Move queue size to unshared longs

jbossas · May 2, 2024 · 9389f88 · 9389f88
1 parent c127c5a
commit 9389f88
Showing 1 changed file with 28 additions and 24 deletions.
diff --git a/src/main/java/org/jboss/threads/EnhancedQueueExecutor.java b/src/main/java/org/jboss/threads/EnhancedQueueExecutor.java
@@ -233,6 +233,12 @@ public final class EnhancedQueueExecutor extends AbstractExecutorService impleme
      *             <li>Bit 63: 1 = shutdown complete; 0 = shutdown not complete</li>
      *         </ul>
      *     </li>
+     *     <li>{@code 1} {@code queueSize}: Information about the current queue size:
+     *          <ul>
+     *              <li>Bit 00..1F: current queue length</li>
+     *              <li>Bit 20..3F: queue limit</li>
+     *          </ul>
+     *     </li>
      * </ul>
      */
     final long[] unsharedLongs = new long[RuntimeFields.unsharedLongsSize];
@@ -243,16 +249,6 @@ public final class EnhancedQueueExecutor extends AbstractExecutorService impleme
     @SuppressWarnings("unused") // used by field updater
     volatile Waiter terminationWaiters;
 
-    /**
-     * Queue size:
-     * <ul>
-     *     <li>Bit 00..1F: current queue length</li>
-     *     <li>Bit 20..3F: queue limit</li>
-     * </ul>
-     */
-    @SuppressWarnings("unused") // used by field updater
-    volatile long queueSize;
-
     /**
      * The thread keep-alive timeout value.
      */
@@ -311,13 +307,11 @@ public final class EnhancedQueueExecutor extends AbstractExecutorService impleme
     // Updaters
     // =======================================================
 
-    private static final int numUnsharedLongs = 1;
+    private static final int numUnsharedLongs = 2;
     private static final int numUnsharedObjects = 2;
 
     private static final long terminationWaitersOffset;
 
-    private static final long queueSizeOffset;
-
     private static final long peakThreadCountOffset;
     private static final long activeCountOffset;
     private static final long peakQueueSizeOffset;
@@ -329,7 +323,9 @@ private static final class RuntimeFields {
 
         private static final long headOffset;
         private static final long tailOffset;
+
         private static final long threadStatusOffset;
+        private static final long queueSizeOffset;
 
         static {
             int cacheLine = CacheInfo.getSmallestDataCacheLineSize();
@@ -346,15 +342,14 @@ private static final class RuntimeFields {
             headOffset = unsafe.arrayBaseOffset(Object[].class) + cacheLine;
             tailOffset = unsafe.arrayBaseOffset(Object[].class) + cacheLine * 2;
             threadStatusOffset = unsafe.arrayBaseOffset(long[].class) + cacheLine;
+            queueSizeOffset = unsafe.arrayBaseOffset(long[].class) + cacheLine * 2;
         }
     }
 
     static {
         try {
             terminationWaitersOffset = unsafe.objectFieldOffset(EnhancedQueueExecutor.class.getDeclaredField("terminationWaiters"));
 
-            queueSizeOffset = unsafe.objectFieldOffset(EnhancedQueueExecutor.class.getDeclaredField("queueSize"));
-
             peakThreadCountOffset = unsafe.objectFieldOffset(EnhancedQueueExecutor.class.getDeclaredField("peakThreadCount"));
             activeCountOffset = unsafe.objectFieldOffset(EnhancedQueueExecutor.class.getDeclaredField("activeCount"));
             peakQueueSizeOffset = unsafe.objectFieldOffset(EnhancedQueueExecutor.class.getDeclaredField("peakQueueSize"));
@@ -428,7 +423,7 @@ private static final class RuntimeFields {
         // thread stat
         setThreadStatusPlain(withCoreSize(withMaxSize(withAllowCoreTimeout(0L, builder.allowsCoreThreadTimeOut()), maxSize), coreSize));
         timeoutNanos = TimeUtil.clampedPositiveNanos(keepAliveTime);
-        queueSize = withMaxQueueSize(withCurrentQueueSize(0L, 0), builder.getMaximumQueueSize());
+        setQueueSizePlain(withMaxQueueSize(withCurrentQueueSize(0L, 0), builder.getMaximumQueueSize()));
         mxBean = new MXBeanImpl();
         if (! DISABLE_MBEAN && builder.isRegisterMBean()) {
             this.acc = getContext();
@@ -1358,7 +1353,7 @@ public void setKeepAliveTime(final Duration keepAliveTime) {
      * @see Builder#getMaximumQueueSize() Builder.getMaximumQueueSize()
      */
     public int getMaximumQueueSize() {
-        return maxQueueSizeOf(queueSize);
+        return maxQueueSizeOf(getQueueSizeVolatile());
     }
 
