Function stack_worker

port/coroutine_test.cpp:115–127

Stack hygiene: the worker writes a recognisable pattern to a chunk of * its own stack, yields, runs again. The data must survive across the * yield (i.e. the swap really restored the right sp). */

 * its own stack, yields, runs again. The data must survive across the
 * yield (i.e. the swap really restored the right sp). */
void stack_worker(void *arg) {
    volatile uint64_t pattern[256];
    uint64_t seed = (uint64_t)(intptr_t)arg;
    for (int i = 0; i < 256; i++) pattern[i] = seed ^ (uint64_t)i;
    port_coroutine_yield();
    for (int i = 0; i < 256; i++) {
        if (pattern[i] != (seed ^ (uint64_t)i)) {
            fprintf(stderr, "FAIL: stack corrupted at %d (seed=%llx)\n",
                    i, (unsigned long long)seed);
            std::exit(1);
        }
    }
}

void test_stack_preservation() {
    PortCoroutine *a = port_coroutine_create(stack_worker, (void *)0xCAFEBABE, 128 * 1024);