MPI_Win_shared_query(3) MPI MPI_Win_shared_query(3)NAMEMPI_Win_shared_query - Query the size and base pointer for a patch of
a shared memory window.
SYNOPSIS
int MPI_Win_shared_query(MPI_Win win, int rank, MPI_Aint *size, int *disp_unit, void *baseptr)
This function queries the process-local address for remote memory seg‐
ments created with MPI_Win_allocate_shared . This function can return
different process-local addresses for the same physical memory on dif‐
ferent processes.
The returned memory can be used for load/store accesses subject to the
constraints defined in MPI 3.0, Section 11.7. This function can only be
called with windows of type MPI_Win_flavor_shared . If the passed win‐
dow is not of flavor MPI_Win_flavor_shared , the error MPI_ERR_RMA_FLA‐
VOR is raised. When rank is MPI_PROC_NULL , the pointer, disp_unit, and
size returned are the pointer, disp_unit, and size of the memory seg‐
ment belonging the lowest rank that specified size > 0. If all pro‐
cesses in the group attached to the window specified size = 0, then the
call returns size = 0 and a baseptr as if MPI_Alloc_mem was called with
size = 0.
INPUT PARAMETERS
win - window object used for communication (handle)
rank - target rank
OUTPUT PARAMETERS
size - size of the segment at the given rank
disp_unit
- local unit size for displacements, in bytes (positive integer)
baseptr
- base pointer in the calling process' address space of the
shared segment belonging to the target rank.
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_RANK
- Invalid source or destination rank. Ranks must be between
zero and the size of the communicator minus one; ranks in a
receive ( MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also
be MPI_ANY_SOURCE .
MPI_ERR_WIN
- Invalid MPI window object
SEE ALSO
MPI_Win_allocate_shared
11/9/2015 MPI_Win_shared_query(3)
