Initialize the MPI execution environment
int MPI_Init_thread( int *argc, char ***argv, int required, int *provided )
- Pointer to the number of arguments
- Pointer to the argument vector
- Level of desired thread support
- Level of provided thread support
Command line arguments
MPI specifies no command-line arguments but does allow an MPI
implementation to make use of them. See MPI_INIT for a description of
the command line arguments supported by MPI_INIT and MPI_INIT_THREAD.
The valid values for the level of thread support are:
- Only one thread will execute.
- The process may be multi-threaded, but only the main
thread will make MPI calls (all MPI calls are funneled to the
- The process may be multi-threaded, and multiple
threads may make MPI calls, but only one at a time: MPI calls are not
made concurrently from two distinct threads (all MPI calls are serialized).
- Multiple threads may call MPI, with no restrictions.
Notes for Fortran
Note that the Fortran binding for this routine does not have the argc and
argv arguments. (MPI_INIT_THREAD(required, provided, ierror))
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
- No error; MPI routine completed successfully.
- Other error; use MPI_Error_string to get more information
about this error code.