From db0df5d8695b8c521ed287f34a2558f50c898e1e Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 12:35:17 +0100
Subject: [PATCH 01/17] Move from _file_obj object to _close function

---
 xarray/backends/api.py       | 22 +++++++++++-----------
 xarray/backends/apiv2.py     |  2 +-
 xarray/backends/rasterio_.py |  2 +-
 xarray/backends/store.py     |  3 +--
 xarray/conventions.py        |  6 +++---
 xarray/core/common.py        |  6 +++---
 xarray/core/dataarray.py     |  6 ++++--
 xarray/core/dataset.py       | 18 ++++++++++--------
 8 files changed, 34 insertions(+), 31 deletions(-)

diff --git a/xarray/backends/api.py b/xarray/backends/api.py
index faa7e6cf3d3..eae130f9a28 100644
--- a/xarray/backends/api.py
+++ b/xarray/backends/api.py
@@ -522,7 +522,7 @@ def maybe_decode_store(store, chunks):
 
         else:
             ds2 = ds
-        ds2._file_obj = ds._file_obj
+        ds2._close = ds._close
         return ds2
 
     filename_or_obj = _normalize_path(filename_or_obj)
@@ -701,7 +701,7 @@ def open_dataarray(
     else:
         (data_array,) = dataset.data_vars.values()
 
-    data_array._file_obj = dataset._file_obj
+    data_array._close = dataset._close
 
     # Reset names if they were changed during saving
     # to ensure that we can 'roundtrip' perfectly
@@ -716,14 +716,14 @@ def open_dataarray(
 
 
 class _MultiFileCloser:
-    __slots__ = ("file_objs",)
+    __slots__ = ("closers",)
 
-    def __init__(self, file_objs):
-        self.file_objs = file_objs
+    def __init__(self, closers):
+        self.closers = closers
 
-    def close(self):
-        for f in self.file_objs:
-            f.close()
+    def __call__(self):
+        for dataset_close in self.closers:
+            dataset_close()
 
 
 def open_mfdataset(
@@ -918,14 +918,14 @@ def open_mfdataset(
         getattr_ = getattr
 
     datasets = [open_(p, **open_kwargs) for p in paths]
-    file_objs = [getattr_(ds, "_file_obj") for ds in datasets]
+    closers = [getattr_(ds, "_close") for ds in datasets]
     if preprocess is not None:
         datasets = [preprocess(ds) for ds in datasets]
 
     if parallel:
         # calling compute here will return the datasets/file_objs lists,
         # the underlying datasets will still be stored as dask arrays
-        datasets, file_objs = dask.compute(datasets, file_objs)
+        datasets, closers = dask.compute(datasets, closers)
 
     # Combine all datasets, closing them in case of a ValueError
     try:
@@ -963,7 +963,7 @@ def open_mfdataset(
             ds.close()
         raise
 
-    combined._file_obj = _MultiFileCloser(file_objs)
+    combined._close = _MultiFileCloser(closers)
 
     # read global attributes from the attrs_file or from the first dataset
     if attrs_file is not None:
diff --git a/xarray/backends/apiv2.py b/xarray/backends/apiv2.py
index 0f98291983d..a1018abe9fc 100644
--- a/xarray/backends/apiv2.py
+++ b/xarray/backends/apiv2.py
@@ -90,7 +90,7 @@ def _dataset_from_backend_dataset(
             **extra_tokens,
         )
 
-    ds._file_obj = backend_ds._file_obj
+    ds._close = backend_ds._close
 
     # Ensure source filename always stored in dataset object (GH issue #2550)
     if "source" not in ds.encoding:
diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index a0500c7e1c2..3ff568965f3 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -361,6 +361,6 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
         result = result.chunk(chunks, name_prefix=name_prefix, token=token)
 
     # Make the file closeable
-    result._file_obj = manager
+    result._close = manager.close
 
     return result
diff --git a/xarray/backends/store.py b/xarray/backends/store.py
index d314a9c3ca9..57880db06cf 100644
--- a/xarray/backends/store.py
+++ b/xarray/backends/store.py
@@ -19,7 +19,6 @@ def open_backend_dataset_store(
     decode_timedelta=None,
 ):
     vars, attrs = store.load()
-    file_obj = store
     encoding = store.get_encoding()
 
     vars, attrs, coord_names = conventions.decode_cf_variables(
@@ -36,7 +35,7 @@ def open_backend_dataset_store(
 
     ds = Dataset(vars, attrs=attrs)
     ds = ds.set_coords(coord_names.intersection(vars))
-    ds._file_obj = file_obj
+    ds._close = store.close
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/conventions.py b/xarray/conventions.py
index bb0b92c77a1..2fe6dd81aa8 100644
--- a/xarray/conventions.py
+++ b/xarray/conventions.py
@@ -576,12 +576,12 @@ def decode_cf(
         vars = obj._variables
         attrs = obj.attrs
         extra_coords = set(obj.coords)
-        file_obj = obj._file_obj
+        close = obj._close
         encoding = obj.encoding
     elif isinstance(obj, AbstractDataStore):
         vars, attrs = obj.load()
         extra_coords = set()
-        file_obj = obj
+        close = obj.close
         encoding = obj.get_encoding()
     else:
         raise TypeError("can only decode Dataset or DataStore objects")
@@ -599,7 +599,7 @@ def decode_cf(
     )
     ds = Dataset(vars, attrs=attrs)
     ds = ds.set_coords(coord_names.union(extra_coords).intersection(vars))
-    ds._file_obj = file_obj
+    ds._close = close
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/core/common.py b/xarray/core/common.py
index 283114770cf..e7f75636af0 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -1265,9 +1265,9 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
 
