Fix test_bert on GPU (#24692)

DataLoader makes the data diff even if the data of reader is the same on CUDA place. This PR doesn't use DataLoader to pass the test. we will use DataLoader back after we fix it.

python/paddle/fluid/tests/unittests/dygraph_to_static/bert_utils.py

@@ -260,51 +260,48 @@ class DataReader(object):
             yield token_ids, sent_ids, pos_ids, label
 
     def data_generator(self):
-        def wrapper():
-            def reader():
-                for epoch in range(self.epoch):
-                    self.current_epoch = epoch + 1
-                    sample_generator = self.build_fake_data()
-                    for sample in sample_generator:
-                        if sample is None:
-                            continue
-                        yield sample
-
-            def batch_reader(reader, batch_size, in_tokens):
-                batch, total_token_num, max_len = [], 0, 0
-                for parsed_line in reader():
-                    token_ids, sent_ids, pos_ids, label = parsed_line
-                    max_len = max(max_len, len(token_ids))
-                    if in_tokens:
-                        to_append = (len(batch) + 1) * max_len <= batch_size
-                    else:
-                        to_append = len(batch) < batch_size
-                    if to_append:
-                        batch.append(parsed_line)
-                        total_token_num += len(token_ids)
-                    else:
-                        yield batch, total_token_num
-                        batch, total_token_num, max_len = [parsed_line], len(
-                            token_ids), len(token_ids)
-
-                if len(batch) > 0:
+        def reader():
+            for epoch in range(self.epoch):
+                self.current_epoch = epoch + 1
+                sample_generator = self.build_fake_data()
+                for sample in sample_generator:
+                    if sample is None:
+                        continue
+                    yield sample
+
+        def batch_reader(reader, batch_size, in_tokens):
+            batch, total_token_num, max_len = [], 0, 0
+            for parsed_line in reader():
+                token_ids, sent_ids, pos_ids, label = parsed_line
+                max_len = max(max_len, len(token_ids))
+                if in_tokens:
+                    to_append = (len(batch) + 1) * max_len <= batch_size
+                else:
+                    to_append = len(batch) < batch_size
+                if to_append:
+                    batch.append(parsed_line)
+                    total_token_num += len(token_ids)
+                else:
                     yield batch, total_token_num
-
-            for batch_data, total_token_num in batch_reader(
-                    reader, self.batch_size, self.in_tokens):
-                yield prepare_batch_data(
-                    batch_data,
-                    total_token_num,
-                    voc_size=self.voc_size,
-                    pad_id=self.pad_id,
-                    cls_id=self.cls_id,
-                    sep_id=self.sep_id,
-                    mask_id=self.mask_id,
-                    return_input_mask=True,
-                    return_max_len=False,
-                    return_num_token=False)
-
-        return wrapper
+                    batch, total_token_num, max_len = [parsed_line], len(
+                        token_ids), len(token_ids)
+
+            if len(batch) > 0:
+                yield batch, total_token_num
+
+        for batch_data, total_token_num in batch_reader(reader, self.batch_size,
+                                                        self.in_tokens):
+            yield prepare_batch_data(
+                batch_data,
+                total_token_num,
+                voc_size=self.voc_size,
+                pad_id=self.pad_id,
+                cls_id=self.cls_id,
+                sep_id=self.sep_id,
+                mask_id=self.mask_id,
+                return_input_mask=True,
+                return_max_len=False,
+                return_num_token=False)
 
 
 class ModelHyperParams(object):

python/paddle/fluid/tests/unittests/dygraph_to_static/test_bert.py

@@ -17,14 +17,17 @@ import unittest
 
 import numpy as np
 import paddle.fluid as fluid
+from paddle.fluid.dygraph.base import to_variable
 from paddle.fluid.dygraph.dygraph_to_static import ProgramTranslator
 
 from bert_dygraph_model import PretrainModelLayer
 from bert_utils import get_bert_config, get_feed_data_reader
 
 program_translator = ProgramTranslator()
+
 place = fluid.CUDAPlace(0) if fluid.is_compiled_with_cuda() else fluid.CPUPlace(
 )
+
 SEED = 2020
 STEP_NUM = 10
 PRINT_STEP = 2
@@ -35,19 +38,16 @@ def train(bert_config, data_reader):
         fluid.default_main_program().random_seed = SEED
         fluid.default_startup_program().random_seed = SEED
 
-        data_loader = fluid.io.DataLoader.from_generator(
-            capacity=50, iterable=True)
-        data_loader.set_batch_generator(
-            data_reader.data_generator(), places=place)
-
         bert = PretrainModelLayer(
             config=bert_config, weight_sharing=False, use_fp16=False)
 
         optimizer = fluid.optimizer.Adam(parameter_list=bert.parameters())
         step_idx = 0
         speed_list = []
-        for input_data in data_loader():
+        for input_data in data_reader.data_generator():
+            input_data = [to_variable(ele) for ele in input_data]
             src_ids, pos_ids, sent_ids, input_mask, mask_label, mask_pos, labels = input_data
+
             next_sent_acc, mask_lm_loss, total_loss = bert(
                 src_ids=src_ids,
                 position_ids=pos_ids,