Golang heap memory management practice

In the Go language, heap memory is used to store dynamically allocated objects with a longer life cycle. Heap memory allocation uses the new keyword, and manually freeing heap memory can lead to memory leaks. To solve this problem, you can use the defer statement to automatically release the heap memory when the function returns. Heap memory management is very useful in cache systems. Simple key-value caching can be implemented by using map. Note that a synchronization mechanism is required when managing heap memory in a concurrent environment.

Go language heap memory management practice

In the Go language, heap memory is used to store dynamically allocated objects. Compared with stack memory, heap memory has a longer life cycle and can be allocated and released as needed.

Heap memory allocation

Use the new keyword to allocate space for heap memory. It takes a parameter of type and returns a pointer to a newly allocated object of that type.

// 分配一个 int 类型堆内存
p := new(int)      // p 为类型 *int
i := *p           // 解引用 p 访问堆内存中的值
fmt.Println(i)    // 输出 0

Heap memory release

Manually releasing heap memory will cause memory leaks because the Go language does not have a built-in garbage collection mechanism. Instead, you can use the defer statement to automatically free the heap memory when the function returns.

// 使用 defer 自动释放堆内存
func main() {
    p := new(int)
    
    defer func() {
        fmt.Println("释放堆内存")
        *p = 0 // 释放前应将值置为零
        p = nil // 设置 p 为 nil
    }()
    
    // 使用堆内存
    *p = 10
    fmt.Println(*p)
}

Practical case: cache

Heap memory management is very useful in cache systems. Caching stores frequently accessed data in memory to increase access speed.

// 使用 map 实现简单的键值缓存
type Cache struct {
    data map[string]interface{}
}

func NewCache() *Cache {
    return &Cache{
        data: make(map[string]interface{}),
    }
}

func (c *Cache) Get(key string) (interface{}, bool) {
    val, ok := c.data[key]
    return val, ok
}

func (c *Cache) Set(key string, value interface{}) {
    c.data[key] = value
}

Note: Concurrency Safety

Managing heap memory in a concurrent environment requires the use of synchronization mechanisms, such as mutexes or read-write locks, to prevent data races caused by concurrent access.

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