Update async_executor.md

doc/fluid/design/async_executor/async_executor.md

@@ -13,7 +13,6 @@ def train_loop():
     dataset = fluid.DataFeedDesc('train_data/data.prototxt')
     dataset.set_batch_size(128)  # See API doc for how to change other fields
     print dataset.desc()  # Debug purpose: see what we get
-     # define network
     # input text data
     data = fluid.layers.data(
         name="words", shape=[1], dtype="int64", lod_level=1)
@@ -130,13 +129,10 @@ Inside the function ```Trainfiles```,
 void ExecutorThreadWorker::TrainFiles() {
   // todo: configurable
   SetDevice();
-
   int fetch_var_num = fetch_var_names_.size();
   fetch_values_.clear();
-  fetch_values_.resize(fetch_var_num, 0);
-
+  fetch_values_.resize(fetch_var_num);
   thread_reader_->Start();
-
   int cur_batch;
   int batch_cnt = 0;
   while ((cur_batch = thread_reader_->Next()) > 0) {
@@ -144,25 +140,16 @@ void ExecutorThreadWorker::TrainFiles() {
     for (auto& op : ops_) {
       op->Run(*thread_scope_, place_);
     }
-
-    float avg_inspect = 0.0;
-    for (int i = 0; i < fetch_var_num; ++i) {
-      avg_inspect = thread_scope_->FindVar(fetch_var_names_[i])
-                                 ->GetMutable<LoDTensor>()
-                                 ->data<float>()[0];
-      fetch_values_[i] += avg_inspect;
-    }
-
     ++batch_cnt;
     thread_scope_->DropKids();
+    if (debug_ == false || thread_id_ != 0) {
+      continue;
     }
-
-  if (batch_cnt) {
-    // when the number of files is less than the number of threads
     for (int i = 0; i < fetch_var_num; ++i) {
-      fetch_values_[i] = fetch_values_[i] / batch_cnt;
-    }
-  }
+      print_fetch_var(thread_scope_, fetch_var_names_[i]);
+    }  // end for (int i = 0...)
+  }    // end while ()
+}
 
 ```