Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into gen_nccl_id_op

.copyright.hook

@@ -9,7 +9,7 @@ import subprocess
 import platform
 
 COPYRIGHT = '''
-  Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+Copyright (c) 2016 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.

cmake/external/mkldnn.cmake

@@ -53,7 +53,7 @@ ExternalProject_Add(
     ${EXTERNAL_PROJECT_LOG_ARGS}
     DEPENDS             ${MKLDNN_DEPENDS}
     GIT_REPOSITORY      "https://github.com/01org/mkl-dnn.git"
-    GIT_TAG             "v0.11"
+    GIT_TAG             "v0.14"
     PREFIX              ${MKLDNN_SOURCES_DIR}
     UPDATE_COMMAND      ""
     CMAKE_ARGS          -DCMAKE_INSTALL_PREFIX=${MKLDNN_INSTALL_DIR}

contrib/inference/README.md

+# Embed Paddle Inference in Your Application
+
+Paddle inference offers the APIs in `C` and `C++` languages.
+
+One can easily deploy a model trained by Paddle following the steps as below:
+
+1. Optimize the native model;
+2. Write some codes for deployment.
+
+
+Let's explain the steps in detail.
+
+## Optimize the native Fluid Model
+
+The native model that get from the training phase needs to be optimized for that.
+
+- Clean the noise such as the cost operators that do not need inference;
+- Prune unnecessary computation fork that has nothing to do with the output;
+- Remove extraneous variables;
+- Memory reuse for native Fluid executor;
+- Translate the model storage format to some third-party engine's, so that the inference API can utilize the engine for acceleration;
+
+We have an official tool to do the optimization, call `paddle_inference_optimize --help` for more information.
+
+## Write some codes
+
+Read `paddle_inference_api.h` for more information.

contrib/inference/paddle_inference_api.h

+/* Copyright (c) 2018 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. */
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace paddle {
+
+class Predictor {
+public:
+  struct Attr;
+  Predictor() = default;
+
+  // Build the network before inference.
+  bool Init(const Attr& attr);
+
+  // Predict an record.
+  // Arguments:
+  //   inputs: the name of the input variables.
+  //   outputs: the name of the output varaibles.
+  //   input_shapes: the shape of the input variables.
+  //   output_shapes: the shape of the output variables.
+  //   input_data: the data of the input variables.
+  //   output_data: the data of the output variables.
+  bool Run(const std::vector<std::string>& inputs,
+           const std::vector<std::string>& outputs,
+           const std::vector<std::vector<int>>& input_shapes,
+           const std::vector<std::vector<int>>& output_shapes,
+           const std::vector<std::vector<float>>& input_data,
+           std::vector<std::vector<float>>* output_data);
+
+  // Clone a predictor that share the model weights.
+  Predictor* Clone();
+
+  // Destroy the Predictor.
+  ~Predictor();
+
+  struct Attr {
+    enum class EngineKind;
+
+    std::string model_dir;      // path to the model directory.
+    bool enable_engine{false};  // Enable to execute (part of) the model on
+                                // third-party engines.
+    EngineKind engine_kind{Attr::EngineKind::kNone};
+
+    enum class EngineKind {
+      kNone = -1,          // Use the native Fluid facility.
+      kAnakin,             // Use Anakin for inference.
+      kTensorRT,           // Use TensorRT for inference.
+      kAutoMixedAnakin,    // Automatically mix Fluid with Anakin.
+      kAutoMixedTensorRT,  // Automatically mix Fluid with TensorRT.
+    };
+  };
+};
+
+}  // namespace paddle

doc/fluid/build_and_install/paddleci.png

+../../v2/build_and_install/paddleci.png
\ No newline at end of file

doc/fluid/design/motivation/api.md

@@ -77,8 +77,7 @@ print "The sematic-vector of testA: ", paddle.infer(fA, parameters, testA)
 
 ### Example 2. Sharing Parameters between "Models"
 
-We use [GAN](https://github.com/PaddlePaddle/book/tree/develop/gan) in
-this example.  In the following example program, `d0` and `d1`
+We use GAN in this example.  In the following example program, `d0` and `d1`
 correspond to the two networks in the following figure:
 
 <img src="https://github.com/wangyang59/book/raw/00036f4b0da5225041a6824587c1a01cf20159b1/gan/image/gan_ig.png" width=400 />

doc/fluid/design/motivation/refactorization.md

@@ -125,12 +125,12 @@ Compile Time -> IR -> Runtime
 
 ## Operator/OpWithKernel/OpKernel
 
-![class_diagram](http://api.paddlepaddle.org/graphviz?dot=https://gist.githubusercontent.com/reyoung/53df507f6749762675dff3e7ce53372f/raw/49caf1fb70820fb4a6c217634317c9306f361f36/op_op_with_kern_class_diagram.dot)
+![class_diagram](https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/fluid/images/op_op_with_kern_class_diagram.dot)
 
 ---
 
 ## Operator
-![class_diagram](http://api.paddlepaddle.org/graphviz?dot=https://gist.githubusercontent.com/reyoung/53df507f6749762675dff3e7ce53372f/raw/dd598e8f1976f5759f58af5e5ef94738a6b2e661/op.dot)
+![class_diagram](https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/fluid/images/op.dot)
 
 * `Operator` is the fundamental building block of the user interface.
     * Operator stores input/output variable names and attributes.
@@ -141,7 +141,7 @@ Compile Time -> IR -> Runtime
 
 ## OpWithKernel/Kernel
 
-![class_diagram](http://api.paddlepaddle.org/graphviz?dot=https://gist.githubusercontent.com/reyoung/53df507f6749762675dff3e7ce53372f/raw/9d7f4eba185cf41c8e2fbfb40ae21890dbddcd39/op_with_kernel.dot)
+![class_diagram](https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/fluid/images/op_with_kernel.dot)
 
 * `OpWithKernel` inherits `Operator`.
 * `OpWithKernel` contains a Kernel map.

doc/fluid/design/multi_devices/operator_kernel_type.md

@@ -75,7 +75,7 @@ Different layout leads to different implementation of the operator kernel. There
 
 - The inference of Layout is at run-time, not at compile-time.
 
-- Every operator has to implement different kernels for different layouts. Let's take MKLDNN as an example. If we want to implement an MKLDNN convolution operator, we have to implement all the kernels for different layouts, which are listed [here](http://01org.github.io/mkl-dnn/structmkldnn_1_1memory.html). And we will have a special macro to  register kernels for MKLDNN operators.
+- Every operator has to implement different kernels for different layouts. Let's take MKLDNN as an example. If we want to implement an MKLDNN convolution operator, we have to implement all the kernels for different layouts, which are listed [here](http://intel.github.io/mkl-dnn/structmkldnn_1_1memory.html). And we will have a special macro to  register kernels for MKLDNN operators.
 
