diff --git a/dbms/src/DataStreams/ParallelInputsProcessor.h b/dbms/src/DataStreams/ParallelInputsProcessor.h
index b3480e79b76..11511d111b2 100644
--- a/dbms/src/DataStreams/ParallelInputsProcessor.h
+++ b/dbms/src/DataStreams/ParallelInputsProcessor.h
@@ -303,12 +303,12 @@ class ParallelInputsProcessor
             }
         }
 
+        InputData input;
         while (!finish) /// You may need to stop work earlier than all sources run out.
         {
-            InputData input;
-
-            /// Select the next source.
+            if (!input.in)
             {
+                /// Select the next source.
                 std::lock_guard lock(available_inputs_mutex);
 
                 /// If there are no free sources, then this thread is no longer needed. (But other threads can work with their sources.)
@@ -324,31 +324,10 @@ class ParallelInputsProcessor
             /// The main work.
             Block block = input.in->read();
 
-            {
-                if (finish)
-                    break;
-
-                /// If this source is not run out yet, then put the resulting block in the ready queue.
-                {
-                    std::lock_guard lock(available_inputs_mutex);
-
-                    if (block)
-                    {
-                        available_inputs.push(input);
-                    }
-                    else
-                    {
-                        if (available_inputs.empty())
-                            break;
-                    }
-                }
-
-                if (finish)
-                    break;
-
-                if (block)
-                    publishPayload(input.in, block, thread_num);
-            }
+            if (block)
+                publishPayload(input.in, block, thread_num);
+            else
+                input = InputData();
         }
     }