NAME¶
MPI_Win_start - Starts an RMA access epoch for
win
SYNTAX¶
C Syntax¶
#include <mpi.h>
int MPI_Win_start(MPI_Group group, int assert, MPI_Win win)
Fortran Syntax¶
INCLUDE 'mpif.h'
MPI_WIN_START( GROUP, ASSERT, WIN, IERROR)
INTEGER GROUP, ASSERT, WIN, IERROR
C++ Syntax¶
#include <mpi.h>
void MPI::Win::Start(const MPI::Group& group, int assert) const
- group
- The group of target processes (handle).
- assert
- Program assertion (integer).
- win
- Window object (handle).
OUTPUT PARAMETERS¶
- IERROR
- Fortran only: Error status (integer).
DESCRIPTION¶
MPI_Win_start is a one-sided MPI communication synchronization call that starts
an RMA access epoch for
win. RMA calls issued on
win during this
epoch must access only windows at processes in
group. Each process in
group must issue a matching call to MPI_Win_post. MPI_Win_start is
allowed to block until the corresponding MPI_Win_post calls have been
executed, but is not required to.
The
assert argument is used to provide assertions on the context of the
call that may be used for various optimizations. (See Section 6.4.4 of the
MPI-2 Standard.) A value of
assert = 0 is always valid. The following
assertion value is supported:
- MPI_MODE_NOCHECK
- When this value is passed in to this call, the library assumes that the
post call on the target has been called and it is not necessary for the
library to check to see if such a call has been made.
ERRORS¶
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. By
default, this error handler aborts the MPI job, except for I/O function
errors. The error handler may be changed with MPI_Win_set_errhandler; the
predefined error handler MPI_ERRORS_RETURN may be used to cause error values
to be returned. Note that MPI does not guarantee that an MPI program can
continue past an error.
SEE ALSO¶
MPI_Win_post MPI_Win_complete