c - select()无效参数

我有一个由6个套接字组成的数组，每个套接字都设计为监听传入的消息。在每个套接字上，我需要调用select（）来监听传入的消息。这段代码可以编译，但是当我运行它时，我会收到一条消息
select failure: Invalid argument
errno: 22
有人知道我做错了什么吗？谢谢！
此代码位于int main（）中：

int listenfd[6];
fd_set read_set;
struct timeval tv;
time_t start_time;

make_connections(listenfd, neighbor, servAddr, read_set);

FD_ZERO(&read_set);

// add the accepted connections to the read set for use with select()
for (i=0; i<6; i++) {
    FD_SET(listenfd[i], &read_set);
}

tv.tv_sec = 5;                  // seconds
tv.tv_usec = 5000000;    // microseconds

gettimeofday(&tv, NULL);
start_time = tv.tv_sec;

// EDIT: made the following change per suggestion by ThePelaton
//        same error exists, though
//if ( (select(6, &read_set, NULL, NULL, &tv)) == -1) {

int max = listenfd[0];
for (i=1; i<6; i++) {
    if (listenfd[i] > listenfd[i-1]) {
        max = i;
    }
}

if ( (select(listenfd[max]+1, &read_set, NULL, NULL, &tv)) == -1) {
       perror("select failure");
       fprintf(stdout, "errno: %d\n", errno);
       exit(EXIT_FAILURE);
}

我的其他功能：

void make_connections(int listenfd[6], Neighbor neighbor[6], struct sockaddr_in servAddr, fd_set read_set) {

    int num_hosts = 6;
    int i, rc, on=1;
    struct sockaddr_storage their_addr;
    socklen_t addr_size;

    for (i=0; i<6; i++) {
        // Create one socket for each neighbor
        if((listenfd[i] = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
            exit(1);
        }

        /*************************************************************/
        /* Allow socket descriptor to be reuseable                   */
        /*************************************************************/
        rc = setsockopt(listenfd[i], SOL_SOCKET,  SO_REUSEADDR,
                        (char *)&on, sizeof(on));
        if (rc < 0)
        {
            perror("setsockopt() failed");
            close(listenfd[i]);
            exit(-1);
        }

        /*************************************************************/
        /* Set socket to be non-blocking.  All of the sockets for    */
        /* the incoming connections will also be non-blocking since  */
        /* they will inherit that state from the listening socket.   */
        /*************************************************************/
        rc = ioctl(listenfd[i], FIONBIO, (char *)&on);
        if (rc < 0)
        {
            perror("ioctl() failed");
            close(listenfd[i]);
            exit(-1);
        }

        /* get server IP address (input must be IP address, not DNS name) */
        bzero(&servAddr,sizeof(servAddr));                          //zero the struct
        servAddr.sin_family = AF_INET;                              //address family (ipv4)
        servAddr.sin_port = htons(neighbor.port);  //sets port to network byte order
        servAddr.sin_addr.s_addr = INADDR_ANY;

        // first attempt to bind / listen on each port
        if (bind(listenfd[i], (struct sockaddr *)&servAddr, sizeof(servAddr)) < 0) {
            perror("bind failed");
            exit (-1);
        }

        if (listen(listenfd[i], 10) < 0) {
            perror("listen() failed");
            exit (-1);
        }

    }
}

编辑2：很肯定我已经弄明白了。我用我的时间值（tv）对我的进程做了一些时间戳。看起来这是无效参数的来源，而不是套接字。

最佳答案

使用调用中的ListEnfd[] + 1的最大值来选择，而不是6的硬编码值，其他文件描述符，如STDIN等，取前几个时隙。

关于c - select()无效参数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/19895861/

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c - select()无效参数