[cherry-pick 2.4] Fix to_dlpack (#50138) (#50250)

* Fix to_dlpack (#50138)

* fix to_dlpack for loop

* fix reference count

* fix conflicts

paddle/fluid/framework/dlpack_tensor.cc

@@ -134,7 +134,59 @@ struct DLDeviceVisitor
 };
 }  // namespace internal
 
-DLPackTensor::DLPackTensor(const Tensor &tensor, LaneType lanes) {
+struct PaddleDLMTensor {
+  phi::DenseTensor handle;
+  DLManagedTensor tensor;
+};
+
+void deleter(DLManagedTensor *arg) {
+  delete[] arg->dl_tensor.shape;
+  delete[] arg->dl_tensor.strides;
+  delete static_cast<PaddleDLMTensor *>(arg->manager_ctx);
+}
+
+DLManagedTensor *toDLPack(const phi::DenseTensor &src) {
+  PaddleDLMTensor *pdDLMTensor(new PaddleDLMTensor);
+  pdDLMTensor->handle = const_cast<phi::DenseTensor &>(src);
+  pdDLMTensor->tensor.manager_ctx = pdDLMTensor;
+  pdDLMTensor->tensor.deleter = &deleter;
+  pdDLMTensor->tensor.dl_tensor.data = const_cast<void *>(src.data());
+
+  // init ndim
+  using DimType = decltype(pdDLMTensor->tensor.dl_tensor.ndim);  // int
+  pdDLMTensor->tensor.dl_tensor.ndim = static_cast<DimType>(src.dims().size());
+  DimType ndim = pdDLMTensor->tensor.dl_tensor.ndim;
+
+  // init shape
+  auto shape = new int64_t[ndim];
+  for (DimType i = 0; i < ndim; ++i) {
+    shape[i] = src.dims()[i];
+  }
+  pdDLMTensor->tensor.dl_tensor.shape = shape;
+
+  // init stride
+  auto strides = new int64_t[ndim];
+  for (DimType i = 0; i < ndim; ++i) {
+    strides[i] = 1;
+  }
+  for (DimType i = ndim - 2; i >= 0; --i) {
+    strides[i] = shape[i + 1] * strides[i + 1];
+  }
+  pdDLMTensor->tensor.dl_tensor.strides = strides;
+
+  // init device, DLDevice type with device_type and device_id
+  auto place = src.place();
+  pdDLMTensor->tensor.dl_tensor.device =
+      paddle::platform::VisitPlace(place, internal::DLDeviceVisitor());
+
+  pdDLMTensor->tensor.dl_tensor.dtype = internal::GetDLDataTypeFromTypeIndex(
+      framework::TransToProtoVarType(src.dtype()));
+
+  pdDLMTensor->tensor.dl_tensor.byte_offset = 0;
+  return &(pdDLMTensor->tensor);
+}
+
+DLPackTensor::DLPackTensor(const phi::DenseTensor &tensor, LaneType lanes) {
   // init data, data buffer
   t_.data = const_cast<void *>(tensor.data());
 

paddle/fluid/framework/dlpack_tensor.h

@@ -28,7 +28,7 @@ class DLPackTensor {
       std::remove_reference<decltype(::DLTensor::shape[0])>::type;  // int64_t
 
   // lanes is only used in CPU to enable vectorization
-  explicit DLPackTensor(const Tensor& tensor, LaneType lanes = 1);
+  explicit DLPackTensor(const phi::DenseTensor& tensor, LaneType lanes = 1);
 
   inline operator const ::DLTensor&() const { return t_; }
 
@@ -44,5 +44,7 @@ class DLPackTensor {
   ShapeType shape_[DDim::kMaxRank];
 };
 
+DLManagedTensor* toDLPack(const phi::DenseTensor& src);
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/pybind/tensor.cc

@@ -472,23 +472,16 @@ void BindTensor(pybind11::module &m) {  // NOLINT
                   print(t.shape())  # [5, 30]
            )DOC")
       .def("_to_dlpack",
-           [](framework::Tensor &self) {
-             DLPackTensor dlpack_tensor(self, 1);
-             DLManagedTensor *dmt = dlpack_tensor.ToDLManagedTensor();
-             auto capsule = py::capsule(
+           [](phi::DenseTensor &self) {
+             DLManagedTensor *dmt = framework::toDLPack(self);
+             auto capsule = pybind11::capsule(
                  static_cast<void *>(dmt), "dltensor", [](PyObject *ptr) {
-                   if (ptr) {
-                     auto dltensor = new DLManagedTensor;
-                     try {
-                       dltensor = reinterpret_cast<DLManagedTensor *>(
-                           PyCapsule_GetPointer(ptr, "used_dltensor"));
-                       return;
-                     } catch (...) {
-                       dltensor = reinterpret_cast<DLManagedTensor *>(
-                           PyCapsule_GetPointer(ptr, "dltensor"));
-                     }
-                     dltensor->deleter(dltensor);
+                   if (!PyCapsule_IsValid(ptr, "dltensor")) {
+                     return;
                    }
+                   DLManagedTensor *dmt = static_cast<DLManagedTensor *>(
+                       PyCapsule_GetPointer(ptr, "dltensor"));
+                   dmt->deleter(dmt);
                  });
              return capsule;
            })

