test-sync-compare-and-swap.c
286 Bytes
// SPDX-License-Identifier: GPL-2.0
#include <stdint.h>
volatile uint64_t x;
int main(int argc, char *argv[])
{
uint64_t old, new = argc;
(void)argv;
do {
old = __sync_val_compare_and_swap(&x, 0, 0);
} while (!__sync_bool_compare_and_swap(&x, old, new));
return old == new;
}