(10) MPI-IO -- fileview: MPI_File_read_all MPI_File_write_all

最新推荐文章于 2025-10-08 14:01:23 发布

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最新推荐文章于 2025-10-08 14:01:23 发布 · 1.5k 阅读

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本文详细探讨了MPI-IO中的fileview概念，以及如何使用MPI_File_read_all和MPI_File_write_all进行并行文件读写操作。通过实例展示了如何设置fileview来协调不同进程间的数据访问，实现高效的数据并行处理。

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include"mpi.h"
/**
 * all process exe blocking read/write in the context of fileview
 * int MPI_File_read_all(MPI_file fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status)
 * int MPI_File_write_all(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_offset