For CS 153 course at UCR

cs153_lab1_test.c

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

#define WNOHANG 1

int main(int argc, char *argv[]) {
  int getParent(void);
  int exitWait(void);
  int waitPid(void);
  int waitNothing(void);

  printf(1, "\nlab#1\n");
  if (atoi(argv[1]) == 2)
    waitPid();
  else if (atoi(argv[1]) == 1)
    exitWait();
  else if (atoi(argv[1]) == 3)
    waitNothing();
  // End of test
  exit(0);
  return 0;
}

int waitNothing(void) {
  int ret, exit_status = -1;
  ret = wait(&exit_status);
  printf(1, "%d %d\n", ret, exit_status);
  return 0;
}

int exitWait(void) {
  int pid, ret_pid, exit_status;
  int i;
  // use this part to test exit(int status) and wait(int* status)

  //   printf(1, "\n  Parts a & b) testing exit(int status) and wait(int*
  //   status):\n");

  for (i = 0; i < 2; i++) {
    pid = fork();
    if (pid == 0) { // only the child executed this code
      if (i == 0) {
        printf(1, "%d %d\n", getpid(), 0);
        exit(0);
      } else {
        printf(1, "%d %d\n", getpid(), -1);
        exit(-1);
      }
    } else if (pid > 0) { // only the parent executes this code
      ret_pid = wait(&exit_status);
      printf(1, "%d+%d\n", ret_pid, exit_status);
    } else { // something went wrong with fork system call
      printf(2, "\nError using fork\n");
      exit(-1);
    }
  }
  return 0;
}

int waitPid(void) {

  int ret_pid, exit_status;
  int i;
  int pid_a[5] = {0, 0, 0, 0, 0};
  // use this part to test wait(int pid, int* status, int options)

  //   printf(1, "\n  Part c) testing waitpid(int pid, int* status, int
  //   options):\n");

  for (i = 0; i < 5; i++) {
    pid_a[i] = fork();
    if (pid_a[i] == 0) { // only the child executed this code
      printf(1, "%d %d\n", getpid(), getpid() + 4);
      exit(getpid() + 4);
    }
  }
  sleep(5);
  printf(1, "%d\n", pid_a[3]);
  ret_pid = waitpid(pid_a[3], &exit_status, 0);
  printf(1, "%d+%d+%d\n", ret_pid, exit_status, pid_a[3] + 4);
  sleep(5);
  printf(1, "%d\n", pid_a[1]);
  ret_pid = waitpid(pid_a[1], &exit_status, 0);
  printf(1, "%d+%d+%d\n", ret_pid, exit_status, pid_a[1] + 4);
  sleep(5);
  printf(1, "%d\n", pid_a[2]);
  ret_pid = waitpid(pid_a[2], &exit_status, 0);
  printf(1, "%d+%d+%d\n", ret_pid, exit_status, pid_a[2] + 4);
  sleep(5);
  printf(1, "%d\n", pid_a[0]);
  ret_pid = waitpid(pid_a[0], &exit_status, 0);
  printf(1, "%d+%d+%d\n", ret_pid, exit_status, pid_a[0] + 4);
  sleep(5);
  printf(1, "%d\n", pid_a[4]);
  ret_pid = waitpid(pid_a[4], &exit_status, 0);
  printf(1, "%d+%d+%d\n", ret_pid, exit_status, pid_a[4] + 4);

  ret_pid = waitpid(9999, &exit_status, 0);
  printf(1, "%d\n", ret_pid);
  // printf(1, "\n This is the parent: Child# %d has exited with status
  // %d\n",ret_pid, exit_status);

  ret_pid = waitpid(9999, (int *)0xffffffff, 0);
  printf(1, "%d\n", ret_pid);

  return 0;
}