在多線程程序中不接收UDP和輸出數據

Question

uint64_t GetTimeStamp() 
{ 
    struct timespec start; 

    if ((clock_gettime(CLOCK_MONOTONIC, &start)) == -1) 
    { 
     perror("clock gettime\n"); 
    } 

    return(start.tv_sec + start.tv_nsec * 1e-9);    // seconds 
} 

const struct sigevent *intHandler(void *arg, int id) 
{ 
    start_clock = ClockCycles(); 
    // printf("start clock: %lld\n", start_clock); 

    return(&event); 
} 

void *ConfigureISR() 
{ 
    // Get IO privilege 
    ThreadCtl(_NTO_TCTL_IO, 0); 
    // Setup COID and event 
    SIGEV_INTR_INIT(&event); 

    interruptID = InterruptAttach(intrNum, intHandler, NULL, 0, 0); 
    if (interruptID == -1) 
    { 
     fprintf(stderr, "can't attach to IRQ %d\n", intrNum); 
     perror(NULL); 
     exit(EXIT_FAILURE); 
    } 

    while (loop) 
    { 
     InterruptWait(0, NULL); 
     end_clock = ClockCycles(); 
     InterruptLatency = (uint32) ((end_clock - start_clock) * 1000000/(SYSPAGE_ENTRY(qtime)->cycles_per_sec)); 
     printf("Current Interrupt Latency microseconds: %ld\n", InterruptLatency); 
     InterruptUnmask(intrNum, interruptID); 
     measurements[17] = InterruptLatency; 
    } 
    return(EXIT_SUCCESS); 
} 

int CreateSocket() 
{ 
    // pthread_attr_t attr; 
    // Socket creation for UDP 

    acceptSocket = socket(AF_INET, SOCK_DGRAM, 0); 

    if (acceptSocket == -1) 
    { 
     printf("Failure: socket creation is failed, failure code\n"); 
     return 1; 
    } 
    else 
    { 
     printf("Socket started!\n"); 
    } 

    memset(&addr, 0, sizeof(addr)); 

    addr.sin_family = AF_INET; 
    addr.sin_port = htons(port); 
    addr.sin_addr.s_addr = htonl(INADDR_ANY); 

    rc = bind(acceptSocket, (struct sockaddr *)&addr, sizeof(addr)); 

    fcntl(acceptSocket, O_NONBLOCK); 

    if (rc == -1) 
    { 
     printf("Oh dear, something went wrong with bind()! %s\n", strerror(errno)); 
     return -1; 
    } 
    else 
    { 
     printf("Socket an port %d \n", port); 
    } 
    return acceptSocket; 
} 

int main(int argc, char *argv[]) 
{ 
    pthread_t thread_id, thread_id1; 

    Xcp_Initialize(); 

    pthread_create(&thread_id1, NULL, &ConfigureISR, NULL); 

    if ((sock = CreateSocket()) < 0) 
    { 
     perror("Create_socket"); 
     exit(1); 
    } 

    if (pthread_create(&thread_id, NULL, &rastertask, NULL)) 
    { 
     perror("pthread_create"); 
     exit(1); 
    } 

    do 
    { 
     socklen_t len; 
     len = sizeof(client); 
     printf("NEW DATA ARRIVED\n"); 
     // non blocking mode : MSG_DONTWAIT 
     rc = recvfrom(sock, buf, 256, 0, (struct sockaddr *) &client, &len); 
     Receive = GetTimeStamp(); 
     receiveTime = (uint32) (Receive/1000000); 
     printf("Receive time: %lu\n", receiveTime); 
     // printf("RECEIVE from Time in microseconds: %lu\n", ReceiveTimestamp); 
     // measurements[19] = ReceiveTimestamp; 
     if (rc == 0) 
     { 
      printf("Server has no connection..\n"); 
      loop = 0; 
      break; 
     } 
     if (rc == -1) 
     { 
      if (errno == SIGINT) 
       continue; 
      printf("Oh dear, something went wrong with read()! s\n", strerror(errno)); 
      loop = 0; 
      break; 
     } 

     XcpIp_RxCallback((uint16) rc, (uint8 *) buf, (uint16) port); 
    } while (1); 


    close(sock); 

    return 0; 
} 

以上是服務器代碼，它通過ip地址和端口號接收數據。

稍後將數據發送回客戶端。我正在接收數據，但在收到數據後，獲取時間戳（您可以在上面的代碼中看到：Send= GetTimeStamp()）。

爲什麼不打印任何東西？我通過套接字接收數據，然後我給printf("new data arrived\n");，然後它也不打印。我也沒有收到任何時間！有人能告訴我可能是什麼原因嗎？

Answer 1

您的GetTimeStamp()函數返回uint64_t; return語句是：

return (start.tv_sec + start.tv_nsec * 1e-9); 

這將創建一個double值（1e-9是double常數），然後將其截斷爲整數，就好像你已經回來了：

return (start.tv_sec); 

注意這給你幾秒鐘的時間（自Epoch - 1970-01-01 00:00:00 +00：00以來）。

也許你想：

return (start.tv_sec * 1E9 + start.tv_nsec); 

這給你，因爲大紀元納秒的總數。這可能與您遇到的其他問題相切，但沒有得到明智的價值意味着您不會收到明智的價值觀，所以您應該確定您期望從GetTimeStamp()獲得什麼價值。例如：

Receive = GetTimeStamp(); 
    receiveTime = (uint32) (Receive/1000000); 
    printf("Receive time: %lu\n", receiveTime); 

這將打印一個值，如1400（因爲當前時間戳是大約1400755363 = 2014年5月22日10時42分43秒），使值減1萬元是1400劃分。