PetscSequentialPhaseBegin#

Begins a sequential section of code.

Synopsis#

#include "petscsys.h"  
PetscErrorCode PetscSequentialPhaseBegin(MPI_Comm comm, int ng)

Collective

comm - Communicator to sequentialize over
ng - Number in processor group. This many processes are allowed to execute at the same time (usually 1)

PetscSequentialPhaseBegin() and PetscSequentialPhaseEnd() provide a way to force a section of code to be executed by the processes in rank order. Typically, this is done with

      PetscSequentialPhaseBegin(comm, 1);
      <code to be executed sequentially>
      PetscSequentialPhaseEnd(comm, 1);

You should use PetscSynchronizedPrintf() to ensure output between MPI ranks is properly order and not these routines.

intermediate