Files
pytorch/torch/csrc/jit/python/pybind_utils.h
Shen Li bb0377bb24 Expose torch.futures.Future (#39008)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39008

This commit adds a `torch.futures.Future` type and exposes its ctor,
`wait`, `then`, and `set_result` APIs. This type is currently a
wrapper of `c10::ivalue::Future` and mainly used by RPC for now. Later,
we could revamp c10d APIs to return this `Future` type as well. More
utils will be added into `torch.futures` package in followup PRs.

Test Plan: Imported from OSS

Differential Revision: D21723022

Pulled By: mrshenli

fbshipit-source-id: 92e56160544e9bf00d11db3e8347a1b9707882c9
2020-06-02 10:12:56 -07:00

1174 lines
40 KiB
C++

#pragma once
#include <ATen/core/ivalue.h>
#include <ATen/core/jit_type.h>
#include <ATen/core/stack.h>
#include <pybind11/pybind11.h>
#include <torch/csrc/Device.h>
#include <torch/csrc/Dtype.h>
#include <torch/csrc/Layout.h>
#include <torch/csrc/QScheme.h>
#include <torch/csrc/WindowsTorchApiMacro.h>
#include <torch/csrc/jit/api/module.h>
#include <torch/csrc/jit/frontend/schema_matching.h>
#include <torch/csrc/jit/frontend/tracer.h>
#include <torch/csrc/jit/python/module_python.h>
#include <torch/csrc/jit/python/python_custom_class.h>
#include <torch/csrc/jit/python/python_ivalue.h>
#include <torch/csrc/jit/python/python_tracer.h>
#include <torch/csrc/jit/resource_guard.h>
#include <torch/csrc/jit/runtime/operator.h>
#include <torch/csrc/utils/auto_gil.h>
#include <torch/csrc/utils/pybind.h>
#include <torch/csrc/utils/six.h>
#ifdef USE_DISTRIBUTED
#include <torch/csrc/distributed/rpc/py_rref.h>
#include <torch/csrc/distributed/rpc/rref_impl.h>
#endif
#include <ATen/core/function_schema.h>
#include <c10/util/Exception.h>
#include <algorithm>
#include <cstddef>
#include <string>
#include <utility>
#include <vector>
// The visibility attribute is to avoid a warning about storing a field in the
// struct that has a different visibility (from pybind) than the struct.
#ifdef _WIN32
#define VISIBILITY_HIDDEN
#else
#define VISIBILITY_HIDDEN __attribute__((visibility("hidden")))
#endif
namespace torch {
namespace jit {
inline IValue toIValue(
py::handle obj,
const TypePtr& type,
c10::optional<int32_t> N = c10::nullopt);
py::object toPyObject(IValue ivalue);
// The PythonFutureWrapper for ivalue::Future
//
// NB: VISIBILITY_HIDDEN is for silencing compiling error,
// "error: 'torch::jit::PythonFutureWrapper' declared with greater visibility
// than the type of its field 'torch::jit::PythonFutureWrapper::unwrap_func'
// [-Werror=attributes]"
//
// NB: inherit from enable_shared_from_this because then(py::function) needs to
// get a shared_ptr from this pointer.
struct VISIBILITY_HIDDEN PythonFutureWrapper
: std::enable_shared_from_this<PythonFutureWrapper> {
using UnwrapFunc = std::function<void(py::object)>;
explicit PythonFutureWrapper(
c10::intrusive_ptr<c10::ivalue::Future> fut,
c10::optional<UnwrapFunc> unwrap_func = c10::nullopt)
: fut(std::move(fut)), unwrap_func(std::move(unwrap_func)) {}
explicit PythonFutureWrapper(const PythonFutureWrapper&) = delete;
PythonFutureWrapper& operator=(const PythonFutureWrapper&) = delete;
py::object wait() {
fut->wait();
if (jit::tracer::isTracing()) {
auto graph = jit::tracer::getTracingState()->graph;
Value* fut_val = jit::tracer::getValueTrace(fut);
auto output = graph->insert(aten::wait, {fut_val});
jit::tracer::setValueTrace(fut->value(), output);
}
{
// acquiring GIL as toPyObject creates new py::object
// without grabbing the GIL.
py::gil_scoped_acquire acquire;
py::object py_obj = toPyObject(fut->value());
if (unwrap_func) {
(*unwrap_func)(py_obj);
}
return py_obj;
}
}
// The py::function cb arg must take a std::shared_ptr<PythonFutureWrapper>
// (i.e., torch._C.Future) as the only argument. If the type mismatches, an
// error will be thrown when waiting for the value of this returned Future.
std::shared_ptr<PythonFutureWrapper> then(py::function cb) {
// We need this an additional layer of wrapper here to guard the
// destruction of the py::function object. Because, the
// Future owns a reference to the py::function in its callback
// vector, but Future does not acquire GIL on destruction.
auto pf = std::make_shared<PythonFunctionGuard>(std::move(cb));
return std::make_shared<jit::PythonFutureWrapper>(fut->then(
// Capture a copy of the ivalue::Future instead of the `this` pointer
// because the PythonFutureWrapper object could have been deleted
// when the callbacks are fired. For example, RPC only captures the
// ivalue::Future instead of PythonFutureWrapper in FutureMessage's
// callback functions. Hence, if user code does not hold a reference to
// this PythonFutureWrapper object, there is no guarantee that the
// PythonFutureWrapper is still valid when running the callback.
