1 /*
2 * Distributed under the OSI-approved Apache License, Version 2.0. See
3 * accompanying file Copyright.txt for details.
4 *
5 * helloBPFlushWriter.cpp: Example that tests buffer overflow forcing a flush to
6 * transports when writing a large variable in independent N-to-N mode. This
7 * will have performance penalties, but it's safer.
8 *
9 * Created on: Feb 16, 2017
10 * Author: William F Godoy godoywf@ornl.gov
11 */
12
13 #include <ios> //std::ios_base::failure
14 #include <iostream> //std::cout
15 #include <mpi.h>
16 #include <stdexcept> //std::invalid_argument std::exception
17 #include <vector>
18
19 #include <adios2.h>
20
main(int argc,char * argv[])21 int main(int argc, char *argv[])
22 {
23 MPI_Init(&argc, &argv);
24 int rank, size;
25 MPI_Comm_rank(MPI_COMM_WORLD, &rank);
26 MPI_Comm_size(MPI_COMM_WORLD, &size);
27
28 /** Application variable */
29 std::vector<float> myFloats(1000000); //~ 4 MB
30 const std::size_t Nx = myFloats.size();
31
32 try
33 {
34 /** ADIOS class factory of IO class objects */
35 adios2::ADIOS adios(MPI_COMM_WORLD);
36
37 /*** IO class object: settings and factory of Settings: Variables,
38 * Parameters, Transports, and Execution: Engines */
39 adios2::IO bpIO = adios.DeclareIO("BPFile_N2N_Flush");
40 bpIO.SetEngine("BPFile");
41
42 // bpIO.SetParameters({{"MaxBufferSize", "9Mb"},
43 // {"BufferGrowthFactor", "1.5"},
44 // {"Threads", "2"}});
45 // bpIO.AddTransport("File", {{"ProfileUnits", "Microseconds"}});
46
47 /** global array : name, { shape (total) }, { start (local) }, { count
48 * (local) }, all are constant dimensions */
49 adios2::Variable<float> bpFloats = bpIO.DefineVariable<float>(
50 "bpFloats", {size * Nx}, {rank * Nx}, {Nx}, adios2::ConstantDims);
51
52 /** Engine derived class, spawned to start IO operations */
53 adios2::Engine bpWriter =
54 bpIO.Open("myVectorFlush.bp", adios2::Mode::Write);
55
56 for (unsigned int t = 0; t < 100; ++t)
57 {
58 /** values to time step */
59 myFloats.assign(myFloats.size(), static_cast<float>(t));
60 /** Write variable for buffering */
61 bpWriter.Put<float>(bpFloats, myFloats.data());
62 }
63
64 /** Create bp file, engine becomes unreachable after this*/
65 bpWriter.Close();
66 }
67 catch (std::invalid_argument &e)
68 {
69 std::cout << "Invalid argument exception, STOPPING PROGRAM from rank "
70 << rank << "\n";
71 std::cout << e.what() << "\n";
72 }
73 catch (std::ios_base::failure &e)
74 {
75 std::cout
76 << "IO System base failure exception, STOPPING PROGRAM from rank "
77 << rank << "\n";
78 std::cout << e.what() << "\n";
79 }
80 catch (std::exception &e)
81 {
82 std::cout << "Exception, STOPPING PROGRAM from rank " << rank << "\n";
83 std::cout << e.what() << "\n";
84 }
85
86 MPI_Finalize();
87
88 return 0;
89 }
90