uint64_t block_size, size_t max_bytes, uint64_t max_staleness,
          uint64_t stat_cache_max_age, size_t stat_cache_max_entries);
} GCSFile;

// This function is used to initialize a filesystem without the need of setting
// manually environement variables.
void InitTest(TF_Filesystem* filesystem, bool compose, uint64_t block_size,
              size_t max_bytes, uint64_t max_staleness,

// an array of length at least `max_inputs` (ideally set to
// TF_OperationNumInputs(oper)).  Beware that a concurrent
// modification of the graph can increase the number of inputs of
// an operation.
TF_CAPI_EXPORT extern void TF_OperationAllInputs(TF_Operation* oper,
                                                 TF_Output* inputs,
                                                 int max_inputs);

  absl::optional<std::vector<std::unique_ptr<ParallelTensor>>> Execute(
      TFE_Context* context, const std::vector<ParallelTensor*>& inputs,
      const char* operation_name, const TFE_OpAttrs* attributes,
      int expected_max_outputs, TF_Status* status) const;

  // A non-blocking version of `Execute`. After each call, `Join` must be called
  // before `StartExecute` is called again. Using `StartExecute` with `Join`

static void*
goDummyCallbackThread(void* p)
{
	int i, max;

	max = *(int*)p;
	for(i=0; i<max; i++)
		goDummy();
	return NULL;
}

int
callGoInCThread(int max)
{
	pthread_t thread;

	if (pthread_create(&thread, NULL, goDummyCallbackThread, (void*)(&max)) != 0)
		return -1;
	if (pthread_join(thread, NULL) != 0)
		return -1;

	return max;

static unsigned int
goDummyCallbackThread(void* p)
{
	int i, max;

	max = *(int*)p;
	for(i=0; i<max; i++)
		goDummy();
	return 0;
}

int
callGoInCThread(int max)
{
	uintptr_t thread_id;
	thread_id = _beginthreadex(0, 0, goDummyCallbackThread, &max, 0, 0);
	WaitForSingleObject((HANDLE)thread_id, INFINITE);
	CloseHandle((HANDLE)thread_id);
	return max;

                   std::function<uint64_t()> timer_seconds = TF_NowSeconds)
      : max_age_(max_age),
        max_entries_(max_entries),
        timer_seconds_(timer_seconds) {}

  /// Insert `value` with key `key`. This will replace any previous entry with
  /// the same key.
  void Insert(const std::string& key, const T& value) {
    if (max_age_ == 0) {
      return;
    }
    absl::MutexLock lock(&mu_);

      BlockFetcher;

  RamFileBlockCache(size_t block_size, size_t max_bytes, uint64_t max_staleness,
                    BlockFetcher block_fetcher,
                    std::function<uint64_t()> timer_seconds = TF_NowSeconds)
      : block_size_(block_size),
        max_bytes_(max_bytes),
        max_staleness_(max_staleness),
        block_fetcher_(block_fetcher),
        timer_seconds_(timer_seconds),