fenix_data_buffer.hpp

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// Copyright (C) 2016 Rutgers University and Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
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// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
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// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright
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// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
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// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// Author Marc Gamell, Eric Valenzuela, Keita Teranishi, Manish Parashar,
//        Michael Heroux, and Matthew Whitlock
//
// Questions? Contact Keita Teranishi (knteran@sandia.gov) and
//                    Marc Gamell (mgamell@cac.rutgers.edu)
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#ifndef FENIX_DATA_BUFFER_HPP
#define FENIX_DATA_BUFFER_HPP
 
#include <memory>
#include <vector>
 
#include <mpi.h>
#include "fenix/tasks/forward.hpp"
 
namespace fenix {
namespace detail {
 
template <typename T>
struct UninitializedCharAllocator : public std::allocator<T> {
  UninitializedCharAllocator() noexcept {};
  template <typename U>
  UninitializedCharAllocator(const U& other) noexcept {};
 
  using value_type = T;
  void construct(char*) {};
 
  template <typename U>
  struct rebind {
    using other = UninitializedCharAllocator<U>;
  };
};
 
using BufferVec = std::vector<char, UninitializedCharAllocator<char>>;
 
}
 
class DataBuffer : public detail::BufferVec {
 public:
  using BufferVec = detail::BufferVec;
  using MPITask   = tasks::mpi::MPITask;
 
  //Set to new size, possibly discarding old data
  void reset(size_t new_size = 0) {
    //Clear first, to be sure any re-allocations don't actually move data
    clear();
    resize(new_size);
  }
 
  MPITask send(int dst, int tag, MPI_Comm comm);
 
  //Recv n bytes
  MPITask recv(int n, int src, int tag, MPI_Comm comm);
 
  //Recv an unknown amount of data and resize to fit
  MPITask recv_unknown(int src, int tag, MPI_Comm comm);
};
 
} // namespace fenix
 
#endif //FENIX_DATA_BUFFER_HPP