private:
static void* create() {
auto ptr = mmap(nullptr, 1, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- checkUnixError(reinterpret_cast<uintptr_t>(ptr), "mmap");
+ checkUnixError(reinterpret_cast<ssize_t>(ptr), "mmap");
// Optimistically try to lock the page so it stays resident. Could make
// the heavy barrier faster.