Function do_fill

examples/sync-primitive/sync-primitive.cpp:50–53

static std::atomic<uint64_t> qps{0}, latency{0};

__attribute__ ((noinline))
static void do_fill(char* buf, size_t size) {
    memset(buf, 0, size);
}

// A function that costs approximately 1 us
static void func_1us() {