cow: CopyOnWriteArrayList - deterministic iterator-snapshot and synchronizedList CME demos, JMH read/write throughput, and the addLast/removeFirst fix for a real concurrent-writer race

2026-10-01 12:09:44 +00:00
parent 2eaa464bad
commit 434054f246
17 changed files with 709 additions and 0 deletions
@@ -0,0 +1,17 @@
+list before any iterator is taken = [Apple, Banana, Cherry]
+beforeWrite.next() = Apple
+[writer] added Date and Elderberry - list is now [Apple, Banana, Cherry, Date, Elderberry]
+
+=== beforeWrite iterator was created BEFORE the write - draining the rest of it ===
+beforeWrite.next() = Banana
+beforeWrite.next() = Cherry
+beforeWrite never saw Date or Elderberry, and threw no exception.
+
+=== afterWrite iterator is created AFTER the write - it sees the current array ===
+afterWrite.next() = Apple
+afterWrite.next() = Banana
+afterWrite.next() = Cherry
+afterWrite.next() = Date
+afterWrite.next() = Elderberry
+
+Final list = [Apple, Banana, Cherry, Date, Elderberry]