Golang 协程内存泄漏

我不明白为什么没有释放内存。内存配置文件显示几乎所有内存都被 runtime.malg 使用。如果我在 DoSomeWork 中删除 range over channel 一切正常。

这里是 fmt.Println 的输出:

Memory Acquired:  4196600
Memory Used    :  745192

Memory Acquired:  2651299576
Memory Used    :  393923440

源代码:

func DoSomeWork(work chan int) {
    for _ = range work {
    }
}

func main() {
    k := make(chan int)
    m := &runtime.MemStats{}
    runtime.ReadMemStats(m)
    fmt.Println("Memory Acquired: ", m.Sys)
    fmt.Println("Memory Used    : ", m.Alloc)

    wg := new(sync.WaitGroup)
    // generate a lot of goroutines that reads from channel
    for i:=0;i<1000000;i++ {
        wg.Add(1)
        go func() {
            DoSomeWork(k)
            wg.Done()
        }()
    }

    close(k)
    wg.Wait()

    // make GC
    runtime.GC()

    // show memory after garbage collector
    runtime.ReadMemStats(m)
    fmt.Println("Memory Acquired: ", m.Sys)
    fmt.Println("Memory Used    : ", m.Alloc)
}