地址已在使用中

最近我一直在编写一些客户端代码，用于使用线程从服务器发送和接收消息。以下代码在运行时表现异常。在输入要发送到服务器的消息后，代码完成了任务，尽管出现了"套接字已在使用"错误，但服务器会收到它。但我尝试发送到服务器上的每一条后续消息都没有立即收到，但当客户端程序终止时，似乎都会同时收到。

（此外，我确信错误发生在客户端，如果对输出函数进行注释，则不会显示出奇怪的行为。）

如何修复此错误？

客户端

#include <stdio.h>
#include <cstdlib>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <string>
#include <iostream>
#include <errno.h>
#include <pthread.h>    
void* input(void* ptr)
{
    int on = 1;
    bool *input_done = ((struct thread_args*)ptr)->process_done;
    struct addrinfo *res = ((struct thread_args*)ptr)->result;
    char msg[256];
    int sock = socket(res->ai_family,res->ai_socktype,res->ai_protocol);
    setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&on,sizeof(on));
    bind(sock,res->ai_addr,res->ai_addrlen);
    connect(sock,res->ai_addr,res->ai_addrlen);
    cin.getline(msg,256);
    if (msg[0] == '/') {exit(1);}
    send(sock,msg,sizeof msg,0);
    cout << "You:" << msg << endl;
    *input_done = 1;
    close(sock);
    pthread_exit(NULL);
}
void* output(void* ptr)
{
        int on = 1;
        bool *output_done = ((struct thread_args*)ptr)->process_done;
    struct addrinfo *res = ((struct thread_args*)ptr)->result;
    char msg[256];
    int sock = socket(res->ai_family,res->ai_socktype,res->ai_protocol);
    bind(sock,res->ai_addr,res->ai_addrlen);
    connect(sock,res->ai_addr,res->ai_addrlen);
    recv(sock,msg,sizeof msg,0);
    cout << "Recieved:" << msg;
    *output_done = 1;
    close(sock);
    pthread_exit(NULL);
}
void io_client()
{
    //thread function variables
    pthread_t t1,t2;
    bool input_done = 1, output_done = 1;
    //socket setup variables
    struct addrinfo hints, *res;
    memset(&hints,0,sizeof hints);
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    getaddrinfo("localhost","8080",&hints,&res);
    //setting up structures to pass data to threaded functions
    struct thread_args i_args, o_args;
    i_args.result = res; i_args.process_done = &input_done;
    o_args.result = res; o_args.process_done = &output_done;
    while(1)
    {
        if (output_done)
        {
            pthread_create(&t2,NULL,output,&o_args);
            output_done = 0;
        }
        if (input_done)
        {
            pthread_create(&t1,NULL,input,&i_args);
            input_done = 0;
        }
    }
}
int main()
{
    io_client();
}

服务器

void server()
{
    struct addrinfo hints, *res;
    int sock=-1, newsock=-1;
    int length, on=1;
    char **address_list; int entries = 0;
    //fd_set read_fd;
    //struct timeval timeout;
    char buffer[100];
    memset(&hints,0,sizeof hints);
    res = NULL;
    memset(&res,0,sizeof res);
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    getaddrinfo("localhost","8080",&hints,&res);
    sock = socket(res->ai_family,res->ai_socktype,res->ai_protocol);
    setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&on,sizeof(on));
    bind(sock,res->ai_addr,res->ai_addrlen);
    listen(sock,10);
    while(1)
    {
        struct sockaddr_storage addr;
        char ipstr[INET6_ADDRSTRLEN];
        socklen_t len;
        len = sizeof addr;
        newsock = accept(sock,NULL,NULL);
        getpeername(newsock,(struct sockaddr*)&addr,&len);
        struct sockaddr_in *s = (struct sockaddr_in*)&addr;
        inet_ntop(AF_INET,&s->sin_addr,ipstr,sizeof ipstr);
        length = 100;
        setsockopt(newsock,SOL_SOCKET,SO_RCVLOWAT, (char*)&length,sizeof length);
        recv(newsock,buffer,sizeof buffer,0);
        cout << buffer << endl;
    }
    if (newsock != -1)
    {
        close(newsock);
    }
    if (sock != -1)
    {
        close(sock);
    }
}
int main()
{
    server();
}