/**
     * Test that the volatile alive field is visible across threads.
     * One thread sets alive to false, other threads should see the change immediately.
     */
    @Test
    public void test_aliveField_volatileVisibility() throws Exception {
        // Ensure alive starts as true
        assertTrue(dataStore.alive);

        final int readerThreadCount = 5;
        final long testDurationMs = 200; // Run for 200ms