Question

我试图让MPI从D工作。网上有几个帖子，但我找不到的确实有效......所以这就是我到目前为止所做的：

我从这里https://github.com/1100110/OpenMPI/blob/master/mpi.d获取了mpi.d并设置了一个最小程序：

import mpi;
import std.stdio;

void* MPI_COMM_WORLD = cast(void*)0;

int main(string[] args)
{

  int rank, size;
  int argc = cast(int)args.length;
  char *** argv = cast(char***)&args;


  MPI_Init (&argc, argv);   /* starts MPI */
  MPI_Comm_rank (MPI_COMM_WORLD, &rank);    /* get current process id */
  MPI_Comm_size (MPI_COMM_WORLD, &size);    /* get number of processes */
  writefln( "Hello world from process %d of %d", rank, size );
  MPI_Finalize();

  return 0;
}

我用

编译

dmd test_mpi.d -L-L/usr/lib/openmpi -L-lmpi -L-ldl -L-lhwloc

或

gdc test_mpi.d -pthread -L/usr/lib/openmpi -lmpi -ldl -lhwloc -o test_mpi

并使用

运行

mpirun -n 2 ./test_mpi

这是我得到的错误：

[box:1871] *** An error occurred in MPI_Comm_rank
[box:1871] *** on communicator MPI_COMM_WORLD
[box:1871] *** MPI_ERR_COMM: invalid communicator
[box:1871] *** MPI_ERRORS_ARE_FATAL: your MPI job will now abort
--------------------------------------------------------------------------
mpirun has exited due to process rank 0 with PID 1870 on
node bermuda-iii exiting improperly. There are two reasons this could occur:

1. this process did not call "init" before exiting, but others in
the job did. This can cause a job to hang indefinitely while it waits
for all processes to call "init". By rule, if one process calls "init",
then ALL processes must call "init" prior to termination.

2. this process called "init", but exited without calling "finalize".
By rule, all processes that call "init" MUST call "finalize" prior to
exiting or it will be considered an "abnormal termination"

This may have caused other processes in the application to be
terminated by signals sent by mpirun (as reported here).
--------------------------------------------------------------------------
[box:01869] 1 more process has sent help message help-mpi-errors.txt / mpi_errors_are_fatal
[box:01869] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages

显然我会调用MPI_Init和MPI_Finalize。那我错过了什么？

Answer 1

在Open MPI C中，通信器句柄是指向真实通信器结构的指针。 MPI_COMM_WORLD是指向预先创建的世界通信器结构的指针，而不是定义它时的NULL指针。这就是为什么Open MPI在调用MPI_COMM_RANK时中止的原因 - 它等同于在C中调用MPI_Comm_rank(NULL, &rank)。

如果您查看mpi.d的{{3}}，您会发现MPI_COMM_WORLD已被定义为：

MPI_COMM_WORLD      = cast(void*) &(ompi_mpi_comm_world),

因此，如果删除重新定义MPI_COMM_WORLD的行，

，则代码应该有效

Answer 2

您没有将string[]强制转换为char***。你应该这样做：

import std.string, std.algorithm, std.array;

char** argv = cast(char**)map!(toStringz)(args).array.ptr;
MPI_Init (&argc, &argv);

以下是它的工作原理：

每个toStringz元素上的地图args。
由于地图返回范围，我们使用array来获取数组。
获取数组指针。

用于D编程语言的MPI

2 个答案: