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

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

// N should be set HIGHER than the limit!
#define N  10000

void
print(const char *s)
{
  write(1, s, strlen(s));
}

void printdec(unsigned int i) {
	if (i == 0) {
		print("0");
		return;
	}
	char foo[11];
	int idx = 10;
	while (i > 0) {
		idx--;
		foo[idx] = '0' + (i%10);
		i /= 10;
	}
	foo[10] = 0;
	print(foo+idx);
}

void
forktest(void)
{
  int n, pid;

  print("fork test\n");
  
  //print("testing printdec(12345)="); printdec(12345); print("\n");
  print("attempting to fork up to N="); printdec(N); print(" processes...\n");

  for(n=0; n<N; n++){
    pid = fork();
    if(pid < 0)
      break;
    if (pid == 0) {
      int i, j, ch, pr;
      pr = 7-(getpid() % 4);
      ch = '0'+pr;
      prio(getpid(), pr, 4);
      sleep(1);
      for (i = 0; i < 100; i++) {
        for (j = 0; j < 256; j++) {
          ch++;
		}
		char str[2];
		str[0] = (char)ch;
		str[1] = 0;
		print(str);
	  }
      exit(0);
    }
  }
  
  
  print("forked "); printdec(n); print(" processes\n");

  if(n == N){
    print("fork claimed to work N times! forktest should be updated so N is greater than the kernel's NPROC!\n");
    exit(1);
  }

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

  if(wait(0) != -1){
    print("wait got too many\n");
    exit(1);
  }

  print("fork test OK\n");
}

int
main(void)
{
  forktest();
  exit(0);
}