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pytorch/torch/multiprocessing/__init__.py
PyTorch MergeBot 3c9479dc30 Revert "FIX make sure we import the correct object from multiprocessing (#53282)"
This reverts commit e103d6af3dadb62348eedc2b6c68410f5441d542.

Reverted https://github.com/pytorch/pytorch/pull/53282 on behalf of https://github.com/janeyx99 due to Sorry, reverting as this breaks 10.2 tests on trunk e103d6af3d
2022-07-20 20:28:39 +00:00

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2.4 KiB
Python

"""
torch.multiprocessing is a wrapper around the native :mod:`multiprocessing`
module. It registers custom reducers, that use shared memory to provide shared
views on the same data in different processes. Once the tensor/storage is moved
to shared_memory (see :func:`~torch.Tensor.share_memory_`), it will be possible
to send it to other processes without making any copies.
The API is 100% compatible with the original module - it's enough to change
``import multiprocessing`` to ``import torch.multiprocessing`` to have all the
tensors sent through the queues or shared via other mechanisms, moved to shared
memory.
Because of the similarity of APIs we do not document most of this package
contents, and we recommend referring to very good docs of the original module.
"""
import torch
import sys
from .reductions import init_reductions
import multiprocessing
__all__ = ['set_sharing_strategy', 'get_sharing_strategy',
'get_all_sharing_strategies']
from multiprocessing import * # noqa: F403
__all__ += multiprocessing.__all__ # type: ignore[attr-defined]
# This call adds a Linux specific prctl(2) wrapper function to this module.
# See https://github.com/pytorch/pytorch/pull/14391 for more information.
torch._C._multiprocessing_init()
"""Add helper function to spawn N processes and wait for completion of any of
them. This depends `mp.get_context` which was added in Python 3.4."""
from .spawn import spawn, SpawnContext, start_processes, ProcessContext, \
ProcessRaisedException, ProcessExitedException
if sys.platform == 'darwin' or sys.platform == 'win32':
_sharing_strategy = 'file_system'
_all_sharing_strategies = {'file_system'}
else:
_sharing_strategy = 'file_descriptor'
_all_sharing_strategies = {'file_descriptor', 'file_system'}
def set_sharing_strategy(new_strategy):
"""Sets the strategy for sharing CPU tensors.
Args:
new_strategy (str): Name of the selected strategy. Should be one of
the values returned by :func:`get_all_sharing_strategies()`.
"""
global _sharing_strategy
assert new_strategy in _all_sharing_strategies
_sharing_strategy = new_strategy
def get_sharing_strategy():
"""Returns the current strategy for sharing CPU tensors."""
return _sharing_strategy
def get_all_sharing_strategies():
"""Returns a set of sharing strategies supported on a current system."""
return _all_sharing_strategies
init_reductions()