scan with timeout

[Joel Sherrill]

Stan wrote:
> 
> Hi,
> 
> I should like all input operation (read...scan...) return on timeout.
> What are best way for that ?
> 
> This code you seem good ?
> In fact, the first call to the function scan return on timeout, but not the
> following.
> An idea?

Read up on termios :)  It includes POSIX's way of specifying a timeout
or
minimum number of bytes to read.

http://www.opengroup.org/cgi-bin/dbcgix?TPL=sd_formframes&TOKEN=BWBNB&override=sd_search

> /**********************************************************************/
> /* transfer character from the buffer */
> char inbyte(int minor, int* timeout) {
>   register char a;
>   register int length;
> 
>   while ((char *)(((int)rcv[minor].in+1) & ((int)BUFFER_LENGTH-1))==
> rcv[minor].out){
>     if(*timeout) (*timeout)--; else return '\0';
>     rtems_task_wake_after(1);
>   }
>   a=*(char *)((int)rcv[minor].offset+(int)rcv[minor].out);
>   rcv[minor].out= (char *)(((int)rcv[minor].out+1) &
> ((int)BUFFER_LENGTH-1));
>   length = (BUFFER_LENGTH -1) & (
>     ( ((int)rcv[minor].out <= (int)rcv[minor].in) ? 0 : BUFFER_LENGTH) -
> (int)rcv[minor].out
>     + (int)rcv[minor].in + 1);
> 
>   if ((params[minor].mode & MODE_RTSCTS) && length < RTS_START_SIZE)
> StartRemoteTx(minor);
> 
>   return (a);
> }
> 
> rtems_device_driver console_read(
>   rtems_device_major_number major,
>   rtems_device_minor_number minor,
>   void *arg
> )
> {
> 
>   rtems_libio_rw_args_t *rw_args;
>   char *buffer;
>   int maximum;
>   int count = 0;
>   volatile int timeout;
> 
>   rw_args = (rtems_libio_rw_args_t *) arg;
> 
>   buffer = rw_args->buffer;
>   maximum = rw_args->count;
> 
>   for (count = 0; count < maximum; count++) {
>     timeout = 100*60;  /* 100*60*5 = 5 minutes */
>     buffer[ count ] = (char) inbyte(minor, &timeout);
>     if(timeout==0) break;
>     if ( params[minor].mode & MODE_CANON && (buffer[ count ] == '\n' ||
> buffer[ count ] == '\r')){
>         if ( params[minor].mode &  MODE_ADD_LF ) buffer[ count]  = '\n';
>         count++;
>         break;
>     }
>   }
> 
>   rw_args->bytes_moved = count;
>   return (count >= 0) ? RTEMS_SUCCESSFUL : RTEMS_UNSATISFIED;
> 
> }
> /***************************************************************************
> */
> 
> thanks.
> 
>         Stan .

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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