MPI_Win_allocate(3) MPI MPI_Win_allocate(3)NAMEMPI_Win_allocate - Create and allocate an MPI Window object for one-
sided communication.
SYNOPSIS
int MPI_Win_allocate(MPI_Aint size, int disp_unit, MPI_Info info,
MPI_Comm comm, void *baseptr, MPI_Win *win)
This is a collective call executed by all processes in the group of
comm. On each process, it allocates memory of at least size bytes,
returns a pointer to it, and returns a window object that can be used
by all processes in comm to perform RMA operations. The returned memory
consists of size bytes local to each process, starting at address
baseptr and is associated with the window as if the user called
MPI_Win_create on existing memory. The size argument may be different
at each process and size = 0 is valid; however, a library might allo‐
cate and expose more memory in order to create a fast, globally symmet‐
ric allocation.
INPUT PARAMETERS
size - size of window in bytes (nonnegative integer)
disp_unit
- local unit size for displacements, in bytes (positive integer)
info - info argument (handle)
comm - communicator (handle)
OUTPUT PARAMETERS
baseptr
- base address of the window in local memory
win - window object returned by the call (handle)
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 com‐
municators), 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 prede‐
fined 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_ARG
- Invalid argument. Some argument is invalid and is not identi‐
fied by a specific error class (e.g., MPI_ERR_RANK ).
MPI_ERR_COMM
- Invalid communicator. A common error is to use a null commu‐
nicator in a call (not even allowed in MPI_Comm_rank ).
MPI_ERR_INFO
- Invalid Info
MPI_ERR_OTHER
- Other error; use MPI_Error_string to get more information
about this error code.
MPI_ERR_SIZE
-
SEE ALSO
MPI_Win_allocate_shared MPI_Win_create MPI_Win_create_dynamic
MPI_Win_free
11/9/2015 MPI_Win_allocate(3)
