text: /**
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  
  // Copyright 2004-present Facebook. All Rights Reserved.
  // -*- c -*-
  
  #ifndef FAISS_GPU_RESOURCES_C_H
  #define FAISS_GPU_RESOURCES_C_H
  
  #include <cublas.h>
  #include <cuda_runtime_api.h>
  #include "faiss_c.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /// Base class of GPU-side resource provider; hides provision of
  /// cuBLAS handles, CUDA streams and a temporary memory manager
  FAISS_DECLARE_CLASS(GpuResources)
  
  FAISS_DECLARE_DESTRUCTOR(GpuResources)
  
  /// Call to pre-allocate resources for a particular device. If this is
  /// not called, then resources will be allocated at the first time
  /// of demand
  int faiss_GpuResources_initializeForDevice(FaissGpuResources*, int);
  
  /// Returns the cuBLAS handle that we use for the given device
  int faiss_GpuResources_getBlasHandle(FaissGpuResources*, int, cublasHandle_t*);
  
  /// Returns the stream that we order all computation on for the
  /// given device
  int faiss_GpuResources_getDefaultStream(FaissGpuResources*, int, cudaStream_t*);
  
  /// Returns the available CPU pinned memory buffer
  int faiss_GpuResources_getPinnedMemory(FaissGpuResources*, void**, size_t*);
  
  /// Returns the stream on which we perform async CPU <-> GPU copies
  int faiss_GpuResources_getAsyncCopyStream(
          FaissGpuResources*,
          int,
          cudaStream_t*);
  
  /// Calls getBlasHandle with the current device
  int faiss_GpuResources_getBlasHandleCurrentDevice(
          FaissGpuResources*,
          cublasHandle_t*);
  
  /// Calls getDefaultStream with the current device
  int faiss_GpuResources_getDefaultStreamCurrentDevice(
          FaissGpuResources*,
          cudaStream_t*);
  
  /// Synchronizes the CPU with respect to the default stream for the
  /// given device
  // equivalent to cudaDeviceSynchronize(getDefaultStream(device))
  int faiss_GpuResources_syncDefaultStream(FaissGpuResources*, int);
  
  /// Calls syncDefaultStream for the current device
  int faiss_GpuResources_syncDefaultStreamCurrentDevice(FaissGpuResources*);
  
  /// Calls getAsyncCopyStream for the current device
  int faiss_GpuResources_getAsyncCopyStreamCurrentDevice(
          FaissGpuResources*,
          cudaStream_t*);
  
  #ifdef __cplusplus
  }
  #endif
  #endif
  