 `Layout` is also defined as a enum variable:
 

doc/fluid/howto/cluster/nccl2_rdma_training.md

+# Distributed Training with NCCL2 and RDMA
+
+When doing distributed multi-GPU training, network bandwith often becomes the
+bottle neck. We introduce a way to use NCCL2 to do such training job to
+achieve best performace.
+
+## Prepare Hardwares with RDMA and Multiple GPUs
+
+I'm using two Linux servers each of them is installed with 8 GPUs and
+one 100Gb RDMA card.
+Base environment is:
+
+* OS: CentOS 7.4
+* RDMA device: "Mellanox Technologies MT27700 Family [ConnectX-4]"
+* Kernel version: `4.4.88-1.el7.elrepo.x86_64`
+* Docker version: `1.12.6`
+* Docker storage driver: `overlay2`
+* IP addresses: 192.168.16.30,192.168.16.34
+
+In general, the steps including:
+
+1. Install GPU drivers
+1. Install RDMA drivers
+1. Install "InfiniBand Support"
+1. Use docker to run tests and make sure GPUs and RDMA can work inside
+   the container.
+
+I'll ommit section "Install GPU drivers" because we can find it easily
+somewhere else.
+
+### Install RDMA drivers
+
+For my case, I've got two machines with device
+"Mellanox Technologies MT27700 Family [ConnectX-4]" installed. The OS was
+"CentOS 7.4" and I updated the kernel to version 4.4 so that docker can
+work with latest overlay2 filesystem.
+
+***NOTE: before you start, make sure you have a way to get a console
+of the server other than ssh because we may need to re-configure the
+network device.***
+
+1. Go to http://www.mellanox.com/page/products_dyn?product_family=26,
+   download `MLNX_OFED` software in the bottom of the page, and upload it
+   onto the server.
+1. Run `./mlnxofedinstall --add-kernel-support` in the software package.
+1. Run `/etc/init.d/openibd restart` to make everything work, note that
+   this operation may cause the network goes down if you are using this
+   RDMA device as default network device and use ssh to login the server.
+1. Re-configure the network interface, for example:
+   `ifconfig eth2 192.168.16.30/20 up`, then add routes if needed:
+   `ip route add default via 192.168.16.1 dev eth2`.
+1. Do the same thing on the other node.
+1. Use `ping` to test if the two nodes have typical ICMP connection.
+1. Use either `udaddy` or `ib_write_bw` to test the network connection is
+   ready and have the desired bandwith.
+
+### Prepare Docker Image to Run RDMA Programs
+
+1. Build a docker image using cuda base image like: `nvidia/cuda:8.0-cudnn5-devel-ubuntu16.04` and install paddlepaddle whl
+   package in it.
+1. Start a docker container and mount GPU driver libs into it (you can
+   skip this step if you are using nvidia-docker).
+1. Mount RDMA dirvers and libs into the docker image (see below section),
+   also `udaddy` and `ib_write_bw` if needed.
+1. Mount GPU devices and RDMA devices into the container using `--device`
+   or just use privileged mode `--privileged`.
+1. Start the container using host network mode: `--net=host`
+
+### RDMA Library Files Needed
+
+Usually, `MLNX_OFED` install latest supported libs under
+`/usr/lib64/mlnx_ofed/valgrind`. Other libs also needed to run RDMA programs
+is listed below. These libs must be mounted into the docker container.
+
+* Libs under `/usr/lib64/mlnx_ofed/valgrind`
+  * libibcm.so
+  * libibverbs.so
+  * libmlx4.so
+  * libmlx5.so
+  * libmlx5-rdmav2.so
+  * librdmacm.so
+* Other libs:
+  * libnl-3.so.200
+  * libnl-route-3.so.200
+  * libnuma.so.1
+
+## Start to Run the Training Job
+
+Setting NCCL environment variables to turn NCCL switches on and off:
+
+
+| Env Name | Description |
+| --- | --- |
+| NCCL_SOCKET_IFNAME | The RDMA device, e.g. eth2 |
+| NCCL_P2P_DISABLE | Set to 1 to disable P2P transfer between GPUs |
+| NCCL_IB_DISABLE | Set to 1 to disable using RDMA |
+| NCCL_IB_CUDA_SUPPORT | Set to 1 to enable GPU Direct if supported |
+| NCCL_DEBUG | Set debug level: VERSION, WARN, INFO |
+
+My two servers are: `192.168.16.30,192.168.16.34`, On node 1, Run :
+
+```bash
+PADDLE_TRAINER_ID=0 PADDLE_PORT=48372 PADDLE_WORKERS=192.168.16.30,192.168.16.34 POD_IP=192.168.16.30 stdbuf -oL python vgg16.py
+```
+
+On node 2, Run:
+
+```bash
+PADDLE_TRAINER_ID=1 PADDLE_PORT=48372 PADDLE_WORKERS=192.168.16.30,192.168.16.34 POD_IP=192.168.16.34 stdbuf -oL python vgg16.py
+```

doc/fluid/images/op.dot

+digraph sample { 
+  graph [rankdir=TD]; node [shape=record];
+  op [label="{Operator| InferShape()=0\lRun()=0\l | map<string, string[]> inputs_\lmap<string, string[]> outputs_ \l AttributeMap attrs_\l}"]; 
+}
\ No newline at end of file

doc/fluid/images/op_op_with_kern_class_diagram.dot

+digraph sample { 
+  graph [rankdir=TD]; node [shape=record];
+  op [label="{Operator| InferShape()=0\lRun()=0\l | map<string, string[]> inputs_\lmap<string, string[]> outputs_ \l AttributeMap attrs_\l}"]; 
+  op_with_kern [label="{OpWithKernel | InferShape()=0\lRun()\l | map<OpKernelKey,OpKernel>kernels_ }"]
+  op_kernel [label="{OpKernel | Compute()=0}"]
+  op_kernel_key [label="{OpKernelKey| Place place\n...}"]
+
+  op -> op_with_kern [dir=back, arrowtail=onormal]
+  op_with_kern -> op_kernel [arrowhead=vee, label="contains many"]
+
+  {
+    rank=same;
+    op_with_kern
+    op_kernel
+  }
+
+  op_kernel -> op_kernel_key [style=invis]
+
+  {
+    rank=same;
+    op_kernel
+    op_kernel_key
+  }
+
+  op_with_kern -> op_kernel_key [arrowhead=vee, label ="\nas map key"]
+
+  mul_op [label="MulOp"]
+  op_with_kern -> mul_op [dir=back, arrowtail=onormal]
+  mul_kernel [label="template <typename Place>\lclass MulOpKernel\l"]
+  op_kernel -> mul_kernel [dir=back, arrowtail=onormal]
+  mul_op -> mul_kernel [arrowhead=vee, label="register many"]
+  
+  {
+    rank=same;
+    mul_op;
+    mul_kernel;
+  }
+}
\ No newline at end of file

doc/fluid/images/op_with_kernel.dot

+digraph sample { 
+  graph [rankdir=TD]; node [shape=record];
+  op [label="{Operator}"]; 
+  op_with_kern [label="{OpWithKernel | InferShape()=0\lRun()\l | map<OpKernelKey,OpKernel>kernels_ }"]
+  op_kernel [label="{OpKernel | Compute()=0}"]
+  op_kernel_key [label="{OpKernelKey| Place place\n...}"]
+
+  op -> op_with_kern [dir=back, arrowtail=onormal]
+  op_with_kern -> op_kernel [arrowhead=vee, label="contains many"]
+
+  {
+    rank=same;
+    op_with_kern
+    op_kernel
+  }
+
+  op_kernel -> op_kernel_key [style=invis]
+
+  {
+    rank=same;
+    op_kernel
+    op_kernel_key
+  }
+
+  op_with_kern -> op_kernel_key [arrowhead=vee, label ="\nas map key"]
+}
\ No newline at end of file

doc/v2/api/config/layer.rst

@@ -142,7 +142,7 @@ gated_unit
 -----------
 ..  autoclass:: paddle.v2.layer.gated_unit
     :noindex:
-    
+
 Recurrent Layer Group
 =====================
 
