Make Unreliables stop calling lambda after timeout occurs (#5)

* Make Unreliables stop calling lambda after timeout occurs

* Tiny test error message fix.

CHANGELOG.md

@@ -1 +1 @@
-See [Releases](https://github.com/rnorth/duct-tape/releases)
+See [Releases](https://github.com/rnorth/duct-tape/releases)

src/main/java/org/rnorth/ducttape/unreliables/Unreliables.java

@@ -7,6 +7,7 @@
 
 import java.util.concurrent.Callable;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.rnorth.ducttape.Preconditions.check;
 
@@ -34,9 +35,10 @@ public static <T> T retryUntilSuccess(final int timeout, @NotNull final TimeUnit
         final int[] attempt = {0};
         final Exception[] lastException = {null};
 
+        final AtomicBoolean doContinue = new AtomicBoolean(true);
         try {
             return Timeouts.getWithTimeout(timeout, timeUnit, () -> {
-                while (true) {
+                while (doContinue.get()) {
                     try {
                         return lambda.call();
                     } catch (Exception e) {
@@ -45,13 +47,16 @@ public static <T> T retryUntilSuccess(final int timeout, @NotNull final TimeUnit
                         lastException[0] = e;
                     }
                 }
+                return null;
             });
         } catch (org.rnorth.ducttape.TimeoutException e) {
             if (lastException[0] != null) {
                 throw new org.rnorth.ducttape.TimeoutException("Timeout waiting for result with exception", lastException[0]);
             } else {
                 throw new org.rnorth.ducttape.TimeoutException(e);
             }
+        } finally {
+            doContinue.set(false);
         }
     }
 

src/test/java/org/rnorth/ducttape/unreliables/UnreliablesTest.java

@@ -5,8 +5,10 @@
 import org.rnorth.ducttape.TimeoutException;
 
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.rnorth.visibleassertions.VisibleAssertions.assertEquals;
+import static org.rnorth.visibleassertions.VisibleAssertions.assertFalse;
 import static org.rnorth.visibleassertions.VisibleAssertions.assertThrows;
 import static org.rnorth.visibleassertions.VisibleAssertions.fail;
 
@@ -115,6 +117,24 @@ public void testRetryUntilSuccessFailsWhenOutsideTimeoutWindow() throws Exceptio
         }
     }
 
+    @Test
+    public void testRetryUntilSuccessLambdaStopsBeingCalledAfterTimeout() throws Exception {
+        AtomicBoolean lambdaCalled = new AtomicBoolean();
+        try {
+            Unreliables.retryUntilSuccess(200, TimeUnit.MILLISECONDS, () -> {
+                lambdaCalled.set(true);
+                throw new RuntimeException();
+            });
+            fail("Expected TimeoutException on retryUntilSuccess that always fails.");
+        } catch (TimeoutException e) {
+            // ok
+            Thread.sleep(200); // give worker thread time to stop calling the lambda
+            lambdaCalled.set(false);
+            Thread.sleep(200); // give worker thread time to call the lambda if it is still running
+            assertFalse("Lambda should stop being executed when retryUntilSuccess times out.", lambdaCalled.get());
+        }
+    }
+
     @Test
     public void testRetryUntilSuccessFailsWhenOutsideTimeoutWindowAndCapturesException() throws Exception {
         try {