     def close(self: Any) -> None:
         """Close any files linked to this object"""
-        if self._file_obj is not None:
-            self._file_obj.close()
-        self._file_obj = None
+        if self._close is not None:
+            self._close()
+        self._close = None
 
     def isnull(self, keep_attrs: bool = None):
         """Test each value in the array for whether it is a missing value.
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index 6fdda8fc418..49fa9b80e80 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -344,6 +344,7 @@ class DataArray(AbstractArray, DataWithCoords):
 
     _cache: Dict[str, Any]
     _coords: Dict[Any, Variable]
+    _close: Optional[Callable[[], None]]
     _indexes: Optional[Dict[Hashable, pd.Index]]
     _name: Optional[Hashable]
     _variable: Variable
@@ -351,7 +352,7 @@ class DataArray(AbstractArray, DataWithCoords):
     __slots__ = (
         "_cache",
         "_coords",
-        "_file_obj",
+        "_close",
         "_indexes",
         "_name",
         "_variable",
@@ -376,6 +377,7 @@ def __init__(
         # internal parameters
         indexes: Dict[Hashable, pd.Index] = None,
         fastpath: bool = False,
+        close: Optional[Callable[[], None]] = None,
     ):
         if fastpath:
             variable = data
@@ -421,7 +423,7 @@ def __init__(
         # public interface.
         self._indexes = indexes
 
-        self._file_obj = None
+        self._close = close
 
     def _replace(
         self,
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index 7edc2fab067..6fd291dea53 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -636,6 +636,7 @@ class Dataset(Mapping, ImplementsDatasetReduce, DataWithCoords):
     _coord_names: Set[Hashable]
     _dims: Dict[Hashable, int]
     _encoding: Optional[Dict[Hashable, Any]]
+    _close: Optional[Callable[[], None]]
     _indexes: Optional[Dict[Hashable, pd.Index]]
     _variables: Dict[Hashable, Variable]
 
@@ -645,7 +646,7 @@ class Dataset(Mapping, ImplementsDatasetReduce, DataWithCoords):
         "_coord_names",
         "_dims",
         "_encoding",
-        "_file_obj",
+        "_close",
         "_indexes",
         "_variables",
         "__weakref__",
@@ -664,6 +665,7 @@ def __init__(
         data_vars: Mapping[Hashable, Any] = None,
         coords: Mapping[Hashable, Any] = None,
         attrs: Mapping[Hashable, Any] = None,
+        close: Optional[Callable[[], None]] = None,
     ):
         # TODO(shoyer): expose indexes as a public argument in __init__
 
@@ -687,7 +689,7 @@ def __init__(
         )
 
         self._attrs = dict(attrs) if attrs is not None else None
-        self._file_obj = None
+        self._close = close
         self._encoding = None
         self._variables = variables
         self._coord_names = coord_names
@@ -703,7 +705,7 @@ def load_store(cls, store, decoder=None) -> "Dataset":
         if decoder:
             variables, attributes = decoder(variables, attributes)
         obj = cls(variables, attrs=attributes)
-        obj._file_obj = store
+        obj._close = store.close
         return obj
 
     @property
@@ -876,7 +878,7 @@ def __dask_postcompute__(self):
             self._attrs,
             self._indexes,
             self._encoding,
-            self._file_obj,
+            self._close,
         )
         return self._dask_postcompute, args
 
@@ -896,7 +898,7 @@ def __dask_postpersist__(self):
             self._attrs,
             self._indexes,
             self._encoding,
-            self._file_obj,
+            self._close,
         )
         return self._dask_postpersist, args
 
@@ -1007,7 +1009,7 @@ def _construct_direct(
         attrs=None,
         indexes=None,
         encoding=None,
-        file_obj=None,
+        close=None,
     ):
         """Shortcut around __init__ for internal use when we want to skip
         costly validation
@@ -1020,7 +1022,7 @@ def _construct_direct(
         obj._dims = dims
         obj._indexes = indexes
         obj._attrs = attrs
-        obj._file_obj = file_obj
+        obj._close = close
         obj._encoding = encoding
         return obj
 
@@ -2122,7 +2124,7 @@ def isel(
             attrs=self._attrs,
             indexes=indexes,
             encoding=self._encoding,
-            file_obj=self._file_obj,
+            close=self._close,
         )
 
     def _isel_fancy(

From cbb89ff8d47708219c0c5c2386d869b312c1b773 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 14:26:44 +0100
Subject: [PATCH 02/17] Remove all references to _close outside of low level

---
 xarray/backends/api.py       |  3 ---
 xarray/backends/apiv2.py     |  2 --
 xarray/backends/rasterio_.py | 11 +++++++----
 xarray/backends/store.py     |  3 +--
 xarray/conventions.py        |  3 +--
 xarray/core/dataarray.py     | 15 ++++++++++++---
 xarray/core/dataset.py       | 24 +++++++++++++++++++++---
 7 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/xarray/backends/api.py b/xarray/backends/api.py
index eae130f9a28..66c2aa2f7f2 100644
--- a/xarray/backends/api.py
+++ b/xarray/backends/api.py
@@ -522,7 +522,6 @@ def maybe_decode_store(store, chunks):
 
         else:
             ds2 = ds
-        ds2._close = ds._close
         return ds2
 
     filename_or_obj = _normalize_path(filename_or_obj)
@@ -701,8 +700,6 @@ def open_dataarray(
     else:
         (data_array,) = dataset.data_vars.values()
 
