Synopsis
int MPI_Win_lock_all(int assert, MPI_Win win)Input Parameters
- assert
-
program assertion (integer)
- win
-
window object (handle)
Notes
This call is not collective.
The assert argument is used to indicate special conditions for the fence that
an implementation may use to optimize the MPI_Win_lock_all operation. The
value zero is always correct. Other assertion values may be or’ed together.
Assertions that are valid for MPI_Win_lock_all are:
-
MPI_MODE_NOCHECK- No other process holds, or will attempt to acquire a conflicting lock, while the caller holds the window lock. This is useful when mutual exclusion is achieved by other means, but the coherence operations that may be attached to the lock and unlock calls are still required.
There may be additional overheads associated with using MPI_Win_lock and
MPI_Win_lock_all concurrently on the same window. These overheads could be
avoided by specifying the assertion MPI_MODE_NOCHECK when possible
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 guarantee 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.