russell@unturf.com
db29a08762
B&W print-friendly diagrams + tinkerpop-0001 + wave-3 proof sections. Squash of 94 local commits onto remote master.
1.2 KiB
1.2 KiB
| id | repo | severity | status | created |
|---|---|---|---|---|
| javac-0002a | openjdk | HIGH | patched | 2026-03-23 |
Defect
File: src/jdk.compiler/.../javac/comp/Infer.java:1850
Pattern: ArrayList.contains in findNode
Complexity: O(N²)
Language: Java
Description
findNode is called during type inference graph construction to check whether a node is already present in the node list. The check is performed using ArrayList.contains, which performs a full linear scan. Because findNode is called once per inference variable during graph construction, and each call scans up to N existing nodes, the total cost of node lookup is O(N²) in the number of inference variables.
Fix
Replace: nodes.contains(node)
With: nodeSet.contains(node)
Data structure change: ArrayList<Node> nodes → HashSet<Node> nodeSet + ArrayList<Node> nodes
Work required
- Patch in
defects/javac/patch/ - Unit test — asserts exact operation counts before/after (in
defects/javac/unit/) - Integration test (in
defects/javac/integration/) - Benchmark — before/after on V=100,200,400,800 (in
defects/javac/bench/) - White paper section