Files
pytorch/torch/csrc/utils/device_lazy_init.h
Yu, Guangye b0810168a3 Generalize poison fork logic for each device backend (#144664)
# Motivation
Generalize the posion_fork code to make it reusable across different devices.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/144664
Approved by: https://github.com/EikanWang, https://github.com/albanD
2025-04-13 09:54:30 +00:00

88 lines
2.7 KiB
C++

#pragma once
#include <c10/core/TensorOptions.h>
#include <torch/csrc/Export.h>
// device_lazy_init() is always compiled, even for CPU-only builds.
namespace torch::utils {
/**
* This mechanism of lazy initialization is designed for each device backend.
* Currently, CUDA and XPU follow this design. This function `device_lazy_init`
* MUST be called before you attempt to access any Type(CUDA or XPU) object
* from ATen, in any way. It guarantees that the device runtime status is lazily
* initialized when the first runtime API is requested.
*
* Here are some common ways that a device object may be retrieved:
* - You call getNonVariableType or getNonVariableTypeOpt
* - You call toBackend() on a Type
*
* It's important to do this correctly, because if you forget to add it you'll
* get an oblique error message seems like "Cannot initialize CUDA without
* ATen_cuda library" or "Cannot initialize XPU without ATen_xpu library" if you
* try to use CUDA or XPU functionality from a CPU-only build, which is not good
* UX.
*/
TORCH_PYTHON_API void device_lazy_init(at::DeviceType device_type);
TORCH_PYTHON_API void set_requires_device_init(
at::DeviceType device_type,
bool value);
inline bool is_device_lazy_init_supported(at::DeviceType device_type) {
// Add more devices here to enable lazy initialization.
return (
device_type == at::DeviceType::CUDA ||
device_type == at::DeviceType::XPU ||
device_type == at::DeviceType::HPU ||
device_type == at::DeviceType::MTIA ||
device_type == at::DeviceType::PrivateUse1);
}
inline void maybe_initialize_device(at::Device& device) {
if (is_device_lazy_init_supported(device.type())) {
device_lazy_init(device.type());
}
}
inline void maybe_initialize_device(std::optional<at::Device>& device) {
if (!device.has_value()) {
return;
}
maybe_initialize_device(device.value());
}
inline void maybe_initialize_device(const at::TensorOptions& options) {
auto device = options.device();
maybe_initialize_device(device);
}
inline void maybe_initialize_device(
std::optional<at::DeviceType>& device_type) {
if (!device_type.has_value()) {
return;
}
maybe_initialize_device(device_type.value());
}
bool is_device_initialized(at::DeviceType device_type);
TORCH_PYTHON_API bool is_device_in_bad_fork(at::DeviceType device_type);
TORCH_PYTHON_API void set_device_in_bad_fork(
at::DeviceType device_type,
bool value);
TORCH_PYTHON_API void register_fork_handler_for_device_init(
at::DeviceType device_type);
inline void maybe_register_fork_handler_for_device_init(
std::optional<at::DeviceType>& device_type) {
if (!device_type.has_value()) {
return;
}
register_fork_handler_for_device_init(device_type.value());
}
} // namespace torch::utils