From dc689ff51487bf75f66bd57f6aec83e3541b68ce Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Tue, 16 Aug 2016 20:05:23 +0300
Subject: [PATCH] Fix concurrent access issues in CallableReference
 implementations

Because of multiple reads from the same non-volatile variable, NPE was possible
to achieve in a multi-threaded application
---
 .../jvm/internal/CallableReference.java       | 14 ++++++++------
 .../jvm/internal/FunctionReference.java       | 19 ++++++++++---------
 .../jvm/internal/PropertyReference.java       |  3 ++-
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java b/core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java
index 1e493b8a609..da51704a44c 100644
--- a/core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java
+++ b/core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java
@@ -122,17 +122,19 @@ public abstract class CallableReference implements KCallable {
     }
 
     public KCallable compute() {
-        if (reflected == null) {
-            reflected = computeReflected();
+        KCallable result = reflected;
+        if (result == null) {
+            result = computeReflected();
+            reflected = result;
         }
-        return reflected;
+        return result;
     }
 
     protected KCallable getReflected() {
-        compute();
-        if (reflected == this) {
+        KCallable result = compute();
+        if (result == this) {
             throw new KotlinReflectionNotSupportedError();
         }
-        return reflected;
+        return result;
     }
 }
diff --git a/core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java b/core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java
index 771c26c17a8..f4374230b64 100644
--- a/core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java
+++ b/core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java
@@ -146,8 +146,7 @@ public class FunctionReference extends FunctionImpl implements KFunction {
                    getSignature().equals(other.getSignature());
         }
         if (obj instanceof KFunction) {
-            compute();
-            return obj.equals(reflected);
+            return obj.equals(compute());
         }
         return false;
     }
@@ -159,7 +158,7 @@ public class FunctionReference extends FunctionImpl implements KFunction {
 
     @Override
     public String toString() {
-        compute();
+        KFunction reflected = compute();
         if (reflected != this) {
             return reflected.toString();
         }
@@ -171,17 +170,19 @@ public class FunctionReference extends FunctionImpl implements KFunction {
     }
 
     public KFunction compute() {
-        if (reflected == null) {
-            reflected = Reflection.function(this);
+        KFunction result = reflected;
+        if (result == null) {
+            result = Reflection.function(this);
+            reflected = result;
         }
-        return reflected;
+        return result;
     }
 
     private KFunction getReflected() {
-        compute();
-        if (reflected == this) {
+        KFunction result = compute();
+        if (result == this) {
             throw new KotlinReflectionNotSupportedError();
         }
-        return reflected;
+        return result;
     }
 }
diff --git a/core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java b/core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java
index 09454de0e69..3341ea18968 100644
--- a/core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java
+++ b/core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java
@@ -16,6 +16,7 @@
 
 package kotlin.jvm.internal;
 
+import kotlin.reflect.KCallable;
 import kotlin.reflect.KProperty;
 
 public abstract class PropertyReference extends CallableReference implements KProperty {
@@ -57,7 +58,7 @@ public abstract class PropertyReference extends CallableReference implements KPr
 
     @Override
     public String toString() {
-        compute();
+        KCallable reflected = compute();
         if (reflected != this) {
             return reflected.toString();
         }