program.html



<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
  <meta charset="utf-8">
  
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  
  <title>Design Doc: PaddlePaddle Programs &mdash; PaddlePaddle  documentation</title>
  

    <link rel="stylesheet" href="../_static/css/theme.css" type="text/css" />
  

        <link rel="index" title="Index"
              href="../genindex.html"/>
        <link rel="search" title="Search" href="../search.html"/>
    <link rel="top" title="PaddlePaddle  documentation" href="../index.html"/> 
<script>
var _hmt = _hmt || [];
(function() {
  var hm = document.createElement("script");
  hm.src = "//hm.baidu.com/hm.js?b9a314ab40d04d805655aab1deee08ba";
  var s = document.getElementsByTagName("script")[0]; 
  s.parentNode.insertBefore(hm, s);
})();
</script>


  <script src="../_static/js/modernizr.min.js"></script>

</head>

<body class="wy-body-for-nav" role="document">

  <div class="wy-grid-for-nav">

    
    <nav data-toggle="wy-nav-shift" class="wy-nav-side">
      <div class="wy-side-scroll">
        <div class="wy-side-nav-search">
          

            <a href="../index_en.html" class="icon icon-home"> PaddlePaddle
          

          </a>

          
<div role="search">
  <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
    <input type="text" name="q" placeholder="Search docs" />
    <input type="hidden" name="check_keywords" value="yes" />
    <input type="hidden" name="area" value="default" />
  </form>
</div>

          
        </div>

        <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
          
<nav class="doc-menu-vertical" role="navigation">

<ul>
<li class="toctree-l1"><a class="reference internal" href="../getstarted/index_en.html">GET STARTED</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../getstarted/quickstart_en.html">Quick Start</a></li>
<li class="toctree-l2"><a class="reference internal" href="../getstarted/concepts/use_concepts_en.html">Basic Concept</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../build_and_install/index_en.html">Install and Build</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../build_and_install/pip_install_en.html">Install using pip</a></li>
<li class="toctree-l2"><a class="reference internal" href="../build_and_install/docker_install_en.html">Run in Docker Containers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../build_and_install/build_from_source_en.html">Build from Sources</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../howto/index_en.html">HOW TO</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../howto/cmd_parameter/index_en.html">Set Command-line Parameters</a><ul>
<li class="toctree-l3"><a class="reference internal" href="../howto/cmd_parameter/use_case_en.html">Use Case</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/cmd_parameter/arguments_en.html">Argument Outline</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/cmd_parameter/detail_introduction_en.html">Detail Description</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="../howto/cluster/index_en.html">Distributed Training</a><ul>
<li class="toctree-l3"><a class="reference internal" href="../howto/cluster/preparations_en.html">Preparations</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/cluster/cmd_argument_en.html">Command-line arguments</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/cluster/multi_cluster/index_en.html">Use different clusters</a><ul>
<li class="toctree-l4"><a class="reference internal" href="../howto/cluster/multi_cluster/fabric_en.html">Fabric</a></li>
<li class="toctree-l4"><a class="reference internal" href="../howto/cluster/multi_cluster/openmpi_en.html">OpenMPI</a></li>
<li class="toctree-l4"><a class="reference internal" href="../howto/cluster/multi_cluster/k8s_en.html">Kubernetes</a></li>
<li class="toctree-l4"><a class="reference internal" href="../howto/cluster/multi_cluster/k8s_aws_en.html">Kubernetes on AWS</a></li>
</ul>
</li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="../howto/rnn/index_en.html">RNN Models</a><ul>
<li class="toctree-l3"><a class="reference internal" href="../howto/rnn/rnn_config_en.html">RNN Configuration</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/rnn/recurrent_group_en.html">Recurrent Group Tutorial</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/rnn/hierarchical_layer_en.html">Layers supporting hierarchical sequence as input</a></li>
<li class="toctree-l3"><a class="reference internal" href="../howto/rnn/hrnn_rnn_api_compare_en.html">API comparision between RNN and hierarchical RNN</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="../howto/optimization/gpu_profiling_en.html">Tune GPU Performance</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../dev/index_en.html">Development</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../dev/contribute_to_paddle_en.html">Contribute Code</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dev/write_docs_en.html">Contribute Documentation</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../faq/index_en.html">FAQ</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../faq/build_and_install/index_en.html">Install, Build and Unit test</a></li>
<li class="toctree-l2"><a class="reference internal" href="../faq/model/index_en.html">Model Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../faq/parameter/index_en.html">Parameter Setting</a></li>
<li class="toctree-l2"><a class="reference internal" href="../faq/local/index_en.html">Local Training and Prediction</a></li>
<li class="toctree-l2"><a class="reference internal" href="../faq/cluster/index_en.html">Cluster Training and Prediction</a></li>
</ul>
</li>
</ul>

