From 6516c36789fedd2635e1aafd4cc33cb4afe7f9f7 Mon Sep 17 00:00:00 2001
From: Eric Meisel <eric.steven.meisel@gmail.com>
Date: Tue, 11 May 2021 16:50:51 -0500
Subject: [PATCH 1/2] Convert startGracefulShutdown() to a CompletableFuture

---
 .../GracefulShutdownCoordinator.java          | 19 +++++++++----------
 .../amazon/kinesis/coordinator/Scheduler.java | 14 +++-----------
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
index e67414c6..981fda52 100644
--- a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
+++ b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
@@ -14,21 +14,20 @@
  */
 package software.amazon.kinesis.coordinator;
 
-import java.util.concurrent.Callable;
-import java.util.concurrent.Future;
-import java.util.concurrent.FutureTask;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
+import java.util.function.Supplier;
 
 import lombok.extern.slf4j.Slf4j;
 
 class GracefulShutdownCoordinator {
 
-    Future<Boolean> startGracefulShutdown(Callable<Boolean> shutdownCallable) {
-        FutureTask<Boolean> task = new FutureTask<>(shutdownCallable);
-        Thread shutdownThread = new Thread(task, "RequestedShutdownThread");
-        shutdownThread.start();
-        return task;
-
+    CompletableFuture<Boolean> startGracefulShutdown(Callable<Boolean> shutdownCallable) {
+        CompletableFuture<Boolean> cf = new CompletableFuture<>();
+        CompletableFuture.runAsync(() -> {
+            try { cf.complete(shutdownCallable.call()); }
+            catch(Throwable ex) { cf.completeExceptionally(ex); }
+        });
+        return cf;
     }
 
     Callable<Boolean> createGracefulShutdownCallable(Callable<GracefulShutdownContext> startWorkerShutdown) {
diff --git a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/Scheduler.java b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/Scheduler.java
index aa0a5568..e9431c15 100644
--- a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/Scheduler.java
+++ b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/Scheduler.java
@@ -31,15 +31,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.ThreadLocalRandom;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -187,7 +179,7 @@ public class Scheduler implements Runnable {
     /**
      * Used to ensure that only one requestedShutdown is in progress at a time.
      */
-    private Future<Boolean> gracefulShutdownFuture;
+    private CompletableFuture<Boolean> gracefulShutdownFuture;
     @VisibleForTesting
     protected boolean gracefuleShutdownStarted = false;
 
@@ -716,7 +708,7 @@ public class Scheduler implements Runnable {
      *         completed successfully. A false value indicates that a non-exception case caused the shutdown process to
      *         terminate early.
      */
-    public Future<Boolean> startGracefulShutdown() {
+    public CompletableFuture<Boolean> startGracefulShutdown() {
         synchronized (this) {
             if (gracefulShutdownFuture == null) {
                 gracefulShutdownFuture = gracefulShutdownCoordinator

From c5fcfc6ee1e70cb074cfb7b06ecba2ac1e819650 Mon Sep 17 00:00:00 2001
From: Eric Meisel <eric.steven.meisel@gmail.com>
Date: Tue, 11 May 2021 16:57:02 -0500
Subject: [PATCH 2/2] Remove added import

---
 .../amazon/kinesis/coordinator/GracefulShutdownCoordinator.java  | 1 -
 1 file changed, 1 deletion(-)

diff --git a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
index 981fda52..29bd699e 100644
--- a/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
+++ b/amazon-kinesis-client/src/main/java/software/amazon/kinesis/coordinator/GracefulShutdownCoordinator.java
@@ -15,7 +15,6 @@
 package software.amazon.kinesis.coordinator;
 
 import java.util.concurrent.*;
-import java.util.function.Supplier;
 
 import lombok.extern.slf4j.Slf4j;