MNG-4041: maven core returns stale project state during extended use. this is a patch which provides intelligent caching and yields a very substantial performance improvement.

Submitted by: Igor Fedorenko



git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@782014 13f79535-47bb-0310-9956-ffa450edef68

maven-core/src/main/java/org/apache/maven/DefaultMaven.java

@@ -171,7 +171,7 @@ public class DefaultMaven
         return result;
     }
     
-    protected Map<String,MavenProject> getProjects( MavenExecutionRequest request )
+    public Map<String,MavenProject> getProjects( MavenExecutionRequest request )
         throws MavenExecutionException, ProjectBuildingException
     {
         // We have no POM file.

maven-core/src/main/java/org/apache/maven/DefaultProjectDependenciesResolver.java

@@ -54,7 +54,7 @@ public class DefaultProjectDependenciesResolver
         
         ArtifactFilter filter; 
 
-        if ( exclusions != null )
+        if ( ! exclusions.isEmpty() )
         {
             filter = new AndArtifactFilter( Arrays.asList( new ArtifactFilter[]{ new ExcludesArtifactFilter( exclusions ), scopeFilter } ) );
         }

maven-core/src/main/java/org/apache/maven/execution/ApplicationInformation.java

@@ -1,25 +0,0 @@
-package org.apache.maven.execution;
-
-import org.apache.maven.artifact.versioning.ArtifactVersion;
-
-public class ApplicationInformation
-{
-    private ArtifactVersion version;
-    private String builtOn;
-    
-    public ApplicationInformation( ArtifactVersion version, String builtOn )
-    {
-        this.version = version;
-        this.builtOn = builtOn;
-    }
-
-    public ArtifactVersion getVersion()
-    {
-        return version;
-    }
-
-    public String getBuiltOn()
-    {
-        return builtOn;
-    }        
-}

maven-core/src/main/java/org/apache/maven/execution/DefaultRuntimeInformation.java

@@ -1,109 +0,0 @@
-package org.apache.maven.execution;
-
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  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.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.Properties;
-
-import org.apache.maven.artifact.versioning.ArtifactVersion;
-import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
-import org.codehaus.plexus.component.annotations.Component;
-import org.codehaus.plexus.personality.plexus.lifecycle.phase.Initializable;
-import org.codehaus.plexus.personality.plexus.lifecycle.phase.InitializationException;
-import org.codehaus.plexus.util.IOUtil;
-
-/**
- * Describes runtime information about the application.
- *
- * @author Jason van Zyl
- * @author <a href="mailto:brett@apache.org">Brett Porter</a>
- * @version $Id$
- */
-@Component(role = RuntimeInformation.class)
-public class DefaultRuntimeInformation
-    implements RuntimeInformation, Initializable
-{    
-    private ApplicationInformation applicationInformation;
-    
-    public ApplicationInformation getApplicationInformation()
-    {
-        return applicationInformation;
-    }
-
-    /** @deprecated Use getApplicationInformation() */
-    public ArtifactVersion getApplicationVersion()
-    {
-        return applicationInformation.getVersion();
-    }    
-    
-    public void initialize()
-        throws InitializationException
-    {
-        applicationInformation = getVersion( getClass().getClassLoader(), "org.apache.maven", "maven-core" );
-    }
-    
-    public static ApplicationInformation getVersion( ClassLoader loader, String groupId, String artifactId )
-    {
-        String MAVEN_PROPERTIES = "META-INF/maven/" + groupId + "/" + artifactId + "/pom.properties";
-
-        String version = "unknown";
-        String builtOn = "unknown";
-
-        InputStream resourceAsStream = null;
-        try
-        {
-            Properties properties = new Properties();
-            resourceAsStream = loader.getResourceAsStream( MAVEN_PROPERTIES );
-            
-            if ( resourceAsStream == null )
-            {
-                return new ApplicationInformation( new DefaultArtifactVersion( "3.0" ), builtOn );
-            }
-            
-            properties.load( resourceAsStream );
-
-            String property = properties.getProperty( "version" );
-            
-            if ( property != null )
-            {
-                version = property;
-            }
-            
-            property = properties.getProperty( "builtOn" );
-            
-            if ( property != null )
-            {
-                builtOn = property;
-            }
-            
-            return new ApplicationInformation( new DefaultArtifactVersion( version ), builtOn );
-            
-        }
-        catch ( IOException e )
-        {
-            return new ApplicationInformation( new DefaultArtifactVersion( version ), builtOn );
-        }
-        finally
-        {
-            IOUtil.close( resourceAsStream );
-        }        
-    }
-}

