golang channel是什么

ch <- v    // 发送值v到Channel ch中

v := <-ch  // 从Channel ch中接收数据，并将数据赋值给v

type hchan struct {

   qcount   uint           // total data in the queue 队列中存在的个数

   dataqsiz uint           // size of the circular queue buffer大小 实现看起来是个循环数组

   buf      unsafe.Pointer // points to an array of dataqsiz elements 数组指针

   elemsize uint16       //channel类型的大小

   closed   uint32      //channel是否关闭

   elemtype *_type // element type //channel 类型

   sendx    uint   // send index  //发送index

   recvx    uint   // receive index //接收index

   recvq    waitq  // list of recv waiters //接收链表 即读channel的goroutine

   sendq    waitq  // list of send waiters //发送链表 即写channel的goroutine

   // lock protects all fields in hchan, as well as several

   // fields in sudogs blocked on this channel.

   //

   // Do not change another G's status while holding this lock

   // (in particular, do not ready a G), as this can deadlock

   // with stack shrinking.

   lock mutex

}