Merge error

Author: reyoung

paddle/fluid/operators/reader/open_files_op.cc

@@ -18,6 +18,7 @@
 #include "ThreadPool.h"
 #include "paddle/fluid/framework/blocking_queue.h"
 #include "paddle/fluid/operators/reader/blocking_queue.h"
+#include "paddle/fluid/operators/reader/buffered_reader.h"
 #include "paddle/fluid/operators/reader/reader_op_registry.h"
 
 namespace paddle {
@@ -232,12 +233,17 @@ class OpenFilesOp : public framework::OperatorBase {
       container.reset(new OrderedReaderContainer());
     } else {
       container.reset(new PreemptiveReaderContainer(
-          std::min(file_names.size(),
-                   static_cast<size_t>(std::thread::hardware_concurrency()))));
+          static_cast<size_t>(Attr<int>("thread_num"))));
     }
 
-    out->Reset(
-        std::make_shared<MultiFileReader>(file_names, std::move(container)));
+    std::shared_ptr<framework::ReaderBase> reader(
+        new MultiFileReader(file_names, std::move(container)));
+    auto buffer_size = Attr<int>("buffer_size");
+    if (buffer_size > 1) {
+      reader = framework::MakeDecoratedReader<BufferedReader>(
+          reader, platform::CPUPlace(), buffer_size);
+    }
+    out->Reset(reader);
   }
 };
 
@@ -253,6 +259,8 @@ class OpenFilesOpMaker : public FileReaderMakerBase {
       An OpenFilesOp creates a MultiFileReader, which is able to
       read data multi-threaded from multiple files.
     )DOC");
+    AddAttr<int>("thread_num", "Number of thread to read files.");
+    AddAttr<int>("buffer_size", "The reading buffer of these files.");
   }
 };