@@ -354,7 +354,7 @@ dropout
 --------
 ..  autoclass:: paddle.v2.layer.dropout
     :noindex:
-    
+
 dot_prod
 ---------
 .. autoclass:: paddle.v2.layer.dot_prod
@@ -460,6 +460,11 @@ multi_binary_label_cross_entropy_cost
 ..  autoclass:: paddle.v2.layer.multi_binary_label_cross_entropy_cost
     :noindex:
 
+classification_cost
+-------------------
+.. autoclass:: paddle.v2.layer.classification_cost
+   :noindex:
+
 huber_regression_cost
 -------------------------
 ..  autoclass:: paddle.v2.layer.huber_regression_cost
@@ -534,7 +539,7 @@ detection_output
 ----------------
 ..  autoclass:: paddle.v2.layer.detection_output
     :noindex:
-    
+
 Check Layer
 ============
 

doc/v2/design/mkl/mkldnn.md

@@ -5,7 +5,7 @@
 充分展现英特尔平台的优势，有效提升PaddlePaddle在英特尔架构上的性能。
 
 <div align="center">
-<img src="image/overview.png"><br/>
+<img src="https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/v2/images/overview.png"><br/>
 Figure 1. PaddlePaddle on IA
 </div>
 
@@ -42,16 +42,43 @@ Figure 1. PaddlePaddle on IA
 
 MKL，MKLML以及MKL-DNN三者关系如下表：
 
-| Name        |  Open Source     | License     | Descriptions  |
-| :---------- | :--------------- | :---------- | :------------ |
-|   MKL       |     No           | Proprietary | Accelerate math processing routines |
-|   MKLML     |     No           | Proprietary | Small package of MKL, especially for Machine Learning |
-|   MKL-DNN   |     Yes          | Apache 2.0  | Accelerate primitives processing routines especially for Deep Neural Networks  |
+<table>
+<thead>
+<tr>
+<th>Name</th>
+<th>Open Source</th>
+<th>License</th>
+<th>Descriptions</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>MKL</td>
+<td>No</td>
+<td>Proprietary</td>
+<td>Accelerate math processing routines</td>
+</tr>
+<tr>
+<td>MKLML</td>
+<td>No</td>
+<td>Proprietary</td>
+<td>Small package of MKL, especially for Machine Learning</td>
+</tr>
+
+<tr>
+<td>MKL-DNN</td>
+<td>Yes</td>
+<td>Apache 2.0</td>
+<td>Accelerate primitives processing routines especially for Deep Neural Networks</td>
+</tr>
+
+</tbody>
+</table>
 
 MKLML可以与MKL-DNN共同使用，以此达到最好的性能。
 
 <div align="center">
-<img src="image/engine.png"><br/>
+<img src="https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/v2/images/engine.png"><br/>
 Figure 2. PaddlePaddle with MKL Engines
 </div>
 
@@ -103,7 +130,7 @@ MKL-DNN的库目前只有动态库`libmkldnn.so`。
 所以我们定义了一个`MKLDNNMatrix`用于管理MKL-DNN数据的不同格式以及相互之间的转换。
 
 <div align="center">
-<img src="image/matrix.png"><br/>
+<img src="https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/v2/images/matrix.png"><br/>
 Figure 3. MKLDNNMatrix
 </div>
 
@@ -113,7 +140,7 @@ Figure 3. MKLDNNMatrix
 子类只需要使用定义好的接口，实现具体的函数功能即可。
 
 <div align="center">
-<img src="image/layers.png"><br/>
+<img src="https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/v2/images/layers.png"><br/>
 Figure 4. MKLDNNLayer
 </div>
 
@@ -150,7 +177,7 @@ Figure 4. MKLDNNLayer
 所以整体上，在实现每个子类的时候就不需要关心分支的事情了。
 
 <div align="center">
-<img src="image/gradients.png"><br/>
+<img src="https://raw.githubusercontent.com/PaddlePaddle/Paddle/develop/doc/v2/images/gradients.png"><br/>
 Figure 5. Merge Gradients
 </div>
 

doc/v2/howto/cluster/multi_cluster/k8s_distributed_en.md

@@ -41,7 +41,7 @@ Training docker image needs to package the paddle pserver and paddle trainer run
 - Generating the initialization arguments for `Paddle PServer` and `Paddle Training` processes.
 
 Since the paddlepaddle official docker image already has the runtimes we need, we'll take it as the base image and pack some additional scripts for the processes mentioned above to build our training image. for more detail, please find from the following link:
-- https://github.com/PaddlePaddle/Paddle/blob/develop/doc/howto/usage/cluster/src/k8s_train/Dockerfile
+- https://github.com/PaddlePaddle/Paddle/tree/develop/doc/v2/howto/cluster/multi_cluster/src/k8s_train/Dockerfile
 
 
 ```bash
@@ -62,7 +62,7 @@ represent the Docker Image which built in this step.
 ### Prepare Training Data
 
 We can download and split the training job by creating a Kubernetes Job, or custom your image
-by editing [k8s_train](./src/k8s_train/).
+by editing [k8s_train](https://github.com/PaddlePaddle/Paddle/tree/develop/doc/v2/howto/cluster/multi_cluster/src/k8s_train).
 
 Before creating a Job, we need to bind a [persistenVolumeClaim](https://kubernetes.io/docs/user-guide/persistent-volumes) by the different type of
 the different file system, the generated dataset would be saved on this volume.

doc/v2/images/glossary_rnn.dot

+digraph G{
+	subgraph cluster_timestep0 {
+		label="recurrent timestep i-1"
+		bgcolor=lightgray
+		node [style=filled,color=white]
+		fc0_0 [label="fc 0"]
+		fc0_1 [label="fc 1"]
+		fc0_2 [label="fc 2"]
+
+		fc0_0 -> fc0_1
+		fc0_1 -> fc0_2
+	}
+
+	subgraph cluster_timestep1 {
+		label="recurrent timestep i"
+		node [style=filled];
+		fc1_0 [label="fc 0"]
+		fc1_1 [label="fc 1"]
+		fc1_2 [label="fc 2"]
+		color=blue
+
+		fc1_0 -> fc1_1
+		fc1_1 -> fc1_2
+	}
+
+	subgraph cluster_timestep2 {
+		label="recurrent timestep i+1"
+		bgcolor=lightgray
+		node [style=filled,color=white]
+		fc2_0 [label="fc 0"]
+		fc2_1 [label="fc 1"]
+		fc2_2 [label="fc 2"]
+
+		fc2_0 -> fc2_1
+		fc2_1 -> fc2_2
+	}
+	
+	
+	fc0_1 -> fc1_1 [style="dotted" constraint=false]
+	fc1_1 -> fc2_1 [style="dotted" constraint=false]
+
+}
\ No newline at end of file

doc/v2/images/glossary_rnn_with_memory.dot

+digraph G{
+	subgraph cluster_timestep0 {
+		label="recurrent timestep i-1"
+		bgcolor=lightgray
+		node [style=filled,color=white]
+		fc0_0 [label="fc 0"]
+		fc0_1 [label="fc 1"]
+		fc0_2 [label="fc 2"]
+		m0 [label="memory"]
+		fc0_0 -> fc0_1
+		fc0_1 -> fc0_2
+		fc0_1 -> m0
+		m0 -> fc0_1
+	}
+
+	subgraph cluster_timestep1 {
+		label="recurrent timestep i"
+		node [style=filled];
+		fc1_0 [label="fc 0"]
+		fc1_1 [label="fc 1"]
+		fc1_2 [label="fc 2"]
+		m1 [label="memory"]
+		color=blue
+		fc1_0 -> fc1_1
+		fc1_1 -> fc1_2
+		fc1_1 -> m1
+		m1 -> fc1_1
+	}
+
+	subgraph cluster_timestep2 {
+		label="recurrent timestep i+1"
+		bgcolor=lightgray
+		node [style=filled,color=white]
+		fc2_0 [label="fc 0"]
+		fc2_1 [label="fc 1"]
+		fc2_2 [label="fc 2"]
+		m2 [label="memory"]
+		fc2_0 -> fc2_1
+		fc2_1 -> fc2_2
+		fc2_1 -> m2
+		m2 -> fc2_1
+	}
+	
+	
+	m0 -> m1 [style="dotted" constraint=false]
+	m1 -> m2 [style="dotted" constraint=false]
+
+}
\ No newline at end of file

doc/v2/images/simple_full_hierarchical_recurrent.dot

+digraph G {
+  rankdir=LR;
+
+  subgraph cluster_t0 {
+    a [label="4"]
+    b [label="5"]
+    c [label="2"]
+  }
+  
+  subgraph cluster_t1 {
+    d [label="0"]
+    e [label="9"]
+  }
+
+  subgraph cluster_t2 {
+    f [label="8"]
+    g [label="1"]
+    h [label="4"]
+  }
+
+  a -> b;
+  b -> c;
+  c -> d [constraint=false];
+
+  d -> e;
+  e -> f [constraint=false];
+  
+  f -> g;
+  g -> h;
+}
\ No newline at end of file

doc/v2/images/simple_full_recurrent.dot

+digraph G {
+  rankdir=LR;
+  a [label="4"]
+  b [label="5"]
+  c [label="2"]
+  d [label="0"]
+  e [label="9"]
+  f [label="8"]
+  g [label="1"]
+  h [label="4"]
+
+  a -> b;
+  b -> c;
+  c -> d;
+  d -> e;
+  e -> f;
+  f -> g;
+  g -> h;
+}
\ No newline at end of file

paddle/fluid/framework/block_desc.cc

@@ -134,6 +134,11 @@ OpDesc *BlockDesc::PrependOp() {
   return ops_.front().get();
 }
 
+void BlockDesc::PrependAllocatedOp(std::unique_ptr<OpDesc> &&op_desc) {
+  need_update_ = true;
+  ops_.emplace_front(std::move(op_desc));
+}
+
 OpDesc *BlockDesc::InsertOp(size_t index) {
   need_update_ = true;
   auto it = ops_.begin() + index;

paddle/fluid/framework/block_desc.h

@@ -88,6 +88,8 @@ class BlockDesc {
 
   OpDesc *PrependOp();
 
+  void PrependAllocatedOp(std::unique_ptr<OpDesc> &&op_desc);
+
   OpDesc *InsertOp(size_t index);
 
   /*

paddle/fluid/framework/details/broadcast_op_handle.cc

@@ -38,9 +38,7 @@ void BroadcastOpHandle::RunImpl() {
       out_var_handles.size(), places_.size(),
       "The number of output should equal to the number of places.");
 
-  // Wait input done, this Wait is asynchronous operation platform::Place
-  // &in_place;
-  WaitInputVarGenerated(*in_var_handle);
+  WaitInputVarGenerated();
 
   std::vector<const Scope *> var_scopes;
   for (auto *s : local_scopes_) {
@@ -50,29 +48,9 @@ void BroadcastOpHandle::RunImpl() {
   auto *in_var =
       var_scopes.at(in_var_handle->scope_idx_)->FindVar(in_var_handle->name_);
   PADDLE_ENFORCE_NOT_NULL(in_var);
-
   Tensor &in_tensor = VariableVisitor::GetMutableTensor(in_var);
 
-  // NOTE: The tensors' Place of input and output must be all on GPU or all on
-  // CPU.
-  for (auto *out_var_handle : out_var_handles) {
-    if (out_var_handle->IsTheSameVar(*in_var_handle)) {
-      continue;
-    }
-    auto t_out_p = out_var_handle->place_;
-    auto *out_var = var_scopes.at(out_var_handle->scope_idx_)
-                        ->FindVar(out_var_handle->name_);
-    PADDLE_ENFORCE_NOT_NULL(out_var);
-    if (platform::is_gpu_place(in_tensor.place())) {
-      PADDLE_ENFORCE(platform::is_gpu_place(t_out_p),
-                     "Places of input and output must be all on GPU.");
-    } else {
-      t_out_p = platform::CPUPlace();
-    }
-    VariableVisitor::ShareDimsAndLoD(*in_var, out_var);
-    VariableVisitor::GetMutableTensor(out_var).mutable_data(t_out_p,
-                                                            in_tensor.type());
-  }
+  InitOutputValue(*in_var_handle, out_var_handles);
 
   if (platform::is_cpu_place(in_tensor.place())) {
     for (auto *out_var_handle : out_var_handles) {
@@ -147,11 +125,37 @@ void BroadcastOpHandle::RunImpl() {
   }
 }
 
-void BroadcastOpHandle::WaitInputVarGenerated(const VarHandle &in_var) {
-  if (in_var.generated_op_) {
-    for (auto &pair : dev_ctxes_) {
-      in_var.generated_op_->Wait(pair.second);
+void BroadcastOpHandle::InitOutputValue(
+    const VarHandle &in_var_handle,
+    const std::vector<VarHandle *> &out_var_handles) const {
+  std::vector<const Scope *> var_scopes;
+  for (auto *s : local_scopes_) {
+    var_scopes.emplace_back(s->FindVar(kLocalExecScopeName)->Get<Scope *>());
+  }
+  auto *in_var =
+      var_scopes.at(in_var_handle.scope_idx_)->FindVar(in_var_handle.name_);
+
+  Tensor &in_tensor = VariableVisitor::GetMutableTensor(in_var);
+
+  // NOTE: The tensors' Place of input and output must be all on GPU or all on
+  // CPU.
