Files
pytorch/torch/testing/_internal/common_subclass.py
Joel Schlosser 6374a19a6e Fix wrapper subclass serialization with custom sizes / strides (#137030)
Fixes #130154

This PR takes the strategy outlined in the above issue and clears out any cached sizes / strides PyCapsules before serialization. This affects the default subclass serialization logic.

The PyCapsule issue also affects `deepcopy`, so that's fixed here as well.

Note: I originally tried utilizing a context manager to remove / restore cached PyCapsules after serialization, but in practice the state returned from `_reduce_ex_internal()` references the actual `tensor.__dict__()`, so the problem persists once the cached values are restored. Instead, we have to be careful to remove the cached values in the right place so they're not re-cached when pulling out size / stride information for serialization.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137030
Approved by: https://github.com/albanD
2024-10-02 18:55:03 +00:00

347 lines
12 KiB
Python

# mypy: ignore-errors
import torch
from copy import deepcopy
from torch.utils._pytree import tree_map
import torch.utils._pytree as pytree
# TODO: Move LoggingTensor here.
from torch.testing._internal.logging_tensor import LoggingTensor
# Base class for wrapper-style tensors.
class WrapperTensor(torch.Tensor):
@staticmethod
def __new__(cls, *args, **kwargs):
t, kwargs = cls.get_wrapper_properties(*args, **kwargs)
if "size" not in kwargs:
size = t.size()
else:
size = kwargs["size"]
del kwargs["size"]
if "dtype" not in kwargs:
kwargs["dtype"] = t.dtype
if "layout" not in kwargs:
kwargs["layout"] = t.layout
if "device" not in kwargs:
kwargs["device"] = t.device
if "requires_grad" not in kwargs:
kwargs["requires_grad"] = False
# Ignore memory_format and pin memory for now as I don't know how to
# safely access them on a Tensor (if possible??)
wrapper = torch.Tensor._make_wrapper_subclass(cls, size, **kwargs)
wrapper._validate_methods()
return wrapper
@classmethod
def get_wrapper_properties(cls, *args, **kwargs):
# Should return both an example Tensor and a dictionary of kwargs
# to override any of that example Tensor's properly.
# This is very similar to the `t.new_*(args)` API
raise NotImplementedError("You need to implement get_wrapper_properties")
def _validate_methods(self):
# Skip this if not in debug mode?
# Changing these on the python side is wrong as it would not be properly reflected
# on the c++ side
# This doesn't catch attributes set in the __init__
forbidden_overrides = ["size", "stride", "dtype", "layout", "device", "requires_grad"]
for el in forbidden_overrides:
if getattr(self.__class__, el) is not getattr(torch.Tensor, el):
raise RuntimeError(f"Subclass {self.__class__.__name__} is overwriting the "
f"property {el} but this is not allowed as such change would "
"not be reflected to c++ callers.")
class WrapperTensorWithCustomSizes(WrapperTensor):
@classmethod
def get_wrapper_properties(cls, t, requires_grad=False):
return t, {"requires_grad": requires_grad, "dispatch_sizes_strides_policy": "sizes"}
def __init__(self, t, requires_grad=False):
self.t = t
@classmethod
def __torch_dispatch__(cls, func, types, args=(), kwargs=None):
if not all(issubclass(cls, t) for t in types):
return NotImplemented
if kwargs is None:
kwargs = {}
def unwrap(e):
return e.t if isinstance(e, WrapperTensorWithCustomSizes) else e
def wrap(e):
return WrapperTensorWithCustomSizes(e) if isinstance(e, torch.Tensor) else e
rs = tree_map(wrap, func(*tree_map(unwrap, args), **tree_map(unwrap, kwargs or {})))
return rs
def __repr__(self):
return super().__repr__(tensor_contents=f"t={self.t}")
class WrapperTensorWithCustomStrides(WrapperTensor):
@classmethod
