Make shutdownNow() method consistent with ExecutorService

tools4j · Nov 27, 2018 · b7be8a1 · b7be8a1
1 parent ca6f519
commit b7be8a1
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Showing 3 changed files with 15 additions and 4 deletions.
diff --git a/src/main/java/org/tools4j/nobark/run/Shutdownable.java b/src/main/java/org/tools4j/nobark/run/Shutdownable.java
@@ -23,6 +23,7 @@
  */
 package org.tools4j.nobark.run;
 
+import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.TimeUnit;
 
@@ -55,8 +56,10 @@ public interface Shutdownable {
      * to do that.
      * <p>
      * Invocation has no additional effect if already shut down.
+     *
+     * @return list of tasks that never commenced execution if any, otherwise an empty list
      */
-    void shutdownNow();
+    List<Runnable> shutdownNow();
 
     /**
      * Returns {@code true} if this service has been shut down.

diff --git a/src/main/java/org/tools4j/nobark/run/ShutdownableThread.java b/src/main/java/org/tools4j/nobark/run/ShutdownableThread.java
@@ -23,6 +23,8 @@
  */
 package org.tools4j.nobark.run;
 
+import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
@@ -92,12 +94,14 @@ public void shutdown() {
         state.compareAndSet(RUNNING, SHUTDOWN);
     }
 
+
     @Override
-    public void shutdownNow() {
+    public List<Runnable> shutdownNow() {
         final int shutdownAndNow = SHUTDOWN | SHUTDOWN_NOW;
         if (!state.compareAndSet(RUNNING, shutdownAndNow)) {
             state.compareAndSet(SHUTDOWN, shutdownAndNow);
         }
+        return Collections.emptyList();
     }
 
     private boolean isMainRunning() {

diff --git a/src/test/java/org/tools4j/nobark/run/ShutdownableThreadTest.java b/src/test/java/org/tools4j/nobark/run/ShutdownableThreadTest.java
@@ -23,6 +23,7 @@
  */
 package org.tools4j.nobark.run;
 
+import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
@@ -33,6 +34,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.tools4j.nobark.run.StoppableThreadTest.catchAll;
 
@@ -119,10 +121,11 @@ public void shutdownNowAfterShutdown() {
         assertFalse(thread.isTerminated());
 
         //when
-        thread.shutdownNow();
+        final List<Runnable> notStarted = thread.shutdownNow();
 
         //then
         assertTrue(thread.isShutdown());
+        assertTrue(notStarted.isEmpty());
 
         //when
         thread.awaitTermination(5, TimeUnit.SECONDS);
@@ -131,11 +134,12 @@ public void shutdownNowAfterShutdown() {
         assertTrue(thread.isTerminated());
 
         //when
-        thread.shutdownNow();
+        final List<Runnable> stillNotStarted = thread.shutdownNow();
 
         //then
         assertTrue(thread.isShutdown());
         assertTrue(thread.isTerminated());
+        assertSame(notStarted, stillNotStarted);
     }