+  for (auto *out_var_handle : out_var_handles) {
+    if (out_var_handle->IsTheSameVar(in_var_handle)) {
+      continue;
     }
+    auto t_out_p = out_var_handle->place_;
+    auto *out_var = var_scopes.at(out_var_handle->scope_idx_)
+                        ->FindVar(out_var_handle->name_);
+    PADDLE_ENFORCE_NOT_NULL(out_var);
+    if (is_gpu_place(in_tensor.place())) {
+      PADDLE_ENFORCE(platform::is_gpu_place(t_out_p),
+                     "Places of input and output must be all on GPU.");
+    } else {
+      t_out_p = platform::CPUPlace();
+    }
+    VariableVisitor::ShareDimsAndLoD(*in_var, out_var);
+    VariableVisitor::GetMutableTensor(out_var).mutable_data(t_out_p,
+                                                            in_tensor.type());
   }
 }
 

paddle/fluid/framework/details/broadcast_op_handle.h

@@ -57,7 +57,6 @@ struct BroadcastOpHandle : public OpHandleBase {
 
  protected:
   void RunImpl() override;
-  void WaitInputVarGenerated(const VarHandle &in_var);
 
  private:
   const std::vector<Scope *> &local_scopes_;
@@ -65,6 +64,9 @@ struct BroadcastOpHandle : public OpHandleBase {
 #ifdef PADDLE_WITH_CUDA
   const platform::NCCLContextMap *nccl_ctxs_;
 #endif
+
+  void InitOutputValue(const VarHandle &in_var_handle,
+                       const std::vector<VarHandle *> &out_var_handles) const;
 };
 }  // namespace details
 }  // namespace framework

paddle/fluid/framework/details/computation_op_handle.cc

@@ -26,20 +26,20 @@ ComputationOpHandle::ComputationOpHandle(const OpDesc &op_desc, Scope *scope,
       place_(place) {}
 
 void ComputationOpHandle::RunImpl() {
-  auto *cur_ctx = dev_ctxes_[place_];
-  for (auto *in : inputs_) {
-    bool need_wait = in->generated_op_ &&
-                     in->generated_op_->DeviceContext(place_) != cur_ctx;
-    if (need_wait) {
-      in->generated_op_->Wait(cur_ctx);
-    }
-  }
+  WaitInputVarGenerated(place_);
 
   this->RunAndRecordEvent([this] {
     op_->Run(*scope_->FindVar(kLocalExecScopeName)->Get<Scope *>(), place_);
   });
 }
 
+bool ComputationOpHandle::NeedWait(VarHandleBase *in_var) {
+  bool need_wait =
+      in_var && in_var->generated_op_ &&
+      in_var->generated_op_->DeviceContext(place_) != dev_ctxes_[place_];
+  return need_wait;
+}
+
 std::string ComputationOpHandle::Name() const { return op_->Type(); }
 }  // namespace details
 }  // namespace framework

paddle/fluid/framework/details/computation_op_handle.h

@@ -36,6 +36,8 @@ struct ComputationOpHandle : public OpHandleBase {
  protected:
   void RunImpl() override;
 
+  virtual bool NeedWait(VarHandleBase *in_var);
+
  private:
   std::unique_ptr<OperatorBase> op_;
   Scope *scope_;

paddle/fluid/framework/details/fetch_op_handle.cc

@@ -31,7 +31,7 @@ FetchOpHandle::~FetchOpHandle() {
   }
 }
 
-void FetchOpHandle::Wait(platform::DeviceContext *waited_dev) {
+void FetchOpHandle::RecordWaitEventOnCtx(platform::DeviceContext *waited_ctx) {
   PADDLE_THROW("Nobody should wait FetchOp. Unexpceted Error");
 }
 
@@ -45,12 +45,8 @@ void FetchOpHandle::WaitAndMergeCPUTensors() const {
 }
 
 void FetchOpHandle::RunImpl() {
-  auto cpu_ctx =
-      platform::DeviceContextPool::Instance().Get(platform::CPUPlace());
-  for (auto *input : inputs_) {
-    auto *var = static_cast<VarHandle *>(input);
-    var->generated_op_->Wait(cpu_ctx);
-  }
+  WaitInputVarGenerated(platform::CPUPlace());
+
   tensors_.resize(inputs_.size());
   auto *var_handle = static_cast<VarHandle *>(inputs_[0]);
   auto &var_name = var_handle->name_;
@@ -77,6 +73,15 @@ void FetchOpHandle::RunImpl() {
   this->WaitAndMergeCPUTensors();
 }
 
+void FetchOpHandle::WaitInputVarGenerated(const platform::Place &place) {
+  auto cpu_ctx = platform::DeviceContextPool::Instance().Get(place);
+  for (auto *input : inputs_) {
+    if (input->generated_op_) {
+      input->generated_op_->RecordWaitEventOnCtx(cpu_ctx);
+    }
+  }
+}
+
 std::string FetchOpHandle::Name() const { return "Fetch"; }
 
 }  // namespace details

paddle/fluid/framework/details/fetch_op_handle.h

@@ -33,7 +33,7 @@ struct FetchOpHandle : public OpHandleBase {
 
   ~FetchOpHandle();
 
-  void Wait(platform::DeviceContext *waited_dev) override;
+  void RecordWaitEventOnCtx(platform::DeviceContext *waited_ctx) override;
 
   void WaitAndMergeCPUTensors() const;
 
@@ -42,6 +42,8 @@ struct FetchOpHandle : public OpHandleBase {
  protected:
   void RunImpl() override;
 
+  virtual void WaitInputVarGenerated(const platform::Place &place);
+
  private:
   FeedFetchList *data_;
   size_t offset_;

paddle/fluid/framework/details/gather_op_handle.cc

@@ -55,7 +55,7 @@ void GatherOpHandle::RunImpl() {
                  "Currently, gather_op only can gather SelectedRows.");
 
   // Wait input done, this Wait is asynchronous operation
-  WaitInputVarGenerated(in_var_handles);
+  WaitInputVarGenerated();
 
   auto &pre_in_value = pre_in_var->Get<framework::SelectedRows>();
   std::vector<int64_t> out_rows;
@@ -111,17 +111,6 @@ void GatherOpHandle::RunImpl() {
   });
 }
 
-void GatherOpHandle::WaitInputVarGenerated(
-    const std::vector<VarHandle *> &in_var_handles) {
-  for (auto *in : in_var_handles) {
-    if (in->generated_op_) {
-      for (auto pair : dev_ctxes_) {
-        in->generated_op_->Wait(pair.second);
-      }
-    }
-  }
-}
-
 std::string GatherOpHandle::Name() const { return "gather"; }
 }  // namespace details
 }  // namespace framework

paddle/fluid/framework/details/gather_op_handle.h

@@ -39,7 +39,6 @@ struct GatherOpHandle : public OpHandleBase {
 
  protected:
   void RunImpl() override;
-  void WaitInputVarGenerated(const std::vector<VarHandle *> &in_var_handles);
 
  private:
   const std::vector<Scope *> &local_scopes_;

paddle/fluid/framework/details/nccl_all_reduce_op_handle.cc

@@ -34,10 +34,7 @@ void NCCLAllReduceOpHandle::RunImpl() {
     return;  // No need to all reduce when GPU count = 1;
   } else {
     // Wait input done
-    for (auto *in : inputs_) {
-      auto &p = static_cast<VarHandle *>(in)->place_;
-      in->generated_op_->Wait(dev_ctxes_[p]);
-    }
+    WaitInputVarGenerated();
 
     auto &var_name = static_cast<VarHandle *>(this->inputs_[0])->name_;
     int dtype = -1;

paddle/fluid/framework/details/op_handle_base.cc

@@ -56,15 +56,15 @@ void OpHandleBase::Run(bool use_event) {
   RunImpl();
 }
 
-void OpHandleBase::Wait(platform::DeviceContext *waited_dev) {
+void OpHandleBase::RecordWaitEventOnCtx(platform::DeviceContext *waited_ctx) {
 #ifdef PADDLE_WITH_CUDA
