Revert e66fc219ff

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

@@ -76,7 +76,7 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
 public class HashedWheelTimer implements Timer {
 
     static final InternalLogger logger =
-        InternalLoggerFactory.getInstance(HashedWheelTimer.class);
+            InternalLoggerFactory.getInstance(HashedWheelTimer.class);
 
     private static final ResourceLeakDetector<HashedWheelTimer> leakDetector =
             new ResourceLeakDetector<HashedWheelTimer>(
@@ -87,6 +87,7 @@ public class HashedWheelTimer implements Timer {
     final Thread workerThread;
     final AtomicInteger workerState = new AtomicInteger(); // 0 - init, 1 - started, 2 - shut down
 
+    private final long roundDuration;
     final long tickDuration;
     final Set<HashedWheelTimeout>[] wheel;
     final int mask;
@@ -200,6 +201,8 @@ public class HashedWheelTimer implements Timer {
             throw new IllegalArgumentException("tickDuration is too long: " + tickDuration + ' ' + unit);
         }
 
+        roundDuration = tickDuration * wheel.length;
+
         workerThread = threadFactory.newThread(worker);
     }
 
@@ -240,17 +243,17 @@ public class HashedWheelTimer implements Timer {
      */
     public void start() {
         switch (workerState.get()) {
-        case 0:
-            if (workerState.compareAndSet(0, 1)) {
-                workerThread.start();
-            }
-            break;
-        case 1:
-            break;
-        case 2:
-            throw new IllegalStateException("cannot be started once stopped");
-        default:
-            throw new Error();
+            case 0:
+                if (workerState.compareAndSet(0, 1)) {
+                    workerThread.start();
+                }
+                break;
+            case 1:
+                break;
+            case 2:
+                throw new IllegalStateException("cannot be started once stopped");
+            default:
+                throw new Error();
         }
     }
 
@@ -259,8 +262,8 @@ public class HashedWheelTimer implements Timer {
         if (Thread.currentThread() == workerThread) {
             throw new IllegalStateException(
                     HashedWheelTimer.class.getSimpleName() +
-                    ".stop() cannot be called from " +
-                    TimerTask.class.getSimpleName());
+                            ".stop() cannot be called from " +
+                            TimerTask.class.getSimpleName());
         }
 
         if (!workerState.compareAndSet(1, 2)) {
@@ -314,17 +317,20 @@ public class HashedWheelTimer implements Timer {
     }
 
     void scheduleTimeout(HashedWheelTimeout timeout, long delay) {
-        long relativeIndex = (delay + tickDuration - 1) / tickDuration;
-
-        // if the previous line had an overflow going on, then we’ll just schedule this timeout
-        // one tick early; that shouldn’t matter since we’re talking 270 years here
-        if (relativeIndex < 0) {
-            relativeIndex = delay / tickDuration;
-        } else if (relativeIndex == 0) {
-            relativeIndex = 1;
+        // delay must be equal to or greater than tickDuration so that the
+        // worker thread never misses the timeout.
+        if (delay < tickDuration) {
+            delay = tickDuration;
         }
 
-        final long remainingRounds = relativeIndex / wheel.length;
+        // Prepare the required parameters to schedule the timeout object.
+        final long lastRoundDelay = delay % roundDuration;
+        final long lastTickDelay = delay % tickDuration;
+        final long relativeIndex =
+                lastRoundDelay / tickDuration + (lastTickDelay != 0? 1 : 0);
+
+        final long remainingRounds =
+                delay / roundDuration - (delay % roundDuration == 0? 1 : 0);
 
         // Add the timeout to the wheel.
         lock.readLock().lock();
@@ -332,6 +338,7 @@ public class HashedWheelTimer implements Timer {
             int stopIndex = (int) (wheelCursor + relativeIndex & mask);
             timeout.stopIndex = stopIndex;
             timeout.remainingRounds = remainingRounds;
+
             wheel[stopIndex].add(timeout);
         } finally {
             lock.readLock().unlock();
@@ -349,14 +356,14 @@ public class HashedWheelTimer implements Timer {
         @Override
         public void run() {
             List<HashedWheelTimeout> expiredTimeouts =
-                new ArrayList<HashedWheelTimeout>();
+                    new ArrayList<HashedWheelTimeout>();
 
             startTime = System.currentTimeMillis();
             tick = 1;
 
             while (workerState.get() == 1) {
                 final long deadline = waitForNextTick();
-                if (deadline > Long.MIN_VALUE) {
+                if (deadline > 0) {
                     fetchExpiredTimeouts(expiredTimeouts, deadline);
                     notifyExpiredTimeouts(expiredTimeouts);
                 }
@@ -388,7 +395,7 @@ public class HashedWheelTimer implements Timer {
                 HashedWheelTimeout timeout = i.next();
                 if (timeout.remainingRounds <= 0) {
                     i.remove();
-                    if (timeout.deadline - deadline <= 0) {
+                    if (timeout.deadline <= deadline) {
                         expiredTimeouts.add(timeout);
                     } else {
                         // Handle the case where the timeout is put into a wrong
@@ -424,26 +431,12 @@ public class HashedWheelTimer implements Timer {
             expiredTimeouts.clear();
         }
 
-        /**
-         * calculate goal nanoTime from startTime and current tick number,
-         * then wait until that goal has been reached.
-         * @return Long.MIN_VALUE if received a shutdown request, current time otherwise
-         */
         private long waitForNextTick() {
-            final long deadline = startTime + tickDuration * tick;
+            long deadline = startTime + tickDuration * tick;
 
             for (;;) {
-                final long currentTime = System.nanoTime();
-                long sleepTimeMs = (deadline - currentTime + 999999) / 1000000;
-
-                if (sleepTimeMs <= 0) {
-                    tick++;
-                    if (currentTime == Long.MIN_VALUE) {
-                        return -Long.MAX_VALUE;
-                    } else {
-                        return currentTime;
-                    }
-                }
+                final long currentTime = System.currentTimeMillis();
+                long sleepTime = tickDuration * tick - (currentTime - startTime);
 
                 // Check if we run on windows, as if thats the case we will need
                 // to round the sleepTime as workaround for a bug that only affect
@@ -451,17 +444,25 @@ public class HashedWheelTimer implements Timer {
                 //
                 // See https://github.com/netty/netty/issues/356
                 if (PlatformDependent.isWindows()) {
-                    sleepTimeMs = sleepTimeMs / 10 * 10;
+                    sleepTime = sleepTime / 10 * 10;
+                }
+
+                if (sleepTime <= 0) {
+                    break;
                 }
 
                 try {
-                    Thread.sleep(sleepTimeMs);
+                    Thread.sleep(sleepTime);
                 } catch (InterruptedException e) {
                     if (workerState.get() != 1) {
-                        return Long.MIN_VALUE;
+                        return -1;
                     }
                 }
             }
+
+            // Increase the tick.
+            tick ++;
+            return deadline;
         }
     }
 
@@ -521,9 +522,7 @@ public class HashedWheelTimer implements Timer {
                 task.run(this);
             } catch (Throwable t) {
                 if (logger.isWarnEnabled()) {
-                    logger.warn(
-                            "An exception was thrown by " +
-                            TimerTask.class.getSimpleName() + '.', t);
+                    logger.warn("An exception was thrown by " + TimerTask.class.getSimpleName() + '.', t);
                 }
             }
         }