Merge pull request #326 from crusaderky/cupy_to_device

TST: fix cupy `to_device` test on multiple devices

Author: ev-br

tests/test_cupy.py

@@ -5,18 +5,41 @@
 from cupy.cuda import Stream
 
 
-def test_to_device_with_stream():
+@pytest.mark.parametrize(
+    "make_stream",
+    [
+        lambda: Stream(),
+        lambda: Stream(non_blocking=True),
+        lambda: Stream(null=True),
+        lambda: Stream(ptds=True),
+    ],
+)
+def test_to_device_with_stream(make_stream):
     devices = xp.__array_namespace_info__().devices()
-    streams = [
-        Stream(),
-        Stream(non_blocking=True), 
-        Stream(null=True),
-        Stream(ptds=True), 
-        123,  # dlpack stream
-    ]
 
     a = xp.asarray([1, 2, 3])
     for dev in devices:
-        for stream in streams:
-            b = to_device(a, dev, stream=stream)
-            assert device(b) == dev
+        # Streams are device-specific and must be created within
+        # the context of the device...
+        with dev:
+            stream = make_stream()
+        # ... however, to_device() does not need to be inside the
+        # device context.
+        b = to_device(a, dev, stream=stream)
+        assert device(b) == dev
+
+
+def test_to_device_with_dlpack_stream():
+    devices = xp.__array_namespace_info__().devices()
+
+    a = xp.asarray([1, 2, 3])
+    for dev in devices:
+        # Streams are device-specific and must be created within
+        # the context of the device...
+        with dev:
+            s1 = Stream()
+
+        # ... however, to_device() does not need to be inside the
+        # device context.
+        b = to_device(a, dev, stream=s1.ptr)
+        assert device(b) == dev