thrust/device_allocator.h

File members: thrust/device_allocator.h

/*
 *  Copyright 2008-2018 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 <thrust/detail/config.h>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header
#include <thrust/device_ptr.h>
#include <thrust/mr/allocator.h>
#include <thrust/mr/device_memory_resource.h>

#include <limits>
#include <stdexcept>

THRUST_NAMESPACE_BEGIN

template <typename Upstream>
class device_ptr_memory_resource final : public thrust::mr::memory_resource<device_ptr<void>>
{
  using upstream_ptr = typename Upstream::pointer;

public:
  _CCCL_HOST device_ptr_memory_resource()
      : m_upstream(mr::get_global_resource<Upstream>())
  {}

  _CCCL_HOST device_ptr_memory_resource(Upstream* upstream)
      : m_upstream(upstream)
  {}

  _CCCL_NODISCARD _CCCL_HOST virtual pointer
  do_allocate(std::size_t bytes, std::size_t alignment = THRUST_MR_DEFAULT_ALIGNMENT) override
  {
    return pointer(m_upstream->do_allocate(bytes, alignment).get());
  }

  _CCCL_HOST virtual void do_deallocate(pointer p, std::size_t bytes, std::size_t alignment) override
  {
    m_upstream->do_deallocate(upstream_ptr(p.get()), bytes, alignment);
  }

private:
  Upstream* m_upstream;
};

template <typename T>
class device_allocator
    : public thrust::mr::stateless_resource_allocator<T, device_ptr_memory_resource<device_memory_resource>>
{
  using base = thrust::mr::stateless_resource_allocator<T, device_ptr_memory_resource<device_memory_resource>>;

public:
  template <typename U>
  struct rebind
  {
    using other = device_allocator<U>;
  };

  _CCCL_HOST_DEVICE device_allocator() {}

  _CCCL_HOST_DEVICE device_allocator(const device_allocator& other)
      : base(other)
  {}

  template <typename U>
  _CCCL_HOST_DEVICE device_allocator(const device_allocator<U>& other)
      : base(other)
  {}

  device_allocator& operator=(const device_allocator&) = default;

  _CCCL_HOST_DEVICE ~device_allocator() {}
};

THRUST_NAMESPACE_END