From 5c3ec55e15922c58bb2f39145de9fe641840bb50 Mon Sep 17 00:00:00 2001
From: Matthew Jason Benson <mbenson@apache.org>
Date: Thu, 4 Feb 2010 21:46:22 +0000
Subject: [PATCH] [LANG-586] clear ThreadLocal recursion registry (compatibly
 with existing tests, first pass)

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@906673 13f79535-47bb-0310-9956-ffa450edef68
---
 .../commons/lang3/builder/ToStringStyle.java  | 192 ++++++++++--------
 1 file changed, 103 insertions(+), 89 deletions(-)

diff --git a/src/main/java/org/apache/commons/lang3/builder/ToStringStyle.java b/src/main/java/org/apache/commons/lang3/builder/ToStringStyle.java
index 9f2096bb7..95b580bbd 100644
--- a/src/main/java/org/apache/commons/lang3/builder/ToStringStyle.java
+++ b/src/main/java/org/apache/commons/lang3/builder/ToStringStyle.java
@@ -5,9 +5,9 @@
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -19,9 +19,10 @@
 import java.io.Serializable;
 import java.lang.reflect.Array;
 import java.util.Collection;
-import java.util.HashSet;
+import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
+import java.util.WeakHashMap;
 
 import org.apache.commons.lang3.ClassUtils;
 import org.apache.commons.lang3.ObjectUtils;
@@ -46,7 +47,7 @@
  * <p>For example, the detail version of the array based methods will
  * output the whole array, whereas the summary method will just output
  * the array length.</p>
- * 
+ *
  * <p>If you want to format the output of certain objects, such as dates, you
  * must create a subclass and override a method.
  * <pre>
@@ -73,17 +74,17 @@ public abstract class ToStringStyle implements Serializable {
     /**
      * The default toString style. Using the Using the <code>Person</code>
      * example from {@link ToStringBuilder}, the output would look like this:
-     * 
+     *
      * <pre>
      * Person@182f0db[name=John Doe,age=33,smoker=false]
      * </pre>
      */
     public static final ToStringStyle DEFAULT_STYLE = new DefaultToStringStyle();
-    
+
     /**
      * The multi line toString style. Using the Using the <code>Person</code>
      * example from {@link ToStringBuilder}, the output would look like this:
-     * 
+     *
      * <pre>
      * Person@182f0db[
      *   name=John Doe
@@ -93,26 +94,26 @@ public abstract class ToStringStyle implements Serializable {
      * </pre>
      */
     public static final ToStringStyle MULTI_LINE_STYLE = new MultiLineToStringStyle();
-    
+
     /**
      * The no field names toString style. Using the Using the
      * <code>Person</code> example from {@link ToStringBuilder}, the output
      * would look like this:
-     * 
+     *
      * <pre>
      * Person@182f0db[John Doe,33,false]
      * </pre>
      */
     public static final ToStringStyle NO_FIELD_NAMES_STYLE = new NoFieldNameToStringStyle();
-    
+
     /**
      * The short prefix toString style. Using the <code>Person</code> example
      * from {@link ToStringBuilder}, the output would look like this:
-     * 
+     *
      * <pre>
      * Person[name=John Doe,age=33,smoker=false]
      * </pre>
-     * 
+     *
      * @since 2.1
      */
     public static final ToStringStyle SHORT_PREFIX_STYLE = new ShortPrefixToStringStyle();
@@ -120,38 +121,32 @@ public abstract class ToStringStyle implements Serializable {
     /**
      * The simple toString style. Using the Using the <code>Person</code>
      * example from {@link ToStringBuilder}, the output would look like this:
-     * 
+     *
      * <pre>
      * John Doe,33,false
      * </pre>
      */
     public static final ToStringStyle SIMPLE_STYLE = new SimpleToStringStyle();
-    
+
     /**
      * <p>
      * A registry of objects used by <code>reflectionToString</code> methods
      * to detect cyclical object references and avoid infinite loops.
      * </p>
      */
-    private static final ThreadLocal<Set<Object>> registry = new ThreadLocal<Set<Object>>() {
-        @Override
-        protected Set<Object> initialValue() {
-            // The HashSet implementation is not synchronized,
-            // which is just what we need here.
-            return new HashSet<Object>();
-        }
-    };
+    private static final ThreadLocal<WeakHashMap<Object, Object>> REGISTRY = new ThreadLocal<WeakHashMap<Object,Object>>();
 
