Question

我正在使用MPI_Reduce和MPI_Scatter函数在“N”个处理器中分散整数数组并打印部分和累积数组的总和。我在visual studio 2010上使用Microsoft MPI（MSMPI）。但是每次执行时都会在标题“Debug Assertion Failed”下给出一个异常“_CrtlsValidHeapPointer（PuserData）”代码如下

enter code here
#include <mpi.h>
#include<iostream>

using namespace std;

int main(int argc, char *argv[]) {
    int size;
    int rank;
    int partialsum=0;
    int root =0;
    int accum=0;

    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);


    int *globaldata = NULL;
    int *localdata = new int(4);

    if (rank == root) {
      globaldata = new int(size*4);
        for (int i=0; i<(size*4); i++)
        globaldata[i] =  2*i+1;

        cout<<"Processor"<<rank<<" has global data: ";
        for (int i=0; i<(size*4); i++)
         cout<<globaldata[i]<<" ";
        cout<<"\n";
    }

    MPI_Scatter(globaldata, 4, MPI_INT, localdata, 4, MPI_INT, root, MPI_COMM_WORLD);

    cout<<"Processor "<<rank<<"has local data";
    for(int i=0; i<4;i++)
        cout<<" "<<localdata[i];
    cout<<endl;
    for(int k=0;k<4;k++)
      partialsum += localdata[k];

    cout<<"Processor "<<rank<<" Partial Sum = "<<partialsum<<"\n";

    MPI_Reduce(&partialsum,&accum,1,MPI_INT,MPI_SUM, root,MPI_COMM_WORLD);
    if (rank == 0) {
      cout<<"Processor "<<rank<<" Accumulated Sum = "<<accum;
    }

    MPI_Finalize();
    return 0;
}

Answer 1

错误很简单，就在这里：

globaldata = new int(size*4);

使用new运算符分配动态数组的语法是new type[size]：

globaldata = new int[size*4];

在您的情况下，分配单个int的空间并将其设置为size*4，并且紧跟在根分配内存之后的初始化代码将覆盖已分配内存的末尾，从而破坏堆结构。

_CrtlsValidHeapPointer（PuserData），Debug Assertion Failed Visual C ++（MPI）

1 个答案: