Hi,guys:
I put two struct variables into a continuous memory at first by using memcpy(). And then I want to print out each variable's element. Sometimes it works,but sometimes it just prints out "0". Can someone tell me the reason of that?
Thanks,
Printable View
Hi,guys:
I put two struct variables into a continuous memory at first by using memcpy(). And then I want to print out each variable's element. Sometimes it works,but sometimes it just prints out "0". Can someone tell me the reason of that?
Thanks,
The only thing I see wrong is an egregious lack of spacing. BTW, sizeof(char) is defined as 1.
post your code.
Works all the time for me. What do you mean it works sometimes?
The issue happens in the MPI code. The new code is attached.
Code:
#include <stdio.h>
#include <mpi.h>
#include <stdlib.h>
#include <string.h>
typedef struct message message;
struct message
{
message*prev;
message*next;
int recv_pe;
};
//typedef struct message message;
int main (int argc, char **argv)
{
int rank, size;
int iter=1000;
int number=15;
int ierr,errclass;
ierr=0;
MPI_Request request;
MPI_Status status;
int send_buffer[5],recv_buffer[5];
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 */
// MPI_Errhandler_set(MPI_COMM_WORLD,MPI_ERRORS_RETURN); /* return info about
// errors */
// printf( "Hello world from process %d of %d\n", rank, size );
if(rank==0)
{
int kk;
for(kk=0;kk<iter;kk++)
{
int buffsize= number*sizeof(message);
char*buffer=(char*)malloc(buffsize*sizeof(char));
// void*buffer=(char*)malloc((unsigned)buffsize);
int position=0;
message* sendevent[number];
int i;
for(i=0,position=0;i<number;i++,position+=sizeof(message))
{
sendevent[i]=malloc(sizeof(message));
sendevent[i]->recv_pe=i;
memcpy(&buffer[position],sendevent[i],sizeof(message));
}
ierr= MPI_Isend(buffer,buffsize, MPI_BYTE,1, 1,MPI_COMM_WORLD,&request);
}
}
else
{
int kk;
for(kk=0;kk<iter;kk++)
{
int buffsize=number*sizeof(message);
char*buffer=(char*)malloc(sizeof(char)*buffsize);
int position=0;
message *tmp=NULL;
int flag=0;
int i;
MPI_Request request;
while(flag==0)
{
MPI_Iprobe(MPI_ANY_SOURCE,
MPI_ANY_TAG,
MPI_COMM_WORLD,
&flag,
&status);
}
ierr=MPI_Irecv(buffer,buffsize,MPI_BYTE,0,1,MPI_COMM_WORLD,&request);
for(i=0,position=0;i<number;i++,position+=sizeof(message))
{
// MPI_Unpack(buffer,buffsize,&position,&revevent[i],sizeof(revevent[i]),MPI_BYTE,MPI_COMM_WORLD);
tmp=(message*)&buffer[position];
if(i==1&&tmp->recv_pe==0)
printf("error :recv data invalid\n");
}
}
}
MPI_Finalize();
return 0;
}
Post your code means cut and paste it into the edit window when you make a post. Don't attach it as a file, it's a PITA for us. Attachments are more suited for images and the like, non-text files. Be sure to use code tags. Read this link: Announcements - General Programming Boards.