usm bug

Author: jharlow-intel

dpctl/tests/test_sycl_queue_copy.py

@@ -194,17 +194,20 @@ def test_copy_count_is_in_elements(dtype, element_size):
     src = dpctl.memory.MemoryUSMShared(nbytes, queue=q)
     dst = dpctl.memory.MemoryUSMShared(nbytes, queue=q)
 
+    # USM allocations are uninitialized, so seed dst with a known sentinel
+    # to verify the untouched half is left intact.
     src_mv = memoryview(src)
+    dst_mv = memoryview(dst)
     for i in range(nbytes):
         src_mv[i] = i % 256
-    dst_mv = memoryview(dst)
+        dst_mv[i] = 0xAA
 
     # Copying half the elements transfers exactly half the bytes.
     q.copy(dst, src, num_elements // 2, dtype=dtype)
 
     half_bytes = (num_elements // 2) * element_size
     assert dst_mv[:half_bytes].tobytes() == src_mv[:half_bytes].tobytes()
-    assert dst_mv[half_bytes:nbytes].tobytes() == bytes(nbytes - half_bytes)
+    assert dst_mv[half_bytes:nbytes].tobytes() == b"\xaa" * (nbytes - half_bytes)
 
 
 def test_copy_with_invalid_dtype():