maven-core/src/main/java/org/apache/maven/execution/RuntimeInformation.java

@@ -1,38 +0,0 @@
-package org.apache.maven.execution;
-
-import org.apache.maven.artifact.versioning.ArtifactVersion;
-
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  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.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-/**
- * Describes runtime information about the application.
- *
- * @author <a href="mailto:brett@apache.org">Brett Porter</a>
- * @version $Id$
- */
-public interface RuntimeInformation
-{
-    ApplicationInformation getApplicationInformation();
-    
-    /** @deprecated Use getApplicationInformation() */
-    //!!BC Used by the Eclipse Plugin
-    ArtifactVersion getApplicationVersion();
-     
-}

maven-core/src/main/java/org/apache/maven/lifecycle/DefaultLifecycleExecutor.java

@@ -47,6 +47,7 @@ import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoNotFoundException;
 import org.apache.maven.plugin.PluginDescriptorParsingException;
 import org.apache.maven.plugin.PluginManager;
+import org.apache.maven.plugin.PluginManagerException;
 import org.apache.maven.plugin.PluginNotFoundException;
 import org.apache.maven.plugin.PluginResolutionException;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
@@ -221,7 +222,7 @@ public class DefaultLifecycleExecutor
     // 4. Bind those mojos found in the lifecycle mapping for the packaging to the lifecycle
     // 5. Bind mojos specified in the project itself to the lifecycle
     public MavenExecutionPlan calculateExecutionPlan( MavenSession session, String... tasks )
-        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, NoPluginFoundForPrefixException, InvalidPluginDescriptorException
+        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, NoPluginFoundForPrefixException, InvalidPluginDescriptorException, PluginManagerException
     {        
         MavenProject project = session.getCurrentProject();
                 
@@ -394,7 +395,13 @@ public class DefaultLifecycleExecutor
             // org.apache.maven.plugins:maven-remote-resources-plugin:1.0:process
             //                        
             MojoDescriptor mojoDescriptor = pluginManager.getMojoDescriptor( 
-                mojoExecution.getGroupId(), mojoExecution.getArtifactId(), mojoExecution.getVersion(), mojoExecution.getGoal(), session.getLocalRepository(), project.getRemoteArtifactRepositories() );
+                mojoExecution.getGroupId(), mojoExecution.getArtifactId(), mojoExecution.getVersion(), mojoExecution.getGoal(), session.getLocalRepository(), project.getPluginArtifactRepositories() );
+
+            PluginDescriptor pluginDescriptor = mojoDescriptor.getPluginDescriptor();
+            if ( pluginDescriptor.getPlugin().isExtensions() )
+            {
+                pluginDescriptor.setClassRealm( pluginManager.getPluginRealm( session, pluginDescriptor ) );
+            }
 
             requiredDependencyResolutionScope = calculateRequiredDependencyResolutionScope( requiredDependencyResolutionScope, mojoDescriptor.isDependencyResolutionRequired() );          
             

maven-core/src/main/java/org/apache/maven/lifecycle/LifecycleExecutor.java

@@ -30,6 +30,7 @@ import org.apache.maven.plugin.CycleDetectedInPluginGraphException;
 import org.apache.maven.plugin.InvalidPluginDescriptorException;
 import org.apache.maven.plugin.MojoNotFoundException;
 import org.apache.maven.plugin.PluginDescriptorParsingException;
+import org.apache.maven.plugin.PluginManagerException;
 import org.apache.maven.plugin.PluginNotFoundException;
 import org.apache.maven.plugin.PluginResolutionException;
 
@@ -50,7 +51,7 @@ public interface LifecycleExecutor
      * @throws LifecycleExecutionException
      */
     MavenExecutionPlan calculateExecutionPlan( MavenSession session, String... tasks )
-        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, NoPluginFoundForPrefixException, InvalidPluginDescriptorException;
+        throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, NoPluginFoundForPrefixException, InvalidPluginDescriptorException, PluginManagerException;
         
     // For a given project packaging find all the plugins that are bound to any registered
     // lifecycles. The project builder needs to now what default plugin information needs to be

maven-core/src/main/java/org/apache/maven/plugin/DefaultPluginClassLoaderCache.java