python/paddle/tests/test_dlpack.py

@@ -22,7 +22,6 @@ from paddle.fluid.framework import _test_eager_guard, in_dygraph_mode
 
 
 class TestDLPack(unittest.TestCase):
-
     def func_test_dlpack_dygraph(self):
         paddle.disable_static()
         tensor = paddle.to_tensor(np.array([1, 2, 3, 4]).astype('int'))
@@ -30,11 +29,13 @@ class TestDLPack(unittest.TestCase):
         out_from_dlpack = paddle.utils.dlpack.from_dlpack(dlpack)
         if paddle.fluid.framework.in_dygraph_mode():
             self.assertTrue(
-                isinstance(out_from_dlpack, paddle.fluid.core.eager.Tensor))
+                isinstance(out_from_dlpack, paddle.fluid.core.eager.Tensor)
+            )
         else:
             self.assertTrue(isinstance(out_from_dlpack, paddle.Tensor))
-        np.testing.assert_array_equal(np.array(out_from_dlpack),
-                                      np.array([1, 2, 3, 4]).astype('int'))
+        np.testing.assert_array_equal(
+            np.array(out_from_dlpack), np.array([1, 2, 3, 4]).astype('int')
+        )
 
     def test_dlpack_dygraph(self):
         with _test_eager_guard():
@@ -58,26 +59,32 @@ class TestDLPack(unittest.TestCase):
     def test_dlpack_static(self):
         paddle.enable_static()
         tensor = fluid.create_lod_tensor(
-            np.array([[1], [2], [3], [4]]).astype('int'), [[1, 3]],
-            fluid.CPUPlace())
+            np.array([[1], [2], [3], [4]]).astype('int'),
+            [[1, 3]],
+            fluid.CPUPlace(),
+        )
         dlpack = paddle.utils.dlpack.to_dlpack(tensor)
         out_from_dlpack = paddle.utils.dlpack.from_dlpack(dlpack)
         self.assertTrue(isinstance(out_from_dlpack, fluid.core.Tensor))
         np.testing.assert_array_equal(
             np.array(out_from_dlpack),
-            np.array([[1], [2], [3], [4]]).astype('int'))
+            np.array([[1], [2], [3], [4]]).astype('int'),
+        )
 
         # when build with cuda
         if core.is_compiled_with_cuda():
             gtensor = fluid.create_lod_tensor(
-                np.array([[1], [2], [3], [4]]).astype('int'), [[1, 3]],
-                fluid.CUDAPlace(0))
+                np.array([[1], [2], [3], [4]]).astype('int'),
+                [[1, 3]],
+                fluid.CUDAPlace(0),
+            )
             gdlpack = paddle.utils.dlpack.to_dlpack(gtensor)
             gout_from_dlpack = paddle.utils.dlpack.from_dlpack(gdlpack)
             self.assertTrue(isinstance(gout_from_dlpack, fluid.core.Tensor))
             np.testing.assert_array_equal(
                 np.array(gout_from_dlpack),
-                np.array([[1], [2], [3], [4]]).astype('int'))
+                np.array([[1], [2], [3], [4]]).astype('int'),
+            )
 
     def func_test_dlpack_dtype_conversion(self):
         paddle.disable_static()
@@ -104,7 +111,8 @@ class TestDLPack(unittest.TestCase):
         for dtype in complex_dtypes:
             x = paddle.to_tensor(
                 [[1 + 6j, 2 + 5j, 3 + 4j], [4 + 3j, 5 + 2j, 6 + 1j]],
-                dtype=dtype)
+                dtype=dtype,
+            )
             dlpack = paddle.utils.dlpack.to_dlpack(x)
             o = paddle.utils.dlpack.from_dlpack(dlpack)
             self.assertEqual(x.dtype, o.dtype)
@@ -115,12 +123,18 @@ class TestDLPack(unittest.TestCase):
             self.func_test_dlpack_dtype_conversion()
         self.func_test_dlpack_dtype_conversion()
 
+    def test_to_dlpack_for_loop(self):
+        # See Paddle issue 50120
+        for i in range(10):
+            x = paddle.rand([3, 5])
+            dlpack = paddle.utils.dlpack.to_dlpack(x)
 
-class TestRaiseError(unittest.TestCase):
 
+class TestRaiseError(unittest.TestCase):
     def func_test_from_dlpack_raise_type_error(self):
-        self.assertRaises(TypeError, paddle.utils.dlpack.from_dlpack,
-                          np.zeros(5))
+        self.assertRaises(
+            TypeError, paddle.utils.dlpack.from_dlpack, np.zeros(5)
+        )
 
     def test_from_dlpack_raise_type_error(self):
         with _test_eager_guard():