     /**
      * <p>
      * Returns the registry of objects being traversed by the <code>reflectionToString</code>
      * methods in the current thread.
      * </p>
-     * 
+     *
      * @return Set the registry of objects being traversed
      */
     static Set<Object> getRegistry() {
-        return registry.get();
+        WeakHashMap<Object, Object> m = REGISTRY.get();
+        return m == null ? Collections.<Object> emptySet() : m.keySet();
     }
 
     /**
@@ -159,7 +154,7 @@ static Set<Object> getRegistry() {
      * Returns <code>true</code> if the registry contains the given object.
      * Used by the reflection methods to avoid infinite loops.
      * </p>
-     * 
+     *
      * @param value
      *                  The object to lookup in the registry.
      * @return boolean <code>true</code> if the registry contains the given
@@ -174,13 +169,21 @@ static boolean isRegistered(Object value) {
      * Registers the given object. Used by the reflection methods to avoid
      * infinite loops.
      * </p>
-     * 
+     *
      * @param value
      *                  The object to register.
      */
     static void register(Object value) {
         if (value != null) {
-            getRegistry().add(value);
+            WeakHashMap<Object, Object> m;
+            synchronized (ToStringStyle.class) {
+                m = REGISTRY.get();
+                if (m == null) {
+                    m = new WeakHashMap<Object, Object>();
+                    REGISTRY.set(m);
+                }
+            }
+            m.put(value, null);
         }
     }
 
@@ -188,33 +191,44 @@ static void register(Object value) {
      * <p>
      * Unregisters the given object.
      * </p>
-     * 
+     *
      * <p>
      * Used by the reflection methods to avoid infinite loops.
      * </p>
-     * 
+     *
      * @param value
      *                  The object to unregister.
      */
     static void unregister(Object value) {
-        getRegistry().remove(value);
+        if (value != null) {
+            WeakHashMap<Object, Object> m;
+            synchronized (ToStringStyle.class) {
+                m = REGISTRY.get();
+                if (m != null) {
+                    m.remove(value);
+                    if (m.isEmpty()) {
+                        REGISTRY.remove();
+                    }
+                }
+            }
+        }
     }
 
     /**
      * Whether to use the field names, the default is <code>true</code>.
      */
     private boolean useFieldNames = true;
-    
+
     /**
      * Whether to use the class name, the default is <code>true</code>.
      */
     private boolean useClassName = true;
-    
+
     /**
      * Whether to use short class names, the default is <code>false</code>.
      */
     private boolean useShortClassName = false;
-    
+
     /**
      * Whether to use the identity hash code, the default is <code>true</code>.
      */
@@ -224,78 +238,78 @@ static void unregister(Object value) {
      * The content start <code>'['</code>.
      */
     private String contentStart = "[";
-    
+
     /**
      * The content end <code>']'</code>.
      */
     private String contentEnd = "]";
-    
+
     /**
      * The field name value separator <code>'='</code>.
      */
     private String fieldNameValueSeparator = "=";
-    
+
     /**
      * Whether the field separator should be added before any other fields.
      */
     private boolean fieldSeparatorAtStart = false;
-    
+
     /**
      * Whether the field separator should be added after any other fields.
      */
     private boolean fieldSeparatorAtEnd = false;
-    
+
     /**
      * The field separator <code>','</code>.
      */
     private String fieldSeparator = ",";
-    
+
     /**
      * The array start <code>'{'</code>.
      */
     private String arrayStart = "{";
-    
+
     /**
      * The array separator <code>','</code>.
      */
     private String arraySeparator = ",";
-    
+
     /**
      * The detail for array content.
      */
     private boolean arrayContentDetail = true;
-    
+
     /**
      * The array end <code>'}'</code>.
      */
     private String arrayEnd = "}";
-    
+
     /**
      * The value to use when fullDetail is <code>null</code>,
      * the default value is <code>true</code>.
      */
     private boolean defaultFullDetail = true;
-    
+
     /**
      * The <code>null</code> text <code>'&lt;null&gt;'</code>.
      */
     private String nullText = "<null>";
-    
+
     /**
      * The summary size text start <code>'<size'</code>.
      */
     private String sizeStartText = "<size=";
-    
+
     /**
      * The summary size text start <code>'&gt;'</code>.
      */
     private String sizeEndText = ">";
-    
+
     /**
      * The summary object text start <code>'&lt;'</code>.
      */
     private String summaryObjectStartText = "<";
-    
+
     /**
      * The summary object text start <code>'&gt;'</code>.
      */
@@ -315,9 +329,9 @@ protected ToStringStyle() {
     /**
      * <p>Append to the <code>toString</code> the superclass toString.</p>
      * <p>NOTE: It assumes that the toString has been created from the same ToStringStyle. </p>
-     * 
+     *
      * <p>A <code>null</code> <code>superToString</code> is ignored.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param superToString  the <code>super.toString()</code>
      * @since 2.0
@@ -329,9 +343,9 @@ public void appendSuper(StringBuffer buffer, String superToString) {
     /**
      * <p>Append to the <code>toString</code> another toString.</p>
      * <p>NOTE: It assumes that the toString has been created from the same ToStringStyle. </p>
-     * 
+     *
      * <p>A <code>null</code> <code>toString</code> is ignored.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param toString  the additional <code>toString</code>
      * @since 2.0
@@ -353,7 +367,7 @@ public void appendToString(StringBuffer buffer, String toString) {
 
