# Copyright 2026 Tensor Auto Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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"""Utilities for managing Accelerate accelerator instances.
This module provides functions for setting and getting a global accelerator
instance, which is useful for accessing accelerator state throughout the codebase.
"""
import warnings
from accelerate import Accelerator
_acc: Accelerator | None = None
[docs]
def set_proc_accelerator(accelerator: Accelerator, allow_reset: bool = False) -> None:
"""Set the global accelerator instance for the current process.
Args:
accelerator: Accelerator instance to set.
allow_reset: If True, allow resetting an already-set accelerator.
Defaults to False.
Raises:
AssertionError: If accelerator is not an Accelerator instance.
RuntimeError: If accelerator is already set and allow_reset is False.
"""
global _acc
assert isinstance(accelerator, Accelerator), (
f"Expected an `Accelerator` got {type(accelerator)} with value {accelerator}."
)
if _acc is not None:
if allow_reset:
warnings.warn(
"Resetting the accelerator. This could have unintended side effects.",
UserWarning,
stacklevel=2,
)
else:
raise RuntimeError("Accelerator has already been set.")
_acc = accelerator
[docs]
def get_proc_accelerator() -> Accelerator:
"""Get the global accelerator instance for the current process.
Returns:
The accelerator instance, or None if not set.
"""
return _acc
[docs]
def acc_print(*args, **kwargs) -> None:
"""Print with process index prefix when using accelerate.
If an accelerator is set, prints with a prefix showing the process index.
Otherwise, prints normally.
Args:
*args: Positional arguments to pass to print.
**kwargs: Keyword arguments to pass to print.
"""
acc = get_proc_accelerator()
if acc is None:
print(*args, **kwargs)
else:
print(f"Acc[{acc.process_index} of {acc.num_processes}]", *args, **kwargs)