pthread_cond_timedwait()

Question

void wait(int timeInMs)
{
    struct timespec timeToWait;
    timeToWait.tv_sec = 5;
    timeToWait.tv_nsec = timeInMs*1000;

    int rt;

    pthread_mutex_lock(&am         


        

Answer 1

Here is an example where I have created a thread from main loop which does a scan of a directory and have a timeout of 5 sec. And signalling from the thread happens using a conditional variable which is a global. We keep checking for this signal from thread:

    pthread_cond_t C_KISU_SwagntUtilityBase::m_cond; /*Global variable*/
/*Inside main function*/    
/*Local variables*/
          pthread_condattr_t l_attr;
          pthread_condattr_init(&l_attr);
          pthread_condattr_setclock(&l_attr, CLOCK_MONOTONIC);
          pthread_cond_init(&C_KISU_SwagntUtilityBase::m_cond, &l_attr);

          Int32 l_threadid = pthread_create(&l_updatethread,NULL,C_KISU_SwagntUtilityBase::ThreadScanDirectoryByFilter,&l_filer);
          if(CMP_ZERO == l_threadid)
          {
            pthread_mutex_t l_mutex = PTHREAD_MUTEX_INITIALIZER;
            struct timespec l_ts;
            if (clock_gettime(CLOCK_MONOTONIC, &l_ts) == INIT_NEGONE)
            {
             /* Handle error */
            }
            printf("\n Setting max time to  run ThreadScanDirectoryByFilter as 5 second"));
            l_ts.tv_sec += l_filer.m_max_scan_time;

            if(l_filer.m_scan_status == 0)
            {
              pthread_mutex_lock(&l_mutex);
              int l_rt = pthread_cond_timedwait(&C_KISU_SwagntUtilityBase::m_cond, &l_mutex, &l_ts);
              if (ETIMEDOUT == l_rt)
              {
                printf("\n timeout has happened before scan routine could finish"));
              }
              else if (EOK  == l_rt)
              {
                printf("\n Scan successful"));
              }
              else
              {
                printf("\n Unknown error while timeout condition check"));
              }
              pthread_mutex_unlock(&l_mutex);
            }
          }
          else
          {
            printf("\n Error while creating thread\n");

          }