pub fn gather_to_all<T: Equivalence, C: CommunicatorCollectives>(
arr: &[T],
comm: &C,
) -> Vec<T>Expand description
Gather array to all processes
Examples found in repository?
examples/mpi_complete_tree_debug.rs (line 98)
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pub fn main() {
// Initialise MPI
let universe = mpi::initialize().unwrap();
// Get the world communicator
let comm = universe.world();
// Initialise a seeded Rng.
let mut rng = ChaCha8Rng::seed_from_u64(comm.rank() as u64);
// Create `npoints` per rank.
let npoints = 10000;
// Generate random points.
let mut points = generate_random_points(npoints, &mut rng, &comm);
// Make sure that the points live on the unit sphere.
for point in points.iter_mut() {
let len = point.coords()[0] * point.coords()[0]
+ point.coords()[1] * point.coords()[1]
+ point.coords()[2] * point.coords()[2];
let len = len.sqrt();
point.coords_mut()[0] /= len;
point.coords_mut()[1] /= len;
point.coords_mut()[2] /= len;
}
let tree = Octree::new(&points, 15, 50, &comm);
// We now check that each node of the tree has all its neighbors available.
let leaf_tree = tree.leaf_keys();
let all_keys = tree.all_keys();
assert!(is_complete_linear_and_balanced(leaf_tree, &comm));
for &key in leaf_tree {
// We only check interior keys. Leaf keys may not have a neighbor
// on the same level.
let mut parent = key.parent();
while parent.level() > 0 {
// Check that the key itself is there.
assert!(all_keys.contains_key(&key));
// Check that all its neighbours are there.
for neighbor in parent.neighbours().iter().filter(|&key| key.is_valid()) {
assert!(all_keys.contains_key(neighbor));
}
parent = parent.parent();
// Check that the parent is there.
assert!(all_keys.contains_key(&parent));
}
}
// At the end check that the root of the tree is also contained.
assert!(all_keys.contains_key(&MortonKey::root()));
// Count the number of ghosts on each rank
// Count the number of global keys on each rank.
// Assert that all ghosts are from a different rank and count them.
let nghosts = all_keys
.iter()
.filter_map(|(_, &value)| {
if let KeyType::Ghost(rank) = value {
assert!(rank != comm.size() as usize);
Some(rank)
} else {
None
}
})
.count();
if comm.size() == 1 {
assert_eq!(nghosts, 0);
} else {
assert!(nghosts > 0);
}
let nglobal = all_keys
.iter()
.filter(|(_, &value)| matches!(value, KeyType::Global))
.count();
// Assert that all globals across all ranks have the same count.
let nglobals = gather_to_all(std::slice::from_ref(&nglobal), &comm);
assert_eq!(nglobals.iter().unique().count(), 1);
// Check that the points are associated with the correct leaf keys.
let mut npoints = 0;
let leaf_point_map = tree.leaf_keys_to_local_point_indices();
for (key, point_indices) in leaf_point_map {
for &index in point_indices {
assert!(key.is_ancestor(tree.point_keys()[index]));
}
npoints += point_indices.len();
}
// Make sure that the number of points and point keys lines up
// with the points stored for each leaf key.
assert_eq!(npoints, tree.points().len());
assert_eq!(npoints, tree.point_keys().len());
// Check the neighbour relationships.
let all_neighbours = tree.neighbour_map();
let all_keys = tree.all_keys();
for (key, key_type) in all_keys {
// Ghost keys should not be in the neighbour map.
match key_type {
KeyType::Ghost(_) => assert!(!all_neighbours.contains_key(key)),
_ => {
// If it is not a ghost the key should be in the neighbour map.
assert!(all_neighbours.contains_key(key));
}
}
}
if comm.rank() == 0 {
println!("No errors were found in setting up tree.");
}
}