/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.

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.
==============================================================================*/

#ifndef TENSORFLOW_COMPILER_XLA_SERVICE_GPU_COPY_THUNK_H_
#define TENSORFLOW_COMPILER_XLA_SERVICE_GPU_COPY_THUNK_H_

#include "tensorflow/compiler/xla/service/buffer_assignment.h"
#include "tensorflow/compiler/xla/service/gpu/buffer_allocations.h"
#include "tensorflow/compiler/xla/service/gpu/thunk.h"
#include "tensorflow/compiler/xla/service/hlo_instruction.h"
#include "tensorflow/core/platform/stream_executor_no_cuda.h"
#include "tensorflow/core/platform/types.h"

namespace xla {
namespace gpu {

// A thunk that copies data. For now, it copies data only from host to device.
// But it can be extended to perform device-to-host or intra-device copying.
class CopyThunk : public Thunk {
 public:
  // Constructs a CopyThunk that copies host data from `source_address` to the
  // device buffer `destination_buffer`. `mem_size` is the size of the data in
  // bytes.
  CopyThunk(const void* source_address,
            const BufferAllocation::Slice& destination_buffer, uint64 mem_size,
            const HloInstruction* hlo_instruction);

  CopyThunk(const CopyThunk&) = delete;
  CopyThunk& operator=(const CopyThunk&) = delete;

  tensorflow::Status ExecuteOnStream(
      const BufferAllocations& buffer_allocations,
      perftools::gputools::Stream* stream) override;

 private:
  const void* source_address_;
  const BufferAllocation::Slice destination_buffer_;
  const uint64 mem_size_;
};

}  // namespace gpu
}  // namespace xla

#endif  // TENSORFLOW_COMPILER_XLA_SERVICE_GPU_COPY_THUNK_H_
