__code cbc_consoleread2 ()
{   
    struct inode *ip = proc->cbc_arg.cbc_console_arg.ip;
    __code(*next)(int ret) = proc->cbc_arg.cbc_console_arg.next;
    if (input.r == input.w) {
        if (proc->killed) {
            release(&input.lock);
            ilock(ip);
            goto next(-1);
        }
       goto cbc_sleep(&input.r, &input.lock, cbc_consoleread2);
    }
    goto cbc_consoleread1();
}

__code cbc_consoleread1 ()
{   
    int cont = 1;
    int n = proc->cbc_arg.cbc_console_arg.n;
    int target = proc->cbc_arg.cbc_console_arg.target;
    char* dst = proc->cbc_arg.cbc_console_arg.dst;
    struct inode *ip = proc->cbc_arg.cbc_console_arg.ip;
    __code(*next)(int ret) = proc->cbc_arg.cbc_console_arg.next;
    
    int c = input.buf[input.r++ % INPUT_BUF];
    
    if (c == C('D')) {  // EOF
        if (n < target) {
            // Save ^D for next time, to make sure
            // caller gets a 0-byte result.
            input.r--;
        }
        cont = 0;
    }
    
    *dst++ = c;
    --n;
    
    if (c == '\n') {
        cont = 0;
    }
    
    if (cont == 1) {
        if (n > 0) {
            proc->cbc_arg.cbc_console_arg.n = n; 
            proc->cbc_arg.cbc_console_arg.target = target;
            proc->cbc_arg.cbc_console_arg.dst = dst;
            proc->cbc_arg.cbc_console_arg.ip = ip;
            proc->cbc_arg.cbc_console_arg.next = next;
            goto cbc_sleep(&input.r, &input.lock, cbc_consoleread2);
        }
    }
    
    release(&input.lock);
    ilock(ip);
    
    goto next(target - n);
}

__code cbc_consoleread (struct inode *ip, char *dst, int n, __code(*next)(int ret))
{   
    uint target;
    
    iunlock(ip);
    
    target = n;
    acquire(&input.lock);
    
    if (n > 0) {
        proc->cbc_arg.cbc_console_arg.n = n; 
        proc->cbc_arg.cbc_console_arg.target = target;
        proc->cbc_arg.cbc_console_arg.dst = dst;
        proc->cbc_arg.cbc_console_arg.ip = ip;
        proc->cbc_arg.cbc_console_arg.next = next;
        if (input.r == input.w) {
            if (proc->killed) {
                release(&input.lock);
                ilock(ip);
                goto next(-1);
            }
            
            goto cbc_sleep(&input.r, &input.lock, cbc_consoleread2);
        }
    goto cbc_consoleread1();
    }
}

int consoleread (struct inode *ip, char *dst, int n)
{
    uint target;
    int c;

    iunlock(ip);

    target = n;
    acquire(&input.lock);

    while (n > 0) {
        while (input.r == input.w) {
            if (proc->killed) {
                release(&input.lock);
                ilock(ip);
                return -1;
            }

            sleep(&input.r, &input.lock);
        }

        c = input.buf[input.r++ % INPUT_BUF];

        if (c == C('D')) {  // EOF
            if (n < target) {
                // Save ^D for next time, to make sure
                // caller gets a 0-byte result.
                input.r--;
            }

            break;
        }

        *dst++ = c;
        --n;

        if (c == '\n') {
            break;
        }
    }

    release(&input.lock);
    ilock(ip);

    return target - n;
}

void consoleinit (void)
{
    initlock(&cons.lock, "console");
    initlock(&input.lock, "input");

    devsw[CONSOLE].write = consolewrite;
    devsw[CONSOLE].read = consoleread;
    cbc_devsw[CONSOLE].write = cbc_consolewrite;
    cbc_devsw[CONSOLE].read = cbc_consoleread;

    cons.locking = 1;
}