Bug fix in load_dl_windows.py: ctypes.windll.kernel32.LoadLibraryW() returns an incompatible handle. Use win32api.LoadLibraryEx() instead to ensure self-consistency.

Author: rwgk

cuda_bindings/cuda/bindings/_path_finder/load_dl_common.py

@@ -5,23 +5,19 @@
 from typing import Callable, Optional
 
 from cuda.bindings._path_finder.run_python_code_safely import run_python_code_safely
-from cuda.bindings._path_finder.supported_libs import DIRECT_DEPENDENCIES
+from cuda.bindings._path_finder.supported_libs import DIRECT_DEPENDENCIES, IS_WINDOWS
 
+if IS_WINDOWS:
+    import pywintypes
 
-@dataclass
-class LoadedDL:
-    """Represents a loaded dynamic library.
+    HandleType = pywintypes.HANDLE
+else:
+    HandleType = int
 
-    Attributes:
-        handle: The library handle (can be converted to void* in Cython)
-        abs_path: The absolute path to the library file
-        was_already_loaded_from_elsewhere: Whether the library was already loaded
-    """
 
-    # ATTENTION: To convert `handle` back to `void*` in cython:
-    #     Linux:   `cdef void* ptr = <void*><uintptr_t>`
-    #     Windows: `cdef void* ptr = <void*><intptr_t>`
-    handle: int
+@dataclass
+class LoadedDL:
+    handle: HandleType
     abs_path: Optional[str]
     was_already_loaded_from_elsewhere: bool
 

cuda_bindings/cuda/bindings/_path_finder/load_dl_windows.py

@@ -35,7 +35,7 @@ def add_dll_directory(dll_abs_path: str) -> None:
     os.environ["PATH"] = dirpath if curr_path is None else os.pathsep.join((curr_path, dirpath))
 
 
-def abs_path_for_dynamic_library(libname: str, handle: int) -> str:
+def abs_path_for_dynamic_library(libname: str, handle: pywintypes.HANDLE) -> str:
     """Get the absolute path of a loaded dynamic library on Windows.
 
     Args:
@@ -117,8 +117,11 @@ def load_with_system_search(libname: str, _unused: str) -> Optional[LoadedDL]:
     from cuda.bindings._path_finder.supported_libs import SUPPORTED_WINDOWS_DLLS
 
     for dll_name in SUPPORTED_WINDOWS_DLLS.get(libname, ()):
-        handle = ctypes.windll.kernel32.LoadLibraryW(ctypes.c_wchar_p(dll_name))
-        if handle:
+        try:
+            handle = win32api.LoadLibraryEx(dll_name, 0, 0)
+        except pywintypes.error:
+            continue
+        else:
             return LoadedDL(handle, abs_path_for_dynamic_library(libname, handle), False)
 
     return None