项目上之前出现map并发问题，查找资料后自己整理一下。

代码如下：

//map 并发存取
type BeeMap struct {
    lock *sync.RWMutex
    bm   map[string]interface{}
}

func NewBeeMap() *BeeMap {
    return &BeeMap{
        lock: new(sync.RWMutex),bm:   make(map[string]interface{}),}
}

//Get from maps return the k's value
func (m *BeeMap) Get(k string) interface{} {
    m.lock.RLock()
    defer m.lock.RUnlock()
    if val,ok := m.bm[k]; ok {
        return val
    }
    return nil
}

// Maps the given key and value. Returns false
// if the key is already in the map and changes nothing.
func (m *BeeMap) Set(k string,v interface{}) bool {
    m.lock.Lock()
    defer m.lock.Unlock()
    if val,ok := m.bm[k]; !ok {
        m.bm[k] = v
    } else if val != v {
        m.bm[k] = v
    } else {
        return false
    }
    return true
}

// Returns true if k is exist in the map.
func (m *BeeMap) Check(k string) bool {
    m.lock.RLock()
    defer m.lock.RUnlock()
    if _,ok := m.bm[k]; !ok {
        return false
    }
    return true
}

func (m *BeeMap) Delete(k string) {
    m.lock.Lock()
    defer m.lock.Unlock()
    delete(m.bm,k)
}