Broadcasting can be useful when needing to halt the program while other processors are still operating, or conveying an important information only available to one processor but needed on all the processors. Here is the synopsis of the operation:
int MPI_Bcast ( void *buffer, int count, MPI_Datatype datatype, int root,
MPI_Comm comm )
*buffer: initial address of the send buffer
count: number of elements to be sent (nonnegative integer)
datatype: datatype to be sent (e.g. MPI_INT, MPI_DOUBLE, etc.)
root: processor id of the sender
comm: MPI Communicator handle
As described before, the processes running the code with MPI_Bcast calls probably will run
with the same sets of variables. So when using MPI_Bcast, caution is needed not to overwrite
important information on the non-broadcasting processes.