/*
 * thread-test.c
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/mman.h>
#include <sys/wait.h>

int global_var = 0;

void *child_func(void *data);

typedef struct {
    int local_var;
    int *heap_var, *mmap_shared_var, *mmap_private_var;
} vars_t;

int
main(int argc, char *argv[])
{
    vars_t vars;
    pthread_t child;

    vars.local_var = 0;

    vars.heap_var = (int *) malloc(sizeof(int));
    *(vars.heap_var) = 0;

    vars.mmap_private_var = (int *) mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE,
            MAP_PRIVATE | MAP_ANON, -1, 0);
    *(vars.mmap_private_var) = 0;

    vars.mmap_shared_var = (int *) mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE,
            MAP_SHARED | MAP_ANON, -1, 0);
    *(vars.mmap_shared_var) = 0;

    pthread_create(&child, NULL, child_func, &vars);

    global_var = 12;
    vars.local_var = 24;
    *(vars.heap_var) = 36;
    *(vars.mmap_private_var) = 48;
    *(vars.mmap_shared_var) = 60;

    pthread_join(child, NULL);
}

void *
child_func(void *data)
{
    vars_t *vars = (vars_t *) data;

    sleep(1);

    printf("global_var is       %d\n", global_var);
    printf("local_var is        %d\n", vars->local_var);
    printf("heap_var is         %d\n", *(vars->heap_var));
    printf("mmap_private_var is %d\n", *(vars->mmap_private_var));
    printf("mmap_shared_var is  %d\n", *(vars->mmap_shared_var));

    return NULL;
}