Question

所以，我正在尝试构建一个充当Websockets Server的C应用程序。这里有很多相关的问题，但它们似乎都没有能够帮助解决这个问题。该程序能够初始建立连接，成功完成websocket的握手，但是，似乎无法保持连接打开。在客户端，我收到错误

WebSocket.js：7605未捕获错误：尝试在未打开或关闭的WebSocket上发送消息 at _8b2.window.WebSocket._8d2.send（WebSocket.js：7605）在（指数）：34

每当我尝试在客户端的websocket连接上使用send（）函数时。它也给了我错误

与'ws：//127.0.0.1：5959 /？.kl = Y'的WebSocket连接失败：在建立连接之前WebSocket已关闭。

以下是服务器的源代码：

 int new_socket;
int activity;
int i;
int sd;
int max_sd;
int bytes_read;
fd_set readfds;
int master_socket;
noPollConn* new_conn;
/*Create no poll context*/
noPollCtx* ctx = nopoll_ctx_new();
noPollConn* conn;
char buffer[3000];
/*Create a connection listener at 127.0.0.1 (loopback) on port 5959*/
noPollConn * listener = nopoll_listener_new(ctx, "127.0.0.1","5959");
/*Get the socket of the lister*/
master_socket = nopoll_conn_socket(listener);
if(!nopoll_conn_is_ok(listener)) {
    perror("There was an error creating the listener!\n");
    exit(EXIT_FAILURE);
}
puts("Waiting for connections ...");

while(TRUE){
    printf("Start of the while loop\n");
    FD_ZERO(&readfds);
    FD_SET(master_socket, &readfds);
    max_sd = master_socket;
    printf("The number of connections is %i\n",cons);

    for (i = 0 ; i < cons ; i++) {
        sd = nopoll_conn_socket((noPollConn*)vector_get(clients,i));
        if(sd > 0)
            FD_SET(sd,&readfds);

        if(sd > max_sd)
            max_sd = sd;
    }
    printf("The max fd is %i\n",max_sd);
    activity = select(max_sd + 1 , &readfds , NULL , NULL , NULL);

    if ((activity < 0) && (errno!=EINTR)) {
        puts("select error");
        exit(EXIT_FAILURE);
    }

    if (FD_ISSET(master_socket, &readfds)){
        new_conn =  nopoll_conn_accept(ctx,listener);
        puts("Waiting for the connection to be ready");
        nopoll_conn_is_ready(conn);
        /*Vector is actually a doubly linked list*/
        vector_push(&clients,new_conn);
        cons++;
    }
    /*TODO: Implement disconnect*/
    for (i = 0; i < cons; i++){
        printf("Checking on user %i\n",i);
        conn = (noPollConn*)vector_get(clients,i);
        sd = nopoll_conn_socket(conn);
        if (FD_ISSET(sd, &readfds)){
            printf("Receiving info from socket no. %d...\n",sd);
            bytes_read = recv(sd,buffer,4000,MSG_DONTWAIT);
            buffer[bytes_read] = '\0';
            printf("Received the msg --> %s\n",buffer);

        }
    }
    memset(buffer,0,3000);
}

虽然只是一个警告，但是这段代码现在无限循环，因为我没有实现与服务器端客户端的断开连接。

For the client
<pre><code>
            var connection = new WebSocket('ws://127.0.0.1:5959');
            connection.onopen = function(){
                connection.send("TEST");
                alert("Connected");
            }
            connection.onerror = function(error){
               console.log('Error detected: ' + error);
            }
            connection.onmessage = function (event) {
                alert(event.data);
            }

            connection.close();
</code></pre>

也许我错过了一些非常重要的事情？我经历了很多教程，似乎无法弄清楚问题是什么。任何帮助是极大的赞赏！在.send()函数中调用.onopen()会导致错误：

与'ws：//127.0.0.1：5959 /？.kl = Y'的WebSocket连接失败：在建立连接之前WebSocket已关闭。   的更新
  错误发生在服务器端。它可能与我处理连接有关，就好像它在C代码中的某些方面是一个套接字。

Answer 1

如果服务器上未记录任何错误，则可能会在.send()事件发生之前调用open。在.send()事件处理程序中调用open。否则，问题出在服务器上。

const socket = new WebSocket("ws://echo.websocket.org/");

socket.onopen = function(e) {
  socket.send("WebSocket rocks");
  console.log("self.socket event.type:", e.type);
};

socket.onmessage = function(e) {
  console.log(e.data);
};

socket.onerror = function(e) {
  console.log("self.socket error", e);
};

socket.onclose = function(e) {
  console.log("self.socket event.type", e.type);
};

请参阅How do I test my WebSocket which is developed in JavaScript

plnkr http://plnkr.co/edit/W8Wgyw0mbxdMkMMe4wg4?p=preview

Websocket连接过早地关闭连接

1 个答案: