[#1959] Proposed fix to correctly handle timeouts that overflow the ticks in the wheel

common/src/main/java/io/netty/util/HashedWheelTimer.java

@@ -485,9 +485,10 @@ public class HashedWheelTimer implements Timer {
             this.task = task;
             this.deadline = deadline;
 
-            final long ticks = Math.max(deadline / tickDuration, tick); // Ensure we don't schedule for past.
+            long calculated = deadline / tickDuration;
+            final long ticks = Math.max(calculated, tick); // Ensure we don't schedule for past.
             stopIndex = (int) (ticks & mask);
-            remainingRounds = ticks / wheel.length;
+            remainingRounds = (calculated - tick) / wheel.length;
         }
 
         @Override

common/src/test/java/io/netty/util/HashedWheelTimerTest.java

@@ -16,8 +16,12 @@
 package io.netty.util;
 
 import org.junit.Test;
+
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -102,4 +106,21 @@ public class HashedWheelTimerTest {
             }
         }, 1, TimeUnit.SECONDS);
     }
+
+    @Test
+    public void testTimerOverflowWheelLength() throws InterruptedException {
+        final HashedWheelTimer timer = new HashedWheelTimer(
+                Executors.defaultThreadFactory(), 100, TimeUnit.MILLISECONDS, 32);
+        final AtomicInteger counter = new AtomicInteger();
+
+        timer.newTimeout(new TimerTask() {
+            @Override
+            public void run(final Timeout timeout) throws Exception {
+                counter.incrementAndGet();
+                timer.newTimeout(this, 1, TimeUnit.SECONDS);
+            }
+        }, 1, TimeUnit.SECONDS);
+        Thread.sleep(3500);
+        assertEquals(3, counter.get());
+    }
 }