allow to omit lock when reading volatile field in "Unguarded field access" inspection

java/java-analysis-impl/src/com/intellij/codeInspection/concurrencyAnnotations/FieldAccessNotGuardedInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2016 JetBrains s.r.o.
+ * Copyright 2000-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,7 +54,6 @@ public class FieldAccessNotGuardedInspection extends BaseJavaBatchLocalInspectio
     return new Visitor(holder);
   }
 
-
   private static class Visitor extends JavaElementVisitor {
     private final ProblemsHolder myHolder;
 
@@ -83,6 +82,10 @@ public class FieldAccessNotGuardedInspection extends BaseJavaBatchLocalInspectio
       } catch (IncorrectOperationException ignore) {
         return;
       }
+      if (guardExpression instanceof PsiThisExpression && !PsiUtil.isAccessedForWriting(expression) &&
+          field.hasModifierProperty(PsiModifier.VOLATILE)) {
+        return;
+      }
       final PsiMethod containingMethod = PsiTreeUtil.getParentOfType(expression, PsiMethod.class);
       if (containingMethod != null) {
         if (JCiPUtil.isGuardedBy(containingMethod, guard) || containingMethod.isConstructor()) {

java/java-tests/testData/inspection/guarded/cheapReadWriteLock.java

@@ -0,0 +1,13 @@
+import javax.annotation.concurrent.GuardedBy;
+
+class CheapReadWriteLock {
+  // Employs the cheap read-write lock trick
+  // All mutative operations MUST be done with the 'this' lock held
+  @GuardedBy("this") private volatile int value;
+
+  public int getValue() { return value; }
+
+  public synchronized int increment() {
+    return value++;
+  }
+}

java/java-tests/testSrc/com/intellij/codeInspection/FieldAccessedNotGuardedInspectionTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,6 +42,11 @@ public class FieldAccessedNotGuardedInspectionTest extends LightCodeInsightFixtu
     doTest();
   }
 
+  public void testCheapReadWriteLock() {
+    myFixture.addClass("package javax.annotation.concurrent;\n" + getGuardedByAnnotationText());
+    doTest();
+  }
+
   private void doTest() {
     myFixture.testHighlighting(true, false, false, getTestName(true) + ".java");
   }