Merge pull request #11853 from sneaxiy/complete_py_reader_python

Add Python Reader Op (Python side and unittests)

Author: reyoung

paddle/fluid/framework/reader.h

@@ -29,11 +29,11 @@ enum ReaderStatus { kRunning, kStopped };
 
 class ReaderBase {
  public:
-  void ReadNext(std::vector<LoDTensor>* out);
+  virtual void ReadNext(std::vector<LoDTensor>* out);
 
-  void Shutdown();
+  virtual void Shutdown();
 
-  void Start();
+  virtual void Start();
 
   // Return the readers which are the end of decorating chain. Basically
   // they are readers just before read op.
@@ -42,7 +42,7 @@ class ReaderBase {
   virtual ~ReaderBase();
 
  protected:
-  virtual void ReadNextImpl(std::vector<LoDTensor>* out) = 0;
+  virtual void ReadNextImpl(std::vector<LoDTensor>* out) {}
 
   virtual void ShutdownImpl() {}
 

paddle/fluid/operators/reader/blocking_queue.h

@@ -81,6 +81,15 @@ class BlockingQueue {
     }
   }
 
+  void ReOpen() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    closed_ = false;
+    std::deque<T> new_deque;
+    queue_.swap(new_deque);
+    send_cv_.notify_all();
+    receive_cv_.notify_all();
+  }
+
   void Close() {
     std::lock_guard<std::mutex> lock(mutex_);
     closed_ = true;

paddle/fluid/operators/reader/create_py_reader_op.cc

@@ -27,19 +27,17 @@ class PyReader : public framework::FileReader {
     queue_ = queue;
   }
 
-  void ReadNextImpl(std::vector<framework::LoDTensor>* out) override {
+  void ReadNext(std::vector<framework::LoDTensor>* out) override {
     bool success;
     *out = queue_->Pop(&success);
     if (!success) out->clear();
   }
 
- private:
-  void ShutdownImpl() override { /* TODO */
-  }
+  void Shutdown() override { queue_->Close(); }
 
-  void StartImpl() override { /* TODO */
-  }
+  void Start() override { queue_->ReOpen(); }
 
+ private:
   std::shared_ptr<LoDTensorBlockingQueue> queue_;
 };
 

paddle/fluid/operators/reader/lod_tensor_blocking_queue.h

@@ -58,12 +58,15 @@ class LoDTensorBlockingQueue {
 
   inline size_t Size() const { return queue_.Size(); }
 
-  inline void Close() { return queue_.Close(); }
+  inline void ReOpen() { queue_.ReOpen(); }
+
+  inline void Close() { queue_.Close(); }
 
   inline bool IsClosed() const { return queue_.IsClosed(); }
 
  private:
-  void CheckDims(const std::vector<framework::LoDTensor>& lod_tensor_vec) {
+  void CheckDims(
+      const std::vector<framework::LoDTensor>& lod_tensor_vec) const {
     PADDLE_ENFORCE(dims_.size() == lod_tensor_vec.size(),
                    "Expect input size is %d but found %s", dims_.size(),
                    lod_tensor_vec.size());

paddle/fluid/pybind/pybind.cc

@@ -14,6 +14,7 @@ limitations under the License. */
 #include <Python.h>
 #include <algorithm>
 #include <map>
+#include <memory>
 #include <mutex>  // NOLINT // for call_once
 #include <string>
 #include <unordered_map>
@@ -310,7 +311,8 @@ All parameter, weight, gradient are variables in Paddle.
       ::paddle::operators::reader::LoDTensorBlockingQueue;
   using LoDTensorBlockingQueueHolder =
       ::paddle::operators::reader::LoDTensorBlockingQueueHolder;
-  py::class_<LoDTensorBlockingQueue>(m, "LoDTensorBlockingQueue", "")
+  py::class_<LoDTensorBlockingQueue, std::shared_ptr<LoDTensorBlockingQueue>>(
+      m, "LoDTensorBlockingQueue", "")
       .def("push",
            [](LoDTensorBlockingQueue &self,
               const std::vector<framework::LoDTensor> &lod_tensor_vec) {
@@ -325,17 +327,17 @@ All parameter, weight, gradient are variables in Paddle.
   m.def("init_lod_tensor_blocking_queue",
         [](Variable &var, size_t capacity,
            const std::vector<std::vector<int64_t>> &shapes)
-            -> LoDTensorBlockingQueue * {
+            -> std::shared_ptr<LoDTensorBlockingQueue> {
               std::vector<DDim> dims(shapes.size());
               std::transform(shapes.begin(), shapes.end(), dims.begin(),
                              [](const std::vector<int64_t> &shape) {
                                return make_ddim(shape);
                              });
               auto *holder = var.GetMutable<LoDTensorBlockingQueueHolder>();
               holder->InitOnce(capacity, dims);
-              return holder->GetQueue().get();
+              return holder->GetQueue();
             },
-        py::return_value_policy::reference);
+        py::return_value_policy::copy);
 
