From 2f5ea9073b3783d0380ed3bc574638daf0dec59b Mon Sep 17 00:00:00 2001
From: Brett Wooldridge <brett.wooldridge@gmail.com>
Date: Thu, 16 Apr 2015 23:41:13 +0900
Subject: [PATCH] Better.

---
 .../com/zaxxer/hikari/util/ConcurrentBag.java | 36 ++++---------------
 1 file changed, 6 insertions(+), 30 deletions(-)

diff --git a/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java b/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java
index f181da22..73a78997 100644
--- a/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java
+++ b/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java
@@ -100,7 +100,6 @@ public class ConcurrentBag<T extends IConcurrentBagEntry>
             for (int i = list.size() - 1; i >= 0; i--) {
                final IConcurrentBagEntry bagEntry = list.remove(i).get();
                if (bagEntry != null && bagEntry.state().compareAndSet(STATE_NOT_IN_USE, STATE_IN_USE)) {
-                  // LOGGER.debug("{} fastpath bag item", Thread.currentThread());
                   return (T) bagEntry;
                }
             }
@@ -118,14 +117,13 @@ public class ConcurrentBag<T extends IConcurrentBagEntry>
             startSeq = sequence.get();
             for (final T bagEntry : sharedList) {
                if (bagEntry.state().compareAndSet(STATE_NOT_IN_USE, STATE_IN_USE)) {
-                  LOGGER.debug("{} got bag item {}", Thread.currentThread(), startSeq);
+                  // LOGGER.debug("{} got bag item {}", Thread.currentThread(), startSeq);
                   return bagEntry;
                }
             }
          } while (startSeq < sequence.get());
 
          if (addItemFuture == null || addItemFuture.isDone()) {
-            // LOGGER.debug("{} requesting addBagItem()", Thread.currentThread());
             addItemFuture = listener.addBagItem();
          }
 
@@ -133,8 +131,6 @@ public class ConcurrentBag<T extends IConcurrentBagEntry>
             return null;
          }
 
-         // LOGGER.debug("{} woke up to try again", Thread.currentThread());
-
          final long elapsed = (System.nanoTime() - startScan);
          timeout = originTimeout - Math.max(elapsed, 100L);  // don't trust the nanoTime() impl. not to go backwards due to NTP adjustments
       }
@@ -317,42 +313,22 @@ public class ConcurrentBag<T extends IConcurrentBagEntry>
    /**
     * Our private synchronizer that handles notify/wait type semantics.
     */
-   private static final class Synchronizer extends AbstractQueuedLongSynchronizer
+   private final class Synchronizer extends AbstractQueuedLongSynchronizer
    {
       private static final long serialVersionUID = 104753538004341218L;
 
       @Override
       protected long tryAcquireShared(final long seq)
       {
-         // if (hasQueuedPredecessors()) {
-         //   LOGGER.debug("{} had {} queued predecessors ({})", Thread.currentThread(), this.getQueueLength(), seq);
-         //   return -1L;
-         //}
-
-         // final long ret = getState() > seq ? 0L : -1L;
-         // LOGGER.debug("{} tryAcquireShared({}) returned {}", Thread.currentThread(), seq, ret);
-         final long delta = getState() - (seq + 1);
-         return hasQueuedPredecessors() ? -1L : delta;
+         return hasQueuedPredecessors() ? -1L : getState() - (seq + 1);
       }
 
       /** {@inheritDoc} */
       @Override
-      protected boolean tryReleaseShared(final long updateSeq)
+      protected boolean tryReleaseShared(final long unreliableSequence)
       {
-         long currentSeq = getState();
-         while (updateSeq > currentSeq) {
-            if (compareAndSetState(currentSeq, updateSeq)) {
-               return true;
-            }
-
-            // spin
-            Thread.yield();
-            currentSeq = getState();
-         }
-
-         // LOGGER.debug("tryReleaseShared({}) succeeded", updateSeq);
-
-         return false;
+         setState(sequence.get());
+         return true;
       }
    }
 }