uCos keyboard listener

From: Juha Rossi (juhar_at_evitech.fi)
Date: 01/25/04 

Date: 25 Jan 2004 07:28:54 -0800

hi all,

Im writing a simple application in uCos-II that spans a couple of
processes.
First process (inputField) controls input "field" for words. The idea
is to provide a possibility for user to input a word that is sent (by
Message Queue) to another process that prints it on screen. Third
process also listens keyboard:

void KeyListener(void *pdata)
{
   while(1)
   {
  OSSemPend(Priority_over_CPU, 0, &err); //get exclusive control
  if(kbhit())
  {
    if(ch == 27) //esc
          OSSemPost(EscPressed); //signal process that kills
application
  }
  OSSemPost(Priority_over_CPU); // release control
  OSTimeDly(1);
  }
}

-----------------
Source code for the first process:

void InputField(void *pdata)
{
  while(1)
  {
  OSSemPend(Priority_over_CPU, 0, &err)
  ch = getch();
   if(ch != 13)
    input[next_pos] = ch; //append to array
   else //enter pressed->sent written word to another process
    OSQPost(MsgQueue, (void *)&input[0]);

   OSTimeDly(1);
 }

}

Problem: For some reason the program crashes when task-InputField()
gets
control and tries to listen keyboard (it has lower prio than
KeyListener). How can I get 2 processes listen keyboard? Should I
somehow encapsulate keyboard functions and provide exclusive access to
them when processes get their turn?

-Juha Rossi