def get_wrapper_properties(cls, t, requires_grad=False):
return t, {"requires_grad": requires_grad, "dispatch_sizes_strides_policy": "strides"}
def __init__(self, t, requires_grad=False):
self.t = t
@classmethod
def __torch_dispatch__(cls, func, types, args=(), kwargs=None):
if not all(issubclass(cls, t) for t in types):
return NotImplemented
if kwargs is None:
kwargs = {}
def unwrap(e):
return e.t if isinstance(e, WrapperTensorWithCustomStrides) else e
def wrap(e):
return WrapperTensorWithCustomStrides(e) if isinstance(e, torch.Tensor) else e
rs = tree_map(wrap, func(*tree_map(unwrap, args), **tree_map(unwrap, kwargs or {})))
return rs
def __repr__(self):
return super().__repr__(tensor_contents=f"t={self.t}")
class DiagTensorBelow(WrapperTensor):
@classmethod
def get_wrapper_properties(cls, diag, requires_grad=False):
assert diag.ndim == 1
return diag, {"size": diag.size() + diag.size(), "requires_grad": requires_grad}
def __init__(self, diag, requires_grad=False):
self.diag = diag
handled_ops = {}
@classmethod
def __torch_dispatch__(cls, func, types, args=(), kwargs=None):
if not all(issubclass(cls, t) for t in types):
return NotImplemented
# For everything else, call the handler:
fn = cls.handled_ops.get(func.__name__, None)
if fn:
return fn(*args, **(kwargs or {}))
else:
# Note that here, because we don't need to provide the autograd formulas
# we can have a default "fallback" that creates a plain Tensor based
# on the diag elements and calls the func again.
def unwrap(e):
return e.diag.diag() if isinstance(e, DiagTensorBelow) else e
def wrap(e):
if isinstance(e, torch.Tensor) and e.ndim == 1:
return DiagTensorBelow(e)
if isinstance(e, torch.Tensor) and e.ndim == 2 and e.count_nonzero() == e.diag().count_nonzero():
return DiagTensorBelow(e.diag())
return e
rs = tree_map(wrap, func(*tree_map(unwrap, args), **tree_map(unwrap, kwargs or {})))
return rs
def __repr__(self):
return super().__repr__(tensor_contents=f"diag={self.diag}")
class SparseTensor(WrapperTensor):
@classmethod
def get_wrapper_properties(cls, size, values, indices, requires_grad=False):
assert values.device == indices.device
return values, {"size": size, "requires_grad": requires_grad}
def __init__(self, size, values, indices, requires_grad=False):
self.values = values
self.indices = indices
def __repr__(self):
return super().__repr__(tensor_contents=f"values={self.values}, indices={self.indices}")
def sparse_to_dense(self):
res = torch.zeros(self.size(), dtype=self.values.dtype)
res[self.indices.unbind(1)] = self.values
return res
@staticmethod
def from_dense(t):
indices = t.nonzero()
values = t[indices.unbind(1)]
return SparseTensor(t.size(), values, indices)
@classmethod
def __torch_dispatch__(cls, func, types, args=(), kwargs=None):
func_name = f"{func.__module__}.{func.__name__}"
res = cls._try_call_special_impl(func_name, args, kwargs)
if res is not NotImplemented:
return res
# Otherwise, use a default implementation that construct dense
# tensors and use that to compute values
def unwrap(e):
return e.sparse_to_dense() if isinstance(e, SparseTensor) else e
# Wrap back all Tensors into our custom class
def wrap(e):
# Check for zeros and use that to get indices
return SparseTensor.from_dense(e) if isinstance(e, torch.Tensor) else e
rs = tree_map(wrap, func(*tree_map(unwrap, args), **tree_map(unwrap, kwargs or {})))
return rs
# To show how things happen later
def __rmul__(self, other):
return super().__rmul__(other)
_SPECIAL_IMPLS = {}
@classmethod
def _try_call_special_impl(cls, func, args, kwargs):
if func not in cls._SPECIAL_IMPLS:
return NotImplemented
return cls._SPECIAL_IMPLS[func](args, kwargs)
# Example non-wrapper subclass that stores extra state.
class NonWrapperTensor(torch.Tensor):
