结构体

type hchan struct {
    qcount   uint           // total data in the queue
    dataqsiz uint           // size of the circular queue
    buf      unsafe.Pointer // points to an array of dataqsiz elements
    elemsize uint16
    closed   uint32 //状态值 0未开启，1为关闭
    elemtype *_type // element type
    sendx    uint   // send index
    recvx    uint   // receive index
    recvq    waitq  // list of recv waiters 接收队列
    sendq    waitq  // list of send waiters 发送协程的链表
    // 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 
    // 互斥锁并不是排队发送/接收数据
    // 互斥锁保护的hchan结构体本身
    // channel并不是无锁的
}

发送数据的底层原理

直接发送

放入缓存

休眠等待

总结