MPI_Comm_connect issue

[Manhas__Ujwal]

Hi ,

i am trying to connect processes running as clients and a server .

I run the server as mpiexec -n 1  -genv I_MPI_FABRICS shm:tcp ./ConsoleApplication1.exe

and the clients as mpiexec -n 2 .\ConsoleApplication2.exe

The code for server is as shown below

int num_errors = 0;

int rank, size,again;

char port_name[MPI_MAX_PORT_NAME] , pname2[MPI_MAX_PORT_NAME];

MPI_Status status;

//MPI_Comm comm1, comm2;

MPI_Comm client;

int data = 0;

double buf[MAX_DATA];

MPI_Init(NULL, NULL);

MPI_Comm_size(MPI_COMM_WORLD, &size);

MPI_Comm_rank(MPI_COMM_WORLD, &rank);

if (rank == 0)

{

MPI_Open_port(MPI_INFO_NULL, port_name);

while (1) {

MPI_Comm_accept(port_name, MPI_INFO_NULL, 0, MPI_COMM_WORLD,

&client);

again = 1;

while (again) {

MPI_Request rq;

MPI_Recv(buf, MAX_DATA, MPI_DOUBLE,

MPI_ANY_SOURCE, MPI_ANY_TAG, client, &status);

//MPI_Wait(&rq, &status);

switch (status.MPI_TAG) {

case 0: MPI_Comm_free(&client);

MPI_Close_port(port_name);

MPI_Finalize();

return 0;

case 1: MPI_Comm_disconnect(&client);

again = 0;

break;

case 2: printf("value received%lf", buf[0]);

break;

default:

/* Unexpected message type */

MPI_Abort(MPI_COMM_WORLD, 1);

}

}

}

}

MPI_Finalize();

return 0;

and the code for client ( a test code only ) is as shown below 

MPI_Comm server;

double buf[MAX_DATA];

char port_name[MPI_MAX_PORT_NAME];

int tag = 2 , n= MAX_DATA;

int rank, size;

MPI_Init(&argc, &argv);

int prov;

//MPI_Init_thread(NULL, NULL, MPI_THREAD_MULTIPLE, &prov);

MPI_Comm_size(MPI_COMM_WORLD, &size);

MPI_Comm_rank(MPI_COMM_WORLD, &rank);

ifstream ifs("E:/mpi_port_name.txt", ios_base::in);

ifs.getline(port_name, MPI_MAX_PORT_NAME + 1);

ifs.close();

MPI_Comm_connect(port_name, MPI_INFO_NULL, 0, MPI_COMM_SELF,

&server);

////while (!done) {

// tag = 2; /* Action to perform */

// buf[0] = 3.1415926;

// MPI_Send(buf, n, MPI_DOUBLE, 0, tag, server);

// /* etc */

////}

//MPI_Send(buf, 0, MPI_DOUBLE, 0, 1, server);

//MPI_Comm_disconnect(&server);

MPI_Finalize();

return 0;

Now the problem i am facing is that the client code hangs in the MPI_Comm_connect call whereas if i run a single client the connection is established properly.

My problem is i have to connect more than one process of a job with another process dynamically . I am new to MPI so any help will be much appreciated .

Regards

Ujwal

[TimP]

This question would be more likely to get attention on the companion forum on hpc and cluster computing.