dense tensor in eager mode support data_ptr (#48235)

* dense tensor in eager mode support data_ptr

paddle/fluid/pybind/eager_method.cc

@@ -1845,6 +1845,19 @@ static PyObject* tensor__unset_fake_empty(TensorObject* self,
   EAGER_CATCH_AND_THROW_RETURN_NULL
 }
 
+static PyObject* tensor_data_ptr(TensorObject* self,
+                                 PyObject* args,
+                                 PyObject* kwargs) {
+  EAGER_TRY
+  if (self->tensor.initialized() && self->tensor.is_dense_tensor()) {
+    ToPyObject((int64_t)std::dynamic_pointer_cast<phi::DenseTensor>(  // NOLINT
+                   self->tensor.impl())
+                   ->data());
+  }
+  RETURN_PY_NONE
+  EAGER_CATCH_AND_THROW_RETURN_NULL
+}
+
 #if defined(PADDLE_WITH_CUDA)
 static PyObject* tensor_method__uva(TensorObject* self,
                                     PyObject* args,
@@ -2100,6 +2113,10 @@ PyMethodDef variable_methods[] = {
      (PyCFunction)(void (*)(void))tensor__unset_fake_empty,
      METH_VARARGS | METH_KEYWORDS,
      NULL},
+    {"data_ptr",
+     (PyCFunction)(void (*)(void))tensor_data_ptr,
+     METH_VARARGS | METH_KEYWORDS,
+     NULL},
 #if defined(PADDLE_WITH_CUDA)
     {"_tensor_uva",
      (PyCFunction)(void (*)(void))tensor_method__uva,

python/paddle/fluid/tests/unittests/test_tensor_data_ptr.py

+#   Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+import numpy as np
+
+import paddle
+
+
+class TestTensorDataPtr(unittest.TestCase):
+    def test_tensor_data_ptr(self):
+        np_src = np.random.random((3, 8, 8))
+        src = paddle.to_tensor(np_src, dtype="float64")
+        dst = paddle.Tensor()
+        src._share_buffer_to(dst)
+        self.assertEqual(src.data_ptr(), dst.data_ptr())
+
+
+if __name__ == '__main__':
+    unittest.main()