Communicator.hpp 7.12 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
#pragma once

#if HAVE_MPI
#include <array>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <string>
#include <type_traits>
#include <vector>

#include <mpi.h>

#include <amdis/Environment.hpp>
#include <amdis/common/ConceptsBase.hpp>
#include <amdis/common/TypeTraits.hpp>
#include <amdis/common/parallel/Request.hpp>
#include <amdis/common/parallel/RecvDynamicSize.hpp>
#include <amdis/common/parallel/MpiTraits.hpp>

namespace AMDiS {
namespace Concepts {
  template <class T>
  constexpr bool RawPointer = std::is_pointer<std::decay_t<T>>::value;
}

namespace Mpi
{
  struct Tag
  {
    int value = 0;
  };

  class Communicator
  {
  public:

    /// Constructor, stores an MPI communicator, e.g. MPI_COMM_WORLD
    Communicator(MPI_Comm comm = Environment::comm())
      : comm_(comm)
    {
      MPI_Comm_size(comm_, &size_);
      MPI_Comm_rank(comm_, &rank_);
    }


  public:

    operator MPI_Comm() const { return comm_; }

    int size() const { return size_; }
    int rank() const { return rank_; }

  public:

    // send mpi datatype
    template <class Data, REQUIRES(not Concepts::RawPointer<Data>)>
    void send(Data const& data, int to, Tag tag = {}) const;

    // send array of mpi datatypes
    template <class T>
    void send(T const* data, std::size_t size, int to, Tag tag = {}) const;

    template <class T, std::size_t N>
    void send(T const (&data)[N], int to, Tag tag = {}) const
    {
      send(&data[0], N, to, tag);
    }

    template <class T, std::size_t N>
    void send(std::array<T,N> const& array, int to, Tag tag = {}) const
    {
      send(array.data(), N, to, tag);
    }

    template <class T>
    void send(std::vector<T> const& vec, int to, Tag tag = {}) const;

    void send(std::string const& str, int to, Tag tag = {}) const
    {
      MPI_Send(to_void_ptr(str.data()), int(str.size()), MPI_CHAR, to, tag.value, comm_);
    }


    // -------------------------------------------------------------------------------------


    // send mpi datatype (non-blocking)
    template <class Data, REQUIRES(not Concepts::RawPointer<Data>)>
    Request isend(Data const& data, int to, Tag tag = {}) const;

    // send array of mpi datatypes (non-blocking)
    template <class Data>
    Request isend(Data const* data, std::size_t size, int to, Tag tag = {}) const;

    template <class T, std::size_t N>
    Request isend(T const (&data)[N], int to, Tag tag = {}) const
    {
      return isend(&data[0], N, to, tag);
    }

    template <class T, std::size_t N>
    Request isend(std::array<T,N> const& array, int to, Tag tag = {}) const
    {
      return isend(array.data(), N, to, tag);
    }

    template <class T>
    Request isend(std::vector<T> const& vec, int to, Tag tag = {}) const;

    Request isend(std::string const& str, int to, Tag tag = {}) const
    {
      MPI_Request request;
      MPI_Isend(to_void_ptr(str.data()), int(str.size()), MPI_CHAR, to, tag.value, comm_, &request);
      return {request};
    }

    // -------------------------------------------------------------------------------------

    // receive mpi datatype
    template <class Data, REQUIRES(not Concepts::RawPointer<Data>)>
    MPI_Status recv(Data& data, int from, Tag tag = {}) const;

    // receive array of mpi datatypes
    template <class T>
    MPI_Status recv(T* data, std::size_t size, int from, Tag tag = {}) const;

    template <class T, std::size_t N>
    MPI_Status recv(T (&data)[N], int from, Tag tag = {}) const
    {
      return recv(data, N, from, tag);
    }

    template <class T, std::size_t N>
    MPI_Status recv(std::array<T,N>& data, int from, Tag tag = {}) const
    {
      return recv(data.data(), N, from, tag);
    }

    template <class T>
    MPI_Status recv(std::vector<T>& data, int from, Tag tag = {}) const;

