Obtaining Parallel Processes Information

Utility routine GETNUMCPUS can be called from any Abaqus/Standard user subroutine. GETNUMCPUS returns the number of MPI processes.

Utility routine VGETNUMCPUS can be called from any Abaqus/Explicit user subroutine in a domain-parallel run. VGETNUMCPUS provides the number of processes used for the parallel run.

         CALL GETNUMCPUS( NUMPROCESSES )
         CALL VGETNUMCPUS( NUMPROCESSES )
         ...

Utility routine GETRANK can be called from any Abaqus/Standard user subroutine. GETRANK returns the rank of the MPI process from which the function is called. For example, in a hybrid MPI and thread parallel execution scheme, multiple threads may all return the rank of their parent MPI process (see Parallel Execution in Abaqus/Standard).

Utility routine VGETRANK can be called from any Abaqus/Explicit user subroutine in a domain-parallel run. VGETRANK provides the individual process rank (see Parallel Execution in Abaqus/Explicit).

         CALL GETRANK( KPROCESSNUM )
         CALL VGETRANK( KPROCESSNUM )
         ...

Utility routine GETNUMTHREADS can be called from any Abaqus user subroutine. It returns the number of threads in a process. In a hybrid parallel execution mode, there will be several Abaqus MPI processes, each having several threads.

Fortran:
#include <SMAAspUserSubroutines.hdr>

         integer numThreads 
         numThreads = GETNUMTHREADS()

C++:
         #include <SMAAspUserSubroutines.h>

         int numThreads = GETNUMTHREADS();

You can determine the ID of the thread you are in by calling the utility function get_thread_id. The returned ID is an integer that Abaqus assigns to each of its threads. The main thread will have the ID=0, and each subsequent thread will have an ID of 1, 2, 3, 4, ..., N. This function can be called from any Abaqus user subroutine and from both the Fortran and C/C++ codes.

FOTRAN:
#include <SMAAspUserSubroutines.hdr>    

         INTEGER myThreadID

         myThreadID = get_thread_id()

C++:
         #include <SMAAspUserSubroutines.h>

         int myThreadID = get_thread_id()

Utility function GETCOMMUNICATOR can be called from any Abaqus user subroutine. GETCOMMUNICATOR returns a communicator that Abaqus defines for its worker processes, similar to MPI_COMM_WORLD. In Fortran its type is an INTEGER. The communicator thus obtained can be used for subsequent MPI communication routines. In a nonparallel run, when the MPI subsystem is not initialized, communicators do not exist and GET_COMMUNICATOR() will return 0. Another way of testing is to call the MPI_Initialized(flag) function. This function will set the flag to 1 if MPI has been initialized.

#include <SMAAspUserSubroutines.hdr>

         integer ABA_COMM_WORLD

         ABA_COMM_WORLD = GETCOMMUNICATOR()

         if (ABA_COMM_WORLD.ne.0) then
             ...do some parallel work, using MPI ...
         else
             ...do some work in a single process ...
         end if

Utility function get_communicator can be called from any Abaqus user subroutine. get_communicator returns a communicator that Abaqus defines for its worker processes. In C++ this function is called get_communicator() and returns a value of the type MPI_Comm. The communicator thus obtained can be used for subsequent MPI communication routines. In a nonparallel run, when the MPI subsystem is not initialized, communicators do not exist and get_communicator() will return 0. Another way of testing is to call the MPI_Initialized(flag) function. This function will set the flag to 1 if MPI has been initialized.

         #include <mpi.h>
         #include <SMAAspUserSubroutines.h>

         MPI_Comm ABA_COMM_WORLD = get_communicator()

         if (ABA_COMM_WORLD) {
            // ... do some parallel work, using MPI ... 
         }
         else{
            // ...do some work in a single process ...
         }