如何安装Openmpi for xcode？

Question

我正在尝试在xcode 4中运行一些MPI程序.我通过键入安装了来自MacPort的openmpi sudo port install openmpi并且安装正常完成.然后我将opt/local/include/openmpi添加到我的用户头搜索路径,将"libmpi.dylib"和"libmpi_cxx.dylib"拖到我的项目中.

但是当我尝试运行该程序时,我收到以下错误消息:

Undefined symbols for architecture x86_64:
  "_MPI_Comm_accept", referenced from:
      MPI::Intracomm::Accept(char const*, MPI::Info const&, int) const in main.o
  "_MPI_Comm_connect", referenced from:
      MPI::Intracomm::Connect(char const*, MPI::Info const&, int) const in main.o
  "_MPI_Comm_disconnect", referenced from:
      MPI::Comm::Disconnect() in main.o
  "_MPI_Comm_get_errhandler", referenced from:
      MPI::Comm::Get_errhandler() const in main.o
  "_MPI_Comm_set_errhandler", referenced from:
      MPI::Comm::Set_errhandler(MPI::Errhandler const&) const in main.o
  "_MPI_Comm_spawn", referenced from:
      MPI::Intracomm::Spawn(char const*, char const**, int, MPI::Info const&, int) const in main.o
      MPI::Intracomm::Spawn(char const*, char const**, int, MPI::Info const&, int, int*) const in main.o
  "_MPI_Comm_spawn_multiple", referenced from:
      MPI::Intracomm::Spawn_multiple(int, char const**, char const***, int const*, MPI::Info const*, int) in main.o
      MPI::Intracomm::Spawn_multiple(int, char const**, char const***, int const*, MPI::Info const*, int, int*) in main.o
  "_MPI_Grequest_complete", referenced from:
      MPI::Grequest::Complete() in main.o
  "_MPI_Op_commutative", referenced from:
      MPI::Op::Is_commutative() const in main.o
  "_MPI_Reduce_local", referenced from:
      MPI::Op::Reduce_local(void const*, void*, int, MPI::Datatype const&) const in main.o
  "_MPI_Win_call_errhandler", referenced from:
      MPI::Win::Call_errhandler(int) const in main.o
  "_MPI_Win_get_errhandler", referenced from:
      MPI::Win::Get_errhandler() const in main.o
  "_MPI_Win_set_errhandler", referenced from:
      MPI::Win::Set_errhandler(MPI::Errhandler const&) const in main.o
  "_ompi_mpi_comm_null", referenced from:
      MPI::Intracomm::Intracomm(ompi_communicator_t*) in main.o
      MPI::Graphcomm::Graphcomm(ompi_communicator_t* const&) in main.o
      MPI::Cartcomm::Cartcomm(ompi_communicator_t* const&) in main.o
  "_ompi_mpi_comm_world", referenced from:
      _main in main.o
  "_ompi_mpi_double", referenced from:
      _main in main.o
  "_ompi_mpi_op_sum", referenced from:
      _main in main.o
  "_ompi_op_set_cxx_callback", referenced from:
      MPI::Op::Init(void (*)(void const*, void*, int, MPI::Datatype const&), bool) in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

我在上述安装过程中遗漏了什么吗？

Answer 1

首先一定要安装MPI.我个人使用brew这样做.

brew update
brew install open-mpi

然后检查c ++的要求:

mpic++ -showme

要么 mpicc -showme for c

我用mpic ++的输出是:

clang++ -I/usr/local/Cellar/open-mpi/1.8.6/include -L/usr/local/opt/libevent/lib -L/usr/local/Cellar/open-mpi/1.8.6/lib -lmpi_cxx -lmpi

然后我们得到了包含路径,库路径和其他一些标志.从上一个命令的输出我们得到了我们需要添加:

1. " 搜索路径 - 标题搜索路径"中的"/usr/local/Cellar/open-mpi/1.8.6/include "
2. " 搜索路径 - 库搜索路径"中的 "/ usr/local/opt/libevent/lib"和"/usr/local/Cellar/open-mpi/1.8.6/lib "
3. " 链接 - 其他链接器标志"中的"-lmpi_cxx -lmpi "

这些可以通过Xcode项目的Build Settings选项完成.

因为mpi需要使用它自己的程序来运行我们的程序,我们需要更改可执行文件.

1. 选择"编辑方案"
2. 在下面的对话框中信息的可执行文件中选择其他...从ComboBox.
3. 将其更改为mpiexec,它是"orterun"的别名.对我来说,它位于/usr/local/Cellar/open-mpi/1.8.6/bin.请注意,这通常是隐藏文件夹.你可以按下打开它cmd + shift + g.

4. 对于运行mpiexec,需要知道处理器数量和可执行文件的参数.因此,在Arguments下的相同对话框中

   • 添加"-n X",其中X是您要使用的处理器数量"对于此示例,我将使用2".
   • 添加"$ BUILT_PRODUCTS_DIR/$ EXECUTABLE_PATH",它是指定可执行文件的环境变量的组合.

• 然后<mpi.h>在源代码中添加标题.
• 运行它,你会看到2 "Hello,World!" (因为我使用-n 2作为例子).

来源:open-mpi xcode FAQ,调试和运行Xcode中的MPI程序

Answer 2

我遇到了同样的问题,当我从源代码编译openmpi时,添加了头和库搜索路径,但忘了将库添加为构建设置的链接器标志.添加它们就解决了这个 您可以键入mpicc –showme以查看mpi运行所必需的库.