(9) MPI-IO: fileview MPI_File_read MPI_File_write

最新推荐文章于 2024-07-30 14:04:13 发布

原创

最新推荐文章于 2024-07-30 14:04:13 发布 · 1.6k 阅读

2 ·

CC 4.0 BY-SA版权

本文详细探讨了MPI-IO中的fileview概念，以及如何使用MPI_File_read和MPI_File_write进行并行文件读写操作。通过实例解析，阐述了在并行计算环境中如何高效地管理和访问文件数据。

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include"mpi.h"
/**
 * blocking read/write in the context of a specific process's fileview
 *
 * int MPI_File_read(MPI_file fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status);
 *
 * int MPI_File_write(MPI_file fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status)
 */
int main(int argc, char *argv[])
{
	int totalTaskNum, rankID;

	MPI_Init(&argc, &argv);
	MPI_Comm_rank(MPI_COMM_WORLD, &rankID);
	MPI_Comm_size(MPI_COMM_WORLD, &totalTaskNum);

	char *filename = "file.txt";
	MPI_File fh;
	MPI_Status status;
	MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh);

	MPI_Offset offset = rankID * 128;
	//each process will has its file view which starts with offset
	MPI_File_set_view(fh, offset, MPI_CHAR, MPI_CHAR, "native", MPI_INFO_NULL);

	MPI_Offset seek_of