From 4d52be5cf29caa02f90d341e91ee25ca0d69f836 Mon Sep 17 00:00:00 2001
From: Andreas Dangel <adangel@users.sourceforge.net>
Date: Thu, 7 Jul 2016 20:47:53 +0200
Subject: [PATCH] PMDASMClassloader: minor refactoring

---
 .../java/typeresolution/PMDASMClassLoader.java | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/typeresolution/PMDASMClassLoader.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/typeresolution/PMDASMClassLoader.java
index 02681fc85d..62b4bee117 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/typeresolution/PMDASMClassLoader.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/typeresolution/PMDASMClassLoader.java
@@ -6,11 +6,10 @@ package net.sourceforge.pmd.lang.java.typeresolution;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 
 import org.objectweb.asm.ClassReader;
 
@@ -29,6 +28,9 @@ import net.sourceforge.pmd.lang.java.typeresolution.visitors.PMDASMVisitor;
  * the negative cases only. The cache is shared between loadClass and getImportedClasses,
  * as they are using the same (parent) class loader, e.g. if the class foo.Bar cannot be loaded,
  * then the resource foo/Bar.class will not exist, too.
+ * 
+ * Note: since git show 46ad3a4700b7a233a177fa77d08110127a85604c the cache is using
+ * a concurrent hash map to avoid synchronizing on the class loader instance.
  */
 public final class PMDASMClassLoader extends ClassLoader {
 
@@ -36,7 +38,7 @@ public final class PMDASMClassLoader extends ClassLoader {
     private static ClassLoader cachedClassLoader;
 
     /** Caches the names of the classes that we can't load or that don't exist. */
-    private final ConcurrentHashMap<String, Boolean> m_dontBotherSet = new ConcurrentHashMap<>();
+    private final ConcurrentMap<String, Boolean> dontBother = new ConcurrentHashMap<>();
 
     static {
         registerAsParallelCapable();
@@ -62,16 +64,16 @@ public final class PMDASMClassLoader extends ClassLoader {
 
     @Override
     public Class<?> loadClass(String name) throws ClassNotFoundException {
-        if(m_dontBotherSet.containsKey(name))
+        if(dontBother.containsKey(name))
             throw new ClassNotFoundException(name);
 
         try {
             return super.loadClass(name);
         } catch (ClassNotFoundException e) {
-            m_dontBotherSet.put(name, Boolean.TRUE);
+            dontBother.put(name, Boolean.TRUE);
             throw e;
         } catch (NoClassDefFoundError e) {
-            m_dontBotherSet.put(name, Boolean.TRUE);
+            dontBother.put(name, Boolean.TRUE);
             // rethrow as ClassNotFoundException, as the remaining part just
             // deals with that
             // see also: https://sourceforge.net/p/pmd/bugs/1319/
@@ -80,7 +82,7 @@ public final class PMDASMClassLoader extends ClassLoader {
     }
 
     public synchronized Map<String, String> getImportedClasses(String name) throws ClassNotFoundException {
-        if (m_dontBotherSet.contains(name)) {
+        if (dontBother.containsValue(name)) {
             throw new ClassNotFoundException(name);
         }
         try {
@@ -102,7 +104,7 @@ public final class PMDASMClassLoader extends ClassLoader {
             }
             return asmVisitor.getPackages();
         } catch (IOException e) {
-            m_dontBotherSet.put(name, Boolean.TRUE);
+            dontBother.put(name, Boolean.TRUE);
             throw new ClassNotFoundException(name, e);
         }
     }