plucky (3) MPI_Ibarrier.openmpi.3.gz

SYNTAX

   C Syntax
          #include <mpi.h>

          int MPI_Barrier(MPI_Comm)
          int MPI_Ibarrier(MPI_Comm comm, MPI_Request *request)
          int MPI_Barrier_init(MPI_Comm comm, MPI_Info info, MPI_Request *request)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_BARRIER(COMM, IERROR)
              INTEGER COMM, IERROR
          MPI_IBARRIER(COMM, REQUEST, IERROR)
              INTEGER COMM, REQUEST, IERROR
          MPI_BARRIER_INIT(COMM, INFO, REQUEST, IERROR)
              INTEGER COMM, INFO, REQUEST, IERROR

   Fortran 2008 Syntax
          USE mpi_f08
          MPI_Barrier(comm, ierror)
              TYPE(MPI_Comm), INTENT(IN) :: comm
              INTEGER, OPTIONAL, INTENT(OUT) :: ierror
          MPI_Ibarrier(comm, request, ierror)
              TYPE(MPI_Comm), INTENT(IN) :: comm
              TYPE(MPI_Request), INTENT (OUT) :: request
              INTEGER, OPTIONAL, INTENT(OUT) :: ierror
          MPI_Barrier_init(comm, info, request, ierror)
              TYPE(MPI_Comm), INTENT(IN) :: comm
              TYPE(MPI_Info), INTENT(IN) :: info
              TYPE(MPI_Request), INTENT (OUT) :: request
              INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETER

       • comm : Communicator (handle).

       • info : Info (handle, persistent only).

OUTPUT PARAMETERS

       • request : Request (handle, non-blocking only).

       • ierror : Fortran only: Error status (integer).

DESCRIPTION

       An MPI barrier completes after all groups members have entered the barrier.

WHEN COMMUNICATOR IS AN INTER-COMMUNICATOR

       When  the  communicator is an inter-communicator, the barrier operation is performed across all processes
       in both groups. All processes in the first group may exit the barrier when all processes  in  the  second
       group have entered the barrier.

ERRORS

       Almost  all  MPI  routines  return  an  error  value; C routines as the return result of the function and
       Fortran routines in the last argument.

       Before the error value is returned, the current MPI  error  handler  associated  with  the  communication
       object  (e.g.,  communicator, window, file) is called.  If no communication object is associated with the
       MPI call, then the call is considered attached to MPI_COMM_SELF and will call the  associated  MPI  error
       handler.   When   MPI_COMM_SELF   is   not  initialized  (i.e.,  before  MPI_Init/MPI_Init_thread,  after
       MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial  error  handler.
       The  initial  error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using
       the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info  key  to  MPI_Comm_spawn/‐
       MPI_Comm_spawn_multiple.   If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN
       error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is  called  for  all
       other MPI functions.

       Open MPI includes three predefined error handlers that can be used:

       • MPI_ERRORS_ARE_FATAL Causes the program to abort all connected MPI processes.

       • MPI_ERRORS_ABORT An error handler that can be invoked on a communicator, window, file, or session. When
         called on a communicator, it acts as if MPI_Abort was called on  that  communicator.  If  called  on  a
         window  or file, acts as if MPI_Abort was called on a communicator containing the group of processes in
         the corresponding window or file. If called on a session, aborts only the local process.

       • MPI_ERRORS_RETURN Returns an error code to the application.

       MPI applications can also implement their own error handlers by calling:

       • MPI_Comm_create_errhandler then MPI_Comm_set_errhandler

       • MPI_File_create_errhandler then MPI_File_set_errhandler

       • MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init

       • MPI_Win_create_errhandler then MPI_Win_set_errhandler

       Note that MPI does not guarantee that an MPI program can continue past an error.

       See the MPI man page for a full list of MPI error codes.

       See the Error Handling section of the MPI-3.1 standard for more information.

       SEE ALSO:

          • MPI_Bcast

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                                   MPI_IBARRIER(3)