-    data_array._close = dataset._close
-
     # Reset names if they were changed during saving
     # to ensure that we can 'roundtrip' perfectly
     if DATAARRAY_NAME in dataset.attrs:
diff --git a/xarray/backends/apiv2.py b/xarray/backends/apiv2.py
index a1018abe9fc..1d649896e64 100644
--- a/xarray/backends/apiv2.py
+++ b/xarray/backends/apiv2.py
@@ -90,8 +90,6 @@ def _dataset_from_backend_dataset(
             **extra_tokens,
         )
 
-    ds._close = backend_ds._close
-
     # Ensure source filename always stored in dataset object (GH issue #2550)
     if "source" not in ds.encoding:
         if isinstance(filename_or_obj, str):
diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index 3ff568965f3..47df283e55c 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -345,7 +345,13 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
     if cache and chunks is None:
         data = indexing.MemoryCachedArray(data)
 
-    result = DataArray(data=data, dims=("band", "y", "x"), coords=coords, attrs=attrs)
+    result = DataArray(
+        data=data,
+        dims=("band", "y", "x"),
+        coords=coords,
+        attrs=attrs,
+        close=manager.close,
+    )
 
     if chunks is not None:
         from dask.base import tokenize
@@ -360,7 +366,4 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
         name_prefix = "open_rasterio-%s" % token
         result = result.chunk(chunks, name_prefix=name_prefix, token=token)
 
-    # Make the file closeable
-    result._close = manager.close
-
     return result
diff --git a/xarray/backends/store.py b/xarray/backends/store.py
index 57880db06cf..281af0839cf 100644
--- a/xarray/backends/store.py
+++ b/xarray/backends/store.py
@@ -33,9 +33,8 @@ def open_backend_dataset_store(
         decode_timedelta=decode_timedelta,
     )
 
-    ds = Dataset(vars, attrs=attrs)
+    ds = Dataset(vars, attrs=attrs, close=store.close)
     ds = ds.set_coords(coord_names.intersection(vars))
-    ds._close = store.close
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/conventions.py b/xarray/conventions.py
index 2fe6dd81aa8..1a521f56b36 100644
--- a/xarray/conventions.py
+++ b/xarray/conventions.py
@@ -597,9 +597,8 @@ def decode_cf(
         use_cftime=use_cftime,
         decode_timedelta=decode_timedelta,
     )
-    ds = Dataset(vars, attrs=attrs)
+    ds = Dataset(vars, attrs=attrs, close=close)
     ds = ds.set_coords(coord_names.union(extra_coords).intersection(vars))
-    ds._close = close
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index 49fa9b80e80..e021b431b6f 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -431,6 +431,7 @@ def _replace(
         coords=None,
         name: Union[Hashable, None, Default] = _default,
         indexes=None,
+        close: Optional[Callable[[], None]] = _default,
     ) -> "DataArray":
         if variable is None:
             variable = self.variable
@@ -438,7 +439,11 @@ def _replace(
             coords = self._coords
         if name is _default:
             name = self.name
-        return type(self)(variable, coords, name=name, fastpath=True, indexes=indexes)
+        if close is _default:
+            close = self._close
+        return type(self)(
+            variable, coords, name=name, fastpath=True, indexes=indexes, close=close
+        )
 
     def _replace_maybe_drop_dims(
         self, variable: Variable, name: Union[Hashable, None, Default] = _default
@@ -494,7 +499,8 @@ def _from_temp_dataset(
         variable = dataset._variables.pop(_THIS_ARRAY)
         coords = dataset._variables
         indexes = dataset._indexes
-        return self._replace(variable, coords, name, indexes=indexes)
+        close = dataset._close
+        return self._replace(variable, coords, name, indexes=indexes, close=close)
 
     def _to_dataset_split(self, dim: Hashable) -> Dataset:
         """ splits dataarray along dimension 'dim' """
@@ -538,7 +544,10 @@ def _to_dataset_whole(
         indexes = self._indexes
 
         coord_names = set(self._coords)
-        dataset = Dataset._construct_direct(variables, coord_names, indexes=indexes)
+        close = self._close
+        dataset = Dataset._construct_direct(
+            variables, coord_names, indexes=indexes, close=close
+        )
         return dataset
 
     def to_dataset(
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index 6fd291dea53..bb331659447 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1035,6 +1035,7 @@ def _replace(
         indexes: Union[Dict[Any, pd.Index], None, Default] = _default,
         encoding: Union[dict, None, Default] = _default,
         inplace: bool = False,
+        close: Optional[Callable[[], None]] = _default,
     ) -> "Dataset":
         """Fastpath constructor for internal use.
 
