src/gromacs/gpu_utils/devicebuffer.h

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  35 #ifndef GMX_GPU_UTILS_DEVICEBUFFER_H
  36 #define GMX_GPU_UTILS_DEVICEBUFFER_H
  37
  38 /*! \libinternal \file
  39  *  \brief Implements the logic for handling of DeviceBuffer types in OpenCL/CUDA.
  40  *  Can only be included on GPU build paths.
  41  *
  42  *  \author Aleksei Iupinov <a.yupinov@gmail.com>
  43  *
  44  *  \inlibraryapi
  45  */
  46
  47 #include "config.h"
  48
  49 #include "gromacs/gpu_utils/devicebuffer_datatype.h"
  50 #include "gromacs/utility/gmxassert.h"
  51 #include "gromacs/utility/smalloc.h" // TODO: this is only for over_alloc_large
  52
  53 #if GMX_GPU == GMX_GPU_CUDA
  54 #include "gromacs/gpu_utils/devicebuffer.cuh"
  55 #elif GMX_GPU == GMX_GPU_OPENCL
  56 #include "gromacs/gpu_utils/devicebuffer_ocl.h"
  57 #else
  58 #error "devicebuffer.h included on non-GPU build!"
  59 #endif
  60
  61 /*! \brief
  62  *  Reallocates the device-side buffer.
  63  *
  64  *  Reallocates the device-side memory pointed by \p buffer.
  65  *  Allocation is buffered and therefore freeing is only needed
  66  *  if the previously allocated space is not enough.
  67  *  \p currentNumValues and \p currentMaxNumValues are updated.
  68  *  TODO: \p currentNumValues, \p currentMaxNumValues, \p deviceContext
  69  *  should all be encapsulated in a host-side class together with the buffer.
  70  *
  71  *  \tparam        ValueType            Raw value type of the \p buffer.
  72  *  \param[in,out] buffer               Pointer to the device-side buffer
  73  *  \param[in]     numValues            Number of values to accommodate.
  74  *  \param[in,out] currentNumValues     The pointer to the buffer's number of values.
  75  *  \param[in,out] currentMaxNumValues  The pointer to the buffer's capacity.
  76  *  \param[in]     deviceContext        The buffer's device context.
  77  */
  78 template <typename ValueType>
  79 void reallocateDeviceBuffer(DeviceBuffer<ValueType> *buffer,
  80                             size_t                   numValues,
  81                             int                     *currentNumValues,
  82                             int                     *currentMaxNumValues,
  83                             DeviceContext            deviceContext)
  84 {
  85     GMX_ASSERT(buffer, "needs a buffer pointer");
  86     GMX_ASSERT(currentNumValues, "needs a size pointer");
  87     GMX_ASSERT(currentMaxNumValues, "needs a capacity pointer");
  88
  89     /* reallocate only if the data does not fit */
  90     if (static_cast<int>(numValues) > *currentMaxNumValues)
  91     {
  92         if (*currentMaxNumValues >= 0)
  93         {
  94             freeDeviceBuffer(buffer);
  95         }
  96
  97         *currentMaxNumValues = over_alloc_large(numValues);
  98         allocateDeviceBuffer(buffer, *currentMaxNumValues, deviceContext);
  99     }
 100     /* size could have changed without actual reallocation */
 101     *currentNumValues = numValues;
 102 }
 103
 104 #endif