Hello everybody,
I tried to implement one-sided communication with MPI_Put on two processes. On
both processes have two vectors, process 0 updates the vector v[0] with the
value of v[1], i.e. v[0]+=v[1], and send the updated values of v[0] to process
1. Process 1 updates the vector v[1] with v[1]+=v[0] and send the updated values
of v[1] to process 0. I used "post, start, complete and wait" synchronizing the
processes as the program below showed, but the program hanged by MPI_Win_start.
Do you think if there is still error in this program example? But when I created
only one window, it can work and get the right result. And another question, in
some documentes I have read some assert arguments for the function
MPI_Win_start, MPI_Win_post and MPI_Win_fence, e.g. MPI_MODE_NOCHECK,
MPI_MODE_NOPUT, etc. but I can't use these arguments, the compiler said it
could not find it, and I have checked in the head files, they are not defined,
why? Below is the example program. Thanks for helps.
Best Regards
Zenghui Wu
University of Dortmund, Germany
#define ENTRIES 1000
int main(int argc, char *argv[])
{
int i, size, rank;
long j;
double **v;
MPI_Win win[2];
MPI_Group group;
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size); // the size should be 2
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_group(MPI_COMM_WORLD, &group);
v=(double **)calloc(size, sizeof(double *));
for(i=0;i<size;i++)
{
MPI_Alloc_mem(sizeof(double) * ENTRIES, MPI_INFO_NULL, &v[i]);
MPI_Win_create(v[i], sizeof(double) * ENTRIES, sizeof(double),
MPI_INFO_NULL, MPI_COMM_WORLD, &win[i]);
}
// initialize the values of v[0] and v[1]
for(i=0; i<size; i++)
for(j=0; j<ENTRIES; j++)
v[i][j]=1.0;
for(i=0;i<10;i++)
{
for(j=0; j<ENTRIES; j++)
v[rank][j]=v[rank][j]+v[size-1-rank][j];
MPI_Win_post(group, 0, win[size-1-rank]); // The program hang here.
MPI_Barriar(MPI_COMM_WORLD);
MPI_Win_start(group, 0, win[rank]);
MPI_Put(v[rank], ENTRIES, MPI_DOUBLE, (size-1-rank), 0 , ENTRIES,
MPI_DOUBLE, win[rank]);
MPI_Win_complete(win[rank]);
MPI_Win_wait(win[size-1-rank]);
}
MPI_Win_free(&win[0]);
MPI_Win_free(&win[1]);
MPI_Free_mem(v[0]);
MPI_Free_mem(v[1]);
MPI_Finalize();
return(0);
}
|