[pyFut(this->getPtr()), pf(std::move(pf))]() -> IValue {
try {
pybind11::gil_scoped_acquire ag;
return toIValue(pf->func_(pyFut), PyObjectType::get());
} catch (py::error_already_set& e) {
auto err = std::runtime_error(c10::str(
"Got the following error when running the callback: ",
e.what()));
{
pybind11::gil_scoped_acquire ag;
// Release ownership on py::objects and also restore Python
// Error Indicator.
e.restore();
// Clear the Python Error Indicator as we has recorded the
// exception in the response message.
PyErr_Clear();
}
throw err;
}
},
PyObjectType::get()));
}
void markCompleted(const py::object& pyValue) {
DCHECK(PyGILState_Check());
IValue value = toIValue(pyValue, PyObjectType::get());
py::gil_scoped_release release;
fut->markCompleted(std::move(value));
}
c10::intrusive_ptr<c10::ivalue::Future> fut;
// unwrap_func works like a callback for the value returned by
// PythonFutureWrapper::wait().
c10::optional<UnwrapFunc> unwrap_func;
private:
// Wrap Python function to guard deref
struct PythonFunctionGuard {
explicit PythonFunctionGuard(py::function func) : func_(std::move(func)) {}
~PythonFunctionGuard() {
pybind11::gil_scoped_acquire ag;
func_.dec_ref();
// explicitly setting PyObject* to nullptr to prevent py::object's dtor to
// decref on the PyObject again.
// See Note [Destructing py::object] in python_ivalue.h
func_.ptr() = nullptr;
}
py::function func_;
};
std::shared_ptr<PythonFutureWrapper> getPtr() {
return shared_from_this();
}
};
// error reporting: when reporting user-caused errors, these functions should
// not use AT_ERROR macros, since these macros add stack trace information
// that is confusing to display to the end user since it always reports
// locations in libtorch code rather than user code.
inline std::shared_ptr<CompilationUnit> get_python_cu() {
return py::module::import("torch.jit")
.attr("_python_cu")
.cast<std::shared_ptr<CompilationUnit>>();
}
struct TypedIValue : public std::pair<IValue, TypePtr> {
using pair::pair;
IValue& ivalue() {
return this->first;
}
TypePtr& type() {
return this->second;
}
};
inline TypedIValue toDictKeyIValue(py::handle key) {
if (py::isinstance<py::str>(key)) {
return TypedIValue(
ConstantString::create(py::cast<std::string>(key)),
StringType::create());
} else if (py::isinstance<py::int_>(key)) {
return TypedIValue(py::cast<int64_t>(key), IntType::create());
} else if (py::isinstance<py::float_>(key)) {
return TypedIValue(py::cast<double>(key), FloatType::create());
} else {
AT_ERROR("Dictionary inputs may only have string, int, or float keys");
}
}
inline c10::optional<TypePtr> unifyOrInitializeType(
TypePtr accum,
TypePtr unify) {
if (!accum) {
return unify;
}
return unifyTypes(accum, unify);
}
struct InferredType {
InferredType(TypePtr type) : type_(std::move(type)) {}
InferredType(std::string reason)
: type_(nullptr), reason_(std::move(reason)) {}
TypePtr type() const {
TORCH_INTERNAL_ASSERT(type_);
return type_;
}
bool success() const {
return type_ != nullptr;
}
const std::string& reason() const {
TORCH_INTERNAL_ASSERT(!type_);
return reason_;
}
private:
TypePtr type_;
std::string reason_;
};
InferredType tryToInferContainerType(py::handle input);
// Try to infer the type of a Python object
// The type cannot be inferred if:
// input is a None
// input is an empty container (list, dict)
// input is an list with element types that cannot be unified
// input is an dict with key or value types that cannot be unified
inline InferredType tryToInferType(py::handle input) {
// Try tensor types
if (THPVariable_Check(input.ptr())) {
auto tensor = py::cast<at::Tensor>(input);
return InferredType(TensorType::create(tensor));
}
if (input.is(py::none())) {
return InferredType(NoneType::get());
}
if (py::isinstance<StrongFunctionPtr>(input)) {
auto fn = py::cast<StrongFunctionPtr>(input).function_;
return InferredType(FunctionType::create(fn));
}
// Try basic types first
if (py::isinstance<py::bool_>(input)) {
return InferredType(BoolType::get());
} else if (py::isinstance<py::int_>(input)) {
return InferredType(IntType::get());
} else if (py::isinstance<py::float_>(input)) {
return InferredType(FloatType::get());
} else if (py::isinstance<py::str>(input)) {
return InferredType(StringType::get());
} else if (THPLayout_Check(input.ptr())) {
return InferredType(IntType::get());
} else if (THPDevice_Check(input.ptr())) {
return InferredType(DeviceObjType::get());
} else if (THPDtype_Check(input.ptr())) {
return InferredType(IntType::get());
} else if (THPQScheme_Check(input.ptr())) {
return InferredType(IntType::get());
} else if (THPLayout_Check(input.ptr())) {
return InferredType(IntType::get());
}
py::bool_ isClass =
py::module::import("inspect").attr("isclass")(input.get_type());
