Ensure netcdf4 is locked while closing

Author: dschwoerer

xarray/backends/file_manager.py

@@ -8,7 +8,7 @@
 from contextlib import AbstractContextManager, contextmanager
 from typing import Any, Generic, Literal, TypeVar, cast
 
-from xarray.backends.locks import acquire
+from xarray.backends.locks import acquire, NETCDF4_PYTHON_LOCK
 from xarray.backends.lru_cache import LRUCache
 from xarray.core import utils
 from xarray.core.options import OPTIONS
@@ -239,6 +239,11 @@ def close(self, needs_lock: bool = True) -> None:
             default = None
             file = self._cache.pop(self._key, default)
             if file is not None:
+                # Check for string so we do not have to import it
+                if str(type(file)) == "<class 'netCDF4._netCDF4.Dataset'>":
+                    with NETCDF4_PYTHON_LOCK:
+                        file.close()
+                        return
                 file.close()
 
     def __del__(self) -> None:

xarray/backends/locks.py

@@ -281,3 +281,5 @@ def ensure_lock(lock: Lock | None | Literal[False]) -> Lock:
     if lock is None or lock is False:
         return DummyLock()
     return lock
+
+NETCDF4_PYTHON_LOCK = combine_locks([NETCDFC_LOCK, HDF5_LOCK])

xarray/backends/netCDF4_.py

@@ -32,6 +32,7 @@
 from xarray.backends.locks import (
     HDF5_LOCK,
     NETCDFC_LOCK,
+    NETCDF4_PYTHON_LOCK,
     combine_locks,
     ensure_lock,
     get_write_lock,
@@ -66,8 +67,6 @@
 # string used by netCDF4.
 _endian_lookup = {"=": "native", ">": "big", "<": "little", "|": "native"}
 
-NETCDF4_PYTHON_LOCK = combine_locks([NETCDFC_LOCK, HDF5_LOCK])
-
 
 class BaseNetCDF4Array(BackendArray):
     __slots__ = ("datastore", "dtype", "shape", "variable_name")