#pragma once
#include <c10/core/impl/PyInterpreter.h>
#include <c10/macros/Export.h>
#include <c10/util/python_stub.h>
namespace c10 {
// This is an safe owning holder for a PyObject, akin to pybind11's
// py::object, with two major differences:
//
// - It is in c10/core; i.e., you can use this type in contexts where
// you do not have a libpython dependency
//
// - It is multi-interpreter safe (ala torchdeploy); when you fetch
// the underlying PyObject* you are required to specify what the current
// interpreter context is and we will check that you match it.
//
// It is INVALID to store a reference to a Tensor object in this way;
// you should just use TensorImpl directly in that case!
struct C10_API SafePyObject {
// Steals a reference to data
SafePyObject(PyObject* data, c10::impl::PyInterpreter* pyinterpreter)
: data_(data), pyinterpreter_(pyinterpreter) {}
SafePyObject(SafePyObject&& other) noexcept
: data_(std::exchange(other.data_, nullptr)),
pyinterpreter_(other.pyinterpreter_) {}
// In principle this could be copyable if we add an incref to PyInterpreter
// but for now it's easier to just disallow it.
SafePyObject(SafePyObject const&) = delete;
SafePyObject& operator=(SafePyObject const&) = delete;
~SafePyObject() {
if (data_ != nullptr) {
(*pyinterpreter_)->decref(data_, /*has_pyobj_slot*/ false);
}
}
c10::impl::PyInterpreter& pyinterpreter() const {
return *pyinterpreter_;
}
PyObject* ptr(const c10::impl::PyInterpreter*) const;
// stop tracking the current object, and return it
PyObject* release() {
auto rv = data_;
data_ = nullptr;
return rv;
}
private:
PyObject* data_;
c10::impl::PyInterpreter* pyinterpreter_;
};
// Like SafePyObject, but non-owning. Good for references to global PyObjects
// that will be leaked on interpreter exit. You get a copy constructor/assign
// this way.
struct C10_API SafePyHandle {
SafePyHandle() : data_(nullptr), pyinterpreter_(nullptr) {}
SafePyHandle(PyObject* data, c10::impl::PyInterpreter* pyinterpreter)
: data_(data), pyinterpreter_(pyinterpreter) {}
c10::impl::PyInterpreter& pyinterpreter() const {
return *pyinterpreter_;
}
PyObject* ptr(const c10::impl::PyInterpreter*) const;
void reset() {
data_ = nullptr;
pyinterpreter_ = nullptr;
}
operator bool() {
return data_;
}
private:
PyObject* data_;
c10::impl::PyInterpreter* pyinterpreter_;
};
} // namespace c10