     /**
@@ -1374,7 +1369,7 @@ public void setMaximumQueueSize(final int maxQueueSize) {
         if (NO_QUEUE_LIMIT) return;
         long oldVal;
         do {
-            oldVal = queueSize;
+            oldVal = getQueueSizeVolatile();
         } while (! compareAndSetQueueSize(oldVal, withMaxQueueSize(oldVal, maxQueueSize)));
     }
 
@@ -1435,7 +1430,7 @@ public void setTerminationTask(final Runnable terminationTask) {
      * @return an estimate of the current queue size or -1 when {@code jboss.threads.eqe.unlimited-queue} is enabled
      */
     public int getQueueSize() {
-        return NO_QUEUE_LIMIT ? -1 : currentQueueSizeOf(queueSize);
+        return NO_QUEUE_LIMIT ? -1 : currentQueueSizeOf(getQueueSizeVolatile());
     }
 
     /**
@@ -2045,8 +2040,17 @@ boolean compareAndSetPeakQueueSize(final int expect, final int update) {
         return unsafe.compareAndSwapInt(this, peakQueueSizeOffset, expect, update);
     }
 
+    long getQueueSizeVolatile() {
+        return unsafe.getLongVolatile(unsharedLongs, RuntimeFields.queueSizeOffset);
+    }
+
+    long setQueueSizePlain(long queueSize) {
+        unsafe.putLong(unsharedLongs, RuntimeFields.queueSizeOffset, queueSize);
+        return queueSize;
+    }
+
     boolean compareAndSetQueueSize(final long expect, final long update) {
-        return unsafe.compareAndSwapLong(this, queueSizeOffset, expect, update);
+        return unsafe.compareAndSwapLong(unsharedLongs, RuntimeFields.queueSizeOffset, expect, update);
     }
 
     boolean compareAndSetTerminationWaiters(final Waiter expect, final Waiter update) {
@@ -2062,7 +2066,7 @@ Waiter getAndSetTerminationWaiters(final Waiter update) {
     // =======================================================
 
     boolean increaseQueueSize() {
-        long oldVal = queueSize;
+        long oldVal = getQueueSizeVolatile();
         int oldSize = currentQueueSizeOf(oldVal);
         if (oldSize >= maxQueueSizeOf(oldVal)) {
             // reject
@@ -2071,7 +2075,7 @@ boolean increaseQueueSize() {
         int newSize = oldSize + 1;
         while (! compareAndSetQueueSize(oldVal, withCurrentQueueSize(oldVal, newSize))) {
             if (UPDATE_STATISTICS) spinMisses.increment();
-            oldVal = queueSize;
+            oldVal = getQueueSizeVolatile();
             oldSize = currentQueueSizeOf(oldVal);
             if (oldSize >= maxQueueSizeOf(oldVal)) {
                 // reject
@@ -2091,11 +2095,11 @@ boolean increaseQueueSize() {
 
     void decreaseQueueSize() {
         long oldVal;
-        oldVal = queueSize;
+        oldVal = getQueueSizeVolatile();
         assert currentQueueSizeOf(oldVal) > 0;
         while (! compareAndSetQueueSize(oldVal, withCurrentQueueSize(oldVal, currentQueueSizeOf(oldVal) - 1))) {
             if (UPDATE_STATISTICS) spinMisses.increment();
-            oldVal = queueSize;
+            oldVal = getQueueSizeVolatile();
             assert currentQueueSizeOf(oldVal) > 0;
         }
     }