if (py::cast<bool>(isClass)) {
py::str qualifiedName = py::module::import("torch.jit")
.attr("_qualified_name")(input.get_type());
auto pyClass = py::module::import("torch.jit")
.attr("_get_script_class")(qualifiedName);
if (!pyClass.is_none()) {
auto cu = get_python_cu();
const auto classname =
c10::QualifiedName(py::cast<std::string>(qualifiedName));
auto class_type = cu->get_class(classname);
TORCH_INTERNAL_ASSERT(class_type);
return InferredType(class_type);
}
}
if (py::isinstance<Object>(input)) {
auto object = py::cast<Object>(input);
return InferredType(object.type());
#ifdef USE_DISTRIBUTED
} else if (py::isinstance<torch::distributed::rpc::PyRRef>(input)) {
auto rref_ivalue = input.cast<torch::distributed::rpc::PyRRef>().toIValue();
return InferredType(rref_ivalue.type());
#endif
}
// Try container types
return tryToInferContainerType(input);
}
inline InferredType tryToInferContainerType(py::handle input) {
if (six::isTuple(input)) {
py::tuple tuple = py::cast<py::tuple>(input);
std::vector<TypePtr> element_types;
element_types.reserve(tuple.size());
for (py::handle elem : tuple) {
auto type_match = tryToInferType(elem);
if (type_match.success()) {
element_types.push_back(type_match.type());
} else {
// Forward error message along
return type_match.reason();
}
}
return InferredType(TupleType::create(element_types));
} else if (PyDict_Check(input.ptr())) {
// Check to make sure we can generate useful input/output types
auto dict = py::cast<py::dict>(input);
size_t len = py::len(dict);
if (!len) {
return InferredType("Dictionary inputs must have entries");
}
TypePtr key_type = nullptr;
TypePtr value_type = nullptr;
for (auto entry : dict) {
// Try to infer the key type and unify it with the existing one
auto entry_key_type_match = tryToInferType(entry.first);
if (!entry_key_type_match.success()) {
return entry_key_type_match.reason();
}
auto unified_key =
unifyOrInitializeType(key_type, entry_key_type_match.type());
if (!unified_key) {
return InferredType(c10::str(
"Dictionary inputs to traced functions must have consistent type. Found ",
key_type->python_str(),
" and ",
(entry_key_type_match.type())->python_str()));
}
// Try to infer the value type and unify it with the existing one
auto entry_value_type_match = tryToInferType(entry.second);
if (!entry_value_type_match.success()) {
return entry_value_type_match.reason();
}
auto unified_value =
unifyOrInitializeType(value_type, entry_value_type_match.type());
if (!unified_value) {
return InferredType(c10::str(
"Dictionary inputs to traced functions must have consistent type. Found ",
value_type->python_str(),
" and ",
(entry_value_type_match.type())->python_str()));
}
key_type = *unified_key;
value_type = *unified_value;
}
return InferredType(DictType::create(key_type, value_type));
} else if (PyList_Check(input.ptr())) {
auto list = py::cast<py::list>(input);
size_t len = py::len(list);
if (!len) {
return InferredType("List trace inputs must have elements");
}
TypePtr element_type = nullptr;
for (auto elem : list) {
auto element_type_match = tryToInferType(elem);
if (!element_type_match.success()) {
return InferredType(c10::str(
"Could not infer type of list element: ",
element_type_match.reason()));
}
auto unified_type =
unifyOrInitializeType(element_type, element_type_match.type());
if (!unified_type) {
return InferredType(c10::str(
"List inputs to traced functions must have consistent element type. Found ",
element_type->python_str(),
" and ",
(element_type_match.type())->python_str()));
}
element_type = *unified_type;
}
return InferredType(ListType::create(element_type));
} else {
// TODO: this message is not correct anymore, since this InferredType is
// used from a bunch of circumstances unrelated to tracing. We can re-use
// this instead of the attribute_failure stuff in concreteType
return InferredType(c10::str(
"Only tensors and (possibly nested) tuples of tensors, lists, or dicts",
"are supported ",
"as inputs or outputs of traced functions",
", but instead got value of type ",
py::str(input.get_type().attr("__name__")),
"."));
}
}
inline bool isTraceableType(TypePtr type) {
if (type->isSubtypeOf(TensorType::get())) {
return true;
}
if (auto list_type = type->cast<ListType>()) {
return isTraceableType(list_type->getElementType());
}
if (auto tuple_type = type->cast<TupleType>()) {
return std::all_of(
tuple_type->elements().begin(),
tuple_type->elements().end(),
[](TypePtr element_type) { return isTraceableType(element_type); });
}
if (auto dict_type = type->cast<DictType>()) {
return isTraceableType(dict_type->getValueType());
}
return false;
}
inline IValue toTypeInferredIValue(py::handle input) {
auto match = tryToInferType(input);
if (!match.success()) {
AT_ERROR(