@@ -1057,6 +1058,8 @@ def _replace(
                 self._indexes = indexes
             if encoding is not _default:
                 self._encoding = encoding
+            if close is not _default:
+                self._close = close
             obj = self
         else:
             if variables is None:
@@ -1071,8 +1074,10 @@ def _replace(
                 indexes = copy.copy(self._indexes)
             if encoding is _default:
                 encoding = copy.copy(self._encoding)
+            if close is _default:
+                close = self._close
             obj = self._construct_direct(
-                variables, coord_names, dims, attrs, indexes, encoding
+                variables, coord_names, dims, attrs, indexes, encoding, close
             )
         return obj
 
@@ -1332,7 +1337,14 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
         else:
             indexes = {k: v for k, v in self._indexes.items() if k in coords}
 
-        return DataArray(variable, coords, name=name, indexes=indexes, fastpath=True)
+        return DataArray(
+            variable,
+            coords,
+            name=name,
+            indexes=indexes,
+            fastpath=True,
+            close=self._close,
+        )
 
     def __copy__(self) -> "Dataset":
         return self.copy(deep=False)
@@ -4789,7 +4801,13 @@ def to_array(self, dim="variable", name=None):
         dims = (dim,) + broadcast_vars[0].dims
 
         return DataArray(
-            data, coords, dims, attrs=self.attrs, name=name, indexes=indexes
+            data,
+            coords,
+            dims,
+            attrs=self.attrs,
+            name=name,
+            indexes=indexes,
+            close=self._close,
         )
 
     def _normalize_dim_order(

From fed7d90dbc9ade237e5f4428030cd4383bef7215 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 16:13:23 +0100
Subject: [PATCH 03/17] Fix type hints

---
 xarray/core/dataarray.py | 2 +-
 xarray/core/dataset.py   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index e021b431b6f..cb4ef527152 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -431,7 +431,7 @@ def _replace(
         coords=None,
         name: Union[Hashable, None, Default] = _default,
         indexes=None,
-        close: Optional[Callable[[], None]] = _default,
+        close: Union[Callable[[], None], None, Default] = _default,
     ) -> "DataArray":
         if variable is None:
             variable = self.variable
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index bb331659447..ec23f62b888 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1035,7 +1035,7 @@ def _replace(
         indexes: Union[Dict[Any, pd.Index], None, Default] = _default,
         encoding: Union[dict, None, Default] = _default,
         inplace: bool = False,
-        close: Optional[Callable[[], None]] = _default,
+        close: Union[Callable[[], None], None, Default] = _default,
     ) -> "Dataset":
         """Fastpath constructor for internal use.
 

From b2c873992c2d75f66ad8b6b5aac26375204c879e Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 16:47:55 +0100
Subject: [PATCH 04/17] Cleanup code style

---
 xarray/core/dataarray.py | 3 ++-
 xarray/core/dataset.py   | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index cb4ef527152..ac3cff2cd67 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -441,9 +441,10 @@ def _replace(
             name = self.name
         if close is _default:
             close = self._close
-        return type(self)(
+        replaced = type(self)(
             variable, coords, name=name, fastpath=True, indexes=indexes, close=close
         )
+        return replaced
 
     def _replace_maybe_drop_dims(
         self, variable: Variable, name: Union[Hashable, None, Default] = _default
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index ec23f62b888..be1227ede6d 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1337,7 +1337,7 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
         else:
             indexes = {k: v for k, v in self._indexes.items() if k in coords}
 
-        return DataArray(
+        da = DataArray(
             variable,
             coords,
             name=name,
@@ -1345,6 +1345,7 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
             fastpath=True,
             close=self._close,
         )
+        return da
 
     def __copy__(self) -> "Dataset":
         return self.copy(deep=False)
@@ -4800,7 +4801,7 @@ def to_array(self, dim="variable", name=None):
 
         dims = (dim,) + broadcast_vars[0].dims
 
-        return DataArray(
+        da = DataArray(
             data,
             coords,
             dims,
@@ -4809,6 +4810,7 @@ def to_array(self, dim="variable", name=None):
             indexes=indexes,
             close=self._close,
         )
+        return da
 
     def _normalize_dim_order(
         self, dim_order: List[Hashable] = None

From 8b560259092e68dc0325f6dfbeffb9e7885b2972 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 16:53:30 +0100
Subject: [PATCH 05/17] Fix non-trivial type hint problem

---
 xarray/core/common.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xarray/core/common.py b/xarray/core/common.py
index e7f75636af0..e70cde01fda 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -11,6 +11,7 @@
     Iterator,
     List,
     Mapping,
+    Optional,
     Tuple,
     TypeVar,
     Union,
@@ -1265,6 +1266,7 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
 
     def close(self: Any) -> None:
         """Close any files linked to this object"""
+        self._close: Optional[Callable[[], None]]
         if self._close is not None:
             self._close()
         self._close = None

From 4f6b899755e5fede425bb1211dfcb3ac928bc2d7 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 19:07:27 +0100
Subject: [PATCH 06/17] Revert adding the `close` argument and add a set_close
 instead

---
 xarray/backends/rasterio_.py | 2 +-
 xarray/backends/store.py     | 3 ++-
 xarray/conventions.py        | 3 ++-
 xarray/core/common.py        | 8 ++++++--
 xarray/core/dataarray.py     | 6 +++---
 xarray/core/dataset.py       | 7 +++----
 6 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index 47df283e55c..1e2d1d31034 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -350,8 +350,8 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
         dims=("band", "y", "x"),
         coords=coords,
         attrs=attrs,
-        close=manager.close,
     )
+    result.set_close(manager.close)
 
     if chunks is not None:
         from dask.base import tokenize
diff --git a/xarray/backends/store.py b/xarray/backends/store.py
index 281af0839cf..802c78d241d 100644
--- a/xarray/backends/store.py
+++ b/xarray/backends/store.py
@@ -33,7 +33,8 @@ def open_backend_dataset_store(
         decode_timedelta=decode_timedelta,
     )
 
