NAME¶
MPI_Wait - Waits for an MPI request to complete
SYNOPSIS¶
int MPI_Wait(MPI_Request *request, MPI_Status *status)
- request
- - request (handle)
OUTPUT PARAMETER¶
- status
- - status object (Status). May be MPI_STATUS_IGNORE .
NOTES ON THE MPI_STATUS ARGUMENT¶
The
MPI_ERROR field of the status return is only set if the return from
the MPI routine is
MPI_ERR_IN_STATUS . That error class is only
returned by the routines that take an array of status arguments (
MPI_Testall ,
MPI_Testsome ,
MPI_Waitall , and
MPI_Waitsome ). In all other cases, the value of the
MPI_ERROR
field in the status is unchanged. See section 3.2.5 in the MPI-1.1
specification for the exact text.
For send operations, the only use of status is for
MPI_Test_cancelled or
in the case that there is an error in one of the four routines that may return
the error class
MPI_ERR_IN_STATUS , in which case the
MPI_ERROR
field of status will be set. In that case, the value will be set to
MPI_SUCCESS for any send or receive operation that completed
successfully, or
MPI_ERR_PENDING for any operation which has neither
failed nor completed.
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.
The
status argument must be declared as an array of size
MPI_STATUS_SIZE , as in
integer status(MPI_STATUS_SIZE) .
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_REQUEST
- - Invalid MPI_Request . Either null or, in the case
of a MPI_Start or MPI_Startall , not a persistent
request.
- MPI_ERR_ARG
- - Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK ).
LOCATION¶
wait.c
