+ xbt_mutex_acquire(win->mut);
+ // This (simulated) mutex ensures that no process pushes to the vector of requests during the waitall.
+ // Without this, the vector could get redimensionned when another process pushes.
+ // This would result in the array used by smpi_mpi_waitall() to be invalidated.
+ // Another solution would be to copy the data and cleanup the vector *before* smpi_mpi_waitall