"Tracer cannot infer type of ", py::str(input), "\n:", match.reason());
}
return toIValue(input, match.type());
}
inline Stack toTraceableStack(const py::tuple& inputs) {
auto info = toTypeInferredIValue(inputs);
TORCH_CHECK(
isTraceableType(info.type()),
"Type '",
info.type()->python_str(),
"' cannot be traced. Only Tensors and (possibly nested) Lists, Dicts, and"
" Tuples of Tensors can be traced");
return info.toTuple()->elements();
}
inline IValue createGenericList(py::handle obj, const TypePtr& elem_type) {
auto elems = c10::impl::GenericList(elem_type);
for (auto elem : obj) {
elems.push_back(toIValue(std::move(elem), elem_type));
}
return IValue(std::move(elems));
}
inline IValue createGenericDict(
py::dict obj,
const TypePtr& key_type,
const TypePtr& value_type) {
c10::impl::GenericDict elems(key_type, value_type);
elems.reserve(py::len(obj));
for (auto entry : obj) {
elems.insert(
toIValue(entry.first, key_type), toIValue(entry.second, value_type));
}
return IValue(std::move(elems));
}
template <class T>
inline void guardAgainstNamedTensor(const T& var) {
TORCH_CHECK(
!var.has_names(),
"NYI: Named tensors are currently unsupported in TorchScript. As a "
"workaround please drop names via `tensor = tensor.rename(None)`.");
}
inline IValue toIValue(
py::handle obj,
const TypePtr& type,
c10::optional<int32_t> N) {
switch (type->kind()) {
case TypeKind::TensorType: {
auto var = py::cast<autograd::Variable>(obj);
if (var.is_sparse()) {
TORCH_WARN_ONCE(
"Using sparse tensors in TorchScript is experimental. Many optimization "
"pathways have not been thoroughly tested with sparse tensors. Please "
"include the fact that the network is running sparse tensors in any bug "
"reports submitted.");
}
guardAgainstNamedTensor<autograd::Variable>(var);
return var;
}
case TypeKind::FloatType:
return py::cast<double>(obj);
case TypeKind::IntType:
// TODO(xintchen): Handling LayoutType and ScalarTypeType correctly.
case TypeKind::LayoutType:
case TypeKind::ScalarTypeType:
if (THPDtype_Check(obj.ptr())) {
auto dtype = reinterpret_cast<THPDtype*>(obj.ptr());
return static_cast<int64_t>(dtype->scalar_type);
}
if (THPQScheme_Check(obj.ptr())) {
auto qscheme = reinterpret_cast<THPQScheme*>(obj.ptr());
return static_cast<uint8_t>(qscheme->qscheme);
}
if (THPLayout_Check(obj.ptr())) {
auto layout = reinterpret_cast<THPLayout*>(obj.ptr());
return static_cast<int8_t>(layout->layout);
}
return py::cast<int64_t>(obj);
case TypeKind::NoneType:
if (!obj.is_none()) {
throw py::cast_error(
c10::str("Cannot cast ", py::str(obj), " to None"));
}
return {};
case TypeKind::BoolType:
return py::cast<bool>(obj);
case TypeKind::TupleType: {
py::tuple tuple = py::cast<py::tuple>(obj);
size_t tuple_size = tuple.size();
auto tuple_type = type->cast<TupleType>();
const auto& elem_types = tuple_type->elements();
if (elem_types.size() != tuple_size) {
throw py::cast_error(c10::str(
"Object ",
py::str(obj),
" had a different number of elements than type ",
type->python_str()));
}
std::vector<IValue> values;
values.reserve(tuple_size);
for (size_t i = 0; i < tuple_size; ++i) {
values.push_back(toIValue(tuple[i], elem_types[i]));
}
return tuple_type->name()
? c10::ivalue::Tuple::createNamed(std::move(values), tuple_type)
: c10::ivalue::Tuple::create(std::move(values));
}
case TypeKind::StringType:
return ConstantString::create(py::cast<std::string>(obj));
case TypeKind::DeviceObjType: {
auto device = reinterpret_cast<THPDevice*>(obj.ptr());
return device->device;
}
case TypeKind::ListType: {
const auto& elem_type = type->expect<ListType>()->getElementType();
switch (elem_type->kind()) {
// allows single int/float to be broadcasted to a fixed size list
case TypeKind::IntType:
if (!N || !py::isinstance<py::int_>(obj)) {
return IValue(py::cast<std::vector<int64_t>>(obj));
} else {
double value = py::cast<int64_t>(obj);
c10::List<double> repeated;
repeated.reserve(*N);
for (int i = 0; i < *N; ++i) {
repeated.push_back(value);
}
return repeated;
}
case TypeKind::FloatType:
if (!N || !py::isinstance<py::float_>(obj)) {
return IValue(py::cast<std::vector<double>>(obj));
} else {
double value = py::cast<double>(obj);
c10::List<double> repeated;
repeated.reserve(*N);
for (int i = 0; i < *N; ++i) {
repeated.push_back(value);
}
return repeated;
}
case TypeKind::BoolType:
return IValue(py::cast<std::vector<bool>>(obj));
case TypeKind::TensorType:
return IValue(py::cast<std::vector<at::Tensor>>(obj));
default:
return createGenericList(obj, elem_type);
}
}
case TypeKind::DictType: {
const auto& dict_type = type->expect<DictType>();
return createGenericDict(
py::cast<py::dict>(obj),
dict_type->getKeyType(),
dict_type->getValueType());
}
case TypeKind::OptionalType: {
// check if it's a none obj since optional accepts NoneType
