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mpi_win_start(3openmpi) [osx man page]

MPI_Win_start(3OpenMPI) 												   MPI_Win_start(3OpenMPI)

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 INPUT PARAMETERS
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++ func- tions 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 Open MPI 1.2 March 2007 MPI_Win_start(3OpenMPI)

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MPI_Win_start(3)							MPI							  MPI_Win_start(3)

NAME
MPI_Win_start - Start an RMA access epoch for MPI SYNOPSIS
int MPI_Win_start(MPI_Group group, int assert, MPI_Win win) INPUT PARAMETERS
group - group of target processes (handle) assert - Used to optimize this call; zero may be used as a default. See notes. (integer) win - window object (handle) NOTES
The assert argument is used to indicate special conditions for the fence that an implementation may use to optimize the MPI_Win_start oper- ation. The value zero is always correct. Other assertion values may be or'ed together. Assertions tha are valid for MPI_Win_start are: MPI_MODE_NOCHECK - the matching calls to MPI_WIN_POST have already completed on all target processes when the call to MPI_WIN_START is made. The nocheck option can be specified in a start call if and only if it is specified in each matching post call. This is similar to the optimization of ready-send that may save a handshake when the handshake is implicit in the code. (However, ready-send is matched by a regular receive, whereas both start and post must specify the nocheck option.) 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 communicators), 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 predefined 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_WIN - Invalid MPI window object MPI_ERR_OTHER - Other error; use MPI_Error_string to get more information about this error code. LOCATION
win_start.c 5/20/2010 MPI_Win_start(3)
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