DragonFly On-Line Manual Pages
MPI_T_init_thread(3) MPI MPI_T_init_thread(3)
MPI_T_init_thread - Initialize the MPI_T execution environment
int MPI_T_init_thread(int required, int *provided)
- desired level of thread support (integer)
- provided level of thread support (integer)
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_T calls (all MPI_T calls are funneled to the main
- The process may be multi-threaded, and multiple threads may
make MPI_T calls, but only one at a time: MPI_T calls are not
made concurrently from two distinct threads (all MPI_T calls are
- Multiple threads may call MPI_T, with no restrictions.
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.