For CS 153 course at UCR

cs153_lab2_test.c

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

int PScheduler(void);

int main(int argc, char *argv[]) {
  PScheduler();
  exit();
}

int PScheduler(void) {
  int pid;
  int i, j, k;
  setpriority(0);
  for (i = 0; i < 3; i++) {
    pid = fork();
    if (pid > 0) {
      continue;
    } else if (pid == 0) {
      setpriority(30 - 10 * i);
      for (j = 0; j < 50000; j++) {
        asm("nop");
        for (k = 0; k < 10000; k++) {
          asm("nop");
        }
      }
      printf(1, "p i:%d t:%d\n", getpid(), uptime());
      exit();
    } else {
      printf(2, " \n Error fork() \n");
      exit();
    }
  }
  if (pid > 0) {
    for (i = 0; i < 3; i++) {
      wait();
    }
  }
  return 0;
}