fix period case and add specific test

Author: jorisvandenbossche

pandas/core/arrays/period.py

@@ -393,9 +393,9 @@ def __array__(
             # For NumPy 1.x compatibility we cannot use copy=None.  And
             # `copy=False` has the meaning of `copy=None` here:
             if not copy:
-                return np.asarray(self, dtype=dtype)
+                return np.asarray(self.asi8, dtype=dtype)
             else:
-                return np.array(self, dtype=dtype)
+                return np.array(self.asi8, dtype=dtype)
 
         if copy is False:
             raise ValueError(

pandas/tests/arrays/test_datetimelike.py

@@ -1152,9 +1152,17 @@ def test_array_interface(self, arr1d):
         result = np.asarray(arr, dtype=object)
         tm.assert_numpy_array_equal(result, expected)
 
+        # to int64 gives the underlying representation
         result = np.asarray(arr, dtype="int64")
         tm.assert_numpy_array_equal(result, arr.asi8)
 
+        result2 = np.asarray(arr, dtype="int64")
+        assert np.may_share_memory(result, result2)
+
+        result_copy1 = np.array(arr, dtype="int64", copy=True)
+        result_copy2 = np.array(arr, dtype="int64", copy=True)
+        assert not np.may_share_memory(result_copy1, result_copy2)
+
         # to other dtypes
         msg = r"float\(\) argument must be a string or a( real)? number, not 'Period'"
         with pytest.raises(TypeError, match=msg):