Synopsis

int MPI_Alloc_mem(MPI_Aint size, MPI_Info info, void *baseptr)

Input Parameters

size

size of memory segment in bytes (non-negative integer)

info

info argument (handle)

Output Parameters

baseptr

pointer to beginning of memory segment allocated (choice)

Notes

Using this routine from Fortran requires that the Fortran compiler accept a common pointer extension. See Section 4.11 (Memory Allocation) in the MPI-2 standard for more information and examples.

Also note that while baseptr is a void * type, this is simply to allow easy use of any pointer object for this parameter. In fact, this argument is really a void ** type, that is, a pointer to a pointer.

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 guarantee 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_ARG - Invalid argument. Some argument is invalid and is not identified by a specific error class (e.g., 'MPI_ERR_RANK').

  • MPI_ERR_INFO - Invalid Info

  • MPI_ERR_NO_MEM - Insufficient memory available for allocation by 'MPI_Alloc_mem'

  • MPI_ERR_OTHER - Other error; use 'MPI_Error_string' to get more information about this error code.