Programming

pid_t arr[2];
int status;
arr[0]=fork();
if (arr[0]=0)
{
     this is the first child process code block
     to get a status the code has to exit(n) where n==status    
     otherwise status is any value that happens to to be on the stack.
}
arr[1]=fork();
if(arr[1]==0)
{
    this is the second process code block
    exit() this one too.
}
// wait for the children to become done
waitpid(arr[0], &status, 0);
// process status with macros fromn sys/wait.h
waitpid(arr[1], &status, 0);

bool System::WaitForScmi(U32 waitForScmiTimeLimit)
{

  
  int pid = fork();
  vector <int> childList;

  if (pid == -1)
  {
    termError("Fork failure in start method, errno %d = %s",
               errno, strerror(errno));
  }
  else if( pid == 0)
  {
    bool return_I_want_to_save = WaitForScmi2(waitForScmiTimeLimit);
    exit(0);
  }
  else
  {
    print("Executing recoverWaitForScmi, started child process: %u", pid);
    childList.push_back(pid);
  }

  if(return_I_want_to_save)
  {
    print("We did it!!!");
  }

  if(!KillChild(childList))// here is how i make sure all child process get killed
  {
     print("It seems like recoverWaitForScmi could not excute correct & ran in to a termError ");
     return(0);
  }
  else
  {
     return(1);
  }
}



bool System::KillChild(vector<int>& childList)
{
  vector <int>::iterator it;
  int childStatus;

  for ( it=childList.begin(); it < childList.end(); it++ )
  {
    int pid  = (*it);
    waitpid(pid, &childStatus, 0);//Wait for child
    if(childStatus)
    {
      // Kill all other children. 
      for (U32 i = 0; i < childList.size(); i++)
      {
        kill(childList[i], SIGINT);
      }
      print("Killing process: %u Complete.", pid);
      // termError("Exiting...");
      print("Exiting...");
      return(0);//indicating child process failure. This return has nothing to do with
                //if killing pass or fail. 
    }
    else
    {
      print("Process: %u Complete.", pid);
      return(1);//indicating child process success. 
                //Notice this return has nothing to do with if killing pass or fail
    }
  }
}