   py::class_<Scope>(m, "Scope", "")
       .def("var",
@@ -543,6 +545,8 @@ All parameter, weight, gradient are variables in Paddle.
       });
 
   py::class_<LoDTensorArray>(m, "LoDTensorArray")
+      .def("__init__",
+           [](LoDTensorArray &instance) { new (&instance) LoDTensorArray(); })
       .def("__getitem__",
            [](LoDTensorArray &self, size_t i) { return &self.at(i); },
            py::return_value_policy::reference)

python/paddle/fluid/__init__.py

@@ -44,7 +44,7 @@
 import transpiler
 from param_attr import ParamAttr, WeightNormParamAttr
 from data_feeder import DataFeeder
-from core import LoDTensor, CPUPlace, CUDAPlace, CUDAPinnedPlace, Scope
+from core import LoDTensor, LoDTensorArray, CPUPlace, CUDAPlace, CUDAPinnedPlace, Scope
 from transpiler import DistributeTranspiler, InferenceTranspiler, \
     memory_optimize, release_memory
 from concurrency import (Go, make_channel, channel_send, channel_recv,
@@ -72,6 +72,7 @@
               'backward',
               'regularizer',
               'LoDTensor',
+              'LoDTensorArray',
               'CPUPlace',
               'CUDAPlace',
               'CUDAPinnedPlace',

python/paddle/fluid/layers/io.py

@@ -24,7 +24,8 @@
 __all__ = [
     'data', 'BlockGuardServ', 'ListenAndServ', 'Send', 'Recv',
     'open_recordio_file', 'open_files', 'read_file', 'shuffle', 'batch',
-    'double_buffer', 'random_data_generator', 'Preprocessor', 'load'
+    'double_buffer', 'random_data_generator', 'py_reader', 'Preprocessor',
+    'load'
 ]
 
 
@@ -445,6 +446,88 @@ def random_data_generator(low, high, shapes, lod_levels, for_parallel=True):
     return monkey_patch_reader_methods(main_prog_var)
 
 
+def py_reader(capacity, shapes, dtypes, lod_levels=None):
+    """
+    Create a reader and blocking queue for data feeding in Python
+    
+    This layer returns a Reader Variable and a BlockingQueue.
+    The BlockingQueue provides `push()` method to push a `LoDTensorArray` 
+    object into the queue in Python side. In C++ side, the Reader 
+    Variable would invoke `pop()` method of the queue to retrieve the 
+    feeding data. The process of feeding data in Python side and fetching 
+    data in C++ side can run in parallel. The BlockingQueue should be closed 
+    using `close()` method when unused.
+
+    Args:
+       capacity(int): The maximum capacity of the BlockingQueue.
+       shapes(list): List of tuples which declaring data shapes.
+       dtypes(list): List of strs which declaring data type. 
+       lod_levels(list): List of ints which declaring data lod_level.
+
+    Returns:
+       tuple(Variable, BlockingQueue):
+       A Reader Variable from which we can get feeding data.
+       
+       A BlockingQueue object for data feeding.
+
+    Examples:
+
+        .. code-block:: python
+
+            reader, queue = fluid.layers.py_reader(
+                                             capacity=10,
+                                             shapes=[[-1,3,224,224], [-1,1]],
+                                             dtypes=['float32', 'int64'])
+            # Via the reader, we can use 'read_file' layer to get data:
+            image, label = fluid.layers.read_file(reader)
+            
+            # Via the blocking queue, we can feed data using threads
+            def feed_data(queue, feed_images, feed_labels):
+                for feed_image, feed_label in zip(feed_images, feed_labels):
+                    data = core.LoDTensorArray()
+                    data.append(feed_image)
+                    data.append(feed_label)
+                    queue.push(data)
+            
+            thread = threading.Thread(target=feed_data, args=(queue, feed_images, feed_labels))
+            thread.start()
+    """
+    dtypes = [convert_np_dtype_to_dtype_(dt) for dt in dtypes]
+    shape_concat = []
+    ranks = []
+
+    for shape in shapes:
+        shape_concat.extend(shape)
+        ranks.append(len(shape))
+
+    if lod_levels is None:
+        lod_levels = [0] * len(shapes)
+
+    queue_name = unique_name('lod_tensor_blocking_queue')
+    var = global_scope().var(queue_name)
+    feed_queue = core.init_lod_tensor_blocking_queue(var, capacity, shapes)
+
+    startup_blk = default_startup_program().current_block()
+    startup_var = startup_blk.create_var(name=unique_name('create_py_reader'))
+    startup_blk.append_op(
+        type='create_py_reader',
+        inputs={'blocking_queue': queue_name},
+        outputs={'Out': [startup_var]},
+        attrs={
+            'shape_concat': shape_concat,
+            'lod_levels': lod_levels,
+            'ranks': ranks
+        })
+
+    startup_var.desc.set_dtypes(dtypes)
+    startup_var.persistable = True
+
+    main_prog_var = _copy_reader_var_(default_main_program().current_block(),
+                                      startup_var)
+
+    return monkey_patch_reader_methods(main_prog_var), feed_queue
+
+
 def open_files(filenames,
                shapes,
                lod_levels,

