Change __cuda_stream__ from attribute to method

cuda_core/cuda/core/experimental/_stream.py

@@ -89,7 +89,7 @@ def _init(obj=None, *, options: Optional[StreamOptions] = None):
         if obj is not None:
             if not hasattr(obj, "__cuda_stream__"):
                 raise ValueError
-            info = obj.__cuda_stream__
+            info = obj.__cuda_stream__()
             assert info[0] == 0
             self._mnff.handle = cuda.CUstream(info[1])
             # TODO: check if obj is created under the current context/device
@@ -132,7 +132,6 @@ def close(self):
         """
         self._mnff.close()
 
-    @property
     def __cuda_stream__(self) -> Tuple[int, int]:
         """Return an instance of a __cuda_stream__ protocol."""
         return (0, self.handle)
@@ -279,7 +278,6 @@ def from_handle(handle: int) -> Stream:
         """
 
         class _stream_holder:
-            @property
             def __cuda_stream__(self):
                 return (0, handle)
 

cuda_core/docs/source/interoperability.rst

@@ -34,14 +34,13 @@ exposing their own stream types.
 
 To address this issue, we propose the ``__cuda_stream__`` protocol (currently version
 0) as follows: For any Python objects that are meant to be interpreted as a stream, they
-should add a ``__cuda_stream__`` attribute that returns a 2-tuple: The version number
+should add a ``__cuda_stream__`` method that returns a 2-tuple: The version number
 (``0``) and the address of ``cudaStream_t`` (both as Python `int`):
 
 .. code-block:: python
 
    class MyStream:
 
-       @property
        def __cuda_stream__(self):
            return (0, self.ptr)
 

cuda_core/docs/source/release/0.2.0-notes.rst

@@ -0,0 +1,7 @@
+``cuda.core`` v0.2.0 Release notes
+==================================
+
+Highlights
+----------
+
+- Change ``__cuda_stream__`` from attribute to method

cuda_core/examples/simple_multi_gpu_example.py

@@ -81,7 +81,6 @@ class StreamAdaptor:
     def __init__(self, obj):
         self.obj = obj
 
-    @property
     def __cuda_stream__(self):
         # Note: CuPy streams have a .ptr attribute
         return (0, self.obj.ptr)