if (obj.is_none()) {
// check if it's a none obj since optional accepts NoneType
// return an IValue() to denote a NoneType
return {};
}
return toIValue(obj, type->expect<OptionalType>()->getElementType());
}
case TypeKind::ClassType: {
auto classType = type->expect<ClassType>();
if (auto mod = as_module(py::cast<py::object>(obj))) {
// if obj is already a ScriptModule, just return its ivalue
return mod.value()._ivalue();
}
// otherwise is a normal class object, we create a fresh
// ivalue::Object to use from the py object.
// 1. create a bare ivalue
const size_t numAttrs = classType->numAttributes();
auto cu = classType->compilation_unit();
auto userObj = c10::ivalue::Object::create(
c10::StrongTypePtr(cu, classType), numAttrs);
// 2. copy all the contained types
for (size_t slot = 0; slot < numAttrs; slot++) {
const auto& attrType = classType->getAttribute(slot);
const auto& attrName = classType->getAttributeName(slot);
const auto& contained = py::getattr(obj, attrName.c_str());
userObj->setSlot(slot, toIValue(contained, attrType));
}
return userObj;
}
case TypeKind::InterfaceType: {
auto interfaceType = type->expect<InterfaceType>();
// When converting an pyobj to an interface, we check if rhs
// is module or normal torchscript class, get the type and ivalue
// from them correspondingly.
c10::ClassTypePtr classType = nullptr;
IValue res;
if (auto mod = as_module(py::cast<py::object>(obj))) {
classType = mod.value().type();
res = mod.value()._ivalue();
} else {
// We inspect the value to found the compiled TorchScript class
// and then create a ivalue::Object from that class type.
py::str qualified_name = py::module::import("torch.jit")
.attr("_qualified_name")(obj.get_type());
auto pyCu = get_python_cu();
classType = pyCu->get_class(c10::QualifiedName(qualified_name));
if (!classType) {
throw std::runtime_error(c10::str(
"Assigning the object ",
py::str(obj),
" to an interface fails because the value is not "
"a TorchScript compatible type, did you forget to",
"turn it into a user defined TorchScript class?"));
}
res = toIValue(std::move(obj), classType);
}
// check if the classType conform with the interface or not
std::stringstream why_not;
if (!classType->isSubtypeOfExt(interfaceType, &why_not)) {
throw py::cast_error(c10::str(
"Object ",
py::str(obj),
" is not compatible with interface ",
interfaceType->python_str(),
"\n",
why_not.str()));
}
return res;
}
case TypeKind::NumberType: {
if (THPDtype_Check(obj.ptr())) {
auto dtype = reinterpret_cast<THPDtype*>(obj.ptr());
return static_cast<int64_t>(dtype->scalar_type);
}
if (THPQScheme_Check(obj.ptr())) {
auto qscheme = reinterpret_cast<THPQScheme*>(obj.ptr());
return static_cast<uint8_t>(qscheme->qscheme);
}
if (THPLayout_Check(obj.ptr())) {
auto layout = reinterpret_cast<THPLayout*>(obj.ptr());
return static_cast<int8_t>(layout->layout);
}
if (py::isinstance<py::int_>(obj)) {
return py::cast<int64_t>(obj);
} else if (py::isinstance<py::float_>(obj)) {
return py::cast<double>(obj);
} else {
throw py::cast_error(
c10::str("Cannot cast ", py::str(obj), " to ", type->python_str()));
}
}
case TypeKind::RRefType: {
#ifdef USE_DISTRIBUTED
return obj.cast<torch::distributed::rpc::PyRRef>().toIValue();
#else
AT_ERROR("RRef is only supported with the distributed package");
#endif
} break;
case TypeKind::PyObjectType: {
return c10::ivalue::ConcretePyObjectHolder::create(obj);
}
case TypeKind::CapsuleType: {
return IValue::make_capsule(
py::cast<c10::intrusive_ptr<CustomClassHolder>>(obj));
}
case TypeKind::FutureType: {
return obj.cast<std::shared_ptr<PythonFutureWrapper>>()->fut;
}
case TypeKind::AnyType:
return toTypeInferredIValue(obj);
case TypeKind::FunctionType:
case TypeKind::GeneratorType:
case TypeKind::VarType:
case TypeKind::QSchemeType:
case TypeKind::AnyListType:
case TypeKind::AnyTupleType:
case TypeKind::AnyClassType:
break;
}
throw py::cast_error(c10::str(
"toIValue() cannot handle converting to type: ", type->python_str()));
}
// Small wrapper around getting the type name string from Python to make
// types easier to interpret, e.g. give the structural type for a NamedTuple
inline std::string friendlyTypeName(py::handle obj) {
if (py::isinstance<py::tuple>(obj) && py::hasattr(obj, "_fields")) {
auto field_names =
py::cast<std::vector<std::string>>(py::getattr(obj, "_fields"));
std::stringstream ss;
ss << py::str(obj.get_type().attr("__name__"));
ss << " (aka NamedTuple(";
bool first = true;
for (auto& field_name : field_names) {
if (!first) {
ss << ", ";
}
ss << field_name;
first = false;
}
ss << "))";
return ss.str();
} else {
return py::str(obj.get_type().attr("__name__"));
}
}
// Thrown when trying to create a schema for a list of python
// arguments that cannot be converted.
// Can be caught by the caller to attempt to use other schema
// when there is an overloaded operator.
struct schema_match_error : public std::runtime_error {
using std::runtime_error::runtime_error;
};
inline IValue argumentToIValue(
const FunctionSchema& schema,
size_t argumentPosition,
py::handle object) {
const auto& argument = schema.arguments().at(argumentPosition);
try {
return toIValue(object, argument.type(), argument.N());
} catch (const py::cast_error& error) {
throw schema_match_error(c10::str(
schema.formatTypeMismatchMsg(
argument,
friendlyTypeName(object),
argumentPosition,
py::repr(object)),
"\nCast error details: ",
error.what()));
}
}
inline IValue returnToIValue(const TypePtr& type, py::handle object) {
try {
return toIValue(object, type);
} catch (const py::cast_error& error) {
throw std::runtime_error(c10::str(
" expected value of type ",
type->str(),
" for return value but instead got value of type ",
py::str(object.get_type().attr("__name__")),
".",
"\nValue: ",
py::repr(object),
"\nCast error details: ",
error.what()));
}
}
inline py::object toPyObject(IValue ivalue) {
if (ivalue.isNone()) {
return py::none();
} else if (ivalue.isTensor()) {
auto tensor = std::move(ivalue).toTensor();
if (tensor.is_sparse()) {
TORCH_WARN_ONCE(
"Using sparse tensors in TorchScript is experimental. Many optimization "
"pathways have not been thoroughly tested with sparse tensors. Please "
"include the fact that the network is running sparse tensors in any bug "
"reports submitted.");
}
guardAgainstNamedTensor<at::Tensor>(tensor);
return py::cast(autograd::Variable(std::move(tensor)));
} else if (ivalue.isDouble()) {
return py::cast(std::move(ivalue).toDouble());
} else if (ivalue.isInt()) {
return py::cast(std::move(ivalue).toInt());
} else if (ivalue.isBool()) {
return py::cast(std::move(ivalue).toBool());
} else if (ivalue.isString()) {
return py::cast(std::move(ivalue).toStringRef());
} else if (ivalue.isList()) {
auto list = std::move(ivalue).toList();
py::list t{list.size()};
for (size_t i = 0; i < list.size(); ++i) {
t[i] = toPyObject(IValue{list.get(i)});
}
return std::move(t);
} else if (ivalue.isTuple()) {
auto tuple = std::move(ivalue).toTuple();
const auto& elements = tuple->elements();
py::tuple t{elements.size()};
for (size_t i = 0; i < elements.size(); ++i) {
t[i] = toPyObject(IValue{elements.at(i)});
}
if (tuple->type() && tuple->type()->schema() &&
tuple->type()->schema()->name() != "") {
auto unqualName = tuple->type()->name()->name();
auto fieldNames = fmap(
tuple->type()->schema()->arguments(),
[](const Argument& arg) { return arg.name(); });
return py::module::import("torch.jit")
.attr("_create_named_tuple")(t, unqualName, fieldNames);
} else {
return std::move(t);
}
} else if (ivalue.isDevice()) {
return py::cast<py::object>(THPDevice_New(std::move(ivalue).toDevice()));
} else if (ivalue.isGenericDict()) {
auto dict = std::move(ivalue).toGenericDict();
py::dict py_dict;
for (auto& pair : dict) {
py_dict[toPyObject(IValue{pair.key()})] =
toPyObject(IValue{pair.value()});
}
return std::move(py_dict);
} else if (ivalue.isRRef()) {
#ifdef USE_DISTRIBUTED
auto RRefPtr =
c10::dynamic_intrusive_pointer_cast<torch::distributed::rpc::RRef>(
std::move(ivalue).toRRef());
return py::cast(torch::distributed::rpc::PyRRef(RRefPtr));
#else
AT_ERROR("RRef is only supported with the distributed package");
#endif
} else if (ivalue.isObject()) {
const auto obj = std::move(ivalue).toObject();
if (obj->type()->is_module()) {
return py::cast(Module(obj));
}
auto pyCu = get_python_cu();
if (obj->name().find("__torch__.torch.classes") == 0) {
return py::cast(Object(obj));
}
const auto classType = pyCu->get_class(c10::QualifiedName(obj->name()));
AT_ASSERT(classType);
auto pyClass =
py::module::import("torch.jit").attr("_get_script_class")(obj->name());