-    ds = Dataset(vars, attrs=attrs, close=store.close)
+    ds = Dataset(vars, attrs=attrs)
+    ds.set_close(store.close)
     ds = ds.set_coords(coord_names.intersection(vars))
     ds.encoding = encoding
 
diff --git a/xarray/conventions.py b/xarray/conventions.py
index 1a521f56b36..76f242c3f13 100644
--- a/xarray/conventions.py
+++ b/xarray/conventions.py
@@ -597,7 +597,8 @@ def decode_cf(
         use_cftime=use_cftime,
         decode_timedelta=decode_timedelta,
     )
-    ds = Dataset(vars, attrs=attrs, close=close)
+    ds = Dataset(vars, attrs=attrs)
+    ds.set_close(close)
     ds = ds.set_coords(coord_names.union(extra_coords).intersection(vars))
     ds.encoding = encoding
 
diff --git a/xarray/core/common.py b/xarray/core/common.py
index e70cde01fda..3b3ace6a364 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -331,7 +331,9 @@ def get_squeeze_dims(
 class DataWithCoords(SupportsArithmetic, AttrAccessMixin):
     """Shared base class for Dataset and DataArray."""
 
-    __slots__ = ()
+    _close: Optional[Callable[[], None]]
+
+    __slots__ = ("_close",)
 
     _rolling_exp_cls = RollingExp
 
@@ -1264,9 +1266,11 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
 
         return ops.where_method(self, cond, other)
 
+    def set_close(self, close: Optional[Callable[[], None]]) -> None:
+        self._close = close
+
     def close(self: Any) -> None:
         """Close any files linked to this object"""
-        self._close: Optional[Callable[[], None]]
         if self._close is not None:
             self._close()
         self._close = None
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index ac3cff2cd67..6183709d337 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -377,7 +377,6 @@ def __init__(
         # internal parameters
         indexes: Dict[Hashable, pd.Index] = None,
         fastpath: bool = False,
-        close: Optional[Callable[[], None]] = None,
     ):
         if fastpath:
             variable = data
@@ -423,7 +422,7 @@ def __init__(
         # public interface.
         self._indexes = indexes
 
-        self._close = close
+        self._close = None
 
     def _replace(
         self,
@@ -442,8 +441,9 @@ def _replace(
         if close is _default:
             close = self._close
         replaced = type(self)(
-            variable, coords, name=name, fastpath=True, indexes=indexes, close=close
+            variable, coords, name=name, fastpath=True, indexes=indexes
         )
+        replaced.set_close(close)
         return replaced
 
     def _replace_maybe_drop_dims(
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index be1227ede6d..a80e5be1f49 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -665,7 +665,6 @@ def __init__(
         data_vars: Mapping[Hashable, Any] = None,
         coords: Mapping[Hashable, Any] = None,
         attrs: Mapping[Hashable, Any] = None,
-        close: Optional[Callable[[], None]] = None,
     ):
         # TODO(shoyer): expose indexes as a public argument in __init__
 
@@ -689,7 +688,7 @@ def __init__(
         )
 
         self._attrs = dict(attrs) if attrs is not None else None
-        self._close = close
+        self._close = None
         self._encoding = None
         self._variables = variables
         self._coord_names = coord_names
@@ -1343,8 +1342,8 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
             name=name,
             indexes=indexes,
             fastpath=True,
-            close=self._close,
         )
+        da.set_close(self._close)
         return da
 
     def __copy__(self) -> "Dataset":
@@ -4808,8 +4807,8 @@ def to_array(self, dim="variable", name=None):
             attrs=self.attrs,
             name=name,
             indexes=indexes,
-            close=self._close,
         )
+        da.set_close(self._close)
         return da
 
     def _normalize_dim_order(

From eb6e89c2df8f8a572646eae7b7ec2ce5cd2b6fd0 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 19:20:26 +0100
Subject: [PATCH 07/17] Remove helper class for an easier helper function +
 code style

---
 xarray/backends/api.py | 17 +++++------------
 xarray/core/dataset.py | 17 ++---------------
 2 files changed, 7 insertions(+), 27 deletions(-)

diff --git a/xarray/backends/api.py b/xarray/backends/api.py
index 66c2aa2f7f2..2b5c3d255a4 100644
--- a/xarray/backends/api.py
+++ b/xarray/backends/api.py
@@ -712,17 +712,6 @@ def open_dataarray(
     return data_array
 
 
-class _MultiFileCloser:
-    __slots__ = ("closers",)
-
-    def __init__(self, closers):
-        self.closers = closers
-
-    def __call__(self):
-        for dataset_close in self.closers:
-            dataset_close()
-
-
 def open_mfdataset(
     paths,
     chunks=None,
@@ -960,7 +949,11 @@ def open_mfdataset(
             ds.close()
         raise
 
