+ * @brief Get commit fence
+ * @details After all change of a window object are applied to last tdm_hwc_commit,
+ * the fence is signaled.
+ * @param[in] hwc A hwc object
+ * @param[out] commit_fence the commit fence fd of tdm_hwc_commit
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+tdm_error
+tdm_hwc_get_commit_fence(tdm_hwc *hwc, int *commit_fence);
+
+/**
+ * @brief Get release fences
+ * @details Retrieves the windows which the backend requires setting the release fences
+ * the release fence is signaled when the backend is no longer using previous buffer.
+ * @param[in] hwc A hwc object
+ * @param[out] num_elements the number of hwc_windows
+ * @param[out] hwc_windows An array of windows
+ * @param[out] release_fences An array of release fences, each corresponding
+ * to an element of windows
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+tdm_error
+tdm_hwc_get_release_fences(tdm_hwc *hwc, uint32_t *num_elements,
+ tdm_hwc_window **hwc_windows, int *fences);
+
+/**
+ * @brief Set the property which has a given id on the hwc object.
+ * @param[in] hwc A hwc object
+ * @param[in] id The property id
+ * @param[in] value The value of the propery id
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+tdm_error
+tdm_hwc_set_property(tdm_hwc *hwc, uint32_t id, tdm_value value);
+
+/**
+ * @brief Get the property which has a given id on the hwc object.
+ * @param[in] hwc A hwc object
+ * @param[in] id The property id
+ * @param[in] value The value of the propery id
+ * @return #TDM_ERROR_NONE if success. Otherwise, error value.
+ */
+tdm_error
+tdm_hwc_get_property(tdm_hwc *hwc, uint32_t id, tdm_value *value);
+
+/**