Function t8_offset_first_owner_of_tree

Function Documentation

int t8_offset_first_owner_of_tree(const int mpisize, const t8_gloidx_t gtree, const t8_gloidx_t *offset, int *some_owner)

Find the smallest process that has a given tree as local tree.

To increase the runtime, an arbitrary process having this tree as local tree can be passed as an argument. Otherwise, such an owner is computed during the call.

Parameters:

  • mpisize – [in] The number of MPI ranks, also the number of entries in offset minus 1.

  • gtree – [in] The global id of a tree.

  • offset – [in] The partition to be considered.

  • some_owner – [in] If >= 0 considered as input: a process that has gtree as local tree. If < 0 on output a process that has gtree as local tree. Specifying some_owner increases the runtime from O(log mpisize) to O(n), where n is the number of owners of the tree.

Returns:

The smallest rank that has gtree as a local tree.