Add more unittests and fix bugs

paddle/fluid/operators/reader/open_files_op.cc

@@ -122,6 +122,7 @@ void MultipleReader::ScheduleThreadFunc() {
       // No more file to read.
       ++completed_thread_num;
       if (completed_thread_num == prefetchers_.size()) {
+        buffer_->Close();
         break;
       }
     }

python/paddle/fluid/tests/unittests/.gitignore

 mnist.recordio
+mnist_0.recordio
+mnist_1.recordio
+mnist_2.recordio

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

@@ -22,9 +22,10 @@ from shutil import copyfile
 
 class TestMultipleReader(unittest.TestCase):
     def setUp(self):
+        self.batch_size = 64
         # Convert mnist to recordio file
         with fluid.program_guard(fluid.Program(), fluid.Program()):
-            reader = paddle.batch(mnist.train(), batch_size=32)
+            reader = paddle.batch(mnist.train(), batch_size=self.batch_size)
             feeder = fluid.DataFeeder(
                 feed_list=[  # order is image and label
                     fluid.layers.data(
@@ -37,9 +38,8 @@ class TestMultipleReader(unittest.TestCase):
                 './mnist_0.recordio', reader, feeder)
         copyfile('./mnist_0.recordio', './mnist_1.recordio')
         copyfile('./mnist_0.recordio', './mnist_2.recordio')
-        print(self.num_batch)
 
-    def test_multiple_reader(self, thread_num=3):
+    def main(self, thread_num):
         file_list = [
             './mnist_0.recordio', './mnist_1.recordio', './mnist_2.recordio'
         ]
@@ -64,8 +64,11 @@ class TestMultipleReader(unittest.TestCase):
             while not data_files.eof():
                 img_val, = exe.run(fetch_list=[img])
                 batch_count += 1
-                print(batch_count)
-            # data_files.reset()
-            print("FUCK")
-
+                self.assertLessEqual(img_val.shape[0], self.batch_size)
+            data_files.reset()
             self.assertEqual(batch_count, self.num_batch * 3)
+
+    def test_main(self):
+        self.main(thread_num=3)  # thread number equals to file number
+        self.main(thread_num=10)  # thread number is larger than file number
+        self.main(thread_num=2)  # thread number is less than file number