diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml index 83fe9af768964003130d02b7d913ad1c2102dd1d..59661c9c1da53a2ddac0127ed1827fedde811a1d 100644 --- a/.pre-commit-config.yaml +++ b/.pre-commit-config.yaml @@ -31,6 +31,3 @@ - id: go-fmt types: - go - - id: gometalinter - types: - - go diff --git a/doc/design/executor.md b/doc/design/executor.md new file mode 100644 index 0000000000000000000000000000000000000000..b5fb6c5c3c1da3c112ce63878322083dd5c42b70 --- /dev/null +++ b/doc/design/executor.md @@ -0,0 +1,23 @@ +# Executor Design Doc + +## Motivation + +We use executor to do the runtime evaluation of a `ProgramDesc`. + +## Overview + +An executor takes a `ProgramDesc`, a `block_id` and a `Scope`. The `ProgramDesc` is a list of blocks and each block contains the protobuf definition of all the parameters and operators. The `block_id` specifies the entrance block. And the `Scope` is the container of all the variable instance, which is persistent throughout different runs. + +### What does executor do? + +It evaluates all the operators in the `block_id`th block of a `ProgramDesc`. + +### What does executor NOT do? + +It does not do runtime optimization, meaning intelligently parse the dependency of each op a choose which one to be run and in which order they should be run. + +It does not do graph partitioning, meaning dividing the `ProgramDesc` into several small pieces and executing them on different devices. + +## Implementation + +`Executor` evaluates a `ProgramDesc`. Essentially, it instantiates Variables and Operators, then run all the operators in sequence. [[code]](https://github.com/PaddlePaddle/Paddle/blob/develop/paddle/framework/executor.cc) diff --git a/doc/design/infer_var_type.md b/doc/design/infer_var_type.md new file mode 100644 index 0000000000000000000000000000000000000000..d9d5397becba2ef1806d9341cd49cd9aabbf4a6a --- /dev/null +++ b/doc/design/infer_var_type.md @@ -0,0 +1,78 @@ +# Design Doc: InferVarType + +## The Problem Posed + +The variable in our design can hold variant types. Such as `LoDTensor` and `SelectedRows`. An operator should be able to inference the variable types of its output. + +For example, a `lookup table` operator takes two `LoDTensor`; one is a float tensor as the embedding table, the other is an int tensor as word ID. The gradient operator of `lookup table` will generate a `SelectedRows` as its output. A `sum` operator can take both `LoDTensor` and `SelectedRows` as its inputs and will generate a `LoDTensor` if any of its inputs is `LoDTensor`, otherwise, the `sum` operator will generate `SelectedRows` as its output. + +The variable type will be constant at runtime. Every variable's type can either be set by the user (input data and parameter) or be inferred by the operator in compile time. + +## Proposed Solution + +The `InferVarType` is a compile-time function which is registered to each operator. The inferface of that function is: + + +```c++ +using InferVarTypeFN = std::function< + void (const OpDescBind& /*op_desc*/, BlockDescBind* /*block*/)>; +``` + +It takes an operator description as its input and will write the output variable type and store them in block description. + +The `InferVarTypeFN` will be registered in `OpInfo`, to replace `infer_var_type_` field. The `OpInfo` should be + +```cpp +struct OpInfo { + InferVarTypeFN infer_var_type_; + ... +}; +``` + +The default `InferVarType` will set output type as `LoDTensor`. It can be done by `GetInferVarType()`. + +```cpp +void DefaultInferVarType(const OpDescBind& op_desc, BlockDescBind* block) { + // set the output type of variable as `LoDTensor`. + // ... +} + +struct OpInfo { + InferVarTypeFN infer_var_type_; + InferVarTypeFN GetInferVarType() const { + if (infer_var_type_) { + return infer_var_type_; + } else { + return DefaultInferVarType; + } + } +}; +``` + +## Register InferVarType + +We provide a thin base class for registering an `InferVarTypeFN`. To use a base class will ease the implementation of registry since we can detect the registry entry is an `InferVarTypeFN` or not. + +```cpp +class VarTypeInferer { +public: + virtual void operator()(const OpDescBind& op_desc, BlockDescBind* block) const = 0; +} +``` + +Operator developers can write the specialize `VarTypeInferer` as follow. + +```cpp +class SpecialVarTypeInferer : public VarTypeInferer { +public: + virtual void operator()(const OpDescBind& op_desc, BlockDescBind* block) const { + // .. own logic + } +} +``` + +Then user can register the `InferVarType` just like `GradOpDescMaker` and `OpInfoMaker`. + +``` +REGISTER_OPERATOR(some_op, OpType, SpecialVarTypeInferer, ...); +``` diff --git a/doc/design/python_api.md b/doc/design/python_api.md index 56ae1d925a96622b5576013f38e33e5f92cbbb90..cb5fdc765b7126fc66a1c8978d4b96c0dc5a9f2c 100644 --- a/doc/design/python_api.md +++ b/doc/design/python_api.md @@ -179,40 +179,104 @@ init_attr={ `optimize_op_attrs` is not in the `VarDesc` message, but kept in the Python instance, as it will be used in the Python space when creating the optimize operator's `OpDesc`, and will be in the `OpDesc` message. -## Layer Functions +## Layer Function -A layer is a Python function that creates some operators and variables. Layers simplify the work of application programmers. +A layer is a Python function that creates some operators and variables. Layers simplify the work of application programmers. -### Data Layer +Layer functions take `Variable` and configuration parameters as its input and return the output variable(s). + +For example, `FullyConnected` take one or more variable as its input. The input could be input data or another layer's output. There are many configuration options for a `FullyConnected` layer, such as layer size, activation, parameter names, initialization strategies of parameters, and so on. The `FullyConnected` layer will return an output variable. + + +### Necessity for reusing code between layer functions + +There are a lot of code that can be reused. Such as + +* Give the default value of configuration. e.g., default initialize strategy for parameters is uniform random with `min = -1.0`, `max = 1.0`. and default initialize strategy for bias is to fill zero. +* Append the activation operator. +* Create a temporary variable. +* Create parameter. +* Generate a unique name. +* Add a bias. +* ... + +A mechanism to reuse code between layer functions is necessary. It will be around [150 lines of code](https://github.com/PaddlePaddle/Paddle/pull/4724/files#diff-823b27e07e93914ada859232ae23f846R12) if we write a `FullyConnected` layer without any helper functions. + + + +### Comparision between global functions and helper class + +The `FullyConnected` layer will be as follow when we provide global functions: ```python -def data_layer(name, type, column_name): - block = the_current_program.glolal_block() - var = block.create_global_var( - name=name, - shape=[None] + type.dims(), - dtype=type.dtype) - block.prepend_operator(block, - type="Feed", - inputs = None, - outputs = [var], - {column_name: column_name}) - return var +def fc_layer(input, size, param_attr=None, bias_attr=None, act=None, name=None): + if name is None: + name = unique_name("fc") + input = multiple_input(input) + param_attr = default_param_attr(param_attr) + param_attr = multiple_param_attr(param_attr, len(input)) + + # mul + mul_results = [] + for ipt, attr in zip(input, param_attr): + shape = ipt.shape[1:] + [size] + w = g_program.global_block().create_parameter(shape, ipt.dtype, name, attr) + tmp = create_tmp_var(name) + g_program.current_block().append_op("mul", {ipt, w}, {tmp}) + mul_results.append(tmp) + + # add sum + ... + # add bias + ... + # add activation + ... + return out ``` -The input to the feed operator is a special variable in the global scope, which is the output of [Python readers](https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/reader/README.md). +We can provide many helpers functions for layer developers. However, there are several disadvantages for global helper functions: + +1. We need a namespace for these methods, then layer developers can quickly figure out what method they can use. +2. Global functions will force layer developers to pass its parameter time by time. + +So we provide a helper class, `LayerHelper`, to share code between layer functions. The `FullyConnected` Layer will be as follow. + +```python +def fc_layer(input, size, param_attr=None, bias_attr=None, act=None, name=None): + helper = LayerHelper(locals()) # pass all parameter to LayerHelper + + mul_results = [] + for ipt, param in helper.iter_multiple_input_and_param(): + w = helper.create_parameter(shape=ipt.shape[1:] + [size], dtype = ipt.dtype) + tmp = helper.create_tmp_variable() + helper.append_op('mul', {ipt, w}, {tmp}) + mul_results.append(tmp) + + pre_bias = helper.add_sum(mul_results) + pre_activation = helper.add_bias(pre_bias) + return helper.add_activation(pre_activation) +``` + +We not only use the fewer lines of code to write `fc_layer` but also make the code clearer to understand. At the same time, layer developers can figure out what function they can invoke by typing `helper.` in a python editor. + + +### Implementation of layer helper -### FC Layer +We just keep all parameters of a layer function as a dictionary in layer helper as a private data member. Every method of layer helper will look up the dictionary after it is invoked. In that way, we can implement a layer helper for all layer functions even some layer does not contain some operator. For example, The `activation` is used by the FullyConnected layer or convolution layers, but a cross-entropy layer does not use it. The example code of `add_activation` are: ```python -def fc_layer(input, size, ...): - block = program.current_block() - w = block.create_parameter(...) - b = block.create_parameter(...) - out = block.create_var() - op = block.append_operator("FC", X=input, W=w, b=b, out=out) - out.writer = op - return out +class LayerHelper(object): + def __init__(self, **kwargs): # kwargs is short for `keyword arguments` + self.kwargs = kwargs + + def add_activation(self, input_var): + act = self.kwargs.get("act", None) # default value is None + if act is None: # do nothing if no act + return input_var + + tmp = self.create_tmp_var(self) + self.append_op(type=act, input=input_var, output=tmp) + return tmp ``` ## Optimizer diff --git a/doc/howto/deep_model/rnn/rnn_config_cn.rst b/doc/howto/deep_model/rnn/rnn_config_cn.rst index 4d684cf8ad5a8082cf31fb27027119b3d3e700b6..63fa161fafed0f3a8ec8799af21304cbec62d813 100644 --- a/doc/howto/deep_model/rnn/rnn_config_cn.rst +++ b/doc/howto/deep_model/rnn/rnn_config_cn.rst @@ -21,7 +21,7 @@ wmt14数据的提供文件在 `python/paddle/v2/dataset/wmt14.py