    MPI_Status recv(std::string& str, int from, Tag tag = {}) const
    {
      MPI_Status status;
      MPI_Probe(from, tag.value, comm_, &status);

      int size = 0;
      MPI_Get_count(&status, MPI_CHAR, &size);

      str.resize(size);
      MPI_Recv(&str[0], size, MPI_CHAR, from, tag.value, comm_, MPI_STATUS_IGNORE);
      return status;
    }

    // -------------------------------------------------------------------------------------

    // receive mpi datatype
    template <class Data, REQUIRES(not Concepts::RawPointer<Data>)>
    Request irecv(Data& data, int from, Tag tag = {}) const;

    // receive array of mpi datatypes
    template <class Data>
    Request irecv(Data* data, std::size_t size, int from, Tag tag = {}) const;

    template <class T, std::size_t N>
    Request irecv(T (&data)[N], int from, Tag tag = {}) const
    {
      return irecv(&data[0], N, from, tag);
    }

    template <class T, std::size_t N>
    Request irecv(std::array<T,N>& data, int from, Tag tag = {}) const
    {
      return irecv(data.data(), N, from, tag);
    }

    template <class Receiver>
      std::enable_if_t< Concepts::Callable<Receiver,MPI_Status>, Request>
    irecv(Receiver&& recv, int from, Tag tag = {}) const
    {
      return Request{ RecvDynamicSize(from, tag.value, comm_, std::forward<Receiver>(recv)) };
    }

    // receive vector of mpi datatypes
    // 1. until message received, call MPI_Iprobe to retrieve status and size of message
    // 2. resize data-vector
    // 3. receive data into vector
    template <class T>
    Request irecv(std::vector<T>& vec, int from, Tag tag = {}) const;

    Request irecv(std::string& str, int from, Tag tag = {}) const
    {
      return Request{RecvDynamicSize(from,tag.value,comm_,
        [comm=comm_,&str](MPI_Status status) -> MPI_Request
        {
          int size = 0;
          MPI_Get_count(&status, MPI_CHAR, &size);

          str.resize(size);
          MPI_Request req;
          MPI_Irecv(&str[0], size, MPI_CHAR, status.MPI_SOURCE, status.MPI_TAG, comm, &req);

          return req;
        }) };
    }


  protected:

    // free unused buffers
    void check_buffers() const
    {
      using Buffers = std::decay_t<decltype(buffers_)>;

      std::list<typename Buffers::iterator> remove;
      for (auto it = buffers_.begin(); it != buffers_.end(); ++it) {
        int flag;
        MPI_Request_get_status(it->first, &flag, MPI_STATUS_IGNORE);
        if (flag != 0)
          remove.push_back(it);
      }

      for (auto it : remove)
        buffers_.erase(it);
    }


    std::pair<MPI_Request, std::string>& make_buffer(MPI_Status status, std::size_t len) const
    {
      auto it = buffers_.emplace(buffers_.end(), MPI_Request{}, std::string(len,' '));
      buffers_iterators_[{status.MPI_SOURCE, status.MPI_TAG}] = it;
      return buffers_.back();
    }

    std::pair<MPI_Request, std::string>& get_buffer(MPI_Status status) const
    {
      auto it = buffers_iterators_[{status.MPI_SOURCE, status.MPI_TAG}];
      return *it;
    }

  protected:

    MPI_Comm comm_;

    int rank_ = 0;
    int size_ = 1;

    using BufferList = std::list< std::pair<MPI_Request, std::string> >;
    mutable BufferList buffers_;

    using BufferIter = BufferList::iterator;
    mutable std::map<std::pair<int,int>, BufferIter> buffers_iterators_;
  };

}} // end namespace AMDiS::Mpi

#endif // HAVE_MPI

#include <amdis/common/parallel/Communicator.inc.hpp>