Question

我既有TCP服务器又有一个客户端，简单TCP服务器将只接收传入的数据并进行打印，并且客户端将不断创建套接字连接并将数据循环发送到TCP服务器。

我得到的信息是，如果正确关闭了TCP连接，则此过程应继续进行，而不会发生任何崩溃。

但是从客户端到服务器接收到一定数量的数据后，客户端崩溃并显示错误

total times data send: 16373

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x10d7594]

goroutine 1 [running]:
main.sendData()

/Users/apple/Desktop/Personal/umbrellaserver/src/tests/clinet.go:178 
+0xb4
main.main()

/Users/apple/Desktop/Personal/umbrellaserver/src/tests/clinet.go:170 
+0x2a
exit status 2

Server.go

package main

import (
    "bufio"
    "fmt"
    "net"
    "sync"
)

var wg sync.WaitGroup
var count = 0
var timeX string = ""

var connQueue = make(chan string)

func main() {
    tcpListner := startTCPConnection()
    incomingTCPListener(tcpListner)
}

//startTCPConnection
func startTCPConnection() net.Listener {
    tcpListner, tcpConnectonError := net.Listen("tcp", "localhost:3000")
    if tcpConnectonError != nil {
        print(tcpConnectonError)
        return 
    }
    return tcpListner
}

//incomingTCPListener
func incomingTCPListener(tcpListner net.Listener) {

    for {
        incomingConnection, incomingConnectionError := tcpListner.Accept()
        if incomingConnectionError != nil {
            print(incomingConnectionError)
            return
        }
        wg.Add(1)
        go processIncomingRequest(incomingConnection)
        wg.Wait()
    }
}

//processIncomingRequest
func processIncomingRequest(connection net.Conn) {

    defer connection.Close()

    var scanner = bufio.NewScanner(connection)

    var blob = ""
    for scanner.Scan() {
        fmt.Println("sadd")
        text := scanner.Text()
        blob += text
    }
    print(blob)
    count++
    fmt.Println("totalCount", count)
    wg.Done()
}

Client.go

package main

import (
    "fmt"
    "net"
)

var count = 0

func testJSON2() string {
    return `Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32. The standard chunk of Lorem Ipsum used since the 1500s is reproduced below for those interested. Sections 1.10.32 and 1.10.33 from "de Finibus Bonorum et Malorum" by Cicero are also reproduced in their exact original form, accompanied by English versions from the 1914 translation by H. Rackham.`
}

func main() {
    for i := 0; i < 1000000; i++ {
        sendData()
    }

}

func sendData() {

    connection, connectionError := net.Dial("tcp", "localhost:3000")
    defer connection.Close()

    if connectionError != nil {
        fmt.Println(connectionError)
        return 
    }
    newmessage := testJSON2()
    connection.Write([]byte(newmessage + "\n"))
    count++
    fmt.Println(count)
}

有什么方法可以避免此崩溃并使它连续运行？ 我是Go语言的新手，所以，如果我犯了任何愚蠢的错误，对不起。

Answer 1

if connectionError != nil {
        fmt.Println(connectionError)
        return 
    }
defer connection.Close()

推迟连接。Close（）应该在错误检查之后，因为如果有一些错误的拨号返回，连接变量可以为nil。

Answer 2

package main

import (
	"bufio"
	"fmt"
	"net"
	"sync"
)

var wg sync.WaitGroup
var count = 0
var timeX string = ""

var connQueue = make(chan string)

func main() {
	tcpListner := startTCPConnection()
	incomingTCPListener(tcpListner)
    wg.Wait()
}

//startTCPConnection
func startTCPConnection() net.Listener {
	tcpListner, tcpConnectonError := net.Listen("tcp", "localhost:3000")
	if tcpConnectonError != nil {
		print(tcpConnectonError)
        // return 
        log.Fatal(tcpConnectonError)
	}
	return tcpListner
}

//incomingTCPListener
func incomingTCPListener(tcpListner net.Listener) {

	for {
		incomingConnection, incomingConnectionError := tcpListner.Accept()
		if incomingConnectionError != nil {
			print(incomingConnectionError)
            return
		}
		wg.Add(1)
		go processIncomingRequest(incomingConnection)
		// wg.Wait()
	}
}

//processIncomingRequest
func processIncomingRequest(connection net.Conn) {

	defer connection.Close()

	var scanner = bufio.NewScanner(connection)

	var blob = ""
	for scanner.Scan() {
		fmt.Println("sadd")
		text := scanner.Text()
		blob += text
	}
	print(blob)
	count++
	fmt.Println("totalCount", count)
	wg.Done()
}

问题出在server.go中。我的猜测是您通过在传入的TCPListener（）函数而不是main（）中调用wg.Wait（）来耗尽端口。同样，如果在startTCPConnection（）函数中裸返回，则会导致编译器错误。

客户端无法使用golang将数据发送到TCP服务器？

2 个答案: