/*D
   MPI_Comm_join - Create a communicator by joining two processes connected by a socket

Synopsis:
.vb
int MPI_Comm_join(int fd, MPI_Comm *intercomm)
.ve

Input Parameters:
. fd - socket file descriptor (integer)

Output Parameters:
. intercomm - new inter-communicator (handle)

Notes:
The socket must be quiescent before 'MPI_COMM_JOIN' is called and after
'MPI_COMM_JOIN' returns. More specifically, on entry to 'MPI_COMM_JOIN', a
read on the socket will not read any data that was written to the socket
before the remote process called 'MPI_COMM_JOIN'.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_OTHER

D*/