-    combined._close = _MultiFileCloser(closers)
+    def multi_file_closer():
+        for closer in closers:
+            closer()
+
+    combined._close = multi_file_closer
 
     # read global attributes from the attrs_file or from the first dataset
     if attrs_file is not None:
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index a80e5be1f49..cca16dfdfd4 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1336,13 +1336,7 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
         else:
             indexes = {k: v for k, v in self._indexes.items() if k in coords}
 
-        da = DataArray(
-            variable,
-            coords,
-            name=name,
-            indexes=indexes,
-            fastpath=True,
-        )
+        da = DataArray(variable, coords, name=name, indexes=indexes, fastpath=True)
         da.set_close(self._close)
         return da
 
@@ -4800,14 +4794,7 @@ def to_array(self, dim="variable", name=None):
 
         dims = (dim,) + broadcast_vars[0].dims
 
-        da = DataArray(
-            data,
-            coords,
-            dims,
-            attrs=self.attrs,
-            name=name,
-            indexes=indexes,
-        )
+        da = DataArray(data, coords, dims, attrs=self.attrs, name=name, indexes=indexes)
         da.set_close(self._close)
         return da
 

From 552b65247b107c71ff7edeeb1fe8673cce0986be Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 19:40:29 +0100
Subject: [PATCH 08/17] Add set_close docstring

---
 xarray/core/common.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/xarray/core/common.py b/xarray/core/common.py
index 3b3ace6a364..e84b44d7441 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -1266,8 +1266,18 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
 
         return ops.where_method(self, cond, other)
 
-    def set_close(self, close: Optional[Callable[[], None]]) -> None:
-        self._close = close
+    def set_close(self, close_store: Optional[Callable[[], None]]) -> None:
+        """Register the function that releases all resources used by the data store.
+
+        This method is mostly intended for backend developers and it is rarely
+        needed by regular end-users.
+
+        Parameters
+        ----------
+        close_store : callable
+            A callable that releases all resources used by the data store.
+        """
+        self._close = close_store
 
     def close(self: Any) -> None:
         """Close any files linked to this object"""

From 947c3b527c0c1700fb4156a2feced9f3e6d51aa5 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Thu, 14 Jan 2021 19:52:38 +0100
Subject: [PATCH 09/17] Code style

---
 xarray/backends/rasterio_.py | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index 1e2d1d31034..f96a892521a 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -345,12 +345,7 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
     if cache and chunks is None:
         data = indexing.MemoryCachedArray(data)
 
-    result = DataArray(
-        data=data,
-        dims=("band", "y", "x"),
-        coords=coords,
-        attrs=attrs,
-    )
+    result = DataArray(data=data, dims=("band", "y", "x"), coords=coords, attrs=attrs)
     result.set_close(manager.close)
 
     if chunks is not None:

From 3a67acac56ca4d6d6b33f126958c94594853822b Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 09:28:54 +0100
Subject: [PATCH 10/17] Revert changes in _replace to keep cose as an exception

See: https://github.com/pydata/xarray/pull/4809/files#r557628298
---
 xarray/backends/api.py       |  3 +++
 xarray/backends/apiv2.py     |  2 ++
 xarray/backends/rasterio_.py |  4 +++-
 xarray/backends/store.py     |  2 +-
 xarray/conventions.py        |  2 +-
 xarray/core/dataarray.py     | 17 +++--------------
 xarray/core/dataset.py       |  7 +------
 7 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/xarray/backends/api.py b/xarray/backends/api.py
index 2b5c3d255a4..4698664ea37 100644
--- a/xarray/backends/api.py
+++ b/xarray/backends/api.py
@@ -522,6 +522,7 @@ def maybe_decode_store(store, chunks):
 
         else:
             ds2 = ds
+        ds2.set_close(ds._close)
         return ds2
 
     filename_or_obj = _normalize_path(filename_or_obj)
@@ -700,6 +701,8 @@ def open_dataarray(
     else:
         (data_array,) = dataset.data_vars.values()
 
+    data_array.set_close(dataset._close)
+
     # Reset names if they were changed during saving
     # to ensure that we can 'roundtrip' perfectly
     if DATAARRAY_NAME in dataset.attrs:
diff --git a/xarray/backends/apiv2.py b/xarray/backends/apiv2.py
index 1d649896e64..d31fc9ea773 100644
--- a/xarray/backends/apiv2.py
+++ b/xarray/backends/apiv2.py
@@ -90,6 +90,8 @@ def _dataset_from_backend_dataset(
             **extra_tokens,
         )
 
+    ds.set_close(backend_ds._close)
+
     # Ensure source filename always stored in dataset object (GH issue #2550)
     if "source" not in ds.encoding:
         if isinstance(filename_or_obj, str):
diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index f96a892521a..c689c1e99d7 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -346,7 +346,6 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
         data = indexing.MemoryCachedArray(data)
 
     result = DataArray(data=data, dims=("band", "y", "x"), coords=coords, attrs=attrs)
-    result.set_close(manager.close)
 
     if chunks is not None:
         from dask.base import tokenize
@@ -361,4 +360,7 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None, loc
         name_prefix = "open_rasterio-%s" % token
         result = result.chunk(chunks, name_prefix=name_prefix, token=token)
 
