!1380 make ShuffleOp have deterministic behavior for subsequent epochs

Merge pull request !1380 from Peilin/shuffle-subsequent-epoch-deterministic

mindspore/ccsrc/dataset/engine/datasetops/shuffle_op.cc

@@ -83,14 +83,14 @@ ShuffleOp::ShuffleOp(int32_t shuffle_size, uint32_t shuffle_seed, int32_t op_con
 // itself rather than waiting for the reset driven from operators above it in the pipeline.
 Status ShuffleOp::SelfReset() {
   MS_LOG(DEBUG) << "Shuffle operator performing a self-reset.";
-  // If ReshuffleEachEpoch is false, then we always use the same seed for every
+  // If reshuffle_each_epoch is false, then we always use the same seed for every
   // epoch.
-  // If ReshuffleEachEpoch is true, then the first epoch uses the given seed,
+  // If reshuffle_each_epoch is true, then the first epoch uses the given seed,
-  // and all subsequent epochs will then reset the seed based on random device.
+  // and all subsequent epochs will then keep on using the rng_ without resetting it
-  if (reshuffle_each_epoch_) {
+  if (!reshuffle_each_epoch_) {
-    shuffle_seed_ = GetNewSeed();
+    rng_ = std::mt19937_64(shuffle_seed_);
   }
-  rng_ = std::mt19937_64(shuffle_seed_);
+
   shuffle_buffer_ = std::make_unique<TensorTable>();
   buffer_counter_ = 0;
   shuffle_last_row_idx_ = 0;

tests/ut/python/dataset/test_2ops.py

@@ -47,7 +47,7 @@ def test_2ops_repeat_shuffle():
     save_and_check(data1, parameters, filename, generate_golden=GENERATE_GOLDEN)
 
 
-def skip_test_2ops_shuffle_repeat():
+def test_2ops_shuffle_repeat():
     """
     Test Shuffle then Repeat
     """
@@ -159,7 +159,7 @@ def test_2ops_shuffle_batch():
 
 if __name__ == '__main__':
     test_2ops_repeat_shuffle()
-    # test_2ops_shuffle_repeat()
+    test_2ops_shuffle_repeat()
     test_2ops_repeat_batch()
     test_2ops_batch_repeat()
     test_2ops_batch_shuffle()