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MPI_File_seek_shared - Updates the global shared file pointer (collective).
C Syntax
#include <mpi.h>
int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset,
int whence)
INCLUDE ’mpif.h’
MPI_FILE_SEEK_SHARED(FH, OFFSET, WHENCE, IERROR)
INTEGER FH, WHENCE, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) OFFSET
#include <mpi.h>
void MPI::File::Seek_shared(MPI::Offset offset, int whence)
- fh
- File handle (handle).
- offset
- File offset (integer).
- whence
- Update mode (integer).
- IERROR
- Fortran only: Error
status (integer).
MPI_File_seek_shared updates the shared file
pointer according to whence, which could have the following possible values:
- o
- MPI_SEEK_SET - The pointer is set to offset.
- o
- MPI_SEEK_CUR - The pointer is set to the current pointer position
plus offset.
- o
- MPI_SEEK_END - The pointer is set to the end of the file plus offset.
MPI_File_seek_shared is collective; all the processes in the communicator
group associated with the file handle fh must call MPI_File_seek_shared
with the same offset and whence. All processes in the communicator group
are synchronized before the shared file pointer is updated.
The offset
can be negative, which allows seeking backwards. It is erroneous to seek
to a negative position in the view. The end of the view is defined to be
the position of the next elementary data item, relative to the current
view, following the last whole elementary data item accessible.
The MPI standard prescribes portable Fortran syntax for the OFFSET
argument only for Fortran 90. FORTRAN 77 users may use the non-portable
syntax
INTEGER*MPI_OFFSET_KIND OFFSET
where MPI_OFFSET_KIND is a constant defined in mpif.h and gives the length
of the declared integer in bytes.
Almost all MPI routines return
an error value; C routines as the value of the function and Fortran routines
in the last argument. C++ functions do not return errors. If the default
error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the
C++ exception mechanism will be used to throw an MPI::Exception object.
Before the error value is returned, the current MPI error handler is called.
For MPI I/O function errors, the default error handler is set to MPI_ERRORS_RETURN.
The error handler may be changed with MPI_File_set_errhandler; the predefined
error handler MPI_ERRORS_ARE_FATAL may be used to make I/O errors fatal.
Note that MPI does not guarantee that an MPI program can continue past
an error.
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