</nav>

        </div>
      </div>
    </nav>

    <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">

      
      <nav class="wy-nav-top" role="navigation" aria-label="top navigation">
        <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
        <a href="../index_en.html">PaddlePaddle</a>
      </nav>


      <div class="wy-nav-content">
        <div class="rst-content">
          

<div role="navigation" aria-label="breadcrumbs navigation">
  <ul class="wy-breadcrumbs">
    <li><a href="../index_en.html">Docs</a> &raquo;</li>
      
    <li>Design Doc: PaddlePaddle Programs</li>
      <li class="wy-breadcrumbs-aside">
        
          
            <a href="../_sources/design/program.md.txt" rel="nofollow"> View page source</a>
          
        
      </li>
  </ul>
  <hr/>
</div>
          <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
           <div itemprop="articleBody">
            
  <div class="section" id="design-doc-paddlepaddle-programs">
<span id="design-doc-paddlepaddle-programs"></span><h1>Design Doc: PaddlePaddle Programs<a class="headerlink" href="#design-doc-paddlepaddle-programs" title="Permalink to this headline">¶</a></h1>
<div class="section" id="compile-and-execution">
<span id="compile-and-execution"></span><h2>Compile and Execution<a class="headerlink" href="#compile-and-execution" title="Permalink to this headline">¶</a></h2>
<p>A PaddlePaddle program consists of two parts &#8211; the first generates a <code class="docutils literal"><span class="pre">ProgramDesc</span></code> protobuf message that describes the program, and the second runs this message using a C++ class <code class="docutils literal"><span class="pre">Executor</span></code>.</p>
<p>A simple example PaddlePaddle program can be found in <a class="reference internal" href="graph.html"><span class="doc">graph.md</span></a>:</p>
<div class="highlight-python"><div class="highlight"><pre><span></span><span class="n">x</span> <span class="o">=</span> <span class="n">layer</span><span class="o">.</span><span class="n">data</span><span class="p">(</span><span class="s2">&quot;images&quot;</span><span class="p">)</span>
<span class="n">l</span> <span class="o">=</span> <span class="n">layer</span><span class="o">.</span><span class="n">data</span><span class="p">(</span><span class="s2">&quot;label&quot;</span><span class="p">)</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">layer</span><span class="o">.</span><span class="n">fc</span><span class="p">(</span><span class="n">x</span><span class="p">)</span>
<span class="n">cost</span> <span class="o">=</span> <span class="n">layer</span><span class="o">.</span><span class="n">mse</span><span class="p">(</span><span class="n">y</span><span class="p">,</span> <span class="n">l</span><span class="p">)</span>
<span class="n">optimize</span><span class="p">(</span><span class="n">cost</span><span class="p">)</span>
<span class="n">train</span><span class="p">(</span><span class="n">cost</span><span class="p">,</span> <span class="n">reader</span><span class="o">=</span><span class="n">mnist</span><span class="o">.</span><span class="n">train</span><span class="p">())</span>
</pre></div>
</div>
<p>The first five lines of the following PaddlePaddle program generates, or, compiles, the <code class="docutils literal"><span class="pre">ProgramDesc</span></code> message.  The last line runs it.</p>
</div>
<div class="section" id="programs-and-blocks">
<span id="programs-and-blocks"></span><h2>Programs and Blocks<a class="headerlink" href="#programs-and-blocks" title="Permalink to this headline">¶</a></h2>
<p>The basic structure of a PaddlePaddle program is some nested blocks, as a C++ or Java program.</p>
<ul class="simple">
<li>program: some nested blocks</li>
<li><a class="reference internal" href="block.html"><span class="doc">block</span></a>:<ul>
<li>some local variable definitions, and</li>
<li>a sequence of operators</li>
</ul>
</li>
</ul>
<p>The concept of block comes from usual programs.  For example, the following C++ program has three blocks:</p>
<div class="highlight-c++"><div class="highlight"><pre><span></span><span class="kt">int</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span> <span class="c1">// block 0</span>
  <span class="kt">int</span> <span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
  <span class="k">if</span> <span class="p">(</span><span class="n">i</span> <span class="o">&lt;</span> <span class="mi">10</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// block 1</span>
    <span class="k">for</span> <span class="p">(</span><span class="kt">int</span> <span class="n">j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">j</span> <span class="o">&lt;</span> <span class="mi">10</span><span class="p">;</span> <span class="n">j</span><span class="o">++</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// block 2</span>
    <span class="p">}</span>
  <span class="p">}</span>
  <span class="k">return</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>The following PaddlePaddle program has three blocks:</p>
<div class="highlight-python"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">paddle</span> <span class="kn">as</span> <span class="nn">pd</span>  <span class="o">//</span> <span class="n">block</span> <span class="mi">0</span>

