Provide lock for FileManagers

Author: dschwoerer

xarray/backends/file_manager.py

@@ -355,13 +355,15 @@ def __init__(
         opener: Callable[..., T_File],
         *args: Any,
         mode: Any = _OMIT_MODE,
+        lock: Lock | None | Literal[False] = None,
         kwargs: Mapping[str, Any] | None = None,
     ):
         kwargs = {} if kwargs is None else dict(kwargs)
         self._opener = opener
         self._args = args
         self._mode = "a" if mode == "w" else mode
         self._kwargs = kwargs
+        self._lock = lock
 
         # Note: No need for locking with PickleableFileManager, because all
         # opening of files happens in the constructor.

xarray/backends/netCDF4_.py

@@ -419,7 +419,7 @@ def __init__(
                         "argument is provided"
                     )
                 root = manager
-            manager = DummyFileManager(root)
+            manager = DummyFileManager(root, lock=NETCDF4_PYTHON_LOCK)
 
         self._manager = manager
         self._group = group
@@ -508,17 +508,18 @@ def open(
                 "<xarray-in-memory-write>", mode=mode, memory=memory, **kwargs
             )
             close = _CloseWithCopy(filename, nc4_dataset)
-            manager = DummyFileManager(nc4_dataset, close=close)
+            manager = DummyFileManager(nc4_dataset, close=close, lock=lock)
 
         elif isinstance(filename, bytes | memoryview):
             assert mode == "r"
             kwargs["memory"] = filename
             manager = PickleableFileManager(
-                netCDF4.Dataset, "<xarray-in-memory-read>", mode=mode, kwargs=kwargs
+                netCDF4.Dataset, "<xarray-in-memory-read>", mode=mode, kwargs=kwargs,
+                lock=lock
             )
         else:
             manager = CachingFileManager(
-                netCDF4.Dataset, filename, mode=mode, kwargs=kwargs
+                netCDF4.Dataset, filename, mode=mode, kwargs=kwargs, lock=lock
             )
         return cls(manager, group=group, mode=mode, lock=lock, autoclose=autoclose)