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  1. XNIO
  2. XNIO-372

NPE happens on ByteBufferSlicePool.clean() for non-direct buffers

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      1. Configure direct-buffers="false" on <buffer-pool> in the io subsystem:

      /subsystem=io/buffer-pool=default:write-attribute(name=direct-buffers,value=false)
:reload

      2. Shutdown JBoss EAP 7

      Then, you will see NullPointerException on XNIO ByteBufferSlicePool.clean().

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      1. Configure direct-buffers="false" on <buffer-pool> in the io subsystem: /subsystem=io/buffer-pool= default :write-attribute(name=direct-buffers,value= false ) :reload 2. Shutdown JBoss EAP 7 Then, you will see NullPointerException on XNIO ByteBufferSlicePool.clean().

      The following NPE happens on XNIO ByteBufferSlicePool.clean() for non-direct buffers during the shutdown. For example, when direct-buffers="false" is specified to <buffer-pool> in the io subsystem.

      10:02:08,180 WARN  [org.jboss.msc.service.fail] (MSC service thread 1-7) MSC000004: Failure during stop of service org.wildfly.io.buffer-pool.default: java.lang.NullPointerException
	at java.util.concurrent.ConcurrentLinkedQueue.addAll(ConcurrentLinkedQueue.java:530)
	at org.xnio.ByteBufferSlicePool.clean(ByteBufferSlicePool.java:214)
	at org.wildfly.extension.io.BufferPoolService.stop(BufferPoolService.java:62)
	at org.jboss.msc.service.ServiceControllerImpl$StopTask.stopService(ServiceControllerImpl.java:1795)
	at org.jboss.msc.service.ServiceControllerImpl$StopTask.execute(ServiceControllerImpl.java:1764)
	at org.jboss.msc.service.ServiceControllerImpl$ControllerTask.run(ServiceControllerImpl.java:1559)
	at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
	at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1985)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1487)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1378)
	at java.lang.Thread.run(Thread.java:748)

      This issue happens since EAP 7.2.4 that incorporates JBEAP-17380 / (XNIO-345 / XNIO-346).

      This NPE itself is harmless and ignorable as direct buffers is disabled. However, it's better to fix this by adding a null check for "directBuffers". For example:

      diff --git a/api/src/main/java/org/xnio/ByteBufferSlicePool.java b/api/src/main/java/org/xnio/ByteBufferSlicePool.java
index cae23c5..f30125e 100644
--- a/api/src/main/java/org/xnio/ByteBufferSlicePool.java
+++ b/api/src/main/java/org/xnio/ByteBufferSlicePool.java
@@ -206,8 +206,11 @@ public final class ByteBufferSlicePool implements Pool<ByteBuffer> {
         if(!sliceQueue.isEmpty()) {
             sliceQueue.clear();
         }
-        // pass everything that is directly allocated to free direct buffers
-        FREE_DIRECT_BUFFERS.addAll(directBuffers);
+        // only true if using direct allocation
+        if (directBuffers != null) {
+            // pass everything that is directly allocated to free direct buffers
+            FREE_DIRECT_BUFFERS.addAll(directBuffers);
+        }
     }
 
     /**

              rhn-support-mmiura Masafumi Miura
              rhn-support-mmiura Masafumi Miura
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                Created:
                Updated:
                Resolved: