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_CUDA
  54 #    include "gromacs/gpu_utils/devicebuffer.cuh"
  55 #elif GMX_GPU_OPENCL
  56 #    include "gromacs/gpu_utils/devicebuffer_ocl.h"
  57 #elif GMX_GPU_SYCL
  58 #    include "gromacs/gpu_utils/devicebuffer_sycl.h"
  59 #else
  60 #    error "devicebuffer.h included on non-GPU build!"
  61 #endif
  62
  63 /*! \brief
  64  *  Reallocates the device-side buffer.
  65  *
  66  *  Reallocates the device-side memory pointed by \p buffer.
  67  *  Allocation is buffered and therefore freeing is only needed
  68  *  if the previously allocated space is not enough.
  69  *  \p currentNumValues and \p currentMaxNumValues are updated.
  70  *  TODO: \p currentNumValues, \p currentMaxNumValues, \p deviceContext
  71  *  should all be encapsulated in a host-side class together with the buffer.
  72  *
  73  *  \tparam        ValueType            Raw value type of the \p buffer.
  74  *  \param[in,out] buffer               Pointer to the device-side buffer
  75  *  \param[in]     numValues            Number of values to accommodate.
  76  *  \param[in,out] currentNumValues     The pointer to the buffer's number of values.
  77  *  \param[in,out] currentMaxNumValues  The pointer to the buffer's capacity.
  78  *  \param[in]     deviceContext        The buffer's device context.
  79  */
  80 template<typename ValueType>
  81 void reallocateDeviceBuffer(DeviceBuffer<ValueType>* buffer,
  82                             size_t                   numValues,
  83                             int*                     currentNumValues,
  84                             int*                     currentMaxNumValues,
  85                             const DeviceContext&     deviceContext)
  86 {
  87     GMX_ASSERT(buffer, "needs a buffer pointer");
  88     GMX_ASSERT(currentNumValues, "needs a size pointer");
  89     GMX_ASSERT(currentMaxNumValues, "needs a capacity pointer");
  90
  91     /* reallocate only if the data does not fit */
  92     if (static_cast<int>(numValues) > *currentMaxNumValues)
  93     {
  94         if (*currentMaxNumValues >= 0)
  95         {
  96             freeDeviceBuffer(buffer);
  97         }
  98
  99         *currentMaxNumValues = over_alloc_large(numValues);
 100         allocateDeviceBuffer(buffer, *currentMaxNumValues, deviceContext);
 101     }
 102     /* size could have changed without actual reallocation */
 103     *currentNumValues = numValues;
 104 }
 105
 106 #endif