Checking exit codes of two processes

Question

I have this code:

  pid_t pid1 = fork();

  if (pid1 == 0)
  {
    //do some stuff
    if (something)
        exit(0);
    else
        exit(1);
  }
  else if (pid1 == -1)
    printf("error\n");

  pid_t pid2 = fork();

  if (pid2 == 0)
  {
    //do some stuff
    if (something)
        exit(0);
    else
        exit(1);
  }
  else if (pid2 == -1)
    printf("error\n");

//here I want to check both exit codes

The child processes will run in parallel. What I need is to check both exit codes whether they're 1 or 0. I thought I could use something like this:

pid_t pid;
int status;
while( (pid = wait(&status)) > 0)
   printf("%d exit code: %d\n", pid, WEXITSTATUS(status));

I am new to parallel programming so I am not sure if this is a correct solution. Isn't there possibility that one of the child processes exits before parent process reaches cycle so it won't get exit code?

Answer 1

If one or both of the child processes exit before the parent first calls wait(), then the OS will hold the exit code and/or reason for termination until the parent reaches the wait(). This is exactly what a "zombie process" is.