     /**
      * <p>Append to the <code>toString</code> the start of data indicator.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param object  the <code>Object</code> to build a <code>toString</code> for
      */
@@ -370,7 +384,7 @@ public void appendStart(StringBuffer buffer, Object object) {
 
     /**
      * <p>Append to the <code>toString</code> the end of data indicator.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param object  the <code>Object</code> to build a
      *  <code>toString</code> for.
@@ -385,7 +399,7 @@ public void appendEnd(StringBuffer buffer, Object object) {
 
     /**
      * <p>Remove the last field separator from the buffer.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @since 2.0
      */
@@ -456,7 +470,7 @@ protected void appendInternal(StringBuffer buffer, String fieldName, Object valu
             && !(value instanceof Number || value instanceof Boolean || value instanceof Character)) {
            appendCyclicObject(buffer, fieldName, value);
            return;
-        }   
+        }
 
         register(value);
 
@@ -467,77 +481,77 @@ protected void appendInternal(StringBuffer buffer, String fieldName, Object valu
                 } else {
                     appendSummarySize(buffer, fieldName, ((Collection<?>) value).size());
                 }
-    
+
             } else if (value instanceof Map<?, ?>) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (Map<?, ?>) value);
                 } else {
                     appendSummarySize(buffer, fieldName, ((Map<?, ?>) value).size());
                 }
-    
+
             } else if (value instanceof long[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (long[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (long[]) value);
                 }
-    
+
             } else if (value instanceof int[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (int[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (int[]) value);
                 }
-    
+
             } else if (value instanceof short[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (short[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (short[]) value);
                 }
-    
+
             } else if (value instanceof byte[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (byte[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (byte[]) value);
                 }
-    
+
             } else if (value instanceof char[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (char[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (char[]) value);
                 }
-    
+
             } else if (value instanceof double[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (double[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (double[]) value);
                 }
-    
+
             } else if (value instanceof float[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (float[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (float[]) value);
                 }
-    
+
             } else if (value instanceof boolean[]) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (boolean[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (boolean[]) value);
                 }
-    
+
             } else if (value.getClass().isArray()) {
                 if (detail) {
                     appendDetail(buffer, fieldName, (Object[]) value);
                 } else {
                     appendSummary(buffer, fieldName, (Object[]) value);
                 }
-    
+
             } else {
                     if (detail) {
                         appendDetail(buffer, fieldName, value);
@@ -549,17 +563,17 @@ protected void appendInternal(StringBuffer buffer, String fieldName, Object valu
             unregister(value);
         }
     }
-    
+
     /**
      * <p>Append to the <code>toString</code> an <code>Object</code>
      * value that has been detected to participate in a cycle. This
      * implementation will print the standard string value of the value.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param fieldName  the field name, typically not used as already appended
      * @param value  the value to add to the <code>toString</code>,
      *  not <code>null</code>
-     *  
+     *
      * @since 2.2
      */
     protected void appendCyclicObject(StringBuffer buffer, String fieldName, Object value) {
@@ -1428,7 +1442,7 @@ protected void appendSummary(StringBuffer buffer, String fieldName, boolean[] ar
 
     /**
      * <p>Append to the <code>toString</code> the class name.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param object  the <code>Object</code> whose name to output
      */
@@ -1445,7 +1459,7 @@ protected void appendClassName(StringBuffer buffer, Object object) {
 
