DragonFly On-Line Manual Pages
MPI_T_pvar_read(3) MPI MPI_T_pvar_read(3)
MPI_T_pvar_read - Read the value of a performance variable
int MPI_T_pvar_read(MPI_T_pvar_session session, MPI_T_pvar_handle handle, void *buf)
- identifier of performance experiment session (handle)
handle - handle of a performance variable (handle)
buf - initial address of storage location for variable value
The MPI_T_pvar_read() call queries the value of the performance
variable with the handle "handle" in the session identified by the
parameter session and stores the result in the buffer identified by the
parameter buf. The user is responsible to ensure that the buffer is of
the appropriate size to hold the entire value of the performance
variable (based on the datatype and count returned by the corresponding
previous calls to MPI_T_pvar_get_info() and MPI_T_pvar_handle_alloc(),
The constant MPI_T_PVAR_ALL_HANDLES cannot be used as an argument for
the function MPI_T_pvar_read().
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-
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.
- No error; MPI routine completed successfully.
- The MPI tool information interface is not initialized.
- Session argument is not valid.
- The handle is invalid.