if (pyClass.is_none()) {
std::stringstream err;
err << "Unknown reference to ScriptClass ";
err << obj->name();
err << ". Did you forget to import it?)";
throw std::runtime_error(err.str());
}
auto pyObj = pyClass.attr("__new__")(pyClass);
const auto numAttrs = classType->numAttributes();
for (size_t slot = 0; slot < numAttrs; slot++) {
const auto& attrName = classType->getAttributeName(slot);
IValue v = obj->getSlot(slot);
py::setattr(pyObj, attrName.c_str(), toPyObject(std::move(v)));
}
return pyObj;
} else if (ivalue.isPyObject()) {
// return borrowed reference to ensure it correctly incref the underlying
// PyObject
return py::reinterpret_borrow<py::object>(ivalue.toPyObject());
} else if (ivalue.isCapsule()) {
return py::cast(ivalue.toCapsule());
} else if (ivalue.isFuture()) {
return py::cast(std::make_shared<PythonFutureWrapper>(ivalue.toFuture()));
} else if (ivalue.isRRef()) {
#ifdef USE_DISTRIBUTED
return py::cast(torch::distributed::rpc::PyRRef(
c10::static_intrusive_pointer_cast<distributed::rpc::RRef>(
ivalue.toRRef())));
#else
TORCH_CHECK(false, "RRef is only supported with the distributed package");
#endif
} else {
AT_ERROR(
"Missing cases in 'toPyObject'! Can't convert ",
ivalue.tagKind(),
" to a Python object");
}
}
struct VISIBILITY_HIDDEN tuple_slice {
/*implicit*/ tuple_slice(py::tuple tup_)
: tup(std::move(tup_)), b(0), e(tup.size()) {}
tuple_slice(py::tuple tup_, int64_t b_)
: tup(std::move(tup_)), b(b_), e(tup.size()) {}
tuple_slice(py::tuple tup_, int64_t b_, int64_t e_)
: tup(std::move(tup_)), b(b_), e(e_) {}
py::detail::tuple_iterator begin() const {
return {tup, static_cast<pybind11::ssize_t>(b)};
}
py::detail::tuple_iterator end() const {
return {tup, static_cast<pybind11::ssize_t>(e)};
}
size_t size() const {
return e - b;
}
py::detail::tuple_accessor operator[](size_t index) const {
return {tup, static_cast<size_t>(b + index)};
}
private:
py::tuple tup;
int64_t b;
int64_t e;
};
inline Stack createStackForSchema(
const FunctionSchema& schema,
const tuple_slice& args,
const py::kwargs& kwargs,
c10::optional<IValue> self) {
size_t all_arguments = (self ? 1 : 0) + args.size() + kwargs.size();
if (all_arguments > schema.arguments().size()) {
throw schema_match_error(c10::str(
schema.name(),
"() expected at most ",
schema.arguments().size(),
" argument(s) but received ",
all_arguments,
" argument(s). Declaration: ",
schema));
}
Stack stack;
stack.reserve(schema.arguments().size());
if (self) {
push(stack, std::move(*self));
}
// First push all positional args.
for (size_t i = 0; i < args.size(); ++i) {
// Use the type information from the schema to convert the PyObject.
push(stack, argumentToIValue(schema, stack.size(), args[i]));
}
// Now for every remaining non-positional argument in the schema, look for it
// in the kwargs dict and push it if found, or use its default value if it
// has one.
size_t consumed_kwargs = 0;
for (size_t i = stack.size(); i < schema.arguments().size(); ++i) {
const auto& arg = schema.arguments()[i];
if (kwargs.contains(arg.name().c_str())) {
push(stack, argumentToIValue(schema, i, kwargs[arg.name().c_str()]));
consumed_kwargs += 1;
} else if (arg.default_value()) {
push(stack, *arg.default_value());
} else {
throw schema_match_error(c10::str(
schema.name(),
"() is missing value for argument '",
arg.name(),
"'. Declaration: ",
schema));
}
}
if (consumed_kwargs != kwargs.size()) {
std::vector<std::string> names;
for (const auto& kwarg : kwargs) {
names.emplace_back(py::cast<std::string>(kwarg.first));
}
throw schema_match_error(schema.findErrorInKwargs(names));
}
return stack;
}
inline py::object createPyObjectForStack(Stack&& stack) {
if (stack.empty()) {
return py::none();
}
// Return a simple value and not a single-element tuple if there is only one
// return value.
