java-topology/docs/tickets

Tickets

#	Title	Module	Severity	Status
0001	Tarjan SCC: stack.contains(n) — O(V²)	jdk.compiler	high	open
0002	InferenceGraph.findNode() O(N) scan, called O(N³) total	jdk.compiler	high	open
0003	ModuleHashesBuilder$TopoSorter Deque.contains()	java.base	medium	open
0004	Dependencies$Node.addDependency() List.contains() dedup	jdk.compiler	low	open
0005	InferenceContext.isEquiv() List.containsAll() bound comparison	jdk.compiler	low	open

Pattern

Same defect replicated in 4 locations across 2 modules: O(n) linear collection membership check where O(1) is available.

In every case a flag field, HashSet, or dedicated boolean already exists or is trivially addable. The background bytecode scan of all 69 JDK modules confirmed no additional hits beyond these five. The active field in TarjanNode (0001) is the most direct evidence: maintained correctly, never read.

Cascade

javac compilation
  └─ type inference (Infer.java)
       ├─ GraphSolver.solve()
       │    └─ InferenceGraph.initNodes()
       │         └─ GraphUtils.tarjan()  ← DEFECT 0001: O(V²)
       └─ DeferredAttr.buildStuckGraph()
            └─ canInfluence() × N²
                 ├─ findNode()           ← DEFECT 0002: O(N) per call → O(N³) total
                 └─ closure()           ← DEFECT 0002: uncached O(V+E) per call

jlink image creation
  └─ ModuleHashesBuilder.computeHashes()
       └─ TopoSorter.visit()            ← DEFECT 0003: Deque.contains() O(N)

debug compilation (-XDcompletionDeps)
  └─ Dependencies$GraphDependencies
       └─ Node.addDependency()          ← DEFECT 0004: List.contains() O(N)