[example] opt does not depend on Titans (#1811)

examples/language/opt/context.py

+import torch.distributed as dist
+
+from colossalai.context import ParallelMode
+from colossalai.core import global_context as gpc
+
+
+class barrier_context():
+    """
+    This context manager is used to allow one process to execute while blocking all
+    other processes in the same process group. This is often useful when downloading is required
+    as we only want to download in one process to prevent file corruption.
+    Args:
+        executor_rank (int): the process rank to execute without blocking, all other processes will be blocked
+        parallel_mode (ParallelMode): the parallel mode corresponding to a process group
+    Usage:
+        with barrier_context():
+            dataset = CIFAR10(root='./data', download=True)
+    """
+
+    def __init__(self, executor_rank: int = 0, parallel_mode: ParallelMode = ParallelMode.GLOBAL):
+        # the class name is lowercase by convention
+        current_rank = gpc.get_local_rank(parallel_mode=parallel_mode)
+        self.should_block = current_rank != executor_rank
+        self.group = gpc.get_group(parallel_mode=parallel_mode)
+
+    def __enter__(self):
+        if self.should_block:
+            dist.barrier(group=self.group)
+
+    def __exit__(self, exc_type, exc_value, exc_traceback):
+        if not self.should_block:
+            dist.barrier(group=self.group)

examples/language/opt/requirements.txt

@@ -3,3 +3,4 @@ torch >= 1.8.1
 datasets >= 1.8.0
 sentencepiece != 0.1.92
 protobuf
+accelerate == 0.13.2

examples/language/opt/run_clm.py

@@ -32,9 +32,9 @@ import datasets
 import torch
 import torch.distributed as dist
 from accelerate.utils import set_seed
+from context import barrier_context
 from datasets import load_dataset
 from packaging import version
-from titans.utils import barrier_context
 from torch.utils.data import DataLoader
 from tqdm.auto import tqdm
 from utils import colo_memory_cap