i need help!!!!!

[ChiYung]

Hi, I know it is a VC++ forum, but i really need help!!! Let's see my code first:

*****************************************************************************
void operation(int[], char[]);
void waitprocess(int);
void main(void)
{
int i, j;
static char buffer[BUFSIZE+10], X_value[5], message[BUFSIZE];
int f_des[2];

if (pipe(f\_des) == -1)   //create the pipe
  {
    perror("Pipe");
    exit(2);
  }

if (fork()==0)    //In the CHILD
{
  // do nothing here because we will 
  // create 5 CHILDs by PARENT again later.    
}
else            //PARENT
{
  for (j=1; j<=5; j++)   //create 5 CHILD process
    {
      if (fork()==0)  
    {
      static char temp\[BUFSIZE\];
      sprintf(temp, "Thread %d", getpid());    //Get the thread ID
      operation(f\_des, temp);                  //Send the request
    }
    }

    while (X>0)     // keep doing (read from pipe) until X=0    
    {
    close(f\_des\[1\]);
    if (read(f\_des\[0\], message, BUFSIZE) != -1)  //Read from pipe
      {
        sprintf(buffer, " - X  = %d \\n", X);
        strcat(message, buffer);
        write(1, message, sizeof(message));    //display output
        waitprocess(getpid());  //force sleep awhile
        X--;
      }
    else
      {
        printf("error");
      }
    } 
}

}
****************************************************************************

I have to create 5 "threads" but using fork() because i have to use pipe() to communicate with "server". This program is doing that 5 "threads" are trying to decrement the global X until X=0. I use pipe as a mechanisam to protect this "critical section". I don't know whether i did it right or wrong. Please help me to check!!! Also, I found that the output looks strange. The output is always in a pattern. For example, the output looks liked: Thread 1001 - X = 20 Thread 1003 - X = 19 Thread 1002 - X = 18 Thread 1005 - X = 17 Thread 1004 - X = 16 Thread 1001 - X = 15 Thread 1003 - X = 14 Thread 1002 - X = 13 Thread 1005 - X = 12 Thread 1004 - X = 11 * * * You can see the sequence is 1,3,2,5,4,1,3,2,5,4...etc. I think the output should be in random sequence. Why it's happened??? Thanks!!!!!:confused: :-O

[David Wengier]

Hahahaha. You're an idiot.

[Rama Krishna Vavilala]

David Wengier wrote: Hahahaha. You're an idiot. At first I thought that it was pretty rude. Now I understand what is going on. I think the guy is playing.

[David Wengier]

Rama Krishna wrote: At first I thought that it was pretty rude I think my reply was very rude.