int MPI_Query_thread(int *provided)
If MPI_Init was called instead of MPI_Init_thread, the level of thread support is defined by the implementation. This routine allows you to find out the provided level. It is also useful for library routines that discover that MPI has already been initialized and wish to determine what level of thread support is available.
This routine is both thread- and interrupt-safe. This means that this routine may safely be used by multiple threads and from within a signal handler.
All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran.
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.