-  if (platform::is_cpu_place(waited_dev->GetPlace()) || events_.empty()) {
+  if (platform::is_cpu_place(waited_ctx->GetPlace()) || events_.empty()) {
     for (auto &dev_ctx : dev_ctxes_) {
       dev_ctx.second->Wait();
     }
   } else {
     auto stream =
-        static_cast<platform::CUDADeviceContext *>(waited_dev)->stream();
+        static_cast<platform::CUDADeviceContext *>(waited_ctx)->stream();
     for (auto &ev : events_) {
       PADDLE_ENFORCE(cudaStreamWaitEvent(stream, ev.second, 0));
     }
@@ -86,6 +86,28 @@ void OpHandleBase::AddOutput(VarHandleBase *out) {
   out->generated_op_ = this;
 }
 
+void OpHandleBase::WaitInputVarGenerated() {
+  for (auto in_var : inputs_) {
+    if (NeedWait(in_var)) {
+      for (auto &pair : dev_ctxes_) {
+        in_var->generated_op_->RecordWaitEventOnCtx(pair.second);
+      }
+    }
+  }
+}
+
+void OpHandleBase::WaitInputVarGenerated(const platform::Place &place) {
+  for (auto *in : inputs_) {
+    if (NeedWait(in)) {
+      in->generated_op_->RecordWaitEventOnCtx(dev_ctxes_[place]);
+    }
+  }
+}
+
+bool OpHandleBase::NeedWait(VarHandleBase *in_var) {
+  return in_var && in_var->generated_op_;
+}
+
 void OpHandleBase::RunAndRecordEvent(const std::function<void()> &callback) {
 #ifdef PADDLE_WITH_CUDA
   if (!events_.empty()) {  // Use event

paddle/fluid/framework/details/op_handle_base.h

@@ -38,12 +38,24 @@ class OpHandleBase {
 
   void Run(bool use_event);
 
-  virtual void Wait(platform::DeviceContext *waited_dev);
+  virtual void RecordWaitEventOnCtx(platform::DeviceContext *waited_ctx);
 
   void AddInput(VarHandleBase *in);
 
   void AddOutput(VarHandleBase *out);
 
+  // This method adds the wait events of all the input on all the device
+  // context.
+  // NODE: This Wait is asynchronous operation.
+  virtual void WaitInputVarGenerated();
+
+  // This method adds the wait events of all the input on the specified device
+  // context.
+  // NODE: This Wait is asynchronous operation.
+  virtual void WaitInputVarGenerated(const platform::Place &place);
+
+  virtual bool NeedWait(VarHandleBase *in_var);
+
   // If the Op involves data transfer of multiple devices that
   // will likely block other computations.
   virtual bool IsMultiDeviceTransfer() { return false; }

paddle/fluid/framework/details/reduce_op_handle.cc

@@ -51,7 +51,7 @@ void ReduceOpHandle::RunImpl() {
   PADDLE_ENFORCE_NOT_NULL(pre_in_var);
 
   // Wait input done, this Wait is asynchronous operation
-  WaitInputVarGenerated(in_var_handles);
+  WaitInputVarGenerated();
 
   // NOTE: The Places of all input tensor must be all on CPU or all on GPU.
   std::vector<platform::Place> in_places;  // used to get dev_ctx
@@ -80,19 +80,21 @@ void ReduceOpHandle::RunImpl() {
   }
 
   if (pre_in_var->IsType<framework::SelectedRows>()) {
-    std::vector<const SelectedRows *> in_selected_rows =
-        GetInputValues<SelectedRows>(in_var_handles, var_scopes);
-
-    GatherSelectedRows(in_selected_rows, in_places, dev_ctxes_, t_out_p,
-                       out_var->GetMutable<framework::SelectedRows>());
+    this->RunAndRecordEvent([&] {
+      std::vector<const SelectedRows *> in_selected_rows =
+          GetInputValues<SelectedRows>(in_var_handles, var_scopes);
+      GatherSelectedRows(in_selected_rows, in_places, dev_ctxes_, t_out_p,
+                         out_var->GetMutable<framework::SelectedRows>());
+    });
   } else {
     std::vector<const LoDTensor *> lod_tensors =
         GetInputValues<LoDTensor>(in_var_handles, var_scopes);
-
     if (paddle::platform::is_cpu_place(lod_tensors[0]->place())) {
-      ReduceLoDTensor func(lod_tensors,
-                           out_var->GetMutable<framework::LoDTensor>());
-      VisitDataType(ToDataType(lod_tensors[0]->type()), func);
+      this->RunAndRecordEvent([&] {
+        ReduceLoDTensor func(lod_tensors,
+                             out_var->GetMutable<framework::LoDTensor>());
+        VisitDataType(ToDataType(lod_tensors[0]->type()), func);
+      });
     } else if (paddle::platform::is_gpu_place(lod_tensors[0]->place())) {
 #ifdef PADDLE_WITH_CUDA
       auto pre_in = pre_in_var->Get<framework::LoDTensor>();
@@ -157,17 +159,6 @@ std::vector<const T *> ReduceOpHandle::GetInputValues(
   return in_selected_rows;
 }
 
-void ReduceOpHandle::WaitInputVarGenerated(
-    const std::vector<VarHandle *> &in_var_handles) {
-  for (auto *in : in_var_handles) {
-    if (in->generated_op_) {
-      for (auto pair : dev_ctxes_) {
-        in->generated_op_->Wait(pair.second);
-      }
-    }
-  }
-}
-
 std::string ReduceOpHandle::Name() const { return "reduce"; }
 }  // namespace details
 }  // namespace framework

paddle/fluid/framework/details/reduce_op_handle.h

@@ -60,8 +60,6 @@ struct ReduceOpHandle : public OpHandleBase {
  protected:
   void RunImpl() override;
 
-  void WaitInputVarGenerated(const std::vector<VarHandle *> &in_var_handles);
-
   template <typename T>
   std::vector<const T *> GetInputValues(
       const std::vector<VarHandle *> &in_var_handles,

paddle/fluid/framework/details/scale_loss_grad_op_handle.cc

@@ -29,6 +29,7 @@ ScaleLossGradOpHandle::ScaleLossGradOpHandle(size_t num_dev, Scope *scope,
 ScaleLossGradOpHandle::~ScaleLossGradOpHandle() {}
 
 void ScaleLossGradOpHandle::RunImpl() {
+  // Doesn't wait any event
   std::string var_name = static_cast<VarHandle *>(this->outputs_[0])->name_;
   auto &local_scope = *scope_->FindVar(kLocalExecScopeName)->Get<Scope *>();
 

paddle/fluid/framework/details/send_op_handle.cc

@@ -26,13 +26,16 @@ SendOpHandle::SendOpHandle(const framework::OpDesc &op_desc,
       place_(place) {}
 
 void SendOpHandle::RunImpl() {
+  // TODO(wuyi): need further analysis whether wait VarDummyHandle.
   // Wait input done
   for (auto *in : inputs_) {
     auto &p = static_cast<VarHandle *>(in)->place_;
     if (in->DebugString() == "dummy") {  // HACK
       continue;
     }
-    in->generated_op_->Wait(dev_ctxes_[p]);
+    if (in->generated_op_) {
+      in->generated_op_->RecordWaitEventOnCtx(dev_ctxes_[p]);
+    }
   }
   auto &tmp_scope = local_scope_->FindVar(kLocalExecScopeName)->Get<Scope *>();
   // FIXME(wuyi): can not use RunAndRecordEvent here, for it will cause dead

paddle/fluid/framework/details/threaded_ssa_graph_executor.cc

@@ -14,8 +14,6 @@
 
 #include "paddle/fluid/framework/details/threaded_ssa_graph_executor.h"
 
-#include "paddle/fluid/framework/details/fetch_op_handle.h"
-
 namespace paddle {
 namespace framework {
 namespace details {