<span class="n">x</span> <span class="o">=</span> <span class="n">minibatch</span><span class="p">([</span><span class="mi">10</span><span class="p">,</span> <span class="mi">20</span><span class="p">,</span> <span class="mi">30</span><span class="p">])</span> <span class="c1"># shape=[None, 1]</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">var</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span> <span class="c1"># shape=[1], value=1</span>
<span class="n">z</span> <span class="o">=</span> <span class="n">minibatch</span><span class="p">([</span><span class="mi">10</span><span class="p">,</span> <span class="mi">20</span><span class="p">,</span> <span class="mi">30</span><span class="p">])</span> <span class="c1"># shape=[None, 1]</span>
<span class="n">cond</span> <span class="o">=</span> <span class="n">larger_than</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="mi">15</span><span class="p">)</span> <span class="c1"># [false, true, true]</span>

<span class="n">ie</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">ifelse</span><span class="p">()</span>
<span class="k">with</span> <span class="n">ie</span><span class="o">.</span><span class="n">true_block</span><span class="p">():</span>  <span class="o">//</span> <span class="n">block</span> <span class="mi">1</span>
    <span class="n">d</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">layer</span><span class="o">.</span><span class="n">add_scalar</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
    <span class="n">ie</span><span class="o">.</span><span class="n">output</span><span class="p">(</span><span class="n">d</span><span class="p">,</span> <span class="n">pd</span><span class="o">.</span><span class="n">layer</span><span class="o">.</span><span class="n">softmax</span><span class="p">(</span><span class="n">d</span><span class="p">))</span>
<span class="k">with</span> <span class="n">ie</span><span class="o">.</span><span class="n">false_block</span><span class="p">():</span>  <span class="o">//</span> <span class="n">block</span> <span class="mi">2</span>
    <span class="n">d</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">layer</span><span class="o">.</span><span class="n">fc</span><span class="p">(</span><span class="n">z</span><span class="p">)</span>
    <span class="n">ie</span><span class="o">.</span><span class="n">output</span><span class="p">(</span><span class="n">d</span><span class="p">,</span> <span class="n">d</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>
<span class="n">o1</span><span class="p">,</span> <span class="n">o2</span> <span class="o">=</span> <span class="n">ie</span><span class="p">(</span><span class="n">cond</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="blockdesc-and-programdesc">
<span id="blockdesc-and-programdesc"></span><h2><code class="docutils literal"><span class="pre">BlockDesc</span></code> and <code class="docutils literal"><span class="pre">ProgramDesc</span></code><a class="headerlink" href="#blockdesc-and-programdesc" title="Permalink to this headline">¶</a></h2>
<p>All protobuf messages are defined in <code class="docutils literal"><span class="pre">framework.proto</span></code>.</p>
<p><code class="docutils literal"><span class="pre">BlockDesc</span></code> is straight-forward &#8211; it includes local variable definitions, <code class="docutils literal"><span class="pre">vars</span></code>, and a sequence of operators, <code class="docutils literal"><span class="pre">ops</span></code>.</p>
<div class="highlight-protobuf"><div class="highlight"><pre><span></span><span class="kd">message</span> <span class="nc">BlockDesc</span> <span class="p">{</span>
  <span class="k">required</span> <span class="kt">int32</span> <span class="na">parent</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
  <span class="k">repeated</span> <span class="n">VarDesc</span> <span class="na">vars</span> <span class="o">=</span> <span class="mi">2</span><span class="p">;</span>
  <span class="k">repeated</span> <span class="n">OpDesc</span> <span class="na">ops</span> <span class="o">=</span> <span class="mi">3</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>The parent ID indicates the parent block so that operators in a block can refer to variables defined locally and also those defined in their ancestor blocks.</p>
<p>All hierarchical blocks in a program are flattened and stored in an array. The block ID is the index of the block in this array.</p>
<div class="highlight-protobuf"><div class="highlight"><pre><span></span><span class="kd">message</span> <span class="nc">ProgramDesc</span> <span class="p">{</span>
  <span class="k">repeated</span> <span class="n">BlockDesc</span> <span class="na">blocks</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="section" id="global-block">
<span id="global-block"></span><h3>Global Block<a class="headerlink" href="#global-block" title="Permalink to this headline">¶</a></h3>
<p>The global block is the first one in the above array.</p>
</div>
</div>
<div class="section" id="operators-that-use-blocks">
<span id="operators-that-use-blocks"></span><h2>Operators that Use Blocks<a class="headerlink" href="#operators-that-use-blocks" title="Permalink to this headline">¶</a></h2>
<p>In the above example, the operator <code class="docutils literal"><span class="pre">IfElseOp</span></code> has two blocks &#8211; the true branch and the false branch.</p>
<p>The definition of <code class="docutils literal"><span class="pre">OpDesc</span></code> shows that an operator could have some attributes:</p>
<div class="highlight-protobuf"><div class="highlight"><pre><span></span><span class="kd">message</span> <span class="nc">OpDesc</span> <span class="p">{</span>
  <span class="n">AttrDesc</span> <span class="na">attrs</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
  <span class="o">...</span>
<span class="p">}</span>
</pre></div>
</div>
<p>and an attribute could be of type block, which is, in fact, a block ID as described above:</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">message</span> <span class="n">AttrDesc</span> <span class="p">{</span>
  <span class="n">required</span> <span class="n">string</span> <span class="n">name</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>

