP Chinese website!