@@ -45,73 +43,33 @@ FeedFetchList ThreadedSSAGraphExecutor::Run(
   // Should revisit it if overlapping is available.
   std::unordered_set<OpHandleBase *> delayed_ops;
 
-  auto InsertPendingVar = [&pending_vars, &ready_vars](VarHandleBase &var) {
-    pending_vars.insert(&var);
-    if (var.generated_op_ == nullptr) {
-      ready_vars.Push(&var);
-    }
-  };
-
-  auto InsertPendingOp = [&pending_ops](OpHandleBase &op_instance) {
-    pending_ops.insert({&op_instance, op_instance.Inputs().size()});
-  };
-
   // Transform SSAGraph to pending_ops & pending_vars
   for (auto &var_map : graph_->vars_) {
     for (auto &name_pair : var_map) {
       for (auto &version_pair : name_pair.second) {
-        InsertPendingVar(*version_pair);
+        InsertPendingVar(&pending_vars, &ready_vars, version_pair.get());
       }
     }
   }
   for (auto &var : graph_->dep_vars_) {
-    InsertPendingVar(*var);
+    InsertPendingVar(&pending_vars, &ready_vars, var.get());
   }
 
   for (auto &op : graph_->ops_) {
     if (op->Inputs().empty()) {  // Special case, Op has no input.
       ready_ops.insert(op.get());
     } else {
-      InsertPendingOp(*op);
+      InsertPendingOp(&pending_ops, op.get());
     }
   }
 
   // Step 2. Insert FetchOps
   std::vector<std::unique_ptr<FetchOpHandle>> fetch_ops;
-  FeedFetchList fetch_data(fetch_tensors.size());
-
-  std::unordered_map<std::string, std::vector<VarHandleBase *>> fetched_vars;
-
-  for (auto &fetch_var_name : fetch_tensors) {
-    for (auto &var_map : graph_->vars_) {
-      auto it = var_map.find(fetch_var_name);
-      if (it != var_map.end()) {
-        fetched_vars[fetch_var_name].push_back(it->second.rbegin()->get());
-      }
-    }
-  }
-
   std::unordered_set<std::unique_ptr<VarHandleBase>> fetch_dependencies;
-  for (size_t i = 0; i < fetch_tensors.size(); ++i) {
-    auto &var_name = fetch_tensors[i];
-    auto &vars = fetched_vars.at(var_name);
-    auto *op = new FetchOpHandle(&fetch_data, i, &local_scopes_);
-    fetch_ops.emplace_back(op);
-
-    for (auto &p : places_) {
-      op->SetDeviceContext(p, fetch_ctxs_.Get(p));
-    }
-
-    for (auto *var : vars) {
-      op->AddInput(var);
-    }
+  FeedFetchList fetch_data(fetch_tensors.size());
 
-    auto *fetch_dummy = new DummyVarHandle();
-    op->AddOutput(fetch_dummy);
-    fetch_dependencies.emplace(fetch_dummy);
-    InsertPendingVar(*fetch_dummy);
-    InsertPendingOp(*op);
-  }
+  InsertFetchOps(fetch_tensors, &fetch_ops, &fetch_dependencies, &pending_ops,
+                 &pending_vars, &ready_vars, &fetch_data);
 
   auto run_all_ops = [&](std::unordered_set<OpHandleBase *> &set) {
     for (auto *op : set) {
@@ -174,6 +132,60 @@ FeedFetchList ThreadedSSAGraphExecutor::Run(
   return fetch_data;
 }
 
+void ThreadedSSAGraphExecutor::InsertFetchOps(
+    const std::vector<std::string> &fetch_tensors,
+    std::vector<std::unique_ptr<FetchOpHandle>> *fetch_ops,
+    std::unordered_set<std::unique_ptr<VarHandleBase>> *fetch_dependencies,
+    std::unordered_map<OpHandleBase *, size_t> *pending_ops,
+    std::unordered_set<VarHandleBase *> *pending_vars,
+    BlockingQueue<VarHandleBase *> *ready_vars, FeedFetchList *fetch_data) {
+  std::unordered_map<std::string, std::vector<VarHandleBase *>> fetched_vars;
+
+  for (auto &fetch_var_name : fetch_tensors) {
+    for (auto &var_map : graph_->vars_) {
+      auto it = var_map.find(fetch_var_name);
+      if (it != var_map.end()) {
+        fetched_vars[fetch_var_name].push_back(it->second.rbegin()->get());
+      }
+    }
+  }
+
+  for (size_t i = 0; i < fetch_tensors.size(); ++i) {
+    auto &var_name = fetch_tensors[i];
+    auto &vars = fetched_vars.at(var_name);
+    auto *op = new FetchOpHandle(fetch_data, i, &local_scopes_);
+    fetch_ops->emplace_back(op);
+
+    for (auto &p : places_) {
+      op->SetDeviceContext(p, fetch_ctxs_.Get(p));
+    }
+
+    for (auto *var : vars) {
+      op->AddInput(var);
+    }
+
+    auto *fetch_dummy = new DummyVarHandle();
+    op->AddOutput(fetch_dummy);
+    fetch_dependencies->emplace(fetch_dummy);
+    this->InsertPendingVar(pending_vars, ready_vars, fetch_dummy);
+    this->InsertPendingOp(pending_ops, op);
+  }
+}
+
+void ThreadedSSAGraphExecutor::InsertPendingOp(
+    std::unordered_map<OpHandleBase *, size_t> *pending_ops,
+    OpHandleBase *op_instance) const {
+  pending_ops->insert({op_instance, op_instance->Inputs().size()});
+}
+
+void ThreadedSSAGraphExecutor::InsertPendingVar(
+    std::unordered_set<VarHandleBase *> *pending_vars,
+    BlockingQueue<VarHandleBase *> *ready_vars, VarHandleBase *var) const {
+  pending_vars->insert(var);
+  if (var->generated_op_ == nullptr) {
+    ready_vars->Push(var);
+  }
+}
 void ThreadedSSAGraphExecutor::RunOp(
     BlockingQueue<VarHandleBase *> *ready_var_q, details::OpHandleBase *op) {
   auto op_run = [ready_var_q, op, this] {

paddle/fluid/framework/details/threaded_ssa_graph_executor.h

@@ -23,6 +23,7 @@
 #include <functional>
 #include "ThreadPool.h"  // ThreadPool in thrird party
 #include "paddle/fluid/framework/blocking_queue.h"
+#include "paddle/fluid/framework/details/fetch_op_handle.h"
 #include "paddle/fluid/framework/details/ssa_graph_executor.h"
 
 namespace paddle {
@@ -58,6 +59,21 @@ class ThreadedSSAGraphExecutor : public SSAGraphExecutor {
   std::unique_ptr<platform::EnforceNotMet> exception_;
   std::atomic<int> running_ops_;
   bool allow_op_delay_;
+
+  void InsertPendingOp(std::unordered_map<OpHandleBase *, size_t> *pending_ops,
+                       OpHandleBase *op_instance) const;
+
+  void InsertPendingVar(std::unordered_set<VarHandleBase *> *pending_vars,
+                        BlockingQueue<VarHandleBase *> *ready_vars,
+                        VarHandleBase *var) const;
+
+  void InsertFetchOps(
+      const std::vector<std::string> &fetch_tensors,
+      std::vector<std::unique_ptr<FetchOpHandle>> *fetch_ops,
+      std::unordered_set<std::unique_ptr<VarHandleBase>> *fetch_dependencies,
+      std::unordered_map<OpHandleBase *, size_t> *pending_ops,
+      std::unordered_set<VarHandleBase *> *pending_vars,
+      BlockingQueue<VarHandleBase *> *ready_vars, FeedFetchList *fetch_data);
 };
 
 }  // namespace details

paddle/fluid/inference/CMakeLists.txt

@@ -20,7 +20,9 @@ if(NOT APPLE)
 endif()
 
 if(WITH_TESTING)
+  # both tests/book and analysis depends the models that generated by python/paddle/fluid/tests/book
   add_subdirectory(tests/book)
+  add_subdirectory(analysis)
 endif()
 
 if (TENSORRT_FOUND)

