dynamic recurrent op forward c++ implentation (#4597)

cmake/configure.cmake

@@ -24,6 +24,10 @@ if(WITH_DOUBLE)
     add_definitions(-DPADDLE_TYPE_DOUBLE)
 endif(WITH_DOUBLE)
 
+if(WITH_TESTING)
+    add_definitions(-DPADDLE_WITH_TESTING)
+endif(WITH_TESTING)
+
 if(NOT WITH_TIMER)
     add_definitions(-DPADDLE_DISABLE_TIMER)
 endif(NOT WITH_TIMER)

paddle/framework/operator.h

@@ -142,9 +142,9 @@ class OperatorBase {
 // Macro for define a clone method.
 // If you are writing an kernel operator, `Clone` will be defined when you
 // register it. i.e. `Clone` method is not needed to define by yourself.
-#define DEFINE_OP_CLONE_METHOD(cls)                       \
-  std::unique_ptr<OperatorBase> Clone() const final {     \
-    return std::unique_ptr<OperatorBase>(new cls(*this)); \
+#define DEFINE_OP_CLONE_METHOD(cls)                                            \
+  std::unique_ptr<::paddle::framework::OperatorBase> Clone() const final {     \
+    return std::unique_ptr<::paddle::framework::OperatorBase>(new cls(*this)); \
   }
 
 // Macro for define a default constructor for Operator.

paddle/framework/tensor_array.h

@@ -87,12 +87,12 @@ class TensorArray {
   LoDTensor Stack() const;
 
   /*
-   * Unpacks the given division of a rank-`R` tensor into rank-`(R-1)` tensors.
+   * Unstacks the given division of a rank-`R` tensor into rank-`(R-1)` tensors.
    */
   void Unstack(const LoDTensor &source) const;
 
   /*
-   * Unpacks the given division of a rank-`R` tensor into rank-`(R-1)` tensors,
+   * Unstacks the given division of a rank-`R` tensor into rank-`(R-1)` tensors,
    * with memory of tensors shared.
    */
   void UnstackShared(const LoDTensor &source) const;

paddle/operators/CMakeLists.txt

@@ -133,3 +133,4 @@ cc_test(gather_test SRCS gather_test.cc DEPS tensor)
 cc_test(net_op_test SRCS net_op_test.cc DEPS net_op)
 cc_test(scatter_test SRCS scatter_test.cc DEPS tensor)
 cc_test(strided_memcpy_test SRCS strided_memcpy_test.cc DEPS tensor paddle_memory)
+cc_test(dynamic_recurrent_op_test SRCS dynamic_recurrent_op_test.cc DEPS dynamic_recurrent_op recurrent_op tensor_array)

