Method IncRefCount

include/singa/core/common.h:79–81

  size_t size() const { return size_; }
  size_t offset() const { return offset_; }
  int IncRefCount() {
    return ++ref_count_;  // Note do not use ref_count_++;
  }
  int DecRefCount() { return --ref_count_; }
  int ref_count() const { return ref_count_.load(); }