kubernetes/pkg/controlplane/controller/leaderelection/election.go

func pickBestLeaderOldestEmulationVersion(candidates []*v1alpha1.LeaseCandidate) *v1alpha1.LeaseCandidate { … }

// topologicalSortWithOneRoot has a caveat that there may only be one root (indegree=0) node in a valid ordering.
func topologicalSortWithOneRoot(graph map[v1.CoordinatedLeaseStrategy][]v1.CoordinatedLeaseStrategy) []v1.CoordinatedLeaseStrategy { … }

func pickBestStrategy(candidates []*v1alpha1.LeaseCandidate) (v1.CoordinatedLeaseStrategy, error) { … }

func validLeaseCandidateForOldestEmulationVersion(l *v1alpha1.LeaseCandidate) bool { … }

func getEmulationVersionOrZero(l *v1alpha1.LeaseCandidate) semver.Version { … }

func getBinaryVersionOrZero(l *v1alpha1.LeaseCandidate) semver.Version { … }

// -1: lhs better, 1: rhs better
func compare(lhs, rhs *v1alpha1.LeaseCandidate) int { … }

func isLeaseExpired(clock clock.Clock, lease *v1.Lease) bool { … }

func isLeaseCandidateExpired(clock clock.Clock, lease *v1alpha1.LeaseCandidate) bool { … }