# HG changeset patch
# User Doug Simon <doug.simon@oracle.com>
# Date 1502179539 -7200
# Node ID 7d8e0c328b640a0f1c60ea6f59cbf72b04f721e5
# Parent  0137da2b56d9db3f215d88eb38805e3442f2d8b8
fix NPE possibility in HotSpotSpeculationLog.speculate (JDK-8185950)

diff -r 0137da2b56d9 -r 7d8e0c328b64 jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotSpeculationLog.java
--- a/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotSpeculationLog.java	Thu Aug 03 11:53:11 2017 -0700
+++ b/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotSpeculationLog.java	Tue Aug 08 10:05:39 2017 +0200
@@ -39,7 +39,7 @@
     private Set<SpeculationReason> failedSpeculations;
 
     /** Strong references to all reasons embedded in the current nmethod. */
-    private volatile Collection<SpeculationReason> speculations;
+    private Collection<SpeculationReason> speculations;
 
     @Override
     public synchronized void collectFailedSpeculations() {
@@ -70,14 +70,12 @@
          * reason objects that are embedded in nmethods, so we add them to the speculations
          * collection.
          */
-        if (speculations == null) {
-            synchronized (this) {
-                if (speculations == null) {
-                    speculations = new ConcurrentLinkedQueue<>();
-                }
+        synchronized (this) {
+            if (speculations == null) {
+                speculations = new ConcurrentLinkedQueue<>();
             }
+            speculations.add(reason);
         }
-        speculations.add(reason);
 
         return HotSpotObjectConstantImpl.forObject(reason);
     }