paddle/operators/dynamic_recurrent_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve .
+
+   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. */
+
+#include "paddle/operators/dynamic_recurrent_op.h"
+
+#include "paddle/framework/op_registry.h"
+
+namespace paddle {
+namespace operators {
+
+using framework::Scope;
+using framework::TensorArray;
+using framework::LoDTensor;
+using framework::Variable;
+
+namespace detail {
+
+inline void CreateVariables(Scope& scope,
+                            const std::vector<std::string>& var_names) {
+  for (const auto& name : var_names) {
+    scope.NewVar(name);
+  }
+}
+
+}  // namespace detail
+
+class DynamicRecurrentOpProtoAndCheckerMaker
+    : public framework::OpProtoAndCheckerMaker {
+ public:
+  DynamicRecurrentOpProtoAndCheckerMaker(framework::OpProto* proto,
+                                         framework::OpAttrChecker* op_checker)
+      : OpProtoAndCheckerMaker(proto, op_checker) {
+    const auto& name = DynamicRecurrentOp::kArgName;
+    // inputs and outputs stored in proto
+    AddInput(name.inlinks,
+             "the inputs that need to be segmented for each step.")
+        .AsDuplicable();
+    AddInput(name.boot_memories, "variables to initialize memories.")
+        .AsDuplicable();
+
+    AddOutput(name.outlinks, "the outputs that need to concated for all steps.")
+        .AsDuplicable();
+    AddOutput(name.step_scopes, "step scopes");
+
+    // Attributes stored in AttributeMap
+    AddAttr<std::vector<std::string>>(name.pre_memories,
+                                      "names of pre-memories");
+    AddAttr<std::vector<std::string>>(name.memories, "names of memories");
+
+    AddComment("This is a RNN operator for varience-length sequences.");
+  }
+};
+
+void DynamicRecurrentOp::Run(const Scope& scope,
+                             const platform::DeviceContext& dev_ctx) const {
+  cache_.Init(kArgName, *this, scope, &arg_);
+  SplitInputs();
+  CreateScopes();
+  WriteStepInputs();
+  InitStates();
+
+  // call stepnet in all the time steps
+  for (size_t step = 0; step < cache_.num_steps; step++) {
+    auto& step_scope = cache_.GetScope(step);
+    stepnet_->Run(step_scope, dev_ctx);
+  }
+
+  WriteStepOutputs();
+  ConcatOutputs();
+}
+
+void DynamicRecurrentOp::SplitInputs() const {
+  // TODO(superjom) make level a config
+  // TODO(superjom) check all the inputs has the same LoD
+  int level = 0;
+  const auto& inlinks = cache_.inlinks;
+  for (const auto& item : inlinks) {
+    const auto& var = item.second;
+    const auto& tensor = var->Get<LoDTensor>();
+    TensorArray& ta = step_inputs_[item.first];
+    dy_seq_metas_[item.first] =
+        ta.Unpack(tensor, level, true /*length_descend*/);
+
+    if (cache_.num_steps) {
+      PADDLE_ENFORCE_EQ(ta.size(), cache_.num_steps,
+                        "inputs should have the same steps");
+    } else {
+      cache_.num_steps = ta.size();
+    }
+  }
+}
+
+void DynamicRecurrentOp::WriteStepInputs() const {
+  for (const auto& item : cache_.inlinks) {
+    auto ta_it = step_inputs_.find(item.first);
+    PADDLE_ENFORCE(ta_it != step_inputs_.end(),