python/paddle/fluid/tests/unittests/test_py_reader_push_pop.py

@@ -0,0 +1,99 @@
+# 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.
+
+import unittest
+import paddle.fluid as fluid
+import numpy as np
+from threading import Thread
+
+
+def feed_data(feed_queue, inputs):
+    for in_data in inputs:
+        feed_queue.push(in_data)
+
+
+class TestPyReader(unittest.TestCase):
+    def setUp(self):
+        self.capacity = 10
+        self.batch_size_min = 10
+        self.batch_size_max = 20
+        self.shapes = [(-1, 3, 2, 1), (-1, 1)]
+        self.lod_levels = [0, 0]
+        self.dtypes = ['float32', 'int64']
+        self.iterations = 20
+
+    def test_single_thread_main(self):
+        self.main(use_thread=False)
+
+    def test_multiple_thread_main(self):
+        self.main(use_thread=True)
+
+    def main(self, use_thread=False):
+        with fluid.program_guard(fluid.Program(), fluid.Program()):
+            place = fluid.CUDAPlace(0) if fluid.core.is_compiled_with_cuda(
+            ) else fluid.CPUPlace()
+            executor = fluid.Executor(place)
+
+            data_file, feed_queue = fluid.layers.py_reader(
+                capacity=self.capacity,
+                dtypes=self.dtypes,
+                lod_levels=self.lod_levels,
+                shapes=self.shapes)
+
+            read_out_data = fluid.layers.read_file(data_file)
+            self.inputs = []
+
+            for i in range(self.iterations):
+                in_data = fluid.LoDTensorArray()
+                batch_size = np.random.random_integers(self.batch_size_min,
+                                                       self.batch_size_max)
+                for shape, dtype in zip(self.shapes, self.dtypes):
+                    next_data = np.random.uniform(
+                        low=0, high=1000,
+                        size=(batch_size, ) + shape[1:]).astype(dtype)
+                    in_data.append(executor.as_lodtensor(next_data))
+
+                self.inputs.append(in_data)
+
+            executor.run(fluid.default_startup_program())
+            self.outputs = []
+            if use_thread:
+                thread = Thread(
+                    target=feed_data, args=(feed_queue, self.inputs))
+                thread.start()
+                for in_data in self.inputs:
+                    self.outputs.append(
+                        executor.run(fetch_list=list(read_out_data)))
+            else:
+                for in_data in self.inputs:
+                    feed_queue.push(in_data)
+                    self.outputs.append(
+                        executor.run(fetch_list=list(read_out_data)))
+
+            feed_queue.close()
+            self.validate()
+
+    def validate(self):
+        self.assertEqual(len(self.inputs), len(self.outputs))
+        for in_data_list, out_data_list in zip(self.inputs, self.outputs):
+            self.assertEqual(len(in_data_list), len(out_data_list))
+            in_data_list_np = [
+                np.array(in_lod_tensor) for in_lod_tensor in in_data_list
+            ]
+            for in_data, out_data in zip(in_data_list_np, out_data_list):
+                self.assertTrue((in_data == out_data).all())
+
+
+if __name__ == '__main__':
+    unittest.main()