Fixes #28: Size of SpscGrowableArrayQueue can exceeds max capacity

Adjust producer limit in order to allow one more element to be added in place of the unneeded JUMP when the max capacity producer buffer has been allocated
JCTools · Sep 7, 2018 · 63044f1 · 63044f1
1 parent 7ed3462
commit 63044f1
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/jctools-core/src/main/java/org/jctools/queues/SpscGrowableArrayQueue.java b/jctools-core/src/main/java/org/jctools/queues/SpscGrowableArrayQueue.java
@@ -114,7 +114,7 @@ final boolean offerColdPath(
                     long currConsumerIndex = lvConsumerIndex();
                     // use lookAheadStep to store the consumer distance from final buffer
                     this.lookAheadStep = -(index - currConsumerIndex);
-                    producerBufferLimit = currConsumerIndex + maxCapacity - 1;
+                    producerBufferLimit = currConsumerIndex + maxCapacity;
                 }
                 else
                 {

diff --git a/jctools-core/src/main/java/org/jctools/queues/atomic/SpscGrowableAtomicArrayQueue.java b/jctools-core/src/main/java/org/jctools/queues/atomic/SpscGrowableAtomicArrayQueue.java
@@ -106,7 +106,7 @@ final boolean offerColdPath(final AtomicReferenceArray<E> buffer, final long mas
                     long currConsumerIndex = lvConsumerIndex();
                     // use lookAheadStep to store the consumer distance from final buffer
                     this.lookAheadStep = -(index - currConsumerIndex);
-                    producerBufferLimit = currConsumerIndex + maxCapacity - 1;
+                    producerBufferLimit = currConsumerIndex + maxCapacity;
                 } else {
                     producerBufferLimit = index + producerMask - 1;
                     adjustLookAheadStep(newCapacity);