+    # Make the file closeable
+    result.set_close(manager.close)
+
     return result
diff --git a/xarray/backends/store.py b/xarray/backends/store.py
index 802c78d241d..20fa13af202 100644
--- a/xarray/backends/store.py
+++ b/xarray/backends/store.py
@@ -34,8 +34,8 @@ def open_backend_dataset_store(
     )
 
     ds = Dataset(vars, attrs=attrs)
-    ds.set_close(store.close)
     ds = ds.set_coords(coord_names.intersection(vars))
+    ds.set_close(store.close)
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/conventions.py b/xarray/conventions.py
index 76f242c3f13..e33ae53b31d 100644
--- a/xarray/conventions.py
+++ b/xarray/conventions.py
@@ -598,8 +598,8 @@ def decode_cf(
         decode_timedelta=decode_timedelta,
     )
     ds = Dataset(vars, attrs=attrs)
-    ds.set_close(close)
     ds = ds.set_coords(coord_names.union(extra_coords).intersection(vars))
+    ds.set_close(close)
     ds.encoding = encoding
 
     return ds
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index 6183709d337..e13ea44baad 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -430,7 +430,6 @@ def _replace(
         coords=None,
         name: Union[Hashable, None, Default] = _default,
         indexes=None,
-        close: Union[Callable[[], None], None, Default] = _default,
     ) -> "DataArray":
         if variable is None:
             variable = self.variable
@@ -438,13 +437,7 @@ def _replace(
             coords = self._coords
         if name is _default:
             name = self.name
-        if close is _default:
-            close = self._close
-        replaced = type(self)(
-            variable, coords, name=name, fastpath=True, indexes=indexes
-        )
-        replaced.set_close(close)
-        return replaced
+        return type(self)(variable, coords, name=name, fastpath=True, indexes=indexes)
 
     def _replace_maybe_drop_dims(
         self, variable: Variable, name: Union[Hashable, None, Default] = _default
@@ -500,8 +493,7 @@ def _from_temp_dataset(
         variable = dataset._variables.pop(_THIS_ARRAY)
         coords = dataset._variables
         indexes = dataset._indexes
-        close = dataset._close
-        return self._replace(variable, coords, name, indexes=indexes, close=close)
+        return self._replace(variable, coords, name, indexes=indexes)
 
     def _to_dataset_split(self, dim: Hashable) -> Dataset:
         """ splits dataarray along dimension 'dim' """
@@ -545,10 +537,7 @@ def _to_dataset_whole(
         indexes = self._indexes
 
         coord_names = set(self._coords)
-        close = self._close
-        dataset = Dataset._construct_direct(
-            variables, coord_names, indexes=indexes, close=close
-        )
+        dataset = Dataset._construct_direct(variables, coord_names, indexes=indexes)
         return dataset
 
     def to_dataset(
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index cca16dfdfd4..e2dcf580600 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1034,7 +1034,6 @@ def _replace(
         indexes: Union[Dict[Any, pd.Index], None, Default] = _default,
         encoding: Union[dict, None, Default] = _default,
         inplace: bool = False,
-        close: Union[Callable[[], None], None, Default] = _default,
     ) -> "Dataset":
         """Fastpath constructor for internal use.
 
@@ -1057,8 +1056,6 @@ def _replace(
                 self._indexes = indexes
             if encoding is not _default:
                 self._encoding = encoding
-            if close is not _default:
-                self._close = close
             obj = self
         else:
             if variables is None:
@@ -1073,10 +1070,8 @@ def _replace(
                 indexes = copy.copy(self._indexes)
             if encoding is _default:
                 encoding = copy.copy(self._encoding)
-            if close is _default:
-                close = self._close
             obj = self._construct_direct(
-                variables, coord_names, dims, attrs, indexes, encoding, close
+                variables, coord_names, dims, attrs, indexes, encoding
             )
         return obj
 

From 32976b157a7f1af5061eeac4fa218eada20d3927 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 09:32:04 +0100
Subject: [PATCH 11/17] One more bit to revert

---
 xarray/core/dataset.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index e2dcf580600..8a6966319cd 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -1331,9 +1331,7 @@ def _construct_dataarray(self, name: Hashable) -> "DataArray":
         else:
             indexes = {k: v for k, v in self._indexes.items() if k in coords}
 
-        da = DataArray(variable, coords, name=name, indexes=indexes, fastpath=True)
-        da.set_close(self._close)
-        return da
+        return DataArray(variable, coords, name=name, indexes=indexes, fastpath=True)
 
     def __copy__(self) -> "Dataset":
         return self.copy(deep=False)

From 82efe0d8b221b2350cd9f2d32e5ed04717728f9f Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 09:34:20 +0100
Subject: [PATCH 12/17] One more bit to revert

---
 xarray/core/dataset.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index 8a6966319cd..4382c254974 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -4787,9 +4787,9 @@ def to_array(self, dim="variable", name=None):
 
         dims = (dim,) + broadcast_vars[0].dims
 
-        da = DataArray(data, coords, dims, attrs=self.attrs, name=name, indexes=indexes)
-        da.set_close(self._close)
-        return da
+        return DataArray(
+            data, coords, dims, attrs=self.attrs, name=name, indexes=indexes
+        )
 
     def _normalize_dim_order(
         self, dim_order: List[Hashable] = None

From 675b0fe53dbf7d41d461918d063f9fe686c03371 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 10:31:23 +0100
Subject: [PATCH 13/17] Add What's New entry

---
 doc/whats-new.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index db10ec653c5..5465cb7761e 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -103,6 +103,8 @@ Internal Changes
   By `Maximilian Roos <https://github.com/max-sixty>`_.
 - Speed up attribute style access (e.g. ``ds.somevar`` instead of ``ds["somevar"]``) and tab completion
   in ipython (:issue:`4741`, :pull:`4742`). By `Richard Kleijn <https://github.com/rhkleijn>`_.
+- Added the ``set_close`` method to ``Dataset`` and ``DataArray`` for beckends to specify how to voluntary release
+  all resources. (:pull:`#4809`), By `Alessandro Amici <https://github.com/alexamici>`_.
 