+                   "step_inputs_ not compatible with memory set");
+    TensorArray& ta = ta_it->second;
+    for (size_t step = 0; step < ta.size(); step++) {
+      auto tensor = ta.Read(step);
+      auto& step_scope = cache_.GetScope(step);
+      Variable* var = step_scope.FindVar(item.first);
+      if (var == nullptr) {
+        var = step_scope.NewVar(item.first);
+      }
+      var->GetMutable<LoDTensor>()->ShareDataWith<value_type>(tensor);
+    }
+  }
+}
+
+void DynamicRecurrentOp::WriteStepOutputs() const {
+  for (size_t step = 0; step < cache_.scopes->size(); step++) {
+    auto& scope = cache_.GetScope(step);
+    for (auto& item : step_outputs_) {
+      auto* var = scope.FindVar(item.first);
+      if (var == nullptr) {
+        var = scope.NewVar(item.first);
+      }
+      auto* tensor = var->GetMutable<LoDTensor>();
+      item.second.WriteShared(step, *tensor);
+    }
+  }
+}
+
+void DynamicRecurrentOp::CreateScopes() const {
+  PADDLE_ENFORCE_GT(cache_.num_steps, 0);
+  // resize scopes
+  size_t num_scopes_need_create = cache_.num_steps - cache_.scopes->size();
+  for (size_t i = 0; i < num_scopes_need_create; i++) {
+    cache_.scopes->emplace_back(&cache_.scope->NewScope());
+  }
+
+  // init temporary inputs
+  PADDLE_ENFORCE_NOT_NULL(stepnet_, "stepnet should be set first");
+  std::vector<std::string> memories;
+  std::vector<std::string> pre_memories;
+  std::transform(arg_.memories.begin(), arg_.memories.end(),
+                 std::back_inserter(memories),
+                 [](const rnn::MemoryAttr& m) { return m.var; });
+  std::transform(arg_.memories.begin(), arg_.memories.end(),
+                 std::back_inserter(pre_memories),
+                 [](const rnn::MemoryAttr& m) { return m.pre_var; });
+
+  for (size_t step = 0; step < cache_.num_steps; step++) {
+    auto& scope = cache_.GetScope(step);
+    detail::CreateVariables(scope, arg_.inlinks);
+    detail::CreateVariables(scope, arg_.outlinks);
+    detail::CreateVariables(scope, memories);
+    detail::CreateVariables(scope, pre_memories);
+  }
+}
+
+void DynamicRecurrentOp::ConcatOutputs() const {
+  // TODO(superjom) transform this to a config
+  int level = 0;
+  // TODO(superjom) pass in some lod
+  // just a placeholder
+  framework::LoD lod;
+  for (auto& item : step_outputs_) {
+    auto tensor = item.second.Pack(level, dy_seq_metas_[item.first], lod);
+    auto& output = cache_.outlinks[item.first]->Get<LoDTensor>();
+    const_cast<LoDTensor*>(&output)->ShareDataWith<value_type>(tensor);
+  }
+}
+
+void DynamicRecurrentOp::InitStates() const {
+  // init the first state
+  // TODO(superjom) parepare the scenerio that boot state not exists
+  for (auto memory : arg_.memories) {
+    auto* boot_state_var = cache_.scope->FindVar(memory.boot_var);
+    PADDLE_ENFORCE_NOT_NULL(boot_state_var);
+    auto& boot_state = boot_state_var->Get<LoDTensor>();
+    const auto& dims = boot_state.dims();
+
+    for (size_t step = 0; step < cache_.num_steps; step++) {
+      auto& cur_scope = cache_.GetScope(step);
+      // link pre-state to boot_state
+      // init state and pre-state
+      auto* pre_state = cur_scope.FindVar(memory.pre_var);
