lab1_test.c

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

int exitWait(void);
int waitPid(void);

int main(int argc, char *argv[]) {
    printf(1, "####################################################\n");
    printf(1, "# This program tests the correctness of your lab#1\n");
    printf(1, "####################################################\n");
  
    if (atoi(argv[1]) == 1)
        exitWait(); // Test exit and wait
    else if (atoi(argv[1]) == 2)
        waitPid(); // Test waitpid
    // For corner cases
    else 
        printf(1, "\ntype \"lab1 1\" to test exit and wait, \"lab1 2\" to test waitpid \n");
  
    // End of test
    exit(0);
}
  
  
int exitWait(void) {
    int pid, ret_pid, exit_status=0;
    int i;
  
    // use this part to test exit(int status) and wait(int* status)
    printf(1, "Step 1: 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, " - This is child with PID# %d and I will exit with status %d\n", getpid(), 0);
                exit(0);
            } else {
                printf(1, " - This is child with PID# %d and I will exit with status %d\n" ,getpid(), -1);
                exit(-1);
            } 
        } else if (pid > 0) { // only the parent exeecutes this code
            ret_pid = wait(0);
            printf(1, " - This is the parent: child with PID# %d has exited with status %d\n", ret_pid, exit_status);
        } else {  // something went wrong with fork system call
            printf(2, " - Error 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, "Step 2: 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, " - The is child with PID# %d and I will exit with status %d\n", getpid(), 0);
            exit(2);
        }
    }
       
    sleep(5);
    printf(1, " - This is the parent: Now waiting for child with PID# %d\n",pid_a[3]);
    ret_pid = waitpid(pid_a[3], &exit_status, 0);
    printf(1, " - This is the parent: Child# %d has exited with status %d\n",ret_pid, exit_status);
    sleep(5);
    printf(1, " - This is the parent: Now waiting for child with PID# %d\n",pid_a[1]);
    ret_pid = waitpid(pid_a[1], &exit_status, 0);
    printf(1, " - This is the parent: Child# %d has exited with status %d\n",ret_pid, exit_status);
    sleep(5);
    printf(1, " - This is the parent: Now waiting for child with PID# %d\n",pid_a[2]);
    ret_pid = waitpid(pid_a[2], &exit_status, 0);
    printf(1, " - This is the parent: Child# %d has exited with status %d\n",ret_pid, exit_status);
    sleep(5);
    printf(1, " - This is the parent: Now waiting for child with PID# %d\n",pid_a[0]);
    ret_pid = waitpid(pid_a[0], &exit_status, 0);
    printf(1, " - This is the parent: Child# %d has exited with status %d\n",ret_pid, exit_status);
    sleep(5);
    printf(1, " - This is the parent: Now waiting for child with PID# %d\n",pid_a[4]);
    ret_pid = waitpid(getpid(), &exit_status, 0);
    printf(1, " - This is the parent: Child# %d has exited with status %d\n",ret_pid, exit_status);
    return 0;
}