protected function createSegment() {
		$this->shm = shmop_open(
			$this->getIdentifier(),
			self::SHM_CREATE_MODE,
			self::SHM_CREATE_PERMISSIONS,
			$this->size
		);

		if (false === $this->shm) {
			throw new RuntimeException(sprintf('Unable to create shared memory segment with key: %s', $this->getIdentifier()));
		}

		$this->updateSize(0);
	}