NAME

       MPI_Request_free -  Frees a communication request object

SYNOPSIS

       int MPI_Request_free(MPI_Request *request)

INPUT PARAMETERS

       request
              - communication request (handle)

NOTES

       This  routine  is  normally  used to free inactive persistent requests created with either
       MPI_Recv_init or MPI_Send_init and friends.  It is also  permissible  to  free  an  active
       request.  However, once freed, the request can no longer be used in a wait or test routine
       (e.g., MPI_Wait ) to determine completion.

       This routine may also be used to free a non-persistent requests such as those created with
       MPI_Irecv  or  MPI_Isend  and  friends.   Like active persistent requests, once freed, the
       request can no longer be used with test/wait routines to determine completion.

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by  multiple
       threads  without the need for any user-provided thread locks.  However, the routine is not
       interrupt safe.  Typically, this is due to the use of memory allocation routines  such  as
       malloc or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       All  MPI  routines  in  Fortran  (except  for MPI_WTIME and MPI_WTICK ) have an additional
       argument ierr at the end of the argument list.  ierr  is  an  integer  and  has  the  same
       meaning  as  the  return  value  of  the  routine  in  C.   In  Fortran,  MPI routines are
       subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error value;  C  routines  as
       the  value of the function and Fortran routines in the last argument.  Before the value is
       returned, the current MPI error handler is called.  By default, this error handler  aborts
       the  MPI  job.   The  error  handler  may  be  changed  with  MPI_Comm_set_errhandler (for
       communicators), MPI_File_set_errhandler (for files), and MPI_Win_set_errhandler  (for  RMA
       windows).   The  MPI-1  routine  MPI_Errhandler_set may be used but its use is deprecated.
       The predefined error handler MPI_ERRORS_RETURN may be used to cause  error  values  to  be
       returned.   Note  that  MPI  does  not  guarentee that an MPI program can continue past an
       error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_REQUEST
              - Invalid MPI_Request .  Either null or, in the case of a MPI_Start or MPI_Startall
              , not a persistent request.
       MPI_ERR_ARG
              -  Invalid  argument.  Some argument is invalid and is not identified by a specific
              error class (e.g., MPI_ERR_RANK ).

SEE ALSO

       also: MPI_Isend, MPI_Irecv, MPI_Issend, MPI_Ibsend, MPI_Irsend,
       MPI_Recv_init,  MPI_Send_init,   MPI_Ssend_init,   MPI_Rsend_init,   MPI_Wait,   MPI_Test,
       MPI_Waitall, MPI_Waitany, MPI_Waitsome, MPI_Testall, MPI_Testany, MPI_Testsome

                                            11/12/2016                        MPI_Request_free(3)