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MPI_File_set_atomicity - Sets consistency semantics for data-access
operations (collective).
C Syntax
#include <mpi.h>
int MPI_File_set_atomicity(MPI_File fh, int flag)
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_FILE_SET_ATOMICITY(FH, FLAG, IERROR)
INTEGER FH, FLAG, IERROR
USE mpi_f08
MPI_File_set_atomicity(fh, flag, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
LOGICAL, INTENT(IN) :: flag
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
- fh
- File handle (handle).
- flag
- true to enable atomic mode,
false to enable nonatomic mode (boolean).
- IERROR
- Fortran
only: Error status (integer).
The consistency semantics for
data-access operations using the set of file handles created by one collective
MPI_File_open is set by collectively calling MPI_File_set_atomicity. All
processes in the group must pass identical values for fh and flag. If flag
is true, atomic mode is set; if flag is false, nonatomic mode is set.
The
default value on a call to MPI_File_open in Open MPI is true for jobs running
on more than one node, false for jobs running on a single SMP. For more
information, see the MPI-2 standard.
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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