如何用Golang实现文件并发读写 讲解sync.Mutex在I/O中的正确使用

sync.Mutex

os.File

file.Write()

file.Read()

file, _ := os.OpenFile("log.txt", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
for i := 0; i < 10; i++ {
    go func(i int) {
        file.WriteString(fmt.Sprintf("line %d\n", i))
    }(i)
}

sync.Mutex

var mu sync.Mutex
file, _ := os.OpenFile("log.txt", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)

for i := 0; i < 10; i++ {
    go func(i int) {
        mu.Lock()
        defer mu.Unlock()
        file.WriteString(fmt.Sprintf("line %d\n", i))
    }(i)
}

file, _ := os.Open("data.txt")
for i := 0; i < 10; i++ {
    go func() {
        buf := make([]byte, 1024)
        n, _ := file.Read(buf)
        fmt.Println(string(buf[:n]))
    }()
}

sync.RWMutex

sync.RWMutex

var rwMu sync.RWMutex
file, _ := os.OpenFile("data.txt", os.O_CREATE|os.O_RDWR, 0644)

// 写操作
go func() {
    rwMu.Lock()
    defer rwMu.Unlock()
    file.WriteString("new content\n")
}()

// 多个读操作
for i := 0; i < 5; i++ {
    go func() {
        rwMu.RLock()
        defer rwMu.RUnlock()
        buf := make([]byte, 1024)
        n, _ := file.Read(buf)
        fmt.Println(string(buf[:n]))
    }()
}

sync.Mutex

os.Open

os.OpenFile

file.Close()

defer file.Close()

file, err := os.OpenFile("log.txt", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
if err != nil {
    log.Fatal(err)
}
defer file.Close()

sync.Mutex

sync.RWMutex