if (stack.size() == 1) {
return toPyObject(std::move(stack[0]));
}
// If there is more than one return value, pop them into a py::tuple.
py::tuple return_values(stack.size());
for (size_t ret = 0; ret < return_values.size(); ++ret) {
return_values[ret] = toPyObject(std::move(stack[ret]));
}
return std::move(return_values);
}
// TODO: Remove once we clean up the GraphExecutor usage.
inline Stack evilDeprecatedBadCreateStackDoNotUse(
const py::tuple& tuple,
at::ArrayRef<Value*> inputs,
size_t reserve_extra_space = 0) {
if (tuple.size() != inputs.size()) {
AT_ERROR(
"expected " + std::to_string(inputs.size()) + " inputs, but got " +
std::to_string(tuple.size()));
}
Stack result;
result.reserve(tuple.size() + reserve_extra_space);
for (size_t i = 0; i < inputs.size(); ++i) {
result.push_back(toIValue(std::move(tuple[i]), inputs[i]->type()));
}
return result;
}
// Run `callee`, potentially inserting a CallFunction/CallMethod node into the
// tracing graph.
inline py::object runAndInsertCall(
Function& callee,
tuple_slice args,
py::kwargs kwargs,
c10::optional<IValue> self,
// Lambda that tells this function how to insert `callee` into the graph if
// we're tracing.
std::function<Value*(Graph&, const MatchedSchema& match)> callInserter) {
auto stack = createStackForSchema(
callee.getSchema(), std::move(args), std::move(kwargs), std::move(self));
auto tracing_state = tracer::getTracingState();
if (!tracing_state) {
pybind11::gil_scoped_release no_gil_guard;
// If we're not tracing, just run the callee as normal.
callee.run(stack);
} else {
// If we are tracing, insert the appropriate CallFunction or CallMethod node
// and then run the callee with tracing disabled.
// Get the graph `Value`s that represent the input IValues
auto inputs = last(stack, callee.graph()->inputs().size());
auto input_values =
fmap(inputs, [](const IValue& v) { return tracer::getValueTrace(v); });
TORCH_INTERNAL_ASSERT(callee.getSchema().returns().size() == 1)
auto return_type = callee.getSchema().returns().at(0).type();
auto graph = tracing_state->graph;
std::vector<NamedValue> named_values;
for (Value* v : input_values) {
named_values.emplace_back(v);
}
// Add a call node.
MatchedSchema match = matchSchema(
callee.getSchema(),
tracer::getPythonInterpreterSourceRange(),
*graph,
named_values,
{});
auto output_value = callInserter(*graph, match);
// Actually run the callee. Pause the tracer so that we don't double-add the
// callee nodes.
{
pybind11::gil_scoped_release no_gil_guard;
ResourceGuard guard(tracer::pauseTracing());
callee.run(stack);
}
// Associate the output IValues with the output `Value`s in the graph
tracer::setValueTrace(stack.back(), output_value);
}
TORCH_CHECK(
stack.size() > 0,
"Expected values in the stack after execution but found none");
return toPyObject(std::move(stack.back()));
}
inline py::object invokeScriptFunctionFromPython(
Function& callee,
tuple_slice args,
py::kwargs kwargs) {
return runAndInsertCall(
callee,
args,
kwargs,
/*self=*/c10::nullopt,
[&](Graph& graph, const MatchedSchema& match) {
return graph.insertFunctionCall(&callee, match);
});
}
inline py::object invokeScriptMethodFromPython(
Method& callee,
tuple_slice args,
py::kwargs kwargs) {
auto self = callee.owner()._ivalue();
return runAndInsertCall(
callee.function(),
args,
kwargs,
self,
[&](Graph& graph, const MatchedSchema& match) {
return graph.insertMethodCall(callee.name(), match);
});
}
inline py::object invokeOperatorFromPython(
const std::vector<std::shared_ptr<Operator>>& operations,
py::args args,
py::kwargs kwargs) {
Stack stack;
if (operations.size() == 1) {
const Operator& op = *operations.at(0);
// Create a stack full of the arguments and keyword arguments.
stack = createStackForSchema(
op.schema(), std::move(args), std::move(kwargs), c10::nullopt);
op.getOperation()(stack);
} else {
std::vector<schema_match_error> errors;
std::shared_ptr<Operator> found_op = nullptr;
for (const auto& op : operations) {
try {
stack = createStackForSchema(op->schema(), args, kwargs, c10::nullopt);
found_op = op;
break;
} catch (schema_match_error& error) {
errors.push_back(std::move(error));
}
}
if (!found_op) {
std::stringstream ss;
ss << "Overloaded torch operator invoked from Python failed to many any schema:\n";
for (const auto& err : errors) {
ss << err.what() << "\n\n";
}
throw std::runtime_error(ss.str());
}
found_op->getOperation()(stack);
}
return createPyObjectForStack(std::move(stack));
}
} // namespace jit
} // namespace torch