bugfix: fix i/o timeout: connection was bad

[theharveyz]

No description provided.

[lance6716]

Hi, could you explain what's the scenario and problem you want to fix?

[theharveyz]

Hi, could you explain what's the scenario and problem you want to fix?

ping 这里会导致 Conn 的读写期限被设置成很短的值，后面被业务逻辑获取后，会频繁出现 "connection was bad" 的问题。
复现代码：

--

setting a very short deadline for Conn in ping will cause "connection was bad" when it is later used.

reproduce code:

package main

import (
	"context"
	"log"

	"github.com/gin-gonic/gin"
	"github.com/go-mysql-org/go-mysql/client"
	"github.com/sirupsen/logrus"
)

var pool *client.Pool
var l *logrus.Logger

func main() {
	router := gin.New()
	l = logrus.New()
	pool = client.NewPool(l.Debugf, 10, 10, 5, "127.0.0.1:3306", `{user}`, `{pwd}`, `{dbname}`)
	router.GET("/test", Test)
	router.Run("127.0.0.1:8000")
}

func Test(gin *gin.Context) {
	conn, _ := pool.GetConn(context.Background())
	defer pool.PutConn(conn)
	
	res, err := conn.Execute("SELECT * FROM test WHERE id > ?", 0)
	if err != nil {
		log.Printf(" Execute Err : %s\n", err)
	}

	if err != nil {
		gin.SecureJSON(200, err.Error())
	} else {
		gin.SecureJSON(200, err)
	}
}