Sequential writing of volatile (C) and atomic (C++) and dead-store elimination

gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

volatile char toggle = 1;

void *writer(void *unused) {
    for (;;) {
        toggle = 1;
        toggle = 2;
    }

    return unused;
}

int main() {
    pthread_t writer_thread;

    pthread_create(&writer_thread, NULL, &writer, NULL);

    long ones = 0, twos = 0;
    for (int i = 0; i < 100000; i++) {
        if (toggle == 1) {
            ones++;
        } else {
            twos++;
        }
    }
    printf("Ones: %ld; twos: %ld\n", ones, twos);
}

gistfile2.cpp

#include <iostream>
#include <thread>
#include <atomic>
#include "limits.h"

std::atomic<char> toggle;

void writer() {
    for (;;) {
        toggle.store(1);
        toggle.store(2);
    }
}

int main() {
    std::thread writer_thread(writer);

    toggle.store(1);

    long ones = 0, twos = 0;
    for (int i = 0; i < INT_MAX; i++) {
        if (toggle.load() == 1) {
            ones++;
        } else {
            twos++;
        }
    }
    std::cout << "Ones: " << ones << "; twos: " << twos << "\n";
}