From 07736d7ee1669883169c7a10b0060e7b0afa315f Mon Sep 17 00:00:00 2001
From: Stefan Bodewig <bodewig@apache.org>
Date: Wed, 11 Jul 2001 09:58:09 +0000
Subject: [PATCH] help the garbage collector by cleaning out references in
 AntClassLoader and IntrospectionHelper after the build has finished.

This helps applications that run Ant in the same VM over and over
again like CruiseControl or wrappers that run Ant in incremental mode.

PR: 2568
Submitted by:	robert.watkins@qsipayments.com (Robert Watkins)


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269316 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/tools/ant/AntClassLoader.java  | 25 ++++++++++++++++++-
 .../apache/tools/ant/IntrospectionHelper.java | 18 ++++++++++++-
 .../org/apache/tools/ant/ProjectHelper.java   |  2 ++
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/main/org/apache/tools/ant/AntClassLoader.java b/src/main/org/apache/tools/ant/AntClassLoader.java
index 2748865ae..f9dc88dd6 100644
--- a/src/main/org/apache/tools/ant/AntClassLoader.java
+++ b/src/main/org/apache/tools/ant/AntClassLoader.java
@@ -70,7 +70,7 @@ import org.apache.tools.ant.types.Path;
  * @author <a href="mailto:conor@cortexebusiness.com.au">Conor MacNeill</a>
  * @author <a href="mailto:Jesse.Glick@netbeans.com">Jesse Glick</a>
  */
-public class AntClassLoader  extends ClassLoader {
+public class AntClassLoader  extends ClassLoader implements BuildListener {
 
     /**
      * An enumeration of all resources of a given name found within the
@@ -228,6 +228,7 @@ public class AntClassLoader  extends ClassLoader {
      */
     public AntClassLoader(Project project, Path classpath) {
         this.project = project;
+        this.project.addBuildListener(this);
         this.classpath = classpath.concatSystemClasspath("ignore");
     }
 
@@ -839,4 +840,26 @@ public class AntClassLoader  extends ClassLoader {
             return base.loadClass(name);
         }
     }
+
+    public void buildStarted(BuildEvent event) {}
+
+    public void buildFinished(BuildEvent event) {
+        classpath = null;
+        project = null;
+    }
+
+    public void targetStarted(BuildEvent event) {
+    }
+
+    public void targetFinished(BuildEvent event) {
+    }
+
+    public void taskStarted(BuildEvent event) {
+    }
+
+    public void taskFinished(BuildEvent event) {
+    }
+
+    public void messageLogged(BuildEvent event) {
+    }
 }
diff --git a/src/main/org/apache/tools/ant/IntrospectionHelper.java b/src/main/org/apache/tools/ant/IntrospectionHelper.java
index bc99c4a4f..5a3dfd0bb 100644
--- a/src/main/org/apache/tools/ant/IntrospectionHelper.java
+++ b/src/main/org/apache/tools/ant/IntrospectionHelper.java
@@ -68,7 +68,7 @@ import java.util.*;
  *
  * @author <a href="mailto:stefan.bodewig@epost.de">Stefan Bodewig</a>
  */
-public class IntrospectionHelper  {
+public class IntrospectionHelper implements BuildListener {
 
     /**
      * holds the types of the attributes that could be set.
@@ -552,4 +552,20 @@ public class IntrospectionHelper  {
             throws InvocationTargetException, IllegalAccessException, 
                    BuildException;
     }
+
+    public void buildStarted(BuildEvent event) {}
+    public void buildFinished(BuildEvent event) {
+	attributeTypes.clear();
+	attributeSetters.clear();
+	nestedTypes.clear();
+	nestedCreators.clear();
+	addText = null;
+        helpers.clear();
+    }
+
+    public void targetStarted(BuildEvent event) {}
+    public void targetFinished(BuildEvent event) {}
+    public void taskStarted(BuildEvent event) {}
+    public void taskFinished(BuildEvent event) {}
+    public void messageLogged(BuildEvent event) {}
 }
diff --git a/src/main/org/apache/tools/ant/ProjectHelper.java b/src/main/org/apache/tools/ant/ProjectHelper.java
index 02ecdfba6..62bfb2b50 100644
--- a/src/main/org/apache/tools/ant/ProjectHelper.java
+++ b/src/main/org/apache/tools/ant/ProjectHelper.java
@@ -628,6 +628,8 @@ public class ProjectHelper {
         IntrospectionHelper ih = 
             IntrospectionHelper.getHelper(target.getClass());
 
+        project.addBuildListener(ih);
+
         for (int i = 0; i < attrs.getLength(); i++) {
             // reflect these into the target
             String value=replaceProperties(project, attrs.getValue(i),