def __new__(cls, data):
t = torch.Tensor._make_subclass(cls, data)
t.extra_state = {
'last_func_called': None
}
return t
@classmethod
def __torch_function__(cls, func, types, args=(), kwargs=None):
result = super().__torch_function__(func, types, args, kwargs)
if isinstance(result, cls):
# Do something with the extra state. For the example here, just store the name of the
# last function called (skip for deepcopy so the copy has the same extra state).
if func is torch.Tensor.__deepcopy__:
result.extra_state = deepcopy(args[0].extra_state)
else:
result.extra_state = {
'last_func_called': func.__name__,
}
return result
# new_empty() must be defined for deepcopy to work
def new_empty(self, shape):
return type(self)(torch.empty(shape))
# Class used to store info about subclass tensors used in testing.
class SubclassInfo:
__slots__ = ['name', 'create_fn', 'closed_under_ops']
def __init__(self, name, create_fn, closed_under_ops=True):
self.name = name
self.create_fn = create_fn # create_fn(shape) -> tensor instance
self.closed_under_ops = closed_under_ops
# Helper function to create a subclass of the given class and possibly cache sizes / strides.
def _create_and_access_shape(cls, shape):
sub = cls(torch.randn(shape))
# NB: Wrapper subclasses with custom dispatched sizes / strides cache this info
# on the first call via non-serializable PyCapsules. We purposefully trigger cache
# population here for serialization / deepcopy tests to verify that the presence of this
# cache info doesn't cause problems.
sub.size()
sub.stride()
return sub
subclass_db = {
torch.Tensor: SubclassInfo(
'base_tensor', create_fn=torch.randn
),
NonWrapperTensor: SubclassInfo(
'non_wrapper_tensor',
create_fn=lambda shape: NonWrapperTensor(torch.randn(shape))
),
LoggingTensor: SubclassInfo(
'logging_tensor',
create_fn=lambda shape: LoggingTensor(torch.randn(shape))
),
SparseTensor: SubclassInfo(
'sparse_tensor',
create_fn=lambda shape: SparseTensor.from_dense(torch.randn(shape).relu())
),
DiagTensorBelow: SubclassInfo(
'diag_tensor_below',
create_fn=lambda shape: DiagTensorBelow(torch.randn(shape)),
closed_under_ops=False # sparse semantics
),
WrapperTensorWithCustomSizes: SubclassInfo(
'wrapper_with_custom_sizes',
create_fn=lambda shape: _create_and_access_shape(WrapperTensorWithCustomSizes, shape),
closed_under_ops=False,
),
WrapperTensorWithCustomStrides: SubclassInfo(
'wrapper_with_custom_strides',
create_fn=lambda shape: _create_and_access_shape(WrapperTensorWithCustomStrides, shape),
closed_under_ops=False,
),
}
class SubclassWithTensorFactory(torch.Tensor):
@staticmethod
def __new__(cls, src):
shape = src.shape
kwargs = {}
kwargs["strides"] = src.stride()
kwargs["storage_offset"] = src.storage_offset()
kwargs["device"] = src.device
kwargs["layout"] = src.layout
kwargs["requires_grad"] = src.requires_grad
kwargs["dtype"] = src.dtype
out = torch.Tensor._make_wrapper_subclass(cls, shape, **kwargs)
return out
def __init__(self, src):
self.src = src
def __repr__(self):
return f"{self.__class__.__name__}"
def __tensor_flatten__(self):
return ["src"], None
@classmethod
def __tensor_unflatten__(cls, inner_tensors, meta, outer_size, outer_stride):
src = inner_tensors["src"]
return cls(src)
@classmethod
def __torch_dispatch__(cls, func, types, args, kwargs):
if kwargs is None:
kwargs = {}
def _fn(x):
return x.src * torch.ones(x.src.shape) if x.src.dtype == torch.float32 else x.src
_args = pytree.tree_map_only(cls, _fn, args)
_kwargs = pytree.tree_map_only(cls, _fn, kwargs)
_out = func(*_args, **_kwargs)
_out_flat, _out_spec = pytree.tree_flatten(_out)
out_flat = [cls(o) if isinstance(o, torch.Tensor) else o for o in _out_flat]
return pytree.tree_unflatten(out_flat, _out_spec)