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Re: Re: Select() issues


Andrew Lunn wrote:
> 
> >    struct termios ts, ots; /* termios setting, old termios setting */
> >    int            fd = STDIN_FILENO;
> 
> Im not an eCos termios expert, but shouldn't this be a file handle
> returned by opening /dev/termios0 and not standard in?
> 
>          Andrew
> 


On 10-Jan-07, at 10:32 , Andrew Lunn wrote:

   struct termios ts, ots; /* termios setting, old termios setting */
   int            fd = STDIN_FILENO;

Im not an eCos termios expert, but shouldn't this be a file handle
returned by opening /dev/termios0 and not standard in?

         Andrew

Up until this particular issue I have had no problems using "standard in".
I will look to see what effect opening /dev/termios0, but most examples
I have seen use STDIN_FILENO directly.

Changing my code slightly, I now find that I now block at cin.get().
I wondering whether I am doing something wrong when changing to canocial
mode?

char InputHandler::DoPressAnyKey()
{
    struct termios  ts, ots;
    int             c  = 0;
    int             fd = STDIN_FILENO;  
                  
    cout << "--0\n";
          
    tcflush(fd,TCIOFLUSH);    
       
    cout << "--1\n";  
          
    WaitForData();
                        
    tcgetattr(fd, &ts);     /* save tty state */
    ots = ts;               /* structure copy */
    ts.c_lflag &= ~( ICANON );
    ts.c_cc[VMIN] = 1;
    ts.c_cc[VTIME] = 0;
    tcsetattr(fd, TCSAFLUSH, &ts);
         
    cout << "--2\n";
        
    // INFO: make sure to reset terminal attributes before
    //       leaving method 
        
    if ( !IsTimedOut() ) 
    {
       cout << "--2.1\n";
       c = cin.get();
       cout << "--2.2\n";
    }
    
    cout << "--3\n";
        
    tcsetattr(fd, TCSAFLUSH, &ots); /* restore TTY state */
    
    cout << "--4\n";
        
    if ( IsTimedOut() ) 
    {
        c = 0;
    }
    
    return c;
     
}

void InputHandler::WaitForData()
{
    int             fd = STDIN_FILENO;    
    fd_set          fds;
    struct timeval  tv;
    struct timeval  *tvPtr = NULL; 
    
    cout.flush();
           
    do
    {   
        // INFO: if the time out is not zero then define the timeval and have tvPtr
        //       refer to it. if it is zero then tvPtr uses a NULL value. I things this
        //       way to avoid having to duplicate the select call and also not need to
        //       worry about memory allocation/deallocation
        
        cout << "--a\n";
        
        if ( this->timeout != 0 )
        {
            tv.tv_sec = this->timeout; 
            tv.tv_usec = 0;
            tvPtr = &tv;
        }
        else
        {
            tvPtr = NULL;
        }
        FD_ZERO( &fds );
        FD_SET( STDIN_FILENO, &fds );

        cout << "--b\n";
        
        int result = select(fd + 1, &fds, NULL, NULL, tvPtr);
        
        cout << "--c\n";
        
        if ( result == 0 )
        {
            this->timedout = true;
            break;           
        }
        else if ( result > 0 && FD_ISSET(fd,&fds) )
        {      
            break;
        }
        
        cout << "--d\n";
    }
    while ( true );
  
    cout << "--e\n";
}



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