forktest

// Test that fork fails gracefully.
// Tiny executable so that the limit can be filling the proc table.

#include "types.h"
#include "stat.h"
#include "user.h"

#define N  1000

void
heavytest()
{
  int i, j;
  for(i = 1; i < 1000000000; i++){
    j++;
  }
}

void
forktest(void)
{
  int n, pid;

  printf(1, "fork test\n");

  for(n=0; n<N; n++){
    pid = fork();
    if(pid < 0)
      break;
    if(pid == 0)
      exit();
    // For priority testing
    if(n == 10){
      printf(1, "\n* Heavy test on pid %d\n", pid);
      set_priority(2);
      procstat();
      heavytest();
    }
    if(n == 40){
      printf(1, "\n* Heavy test on pid %d\n", pid);
      set_priority(0);
      procstat();
      heavytest();
    }
  }

  if(n == N){
    printf(1, "fork claimed to work %d times!\n", N);
    exit();
  }

  for(; n > 0; n--){
    if(wait() < 0){
      printf(1, "wait stopped early\n");
      exit();
    }
  }

  if(wait() != -1){
    printf(1, "wait got too many\n");
    exit();
  }

  printf(1, "fork test OK\n");
}

int
main(void)
{
  forktest();
  exit();
}