#include "petscsys.h" PetscErrorCode PetscSequentialPhaseBegin(MPI_Comm comm,int ng)Collective
|comm||- Communicator to sequentialize.|
|ng||- Number in processor group. This many processes are allowed to execute at the same time (usually 1)|
PetscSequentialPhaseBegin(comm, 1); <code to be executed sequentially> PetscSequentialPhaseEnd(comm, 1);
Often, the sequential code contains output statements (e.g., printf) to be executed. Note that you may need to flush the I/O buffers before calling PetscSequentialPhaseEnd(). Also, note that some systems do not propagate I/O in any order to the controling terminal (in other words, even if you flush the output, you may not get the data in the order that you want).