fix: TaskExecutor.close() shutdown is very fast now even with NonBlockingLineWriter Task

Author: vorburger

src/dev/enola/be/io/NonBlockingLineWriter.java

@@ -41,6 +41,13 @@ protected void executeIt() throws Exception {
                 delegate.println(line);
             }
         } catch (InterruptedException e) {
+            // We've been interrupted, which is the signal to shut down.
+            // But before we exit, let's process any remaining messages in the queue.
+            Object line;
+            while ((line = queue.poll()) != null) {
+                delegate.println(line);
+            }
+            // Re-set the interrupt flag to be a good citizen.
             Thread.currentThread().interrupt();
         }
     }

src/dev/enola/be/task/TaskExecutor.java

@@ -122,6 +122,11 @@ public Set<UUID> list() {
 
     @Override
     public void close() {
+        // Signal to all running tasks, so they can terminate gracefully & fast
+        for (Task<?, ?> task : tasks.values()) {
+            task.cancel();
+        }
+
         TaskExecutorServices.close(executor);
         TaskExecutorServices.close(timeoutScheduler);
     }

src/dev/enola/be/task/TaskExecutorServices.java

@@ -48,8 +48,6 @@ static void close(ExecutorService executor) {
         var start = System.currentTimeMillis();
         logger.fine(() -> "Starting to shut down ExecutorService " + executor);
 
-        // TODO Signal close() to all running tasks, so they can terminate gracefully & fast
-
         // TODO Then (only) use Java 19+ executor.close()
 
         executor.shutdown();