MPI_Alloc_mem

Allocate memory for message passing and RMA

Synopsis

#ifdef ENABLE_QMPI
#ifndef MPICH_MPI_FROM_PMPI
int QMPI_Alloc_mem(QMPI_Context context, int tool_id, MPI_Aint size, MPI_Info info,
                   void *baseptr) MPICH_API_PUBLIC

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.