The impact of Golang coroutine blocking on performance

Question: What impact does coroutine blocking have on the performance of Go applications? Answer: Coroutine blocking has the following effects on the performance of Go applications: Latency: Blocked coroutines delay the execution of other coroutines, causing the application to become unresponsive. Resource consumption: Frequent coroutine context switching will cause additional memory and CPU overhead. Deadlock: Blocking coroutines can lead to deadlock, which occurs when two or more coroutines are waiting for each other to complete.

The impact of Go coroutine blocking on performance

Introduction

Go Coroutine Thread is a lightweight parallel execution mechanism that achieves concurrency by creating multiple execution bodies in a single thread. However, coroutine blocking can have an impact on performance.

Coroutine blocking

Coroutine blocking means that the coroutine is waiting for other goroutines to complete operations or I/O operations to complete. This may result in the coroutine scheduler having to dequeue the suspended coroutine and requeue it for scheduling. This switching back and forth hurts performance.

Impact

The impact of coroutine blocking on performance can be significant:

• Delay: Blocking The coroutine will delay the execution of other coroutines, causing the application to become unresponsive.
• Resource consumption: Frequent coroutine context switching will cause additional memory and CPU overhead.
• Deadlock: Blocked coroutines may cause deadlock, which occurs when two or more coroutines are waiting for each other to complete.

Practical Case

Consider the following example where a coroutine waits for a query to the database to complete:

func main() {
    ch := make(chan string)

    go func() {
        sql := "SELECT * FROM users"
        rows, err := db.Query(sql)
        if err != nil {
            log.Fatal(err)
        }
        defer rows.Close()

        for rows.Next() {
            var user User
            if err := rows.Scan(&user); err != nil {
                log.Fatal(err)
            }
            ch <- user.Username
        }
    }()

    // 协程在此阻塞，直到查询完成
    for user := range ch {
        fmt.Println(user)
    }
}

In this example, the Database queries are blocking operations. This means that the coroutine will block until the query completes and the results are available. This may cause application performance degradation.

Mitigation measures

In order to alleviate the impact of coroutine blocking, the following measures can be taken:

• Avoid blocking: Avoid blocking operations in coroutines as much as possible. Instead, use non-blocking I/O or channels for communication.
• Use goroutine pool: Using goroutine pool can reduce the overhead of coroutine context switching.
• Keep the number of coroutines small: Keeping the number of coroutines small can reduce the pressure on the scheduler and memory.

Conclusion

Coroutine blocking can have a significant impact on the performance of your Go application. By taking steps to mitigate blocking, you can significantly improve your application's scalability and responsiveness.

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