fix shuffling for ShufflerIterDataPipe instances (#376)

* fix shuffling for ShufflerIterDataPipe instances

* add versioning test for Pytorch

* fix minimum Pytorch version

Co-authored-by: Loubna ben allal <loubnabenallal@gmail.com>

src/accelerate/data_loader.py

@@ -326,12 +326,21 @@ class DataLoaderDispatcher(DataLoader):
     """
 
     def __init__(self, dataset, split_batches: bool = False, **kwargs):
+        shuffle = False
+        if version.parse(torch.__version__) >= version.parse("1.11.0"):
+            from torch.utils.data.datapipes.iter.combinatorics import ShufflerIterDataPipe
+
+            # We need to save the shuffling state of the DataPipe
+            if isinstance(dataset, ShufflerIterDataPipe):
+                shuffle = dataset._shuffle_enabled
         super().__init__(dataset, **kwargs)
         self.split_batches = split_batches
         if version.parse(torch.__version__) < version.parse("1.8.0"):
             raise ImportError(
                 "Using `DataLoaderDispatcher` requires PyTorch 1.8.0 minimum. You have {torch.__version__}."
             )
+        if shuffle:
+            torch.utils.data.graph_settings.apply_shuffle_settings(dataset, shuffle=shuffle)
 
     def __iter__(self):
         state = AcceleratorState()