cuda.hpp

/*
 * Copyright (c) 2022-2025, NVIDIA CORPORATION.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once
 
#include <any>
#include <functional>
 
#include <kvikio/shim/cuda_h_wrapper.hpp>
#include <kvikio/shim/utils.hpp>
#include <stdexcept>
 
namespace kvikio {
 
namespace detail {
class AnyCallable {
 private:
  std::any _callable;
 
 public:
  template <typename Callable>
  void set(Callable&& c)
  {
    _callable = std::function(c);
  }
 
  void reset() { _callable.reset(); }
 
  template <typename... Args>
  CUresult operator()(Args... args)
  {
    using T = std::function<CUresult(Args...)>;
    if (!_callable.has_value()) {
      throw std::runtime_error("No callable has been assigned to the wrapper yet.");
    }
    return std::any_cast<T&>(_callable)(args...);
  }
 
  operator bool() const { return _callable.has_value(); }
};
 
}  // namespace detail
 
class cudaAPI {
 public:
  int driver_version{0};
 
  decltype(cuInit)* Init{nullptr};
  decltype(cuMemHostAlloc)* MemHostAlloc{nullptr};
  decltype(cuMemFreeHost)* MemFreeHost{nullptr};
  decltype(cuMemcpyHtoDAsync)* MemcpyHtoDAsync{nullptr};
  decltype(cuMemcpyDtoHAsync)* MemcpyDtoHAsync{nullptr};
 
  detail::AnyCallable MemcpyBatchAsync{};
 
  decltype(cuPointerGetAttribute)* PointerGetAttribute{nullptr};
  decltype(cuPointerGetAttributes)* PointerGetAttributes{nullptr};
  decltype(cuCtxPushCurrent)* CtxPushCurrent{nullptr};
  decltype(cuCtxPopCurrent)* CtxPopCurrent{nullptr};
  decltype(cuCtxGetCurrent)* CtxGetCurrent{nullptr};
  decltype(cuCtxGetDevice)* CtxGetDevice{nullptr};
  decltype(cuMemGetAddressRange)* MemGetAddressRange{nullptr};
  decltype(cuGetErrorName)* GetErrorName{nullptr};
  decltype(cuGetErrorString)* GetErrorString{nullptr};
  decltype(cuDeviceGet)* DeviceGet{nullptr};
  decltype(cuDeviceGetCount)* DeviceGetCount{nullptr};
  decltype(cuDeviceGetAttribute)* DeviceGetAttribute{nullptr};
  decltype(cuDevicePrimaryCtxRetain)* DevicePrimaryCtxRetain{nullptr};
  decltype(cuDevicePrimaryCtxRelease)* DevicePrimaryCtxRelease{nullptr};
  decltype(cuStreamSynchronize)* StreamSynchronize{nullptr};
  decltype(cuStreamCreate)* StreamCreate{nullptr};
  decltype(cuStreamDestroy)* StreamDestroy{nullptr};
  decltype(cuDriverGetVersion)* DriverGetVersion{nullptr};
 
 private:
  cudaAPI();
 
 public:
  cudaAPI(cudaAPI const&)        = delete;
  void operator=(cudaAPI const&) = delete;
 
  KVIKIO_EXPORT static cudaAPI& instance();
};
 
#ifdef KVIKIO_CUDA_FOUND
bool is_cuda_available();
#else
constexpr bool is_cuda_available() { return false; }
#endif
 
}  // namespace kvikio