+      PADDLE_ENFORCE_NOT_NULL(pre_state);
+      pre_state->GetMutable<LoDTensor>();
+
+      auto* state = cur_scope.FindVar(memory.var);
+      PADDLE_ENFORCE_NOT_NULL(state);
+      state->GetMutable<LoDTensor>()->Resize(dims);
+      state->GetMutable<LoDTensor>()->mutable_data<value_type>(
+          platform::CPUPlace());
+
+      if (step == 0) {
+        auto* pre_state_tensor = pre_state->GetMutable<LoDTensor>();
+        pre_state_tensor->Resize(boot_state.dims());
+        pre_state_tensor->ShareDataWith<value_type>(boot_state);
+      } else {
+        auto& pre_scope = cache_.GetScope(step - 1);
+        auto* state_pre = pre_scope.FindVar(memory.var);
+        PADDLE_ENFORCE_NOT_NULL(state_pre);
+        pre_state->GetMutable<LoDTensor>()->ShareDataWith<value_type>(
+            *state_pre->GetMutable<LoDTensor>());
+      }
+    }
+  }
+}
+
+void DynamicRecurrentOp::ArgCache::Init(
+    const rnn::ArgumentName& name, const paddle::framework::OperatorBase& op,
+    const paddle::framework::Scope& scope, rnn::Argument* arg) {
+  this->scope = &scope;
+  InitArgument(name, op, arg);
+  CacheScopes(scope, *arg);
+  CacheInlinks(scope, arg->inlinks);
+  CacheOutlinks(scope, arg->outlinks);
+}
+
+void DynamicRecurrentOp::ArgCache::InitArgument(const rnn::ArgumentName& name,
+                                                const OperatorBase& op,
+                                                rnn::Argument* arg) {
+  rnn::InitArgument(name, arg, op, false /*is_grad*/);
+}
+
+void DynamicRecurrentOp::ArgCache::CacheScopes(const Scope& scope,
+                                               const rnn::Argument& arg) {
+  auto scopes_var = scope.FindVar(arg.step_scopes);
+  PADDLE_ENFORCE(scopes_var != nullptr,
+                 "the step_scopes output argument [%s] should be created first "
+                 "by framework.",
+                 arg.step_scopes);
+  this->scopes = scopes_var->GetMutable<std::vector<Scope*>>();
+}
+
+void DynamicRecurrentOp::ArgCache::CacheInlinks(
+    const Scope& scope, const std::vector<std::string>& names) {
+  for (auto name : names) {
+    auto* var = GetVariable(scope, name);
+    inlinks[name] = var;
+  }
+}
+
+void DynamicRecurrentOp::ArgCache::CacheOutlinks(
+    const Scope& scope, const std::vector<std::string>& names) {
+  for (auto name : names) {
+    auto* var = GetVariable(scope, name);
+    outlinks[name] = var;
+  }
+}
+
+Variable* DynamicRecurrentOp::ArgCache::GetVariable(const Scope& scope,
+                                                    const std::string& name) {
+  auto* var = scope.FindVar(name);
+  PADDLE_ENFORCE_NOT_NULL(var, "variable [%s] not exist in scope", name);
+  return var;
+}
+
+const rnn::ArgumentName DynamicRecurrentOp::kArgName{
+    "step_net", "step_scopes",  "inlinks",      "outlinks",
+    "memories", "pre_memories", "boot_memories"};
+
+void DynamicRecurrentGradientOp::Run(
+    const Scope& scope, const platform::DeviceContext& dev_ctx) const {}
+
+}  // namespace operators
+}  // namespace paddle
+
+REGISTER_OP_WITHOUT_GRADIENT(
+    dynamic_recurrent, paddle::operators::DynamicRecurrentOp,
+    paddle::operators::DynamicRecurrentOpProtoAndCheckerMaker);