 .. _whats-new.0.16.2:
 

From 538371fe09d78b4710ee58d8950832d842eecbb5 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 19:57:12 +0100
Subject: [PATCH 14/17] Use set_close setter

---
 xarray/backends/api.py | 2 +-
 xarray/core/dataset.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/xarray/backends/api.py b/xarray/backends/api.py
index 4698664ea37..30f9532b29a 100644
--- a/xarray/backends/api.py
+++ b/xarray/backends/api.py
@@ -956,7 +956,7 @@ def multi_file_closer():
         for closer in closers:
             closer()
 
-    combined._close = multi_file_closer
+    combined.set_close(multi_file_closer)
 
     # read global attributes from the attrs_file or from the first dataset
     if attrs_file is not None:
diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
index 4382c254974..136edffb202 100644
--- a/xarray/core/dataset.py
+++ b/xarray/core/dataset.py
@@ -704,7 +704,7 @@ def load_store(cls, store, decoder=None) -> "Dataset":
         if decoder:
             variables, attributes = decoder(variables, attributes)
         obj = cls(variables, attrs=attributes)
-        obj._close = store.close
+        obj.set_close(store.close)
         return obj
 
     @property

From 65e43bfa28e08cec34da7072732609db6d086ece Mon Sep 17 00:00:00 2001
From: alexamici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 20:04:33 +0100
Subject: [PATCH 15/17] Apply suggestions from code review

Co-authored-by: Stephan Hoyer <shoyer@google.com>
---
 xarray/core/common.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/xarray/core/common.py b/xarray/core/common.py
index e84b44d7441..e2b41d6c0e0 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -1269,13 +1269,16 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
     def set_close(self, close_store: Optional[Callable[[], None]]) -> None:
         """Register the function that releases all resources used by the data store.
 
-        This method is mostly intended for backend developers and it is rarely
-        needed by regular end-users.
+        This method controls how xarray cleans up resources associated
+        with this object when the .close() method is called. It is mostly
+        intended for backend developers and it is rarely needed by regular
+        end-users.
 
         Parameters
         ----------
         close_store : callable
-            A callable that releases all resources used by the data store.
+            A callable that when called like ``close_store()`` releases
+            all resources used by the data store.
         """
         self._close = close_store
 

From a8f96b69e60259b9d4bef11f97459dea0226e376 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 20:05:47 +0100
Subject: [PATCH 16/17] Rename user-visible argument

---
 xarray/core/common.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/xarray/core/common.py b/xarray/core/common.py
index e2b41d6c0e0..402ae545e5f 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -1266,7 +1266,7 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
 
         return ops.where_method(self, cond, other)
 
-    def set_close(self, close_store: Optional[Callable[[], None]]) -> None:
+    def set_close(self, close: Optional[Callable[[], None]]) -> None:
         """Register the function that releases all resources used by the data store.
 
         This method controls how xarray cleans up resources associated
@@ -1276,11 +1276,11 @@ def set_close(self, close_store: Optional[Callable[[], None]]) -> None:
 
         Parameters
         ----------
-        close_store : callable
-            A callable that when called like ``close_store()`` releases
+        close : callable
+            A callable that when called like ``close()`` releases
             all resources used by the data store.
         """
-        self._close = close_store
+        self._close = close
 
     def close(self: Any) -> None:
         """Close any files linked to this object"""

From 5f047a6de9535317ee982dda60ff0c859bb48435 Mon Sep 17 00:00:00 2001
From: Alessandro Amici <a.amici@bopen.eu>
Date: Fri, 15 Jan 2021 20:43:57 +0100
Subject: [PATCH 17/17] Sync wording in docstrings.

---
 xarray/core/common.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/xarray/core/common.py b/xarray/core/common.py
index 402ae545e5f..a69ba03a7a4 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -1267,23 +1267,23 @@ def where(self, cond, other=dtypes.NA, drop: bool = False):
         return ops.where_method(self, cond, other)
 
     def set_close(self, close: Optional[Callable[[], None]]) -> None:
-        """Register the function that releases all resources used by the data store.
+        """Register the function that releases any resources linked to this object.
 
         This method controls how xarray cleans up resources associated
-        with this object when the .close() method is called. It is mostly
+        with this object when the ``.close()`` method is called. It is mostly
         intended for backend developers and it is rarely needed by regular
         end-users.
 
         Parameters
         ----------
         close : callable
-            A callable that when called like ``close()`` releases
-            all resources used by the data store.
+            The function that when called like ``close()`` releases
+            any resources linked to this object.
         """
         self._close = close
 
     def close(self: Any) -> None:
-        """Close any files linked to this object"""
+        """Release any resources linked to this object."""
         if self._close is not None:
             self._close()
         self._close = None