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MPI_File_set_size - Resizes a file (collective).
C Syntax#include <mpi.h> int MPI_File_set_size(MPI_File fh, MPI_Offset size)
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_FILE_SET_SIZE(FH, SIZE, IERROR)
INTEGER FH, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) SIZE
#include <mpi.h>
void MPI::File::Set_size(MPI::Offset size)
- fh
- File handle (handle).
- size
- Size to truncate or expand
file (integer).
- IERROR
- Fortran only: Error status (integer).
MPI_File_set_size resizes the file associated with the file
handle fh, truncating UNIX files as necessary. MPI_File_set_size is collective;
all processes in the group must pass identical values for size.
When using
MPI_File_set_size on a UNIX file, if size is larger than the current file
size, the file size becomes size. If size is smaller than the current file
size, the file is truncated at the position defined by size (from the beginning
of the file and measured in bytes). Regions of the file which have been
previously written are unaffected.
MPI_File_set_size does not affect the
individual file pointers or the shared file pointer.
Note that the actual
amount of storage space cannot be allocated by MPI_File_set_size. Use MPI_File_preallocate
to accomplish this.
It is erroneous to call this function if MPI_MODE_SEQUENTIAL
mode was specified when the file was opened.
The MPI standard
prescribes portable Fortran syntax for the SIZE argument only for Fortran
90. FORTRAN 77 users may use the non-portable syntax
INTEGER*MPI_OFFSET_KIND SIZE
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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