paddle/operators/dynamic_recurrent_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   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. */
+
+#pragma once
+
+#ifdef PADDLE_WITH_TESTING
+#include "gtest/gtest.h"
+#endif
+
+#include "paddle/framework/lod_tensor.h"
+#include "paddle/framework/operator.h"
+#include "paddle/framework/tensor_array.h"
+#include "paddle/framework/variable.h"
+#include "paddle/operators/rnn/recurrent_op_utils.h"
+
+namespace paddle {
+namespace operators {
+
+class DynamicRecurrentOp : public framework::OperatorBase {
+ public:
+  static const rnn::ArgumentName kArgName;
+  using value_type = float;
+
+  DynamicRecurrentOp(const std::string& type,
+                     const framework::VariableNameMap& inputs,
+                     const framework::VariableNameMap& outputs,
+                     const framework::AttributeMap& attrs)
+      : OperatorBase(type, inputs, outputs, attrs) {}
+
+  DynamicRecurrentOp(const DynamicRecurrentOp& o)
+      : framework::OperatorBase(
+            static_cast<const framework::OperatorBase&>(o)) {
+    // TODO(yuyang18): Implement copy ctor well.
+    PADDLE_THROW("Not implemented");
+  }
+
+  void Run(const framework::Scope& scope,
+           const platform::DeviceContext& dev_ctx) const override;
+
+  /*
+   * Split the inputs(LoDTensors) to segments for each time step.
+   */
+  void SplitInputs() const;
+
+  /*
+   * Create step-scopes to store temporary outputs in each time steps.
+   */
+  void CreateScopes() const;
+
+  /*
+   * Link TensorArray steps to the corresponding variables located in
+   * step-scopes.
+   */
+  void WriteStepInputs() const;
+
+  /*
+   * Write output of each step to the corresponding TensorArray.
+   */
+  void WriteStepOutputs() const;
+
+  /*
+   * Initialize the states, each state will have a corresponding pre-state,
+   * which share the memory with the state in the previous time state. The
+   * pre-state in the first time step will be initialized with an zero tensor or
+   * a tensor in parent scope if is provided.
+   */
+  void InitStates() const;
+
+  /*
+   * Concatenate outputs in each time step and generate a LoDTensor.
+   */
+  void ConcatOutputs() const;
+
+  /*
+   * set a stepnet that is created according to a RecurrentOp's stepnet.
+   */
+  void SetStepNet(std::unique_ptr<OperatorBase> net) {
+    PADDLE_ENFORCE_NOT_NULL(net);
+    stepnet_ = std::move(net);
+  }
+  const OperatorBase& GetStepNet() const { return *stepnet_; }
+
+ protected:
+  struct ArgCache {
+    framework::Scope const* scope;
+    std::vector<framework::Scope*>* scopes;
+    std::map<std::string, framework::Variable*> inlinks;
+    std::map<std::string, framework::Variable*> outlinks;
+
+    size_t num_steps{0};
+
+    void Init(const rnn::ArgumentName& name, const OperatorBase& op,
+              const framework::Scope& scope, rnn::Argument* arg);
+
+    framework::Scope& GetScope(size_t index) {
+      PADDLE_ENFORCE_LT(index, num_steps);
+      return *scopes->at(index);
+    }
+
+   private:
+    void InitArgument(const rnn::ArgumentName& name, const OperatorBase& op,
+                      rnn::Argument* arg);
+    void CacheScopes(const framework::Scope& scope, const rnn::Argument& arg);
+    void CacheInlinks(const framework::Scope& scope,
+                      const std::vector<std::string>& names);
+    void CacheOutlinks(const framework::Scope& scope,
+                       const std::vector<std::string>& names);
+    framework::Variable* GetVariable(const framework::Scope& scope,
+                                     const std::string& name);
+  };
+
+ private:
+  std::unique_ptr<OperatorBase> stepnet_;
+  mutable framework::TensorArray states_;
+  mutable std::map<std::string, framework::TensorArray> step_inputs_;
+  mutable std::map<std::string, framework::TensorArray> step_outputs_;
+  mutable std::map<std::string, std::vector<framework::DySeqMeta>>
+      dy_seq_metas_;
+  mutable rnn::Argument arg_;
+  mutable ArgCache cache_;
+
+#ifdef PADDLE_WITH_TESTING
+  friend class DynamicRecurrentOpTestHelper;
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, SplitInputs);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, CreateCache);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, CreateScopes);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, WriteStepInputs);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, WriteStepOutputs);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, InitStates);
+  FRIEND_TEST(DynamicRecurrentOpTestHelper, ConcatOutputs);
+#endif
+};
+
+class DynamicRecurrentGradientOp : public framework::OperatorBase {
+ public:
+  DynamicRecurrentGradientOp(const std::string& type,
+                             const framework::VariableNameMap& inputs,
+                             const framework::VariableNameMap& outputs,
+                             const framework::AttributeMap& attrs)
+      : OperatorBase(type, inputs, outputs, attrs) {}
+
+  void Run(const framework::Scope& scope,
+           const platform::DeviceContext& dev_ctx) const override;
+};
+
+}  // namespace operators
+}  // namespace paddle

