Determines if all processors in a communicator share a /tmp or have different ones.
comm - MPI_Communicator that may share /tmp
Options Database Keys#
-shared_tmp - indicates the directory is shared among the MPI ranks
-not_shared_tmp - indicates the directory is not shared among the MPI ranks
-tmp tmpdir - name of the directory you wish to use as /tmp
PETSC_SHARED_TMP- indicates the directory is shared among the MPI ranks
PETSC_NOT_SHARED_TMP- indicates the directory is not shared among the MPI ranks
PETSC_TMP- name of the directory you wish to use as /tmp
Stores the status as a MPI attribute so it does not have to be redetermined each time.
Assumes that all processors in a communicator either
have a common /tmp or
each has a separate /tmp eventually we can write a fancier one that determines which processors share a common /tmp.
This will be very slow on runs with a large number of processors since it requires O(p*p) file opens.
If the environmental variable PETSC_TMP is set it will use this directory as the “/tmp” directory.