C fifo卡在read（），进程被阻止

Question

我正在使用fifo on c编写一个简单的客户端 - 服务器通信程序，

我理解O_WROLNY和O_RDONLY是如何工作的（事实是双方都需要打开，否则他们会阻止这个过程）

在我成功写入client_to_server管道之后，服务器端read（）仍然被阻止，下面是我的代码，请抢劫：）

Server.c：

void initialization(){

    int c_to_s,s_to_c;

    int readError;

    char* clientFifo = "client_to_server_fifo";
    char* serverFifo = "server_to_client_fifo";

    char buf[BUFSIZ];


    if(mkfifo(serverFifo,0666) < 0)
        perror("Cannot create serverFifo.");
    if(s_to_c = open(serverFifo, O_WRONLY) == -1)
        perror("Cannot open serverFifo.");


    if(mkfifo(clientFifo,0666) < 0)
        perror("Cannot create clientFifo.");
    if(c_to_s = open(clientFifo, O_RDONLY) == -1)
        perror("Cannot open clientFifo.");


    printf("Server ON.\n");

    while(1){
        printf("1\n");
        if(readError = read(c_to_s,buf,BUFSIZ) == -1)
            perror("Cannot read client message.");
        printf("2\n");

        if(strcmp("exit",buf) == 0){
            printf("Server OFF.\n");
            break;
        }else{
            printf("Received: %s\n", buf);
            printf("Sending back...\n");
            write(s_to_c,buf,BUFSIZ);
        }

    }
    close(c_to_s);
    close(s_to_c);

    unlink(serverFifo);
    unlink(clientFifo);
}

int main(){
    initialization();
    return 0;
}

Client.c：

void initialization(){
    char pseudo[MESSAGE_SIZE];

    int c_to_s,s_to_c;
    int readError;

    char* clientFifo = "client_to_server_fifo";
    char* serverFifo = "server_to_client_fifo"; 

    char msg[MESSAGE_SIZE] = "";

    if(s_to_c = open(serverFifo, O_RDONLY) == -1)
        perror("Cannot open serverFifo.");

    sleep(1);
    if(c_to_s = open(clientFifo, O_WRONLY) == -1)
        perror("Cannot open clientFifo.");

    printf("Pseudo> ");
    scanf("%s",pseudo);

    printf("Connected.\n");

    while(1){

        printf("Input Message -> ");
        scanf("%s",msg);

        write(c_to_s,msg,sizeof(msg));

        perror(" Write:");

        memset(msg,'\0',sizeof(msg));

        if(readError = read(s_to_c,msg,sizeof(msg)) == -1)
            perror(" Read:");
        else
            printf("...received from server: %s\n", msg);
    }

    close(c_to_s);
    close(s_to_c);


}

int main(){
    initialization();
    return 0;
}

来自客户流程的输出：

Pseudo> Client
Connected.
Input Message -> Hello
Hello Write:: Success

服务器流程的输出：

Server ON.
1

我认为问题依赖于Server.c第37行。

read（）函数如何检测不到客户端的任何输入。