@@ -1,29 +0,0 @@
-package org.apache.maven.plugin;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.codehaus.plexus.classworlds.realm.ClassRealm;
-import org.codehaus.plexus.component.annotations.Component;
-
-@Component(role=PluginClassLoaderCache.class)
-public class DefaultPluginClassLoaderCache
-    implements PluginClassLoaderCache
-{
-    private Map<String,ClassRealm> pluginClassLoaders = new HashMap<String,ClassRealm>();
-    
-    public void put( String key, ClassRealm pluginClassLoader )
-    {
-        pluginClassLoaders.put(  key, pluginClassLoader );
-    }
-
-    public ClassRealm get( String key )
-    {
-        return pluginClassLoaders.get( key );
-    }
-
-    public int size()
-    {
-        return pluginClassLoaders.size();
-    }
-}

maven-core/src/main/java/org/apache/maven/plugin/DefaultPluginManager.java

@@ -15,21 +15,20 @@ package org.apache.maven.plugin;
  * the License.
  */
 
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
-import java.io.Reader;
+import java.io.InputStream;
 import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLConnection;
 import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Enumeration;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.jar.JarFile;
+import java.util.zip.ZipEntry;
 
 import org.apache.maven.ArtifactFilterManager;
 import org.apache.maven.artifact.Artifact;
@@ -52,8 +51,11 @@ import org.apache.maven.plugin.descriptor.PluginDescriptorBuilder;
 import org.apache.maven.project.DuplicateArtifactAttachmentException;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.repository.RepositorySystem;
+import org.codehaus.plexus.MutablePlexusContainer;
 import org.codehaus.plexus.PlexusContainer;
+import org.codehaus.plexus.classworlds.ClassWorld;
 import org.codehaus.plexus.classworlds.realm.ClassRealm;
+import org.codehaus.plexus.classworlds.realm.DuplicateRealmException;
 import org.codehaus.plexus.component.annotations.Component;
 import org.codehaus.plexus.component.annotations.Requirement;
 import org.codehaus.plexus.component.composition.CycleDetectedInComponentGraphException;
@@ -61,23 +63,18 @@ import org.codehaus.plexus.component.configurator.ComponentConfigurationExceptio
 import org.codehaus.plexus.component.configurator.ComponentConfigurator;
 import org.codehaus.plexus.component.configurator.ConfigurationListener;
 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
-import org.codehaus.plexus.component.discovery.ComponentDiscoverer;
-import org.codehaus.plexus.component.discovery.ComponentDiscoveryEvent;
-import org.codehaus.plexus.component.discovery.ComponentDiscoveryListener;
 import org.codehaus.plexus.component.repository.ComponentDescriptor;
-import org.codehaus.plexus.component.repository.ComponentSetDescriptor;
 import org.codehaus.plexus.component.repository.exception.ComponentLifecycleException;
 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
 import org.codehaus.plexus.configuration.PlexusConfiguration;
 import org.codehaus.plexus.configuration.PlexusConfigurationException;
 import org.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
-import org.codehaus.plexus.context.Context;
-import org.codehaus.plexus.context.ContextMapAdapter;
 import org.codehaus.plexus.logging.Logger;
 import org.codehaus.plexus.util.IOUtil;
 import org.codehaus.plexus.util.InterpolationFilterReader;
 import org.codehaus.plexus.util.ReaderFactory;
 import org.codehaus.plexus.util.StringUtils;
+import org.codehaus.plexus.util.xml.XmlStreamReader;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 
 // TODO: get plugin groups
@@ -88,12 +85,12 @@ import org.codehaus.plexus.util.xml.Xpp3Dom;
 
 @Component(role = PluginManager.class)
 public class DefaultPluginManager
-    implements PluginManager, ComponentDiscoverer, ComponentDiscoveryListener
+    implements PluginManager
 {
     @Requirement
     private Logger logger;
 
-    @Requirement
+    @Requirement(role=PlexusContainer.class)
     protected PlexusContainer container;
 
     @Requirement
@@ -106,19 +103,7 @@ public class DefaultPluginManager
     private ResolutionErrorHandler resolutionErrorHandler;
 
     @Requirement
-    private PluginClassLoaderCache pluginClassLoaderCache;
+    private PluginCache pluginCache;
-    
-    private Map<String, PluginDescriptor> pluginDescriptors;
-
-    public DefaultPluginManager()
-    {
-        pluginDescriptors = new HashMap<String, PluginDescriptor>();
-    }
-
-    private String pluginKey( Plugin plugin )
-    {
-        return plugin.getGroupId() + ":" + plugin.getArtifactId() + ":" + plugin.getVersion();
-    }
 