paddle/operators/dynamic_recurrent_op_test.cc

+#include "paddle/operators/dynamic_recurrent_op.h"
+
+#include <gtest/gtest.h>
+
+#include "paddle/framework/ddim.h"
+#include "paddle/framework/lod_tensor.h"
+#include "paddle/framework/op_desc.h"
+#include "paddle/framework/op_registry.h"
+#include "paddle/operators/net_op.h"
+
+namespace paddle {
+namespace operators {
+
+using framework::Scope;
+using framework::TensorArray;
+using framework::LoDTensor;
+using framework::Variable;
+
+class TestOp : public framework::OperatorBase {
+ public:
+  using framework::OperatorBase::OperatorBase;
+  DEFINE_OP_CLONE_METHOD(TestOp);
+  void Run(const Scope& scope,
+           const platform::DeviceContext& dev_ctx) const override {}
+};
+
+void OpDescNewVar(const std::string& param_name,
+                  std::initializer_list<const char*> arguments,
+                  paddle::framework::OpDesc::Var* var) {
+  var->set_parameter(param_name);
+  for (auto& arg_name : arguments) {
+    var->add_arguments(arg_name);
+  }
+}
+
+// create a LoD tensor in scope with specific dims
+LoDTensor* CreateVar(Scope& scope, std::string name, framework::DDim dims,
+                     const platform::Place& place) {
+  auto* var = scope.NewVar(name);
+  auto* tensor = var->GetMutable<LoDTensor>();
+  tensor->Resize(dims);
+  tensor->mutable_data<float>(place);
+  return tensor;
+}
+
+class DynamicRecurrentOpTestHelper : public ::testing::Test {
+ protected:
+  const rnn::ArgumentName argname = DynamicRecurrentOp::kArgName;
+
+  virtual void SetUp() override {
+    CreateGlobalVariables();
+
+    auto op_desc = CreateOpDesc();
+    op = paddle::framework::OpRegistry::CreateOp(op_desc);
+    dop = dynamic_cast<DynamicRecurrentOp*>(op.get());
+    InitCacheManually();
+    InitStepNet();
+  }
+
+  framework::OpDesc CreateOpDesc() {
+    // create op
+    paddle::framework::OpDesc op_desc;
+    op_desc.set_type("dynamic_recurrent");
+
+    OpDescNewVar(argname.inlinks, {"in0"}, op_desc.add_inputs());
+    OpDescNewVar(argname.boot_memories, {"boot_mem"}, op_desc.add_inputs());
+    OpDescNewVar(argname.step_scopes, {"step_scopes"}, op_desc.add_outputs());
+    OpDescNewVar(argname.outlinks, {"out0"}, op_desc.add_outputs());
+
+    // set pre-memories
+    auto pre_memories = op_desc.mutable_attrs()->Add();
+    pre_memories->set_name(argname.pre_memories);
+    pre_memories->set_type(paddle::framework::AttrType::STRINGS);
+    auto pre_memories_item = pre_memories->add_strings();
+    *pre_memories_item = "mem@pre";
+
+    // set memories
+    auto memories = op_desc.mutable_attrs()->Add();
+    memories->set_name(argname.memories);
+    memories->set_type(paddle::framework::AttrType::STRINGS);
+    auto memories_item = memories->add_strings();
+    *memories_item = "mem";
+    return op_desc;
+  }
+
+  void CreateGlobalVariables() {
+    platform::CPUPlace place;
+    scope.NewVar("step_scopes");
+    CreateVar(scope, "boot_mem", framework::make_ddim({10, 20}), place);
+    // auto* out0 =
+    CreateVar(scope, "out0", framework::make_ddim({10, 20}), place);
+    auto* in0 = CreateVar(scope, "in0", framework::make_ddim({10, 8}), place);
+    // 10 instanes with 4 sentences, length is 4, 3, 2, 1 respectively.
+    framework::LoD in0_lod(1);
+    for (int x : std::vector<int>{0, 4, 7, 9, 10}) {
+      in0_lod[0].push_back(x);
+    }
+    in0->set_lod(in0_lod);
+    in0->Resize(framework::make_ddim({10, 8}));
+    // set the content, each sentence content is seqid.batchid
+    // the seqid starts from 0
+    int start = 0;
+    for (size_t seqid = 0; seqid < in0_lod.size() - 1; seqid++) {
