[Java] Return a boolean to indicate if cancelling a timer was success…

…ful or not.
isabella232 · Jan 1, 2018 · 8793abc · 8793abc
1 parent 03e2a27
commit 8793abc
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/agrona/src/main/java/org/agrona/DeadlineTimerWheel.java b/agrona/src/main/java/org/agrona/DeadlineTimerWheel.java
@@ -213,19 +213,24 @@ public long scheduleTimer(final long deadline)
      * Cancel a previously scheduled timer.
      *
      * @param timerId of the timer to cancel.
+     * @return true if successful otherwise false if the timerId did not exist.
      */
-    public void cancelTimer(final long timerId)
+    public boolean cancelTimer(final long timerId)
     {
         final int wheelIndex = tickForTimerId(timerId);
         final int arrayIndex = indexInTickArray(timerId);
 
         final long[] array = wheel[wheelIndex];
 
-        if (array[arrayIndex] != NULL_TIMER)
+        if (NULL_TIMER != array[arrayIndex])
         {
             array[arrayIndex] = NULL_TIMER;
             timerCount--;
+
+            return true;
         }
+
+        return false;
     }
 
     /**

diff --git a/agrona/src/test/java/org/agrona/DeadlineTimerWheelTest.java b/agrona/src/test/java/org/agrona/DeadlineTimerWheelTest.java
@@ -22,6 +22,8 @@
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
+import static junit.framework.TestCase.assertFalse;
+import static junit.framework.TestCase.assertTrue;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertNotNull;
@@ -186,7 +188,8 @@ public void shouldBeAbleToCancelTimer()
         }
         while (-1 == firedTimestamp.value && controlTimestamp < (16 * wheel.tickResolution()));
 
-        wheel.cancelTimer(id);
+        assertTrue(wheel.cancelTimer(id));
+        assertFalse(wheel.cancelTimer(id));
 
         do
         {