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
	elemtype *_type // element type
	sendx    uint   // send index
	recvx    uint   // receive index
	recvq    waitq  // list of recv waiters
	sendq    waitq  // list of send waiters

	// 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
}

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
	"time"
)

/**
 * @Author: yirufeng
 * @Date: 2021/7/10 9:04 下午
 * @Desc:
 **/

type User struct {
	Username string `json:"username"`
}

func main() {
	engine := gin.Default()

	engine.GET("/", func(c *gin.Context) {
		startTime := time.Now()

		c.JSON(http.StatusOK, gin.H{
			"method":         http.MethodGet,
			"elapsedTime/ms": time.Since(startTime).Milliseconds(),
		})
	})

	engine.POST("/", func(c *gin.Context) {
		startTime := time.Now()

		var u User
		err := c.BindJSON(&u)
		if err != nil {
			c.JSON(http.StatusOK, gin.H{
				"error": err.Error(),
			})
			return
		}

		c.JSON(http.StatusOK, gin.H{
			"method":         http.MethodPost,
			"elapsedTime/ms": time.Since(startTime).Milliseconds(),
			"username":       u.Username,
		})
	})

	engine.Run(":8081")
}

// runtime/slice.go
type slice struct {
    array unsafe.Pointer // 元素指针
    len   int // 长度 
    cap   int // 容量
}