Subj : Re: how to use select in each thread
To   : comp.programming.threads
From : David Schwartz
Date : Sun Apr 17 2005 12:21 pm


"Zongjun Qi" <qizongjun@gmail.com> wrote in message 
news:1113752441.212584.168120@o13g2000cwo.googlegroups.com...

>  struct timeval tv;
>  tv.tv_sec= 0;
>  tv.tv_usec=100000*(threadnumber+1);
>  while(1)
>  {
> select(0,NULL,NULL,NULL,&tv);
>  printf("Thread number=%d\n", threadnumber);
>  }
> }

    This is the clasic 'select' bug. You need to set up the parameters 
*each* time you call 'select', not just the first time. Otherwise, you're 
calling 'select' the second time with whatever junk was leftover from the 
first call. Try this:
while(1)
{
 struct timeval tv2=tv;
 select(0,NULL,NULL,NULL,&tv2);
 printf(...
}

.