+      for (size_t batchid = 0;
+           batchid < in0_lod[0][seqid + 1] - in0_lod[0][seqid]; batchid++) {
+        float v = seqid + batchid * 0.1;
+
+        for (size_t dim = 0; dim < 8; dim++) {
+          in0->data<float>()[start * 8 + dim] = v;
+        }
+        start++;
+      }
+    }
+  }
+
+  void InitCacheManually() {
+    dop->cache_.Init(DynamicRecurrentOp::kArgName, *dop, scope, &dop->arg_);
+  }
+
+  void InitStepNet() {
+    std::unique_ptr<framework::OperatorBase> stepnet{new NetOp};
+    dynamic_cast<NetOp*>(stepnet.get())
+        ->AppendOp(std::unique_ptr<TestOp>(new TestOp(
+            "test", {{"inlinks", {"in0"}}, {"boot_memories", {"boot_mem"}}},
+            {{"outlinks", {"out0"}}, {"step_scopes", {"step_scopes"}}}, {})));
+    dop->SetStepNet(std::move(stepnet));
+  }
+
+ protected:
+  DynamicRecurrentOp* dop;
+  std::unique_ptr<framework::OperatorBase> op;
+  paddle::platform::CPUDeviceContext device_context;
+  paddle::framework::Scope scope;
+};
+
+TEST_F(DynamicRecurrentOpTestHelper, CreateCache) {
+  const rnn::Argument& arg = dop->arg_;
+  ASSERT_EQ(arg.inlinks.size(), 1UL);
+  ASSERT_EQ(arg.outlinks.size(), 1UL);
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, SplitInputs) {
+  dop->SplitInputs();
+  auto& in0_ta = dop->step_inputs_["in0"];
+  ASSERT_EQ(in0_ta.size(), 4UL);
+
+  const auto& batch0 = in0_ta.Read(0);
+  const auto& batch1 = in0_ta.Read(1);
+  const auto& batch2 = in0_ta.Read(2);
+  const auto& batch3 = in0_ta.Read(3);
+  EXPECT_EQ(batch0.dims()[0], 4);
+  EXPECT_EQ(batch1.dims()[0], 3);
+  EXPECT_EQ(batch2.dims()[0], 2);
+  EXPECT_EQ(batch3.dims()[0], 1);
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, CreateScopes) {
+  dop->SplitInputs();
+  dop->CreateScopes();
+  ASSERT_EQ(dop->cache_.num_steps, 4UL);
+  ASSERT_EQ(dop->cache_.scopes->size(), 4UL);
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, WriteStepInputs) {
+  dop->SplitInputs();
+  dop->CreateScopes();
+  dop->WriteStepInputs();
+
+  for (size_t step = 0; step < dop->cache_.num_steps; step++) {
+    auto& scope = dop->cache_.GetScope(step);
+    for (auto name : std::vector<std::string>({"in0"})) {
+      ASSERT_TRUE(scope.FindVar(name) != nullptr);
+    }
+  }
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, WriteStepOutputs) {
+  dop->SplitInputs();
+  dop->CreateScopes();
+  dop->WriteStepInputs();
+  dop->WriteStepOutputs();
+
+  for (size_t step = 0; step < dop->cache_.num_steps; step++) {
+    auto& scope = dop->cache_.GetScope(step);
+    for (auto name : std::vector<std::string>({"out0"})) {
+      ASSERT_TRUE(scope.FindVar(name));
+    }
+  }
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, ConcatOutputs) {
+  // Let's leave this test to python unittest.
+}
+
+TEST_F(DynamicRecurrentOpTestHelper, InitStates) {
+  dop->SplitInputs();
+  dop->CreateScopes();
+  dop->WriteStepInputs();
+  dop->WriteStepOutputs();
+  dop->InitStates();
+
+  for (size_t step = 0; step < dop->cache_.num_steps; step++) {
+    auto& scope = dop->cache_.GetScope(step);
+    auto state = scope.FindVar("mem");
+    ASSERT_TRUE(state != nullptr);
+
+    auto* pre_state = scope.FindVar("mem@pre");
+    ASSERT_TRUE(pre_state != nullptr);
+
+    auto* boot_state = scope.FindVar("boot_mem");
+    ASSERT_TRUE(boot_state != nullptr);
+
+    if (step == 0) {
+      // check pre_state is a reference of boot_state
+      ASSERT_EQ(boot_state->Get<LoDTensor>().data<float>(),
+                pre_state->Get<LoDTensor>().data<float>());
+    }
+  }
+}
+
+}  // operators
+}  // namespace paddle