decrease thread yield frequency in ConcurrentBag.unreserve()

brettwooldridge · brettwooldridge · commit cba7ebe4c6b7 · 2025-08-19T20:35:03.000+09:00
diff --git a/CHANGES b/CHANGES
@@ -1,5 +1,9 @@
 HikariCP Changes
 
+Changes in 7.0.2
+
+ * decrease thread yield frequency in ConcurrentBag.unreserve()
+
 Changes in 7.0.1
 
  * merged #2346 fix regression with setSchema behavior
diff --git a/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java b/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java
@@ -57,6 +57,7 @@
  * @param <T> the templated type to store in the bag
  * @hidden
  */
+@SuppressWarnings("DuplicatedCode")
 public class ConcurrentBag<T extends IConcurrentBagEntry> implements AutoCloseable
 {
    private static final Logger LOGGER = LoggerFactory.getLogger(ConcurrentBag.class);
@@ -318,8 +319,16 @@ public void unreserve(final T bagEntry)
    {
       if (bagEntry.compareAndSet(STATE_RESERVED, STATE_NOT_IN_USE)) {
          // spin until a thread takes it or none are waiting
-         while (waiters.get() > 0 && bagEntry.getState() == STATE_NOT_IN_USE && !handoffQueue.offer(bagEntry)) {
-            Thread.yield();
+         for (int i = 1, waiting = waiters.get(); waiting > 0; i++, waiting = waiters.get()) {
+            if (bagEntry.getState() != STATE_NOT_IN_USE || handoffQueue.offer(bagEntry)) {
+               return;
+            }
+            else if ((i & 0xff) == 0xff || (waiting > 1 && i % waiting == 0)) {
+               parkNanos(MICROSECONDS.toNanos(10));
+            }
+            else {
+               Thread.yield();
+            }
          }
       }
       else {
