Prevention and solution of deadlock and starvation in golang function concurrency control

Deadlock and starvation in Go: Preventing and solving deadlock: Coroutines are waiting for each other and cannot perform operations. Use the runtime.SetBlockProfileRate function to detect. Prevent deadlocks: Use fine-grained locking, timeouts, and lock-free data structures to prevent deadlocks. Starvation: The coroutine continues to be unable to obtain resources, and fair locks are used to prevent starvation. Fair lock practice: Create a fair lock and wait for the coroutine to try to acquire the lock for the longest time to acquire the lock first.

Prevention and solution of deadlock and starvation in function concurrency control in Go

When using concurrency in Go, deadlock and starvation are very common bugs that can cause applications to exhibit unpredictable or even confusing behavior.

Deadlock

Deadlock means that there are multiple coroutines waiting for each other, causing the program to be unable to proceed. It can happen when two or more coroutines try to acquire the same lock.

Hungry

Hunger means that the coroutine is unable to execute due to some factors continuing to be unable to obtain resources. It can happen when a coroutine is blocked indefinitely by other coroutines.

Prevention and Solution

1. Use deadlock detection

sync/atomic package provides The runtime.SetBlockProfileRate function is installed, which writes the deadlock situation in the program into memory at a certain frequency. When a deadlock is detected, you can use go tool trace to view the call stack and determine the cause of the deadlock.

2. Fine-grained locking

Using fine-grained locking can reduce lock competition, which helps prevent deadlocks. For example, instead of locking the entire structure at once, lock only the fields that need to be modified.

3. Use timeout

Setting a timeout for the lock operation can prevent the coroutine from waiting indefinitely. If the coroutine cannot obtain the lock within the specified time, it can take other actions or exit.

4. Lock-free data structures

For low contention scenarios, lock-free data structures can be used, such as concurrent mapping or lock-free queues. These data structures do not require explicit Type lock.

5. Fair lock

When releasing the lock, fair lock will give priority to waiting for the coroutine that first tries to acquire the lock, which helps prevent starvation. A fair lock can be created using the sync.Mutex type.

Practical Case

The following example shows how to use fair locks to prevent starvation:

import (
    "sync"
    "time"
)

func main() {
    // 创建一个公平锁
    lock := &sync.Mutex{}

    // 创建 10 个协程，每个协程尝试获取锁
    var wg sync.WaitGroup
    wg.Add(10)
    for i := 0; i < 10; i++ {
        go func(i int) {
            defer wg.Done()

            // 尝试在 100 毫秒内获得锁
            if err := lock.Lock(100 * time.Millisecond); err != nil {
                // 超时，协程退出
                return
            }

            // 对共享资源进行操作

            // 释放锁
            lock.Unlock()
        }(i)
    }

    // 等待所有协程完成
    wg.Wait()
}

In this case, even if some coroutines may Blocked by other coroutines, fair locks will also ensure that each coroutine will eventually obtain the lock.

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