Add structured-concurrency-final module: StructuredTaskScope final in JDK 28 (JEP 543), run on 28-ea, 27, 26 and 25

Runnable demos for the ankurm.com structured-concurrency-java article: the ExecutorService thread leak and its fix, every built-in Joiner, structure violations, timeouts, a custom Joiner, JSON thread dumps (in-process and jcmd), scoped values, javap diffs of the API on 25, 26, 27 and 28-ea, compiler output for six pieces of 25/26-era code, and the preview class-file trap between 27 and 28. Transcripts in output/. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01CifR2BE7PBvRy5hT8TS9oz
2026-10-26 02:01:31 +00:00
parent 2e25042a68
commit c93a1fffbb
37 changed files with 1351 additions and 0 deletions
@@ -0,0 +1,15 @@
+$ javac src/Timeouts.java && java Timeouts     (28-beta+21-ea)
+-- inside the deadline
+  [fast, fast]
+-- deadline 200 ms, one subtask needs 5 s
+  ExecutionException, cause = java.util.concurrent.StructuredTaskScope$CancelledByTimeoutException
+  returned within well under a second (not 5 s): the slow subtask was interrupted
+-- the same deadline with a joiner whose timeout() returns a partial result
+  join() = [fast]
+-- a thread factory decides the subtask thread's name
+  [order-0, order-1]
+
+$ javac src/CollectingJoiner.java && java CollectingJoiner     (28-beta+21-ea)
+collected (sorted): [1, 3]
+-- with a 100 ms timeout and a 5 s subtask
+  CompletionException, cause = java.util.concurrent.StructuredTaskScope$CancelledByTimeoutException