     /**
      * <p>Append the {@link System#identityHashCode(java.lang.Object)}.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param object  the <code>Object</code> whose id to output
      */
@@ -1459,7 +1473,7 @@ protected void appendIdentityHashCode(StringBuffer buffer, Object object) {
 
     /**
      * <p>Append to the <code>toString</code> the content start.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      */
     protected void appendContentStart(StringBuffer buffer) {
@@ -1468,7 +1482,7 @@ protected void appendContentStart(StringBuffer buffer) {
 
     /**
      * <p>Append to the <code>toString</code> the content end.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      */
     protected void appendContentEnd(StringBuffer buffer) {
@@ -1479,7 +1493,7 @@ protected void appendContentEnd(StringBuffer buffer) {
      * <p>Append to the <code>toString</code> an indicator for <code>null</code>.</p>
      *
      * <p>The default indicator is <code>'&lt;null&gt;'</code>.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param fieldName  the field name, typically not used as already appended
      */
@@ -1489,7 +1503,7 @@ protected void appendNullText(StringBuffer buffer, String fieldName) {
 
     /**
      * <p>Append to the <code>toString</code> the field separator.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      */
     protected void appendFieldSeparator(StringBuffer buffer) {
@@ -1498,7 +1512,7 @@ protected void appendFieldSeparator(StringBuffer buffer) {
 
     /**
      * <p>Append to the <code>toString</code> the field start.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param fieldName  the field name
      */
@@ -1511,7 +1525,7 @@ protected void appendFieldStart(StringBuffer buffer, String fieldName) {
 
     /**
      * <p>Append to the <code>toString<code> the field end.</p>
-     * 
+     *
      * @param buffer  the <code>StringBuffer</code> to populate
      * @param fieldName  the field name, typically not used as already appended
      */
@@ -1550,7 +1564,7 @@ protected void appendSummarySize(StringBuffer buffer, String fieldName, int size
      * <code>null</code> indicating that it doesn't care about
      * the detail level. In this case the default detail level is
      * used.</p>
-     * 
+     *
      * @param fullDetailRequest  the detail level requested
      * @return whether full detail is to be shown
      */
@@ -1886,9 +1900,9 @@ protected void setFieldSeparator(String fieldSeparator) {
     //---------------------------------------------------------------------
 
     /**
-     * <p>Gets whether the field separator should be added at the start 
+     * <p>Gets whether the field separator should be added at the start
      * of each buffer.</p>
-     * 
+     *
      * @return the fieldSeparatorAtStart flag
      * @since 2.0
      */
@@ -1897,9 +1911,9 @@ protected boolean isFieldSeparatorAtStart() {
     }
 
     /**
-     * <p>Sets whether the field separator should be added at the start 
+     * <p>Sets whether the field separator should be added at the start
      * of each buffer.</p>
-     * 
+     *
      * @param fieldSeparatorAtStart  the fieldSeparatorAtStart flag
      * @since 2.0
      */
@@ -1910,9 +1924,9 @@ protected void setFieldSeparatorAtStart(boolean fieldSeparatorAtStart) {
     //---------------------------------------------------------------------
 
     /**
-     * <p>Gets whether the field separator should be added at the end 
+     * <p>Gets whether the field separator should be added at the end
      * of each buffer.</p>
-     * 
+     *
      * @return fieldSeparatorAtEnd flag
      * @since 2.0
      */
@@ -1921,9 +1935,9 @@ protected boolean isFieldSeparatorAtEnd() {
     }
 
     /**
-     * <p>Sets whether the field separator should be added at the end 
+     * <p>Sets whether the field separator should be added at the end
      * of each buffer.</p>
-     * 
+     *
      * @param fieldSeparatorAtEnd  the fieldSeparatorAtEnd flag
      * @since 2.0
      */
@@ -2097,7 +2111,7 @@ private static final class DefaultToStringStyle extends ToStringStyle {
 
         /**
          * Required for serialization support.
-         * 
+         *
          * @see java.io.Serializable
          */
         private static final long serialVersionUID = 1L;
@@ -2157,7 +2171,7 @@ private Object readResolve() {
     }
 
     //----------------------------------------------------------------------------
-    
+
     /**
      * <p><code>ToStringStyle</code> that prints out the short
      * class name and no identity hashcode.</p>