LAM: error using complex numbers array

Hi,

I'm working on some code which requires me to send arrays of complex
numbers from a processor to a different processor. The array is
received successfully at the other end but still it gives some
segmentation faults. For example, in the following code, I send an
array of size 64 from processor 0 (master processor) to processor 1.
If i print the data received at processor 1, it prints successfully.
But the code exits giving segmentation faults (as listed below this
code). Could you please give me some pointers to solve this problem.
Thank you in advance.
-rohit

#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#define TEST 1
#define PRINT(A,k,LL) for(k=0;k&lt;LL;k++)
{
        print_complex(A[k]);
        fflush(stdout);

#define FLUSH fflush(stdout)
#define SIZE 64
typedef float Complex[2];

int main(int argc, char **argv)
{
        int myrank,nprocs;
        int tag0=10;

        MPI_Init(&amp;argc,&amp;argv);
        MPI_Comm_size(MPI_COMM_WORLD,&amp;nprocs);
        MPI_Comm_rank(MPI_COMM_WORLD,&amp;myrank);
        MPI_Barrier(MPI_COMM_WORLD);
        if(myrank==0)
        {
                int i=0;
                Complex *input_to_p0 = (Complex*)malloc(SIZE*sizeof(Complex));
                for(i=0;i&lt;SIZE;i++)
                {
                        input_to_p0[i][0] = (float)(4*i);
                        input_to_p0[i][1] = (float)(4*i);
                }

                MPI_Send(input_to_p0,SIZE,MPI_2COMPLEX,1,tag0,MPI_COMM_WORLD);
                free(input_to_p0);
        }
        else if(myrank == 1)
        {
                int i=0;
                Complex *input_from_p0 = (Complex*)malloc(SIZE*sizeof(Complex));

                //Receive the array from processor 0 (of size SIZE)
                MPI_Recv(input_from_p0,SIZE,MPI_2COMPLEX,
0,tag0,MPI_COMM_WORLD,MPI_STATUS_IGNORE);
#if !TEST
                printf(&quot;n input receiverd from p0 (I am in p1) n");
                PRINT(input_from_p0,i,SIZE);
                FLUSH;
                //received successfully
#endif
                free(input_from_p0);

        }
        MPI_Finalize();
        return 0;

-------------------------------------------------------------------------
Error  -

[abhogi:03371] *** Process received signal ***
[abhogi:03371] Signal: Segmentation fault (11)
[abhogi:03371] Signal code: Address not mapped (1)
[abhogi:03371] Failing at address: 0xfd7258
[abhogi:03371] [ 0] [0xcbe440]
[abhogi:03371] [ 1] /opt/openmpi/lib/libopen-pal.so.0(free+0xb4)
[0x138004]
[abhogi:03371] [ 2] bin/fft(main+0x121) [0x8049461]
[abhogi:03371] [ 3] /lib/libc.so.6(__libc_start_main+0xdc) [0x17af2c]
[abhogi:03371] [ 4] bin/fft [0x80488f1]
[abhogi:03371] *** End of error message ***
mpirun noticed that job rank 0 with PID 13726 on node saveri exited on
signal 15 (Terminated).
1 additional process aborted (not shown)

{where abhogi and saveri are the names of the two computers I am
interacting}

 

 

 

Hi,

I'm working on some code which requires me to send arrays of complex
numbers from a processor to a different processor. The array is
received successfully at the other end but still it gives some
segmentation faults. For example, in the following code, I send an
array of size 64 from processor 0 (master processor) to processor 1.
If i print the data received at processor 1, it prints successfully.
But the code exits giving segmentation faults (as listed below this
code). Could you please give me some pointers to solve this problem.
Thank you in advance.
-rohit

#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#define TEST 1
#define PRINT(A,k,LL) for(k=0;k&lt;LL;k++)
{
        print_complex(A[k]);
        fflush(stdout);

#define FLUSH fflush(stdout)
#define SIZE 64
typedef float Complex[2];

int main(int argc, char **argv)
{
        int myrank,nprocs;
        int tag0=10;

 ;       MPI_Init(&amp;argc,&amp;argv);
        MPI_Comm_size(MPI_COMM_WORLD,&amp;nprocs);
        MPI_Comm_rank(MPI_COMM_WORLD,&amp;myrank);
        MPI_Barrier(MPI_COMM_WORLD);
        if(myrank==0)
        {
                int i=0;
                Complex *input_to_p0 = (Complex*)malloc(SIZE*sizeof(Complex));
                for(i=0;i&lt;SIZE;i++)
                {
                        input_to_p0[i][0] = (float)(4*i);
                        input_to_p0[i][1] = (float)(4*i);
                }

 ;               MPI_Send(input_to_p0,SIZE,MPI_2COMPLEX,1,tag0,MPI_COMM_WORLD);
                free(input_to_p0);
        }
        else if(myrank == 1)
        {
                int i=0;
                Complex *input_from_p0 = (Complex*)malloc(SIZE*sizeof(Complex));

 ;               //Receive the array from processor 0 (of size SIZE)
                MPI_Recv(input_from_p0,SIZE,MPI_2COMPLEX,
0,tag0,MPI_COMM_WORLD,MPI_STATUS_IGNORE);
#if !TEST
                printf("n input receiverd from p0 (I am in p1) n");
                PRINT(input_from_p0,i,SIZE);
                FLUSH;
                //received successfully
#endif
                free(input_from_p0);

 ;       }
        MPI_Finalize();
        return 0;

-------------------------------------------------------------------------
Error  -

[abhogi:03371] *** Process received signal ***
[abhogi:03371] Signal: Segmentation fault (11)
[abhogi:03371] Signal code: Address not mapped (1)
[abhogi:03371] Failing at address: 0xfd7258
[abhogi:03371] [ 0] [0xcbe440]
[abhogi:03371] [ 1] /opt/openmpi/lib/libopen-pal.so.0(free+0xb4)
[0x138004]
[abhogi:03371] [ 2] bin/fft(main+0x121) [0x8049461]
[abhogi:03371] [ 3] /lib/libc.so.6(__libc_start_main+0xdc) [0x17af2c]
[abhogi:03371] [ 4] bin/fft [0x80488f1]
[abhogi:03371] *** End of error message ***
mpirun noticed that job rank 0 with PID 13726 on node saveri exited on
signal 15 (Terminated).
1 additional process aborted (not shown)

{where abhogi and saveri are the names of the two computers I am
interacting}

On 27/09/2007, Brian Barrett < brbarretlam-mpi.org"> brbarretlam-mpi.org> wrote:

On Sep 26, 2007, at 5:15 AM, Rohit Prakash wrote:

> &nbsp;   ; &nbsp; &nbsp; &nbsp; &nbsp;   ; MPI_Send(input_to_p0,SIZE,MPI_2COMPLEX,
>; 1,tag0,MPI_COMM_WORLD);
>

MPI_2COMPLEX is a special datatype used for MAXLOC and MINLOC
reductions with Fortran.&nbsp; There is no predefined C datatype to
describe a complex (since C doesn't have a native complex datatype).

The easiest way to handle this would be to use MPI_TYPE_VECTOR to
create a datatype that consists of two consecutive MPI_FLOAT datatypes.

Hope this helps,

Brian
_______________________________________________
This list is archived at http://www.lam-mpi.org/MailArchives/lam/