  <span class="n">enum</span> <span class="n">AttrType</span> <span class="p">{</span>
    <span class="n">INT</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span>
    <span class="n">STRING</span> <span class="o">=</span> <span class="mi">2</span><span class="p">,</span>
    <span class="o">...</span>
    <span class="n">BLOCK</span> <span class="o">=</span> <span class="o">...</span>
  <span class="p">}</span>
  <span class="n">required</span> <span class="n">AttrType</span> <span class="nb">type</span> <span class="o">=</span> <span class="mi">2</span><span class="p">;</span>

  <span class="n">optional</span> <span class="n">int32</span> <span class="n">block</span> <span class="o">=</span> <span class="mi">10</span><span class="p">;</span> <span class="o">//</span> <span class="n">when</span> <span class="nb">type</span> <span class="o">==</span> <span class="n">BLOCK</span>
  <span class="o">...</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="infershape">
<span id="infershape"></span><h2>InferShape<a class="headerlink" href="#infershape" title="Permalink to this headline">¶</a></h2>
<p>With this design, the InferShape function should take the following parameters:</p>
<div class="highlight-c++"><div class="highlight"><pre><span></span><span class="kt">void</span> <span class="nf">InferShape</span><span class="p">(</span><span class="kt">int</span> <span class="n">current_block</span><span class="p">,</span>
                <span class="kt">int</span> <span class="n">current_operator</span><span class="p">,</span>
                <span class="n">ProgramDesc</span><span class="o">*</span> <span class="n">program</span> <span class="c1">// might change VarDesc values.</span>
                <span class="p">)</span> <span class="p">{</span>
  <span class="p">...</span>
<span class="p">}</span>
</pre></div>
</div>
<p>where</p>
<ul class="simple">
<li><code class="docutils literal"><span class="pre">current_block</span></code> indices into <code class="docutils literal"><span class="pre">ProgramDesc::blocks</span></code>,</li>
<li><code class="docutils literal"><span class="pre">current_operator</span></code> indices into <code class="docutils literal"><span class="pre">BlockDesc::ops</span></code>.</li>
</ul>
</div>
</div>


           </div>
          </div>
          <footer>
  

  <hr/>

  <div role="contentinfo">
    <p>
        &copy; Copyright 2016, PaddlePaddle developers.

    </p>
  </div>
  Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>. 

</footer>

        </div>
      </div>

    </section>

  </div>
  

    <script type="text/javascript">
        var DOCUMENTATION_OPTIONS = {
            URL_ROOT:'../',
            VERSION:'',
            COLLAPSE_INDEX:false,
            FILE_SUFFIX:'.html',
            HAS_SOURCE:  true
        };
    </script>
      <script type="text/javascript" src="../_static/jquery.js"></script>
      <script type="text/javascript" src="../_static/underscore.js"></script>
      <script type="text/javascript" src="../_static/doctools.js"></script>
      <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>

  
    <script type="text/javascript" src="../_static/js/theme.js"></script>
  

  <script type="text/javascript">
      jQuery(function () {
          SphinxRtdTheme.StickyNav.enable();
      });
  </script>
   

</body>
</html>