paddle/fluid/inference/analysis/CMakeLists.txt

+cc_library(dot SRCS dot.cc)

paddle/fluid/inference/analysis/dot.cc

+//   Copyright (c) 2018 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.
+
+#include "paddle/fluid/inference/analysis/dot.h"
+
+namespace paddle {
+namespace inference {
+namespace analysis {
+size_t Dot::counter = 0;
+}  // namespace analysis
+}  // namespace inference
+}  // namespace paddle

paddle/fluid/inference/analysis/dot.h

+//   Copyright (c) 2018 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.
+
+/*
+ * This file implements some helper classes and methods for DOT programming
+ * support. It will give a visualization of the graph and that helps to debug
+ * the logics of each Pass.
+ */
+#pragma once
+
+#include <glog/logging.h>
+#include <sstream>
+#include <unordered_map>
+#include <vector>
+
+namespace paddle {
+namespace inference {
+namespace analysis {
+
+/*
+ * A Dot template that helps to build a DOT graph definition.
+ */
+class Dot {
+ public:
+  static size_t counter;
+
+  struct Attr {
+    std::string key;
+    std::string value;
+
+    Attr(const std::string& key, const std::string& value)
+        : key(key), value(value) {}
+
+    std::string repr() const {
+      std::stringstream ss;
+      ss << key << "=" << '"' << value << '"';
+      return ss.str();
+    }
+  };
+
+  struct Node {
+    std::string name;
+    std::vector<Attr> attrs;
+
+    Node(const std::string& name, const std::vector<Attr>& attrs)
+        : name(name),
+          attrs(attrs),
+          id_("node_" + std::to_string(Dot::counter++)) {}
+
+    std::string id() const { return id_; }
+
+    std::string repr() const {
+      std::stringstream ss;
+      CHECK(!name.empty());
+      ss << id_;
+      for (size_t i = 0; i < attrs.size(); i++) {
+        if (i == 0) {
+          ss << "[label=" << '"' << name << '"' << " ";
+        }
+        ss << attrs[i].repr();
+        ss << ((i < attrs.size() - 1) ? " " : "]");
+      }
+      return ss.str();
+    }
+
+   private:
+    std::string id_;
+  };
+
+  struct Edge {
+    std::string source;
+    std::string target;
+    std::vector<Attr> attrs;
+
+    Edge(const std::string& source, const std::string& target,
+         const std::vector<Attr>& attrs)
+        : source(source), target(target), attrs(attrs) {}
+
+    std::string repr() const {
+      std::stringstream ss;
+      CHECK(!source.empty());
+      CHECK(!target.empty());
+      ss << source << "->" << target;
+      for (size_t i = 0; i < attrs.size(); i++) {
+        if (i == 0) {
+          ss << "[";
+        }
+        ss << attrs[i].repr();
+        ss << ((i < attrs.size() - 1) ? " " : "]");
+      }
+      return ss.str();
+    }
+  };
+
+  Dot() = default;
+
+  explicit Dot(const std::vector<Attr>& attrs) : attrs_(attrs) {}
+
+  void AddNode(const std::string& name, const std::vector<Attr>& attrs) {
+    CHECK(!nodes_.count(name)) << "duplicate Node '" << name << "'";
+    nodes_.emplace(name, Node{name, attrs});
+  }
+
+  void AddEdge(const std::string& source, const std::string& target,
+               const std::vector<Attr>& attrs) {
+    CHECK(!source.empty());
+    CHECK(!target.empty());
+    auto sid = nodes_.at(source).id();
+    auto tid = nodes_.at(target).id();
+    edges_.emplace_back(sid, tid, attrs);
+  }
+
+  // Compile to DOT language codes.
+  std::string Build() const {
+    std::stringstream ss;
+    const std::string indent = "   ";
+    ss << "digraph G {" << '\n';
+
+    // Add graph attrs
+    for (const auto& attr : attrs_) {
+      ss << indent << attr.repr() << '\n';
+    }
+    // add nodes
+    for (auto& item : nodes_) {
+      ss << indent << item.second.repr() << '\n';
+    }
+    // add edges
+    for (auto& edge : edges_) {
+      ss << indent << edge.repr() << '\n';
+    }
+    ss << "} // end G";
+    return ss.str();
+  }
+
+ private:
+  std::unordered_map<std::string, Node> nodes_;
+  std::vector<Edge> edges_;
+  std::vector<Attr> attrs_;
+};
+
+}  // namespace analysis
+}  // namespace inference
+}  // namespace paddle

paddle/fluid/inference/engine.h

@@ -19,6 +19,9 @@ limitations under the License. */
 namespace paddle {
 namespace inference {
 
+struct Buffer;
+enum class DeviceType { UNK = -1, CPU, GPU };
+
 /*
  * EngineBase is the base class of all inference engines. An inference engine
  * takes a paddle program as input, and outputs the result in fluid Tensor
@@ -45,8 +48,20 @@ class EngineBase {
   // Execute the engine, that will run the inference network.
   virtual void Execute(int batch_size) = 0;
 
+  // Return the IO buffer that allocated in engine. One can read/write directly
+  // on the buffer. If the buffer's buffer is nullptr, one can also allocate
+  // memory and maintain it outside the engine.
+  virtual Buffer& buffer(const std::string& name) = 0;
+
   virtual ~EngineBase() {}
 };  // class EngineBase
 
+struct Buffer {
+  void* buffer{nullptr};               // buffer should be allocated only once.
+  int max_size;                        // buffer allocated space.
+  int size;                            // data size.
+  DeviceType device{DeviceType::UNK};  // tells which device this buffer is on.
+};
+
 }  // namespace inference
 }  // namespace paddle

paddle/fluid/inference/tensorrt/CMakeLists.txt

+nv_library(tensorrt_engine SRCS engine.cc DEPS framework_proto)
 nv_test(test_tensorrt SRCS test_tensorrt.cc DEPS dynload_cuda device_context dynamic_loader)
-nv_test(test_tensorrt_engine SRCS test_engine.cc engine.cc DEPS dynload_cuda)
-nv_test(test_io_converter SRCS test_io_converter.cc io_converter.cc DEPS dynload_cuda dynamic_loader lod_tensor)
-set(ENGINE_FILE ${CMAKE_CURRENT_SOURCE_DIR}/engine.cc)
+nv_test(test_tensorrt_engine SRCS test_engine.cc DEPS dynload_cuda tensorrt_engine)
+
 add_subdirectory(convert)

paddle/fluid/inference/tensorrt/convert/CMakeLists.txt

-nv_test(test_tensorrt_op_converter SRCS test_op_converter.cc mul_op.cc conv2d_op.cc DEPS ${FLUID_CORE_MODULES})
-nv_test(test_tensorrt_activation_op SRCS test_activation_op.cc ${ENGINE_FILE} activation_op.cc 
-  DEPS ${FLUID_CORE_MODULES} activation_op)
+nv_test(test_op_converter SRCS test_op_converter.cc mul_op.cc conv2d_op.cc DEPS ${FLUID_CORE_MODULES})
+nv_test(test_trt_activation_op SRCS test_activation_op.cc activation_op.cc
+  DEPS ${FLUID_CORE_MODULES} activation_op tensorrt_engine)
+nv_test(test_io_converter SRCS test_io_converter.cc io_converter.cc DEPS dynload_cuda dynamic_loader lod_tensor)