golang sync installation

Golang is a very popular programming language in recent years. It has been widely used and received more and more attention. In Golang, sync is a very important standard library. It provides some synchronization primitives, such as mutex (mutex lock), read-write lock (read-write lock), etc., to help developers reduce conflicts in locking resources. Improve program concurrency performance. This article will introduce how to install and use the sync library in Golang.

1. Preparation

Before installing sync, you need to install the Golang development environment. If you have not installed it yet, please go to the Golang official website (https://golang.org/dl/) to download the latest Golang installation package and follow the prompts to install it.

2. Install sync

1. Use the go command to install

After installing Golang, you can use the go command to install the sync library. Open the terminal and execute the following command:

go get -u golang.org/x/sync/...

This command will download and install the latest version of sync from the go code repository. library and all the other libraries it depends on. After executing the command, you can start using the sync library in your project.

2. Download the source code

If an error occurs when executing the above command, or you prefer to manage dependencies manually, you can also manually download the source code of the sync library. Open the terminal and execute the following command:

git clone https://github.com/golang/sync.git $GOPATH/src/golang.org/x/sync

This command will start from Download the source code from the sync library's GitHub repository and place it in your $GOPATH/src/golang.org/x/sync directory. You can then reference the code in this directory in your own project.

3. Use sync

After installing the sync library, you can use the functions of the sync library in your Golang project. The following are several common use cases:

1. Use mutex lock

The sync.Mutex type is a simple but very useful synchronization primitive, used when multi-threads access shared resources. It ensures that only one goroutine can access the protected code section at the same time. Here is a basic usage example:

package main

import (

"fmt"
"sync"

)

type Counter struct {

mux sync.Mutex // 互斥锁用于保护Counter的值
value int

}

func (c *Counter) Inc() {

c.mux.Lock() // 加锁，确保在修改Counter值的时候不会有其他goroutine同时访问
defer c.mux.Unlock() // 解锁
c.value++

}

func (c *Counter) Value() int {

c.mux.Lock()
defer c.mux.Unlock()
return c.value

}

func main() {

c := Counter{}
var wg sync.WaitGroup
for i := 0; i < 1000; i++ {
    wg.Add(1) // 启动一个goroutine前增加WaitGroup中的计数器
    go func() {
        c.Inc()
        wg.Done() // goroutine结束时减小WaitGroup中的计数器
    }()
}
wg.Wait() // 等待所有goroutine执行完成
fmt.Println(c.Value()) // 输出Counter的值

}

2. Use read-write lock

sync.RWMutex type is a type used to optimize the process of reading data Lock, which allows multiple coroutines to read shared resources at the same time without conflict. Locking is only required when writing. Here is a basic usage example:

package main

import (

"fmt"
"math/rand"
"sync"
"time"

)

type Cache struct {

data map[string]string
mux sync.RWMutex // 读写锁用于保护Cache

}

func (c *Cache) Get(key string) string {

c.mux.RLock() // 加读锁
defer c.mux.RUnlock() // 解锁
return c.data[key]

}

func (c *Cache) Set(key, value string) {

c.mux.Lock() // 加写锁
defer c.mux.Unlock() // 解锁
c.data[key] = value

}

func main() {

c := Cache{data: make(map[string]string)}
var wg sync.WaitGroup
for i := 0; i < 200; i++ {
    wg.Add(1)
    go func() {
        defer wg.Done()
        key := fmt.Sprintf("%d", rand.Intn(10)) // 随机生成key
        value := fmt.Sprintf("%d", time.Now().Unix()) // 生成当前时间戳作为value
        c.Set(key, value)
        time.Sleep(50 * time.Millisecond) // 模拟耗时操作
        fmt.Println(c.Get(key))
    }()
}
wg.Wait()

}

The above are some basic usages of the sync library. Of course, the sync library also provides more synchronization primitives. language. For developers who want to have a deeper understanding of Golang concurrent programming, it is very important to master the use of the sync library.

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