     /**
      * 
@@ -133,24 +118,33 @@ public class DefaultPluginManager
      *                                      happen but if someone has made a descriptor by hand it's possible.
      * @throws CycleDetectedInComponentGraphException A cycle has been detected in the component graph for a plugin that has been dynamically loaded.
      */
-    public PluginDescriptor loadPlugin( Plugin plugin, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
+    public synchronized PluginDescriptor loadPlugin( Plugin plugin, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, InvalidPluginDescriptorException
     {
-        PluginDescriptor pluginDescriptor = getPluginDescriptor( plugin );
+//        PluginDescriptor pluginDescriptor = getPluginDescriptor( plugin );
 
         // There are cases where plugins are discovered but not actually populated. These are edge cases where you are working in the IDE on
         // Maven itself so this speaks to a problem we have with the system not starting entirely clean.
-        if ( pluginDescriptor != null && pluginDescriptor.getClassRealm() != null )
+//        if ( pluginDescriptor != null && pluginDescriptor.getClassRealm() != null )
+//        {
+//            return pluginDescriptor;
+//        }
+
+        PluginDescriptor pluginDescriptor = pluginCache.getPluginDescriptor( plugin, localRepository, remoteRepositories );
+        
+        if ( pluginDescriptor != null )
         {
             return pluginDescriptor;
         }
 
+
         Artifact pluginArtifact = repositorySystem.createPluginArtifact( plugin );
 
         ArtifactResolutionRequest request = new ArtifactResolutionRequest()
             .setArtifact( pluginArtifact )
             .setLocalRepository( localRepository )
-            .setRemoteRepostories( remoteRepositories );
+            .setRemoteRepostories( remoteRepositories )
+            .setResolveTransitively( false );
 
         ArtifactResolutionResult result = repositorySystem.resolve( request );
 
@@ -163,80 +157,98 @@ public class DefaultPluginManager
             throw new PluginResolutionException( plugin, e );            
         }
 
-
-        ClassRealm pluginRealm = pluginClassLoaderCache.get( constructPluginKey( plugin ) );
-        
-        if ( pluginRealm != null )            
-        {
-            return getPluginDescriptor( plugin );            
-        }            
-            
-        pluginRealm = container.createChildRealm( pluginKey( plugin ) );
-
-        Set<Artifact> pluginArtifacts;
-        
         try
         {
-            pluginArtifacts = getPluginArtifacts( pluginArtifact, plugin, localRepository, remoteRepositories );
+            if ( pluginArtifact.getFile().isFile() )
-        }
-        catch ( ArtifactNotFoundException e )
-        {
-            throw new PluginNotFoundException( plugin, e );
-        }
-        catch ( ArtifactResolutionException e )
-        {
-            throw new PluginResolutionException( plugin, e );
-        }
-
-        for ( Artifact a : pluginArtifacts )
             {
+                JarFile pluginJar = new JarFile( pluginArtifact.getFile() );
                 try
                 {
-                pluginRealm.addURL( a.getFile().toURI().toURL() );
+                    ZipEntry pluginDescriptorEntry = pluginJar.getEntry( getComponentDescriptorLocation() );
-            }
+    
-            catch ( MalformedURLException e )
+                    if ( pluginDescriptorEntry != null )
                     {
-                // Not going to happen
+                        InputStream is = pluginJar.getInputStream( pluginDescriptorEntry );
+    
+                        pluginDescriptor = parsebuildPluginDescriptor( is );
+                    }
+                }
+                finally
+                {
+                    pluginJar.close();
+                }
+            }
+            else
+            {
+                File pluginXml = new File( pluginArtifact.getFile(), getComponentDescriptorLocation() );
+
+                if ( pluginXml.canRead() )
+                {
+                    InputStream is = new BufferedInputStream( new FileInputStream( pluginXml ) );
+                    try
+                    {
+                        pluginDescriptor = parsebuildPluginDescriptor( is );
+                    }
+                    finally
+                    {
+                        IOUtil.close( is );
+                    }
                 }
             }
 
             String pluginKey = constructPluginKey( plugin );
 
+            if ( pluginDescriptor == null )
+            {
+                throw new InvalidPluginDescriptorException( "Invalid or missing Plugin Descriptor for " + pluginKey );
+            }
+
             // Check the internal consistent of a plugin descriptor when it is discovered. Most of the time the plugin descriptor is generated
             // by the maven-plugin-plugin, but if you happened to have created one by hand and it's incorrect this validator will report
             // the problem to the user.
             //
             MavenPluginValidator validator = new MavenPluginValidator( pluginArtifact );
 
-        try
+            validator.validate( pluginDescriptor );
-        {
-            container.discoverComponents( pluginRealm, validator );
-        }
-        catch ( PlexusConfigurationException e )
-        {
-            throw new PluginDescriptorParsingException( plugin, e );
-        }
-        catch ( CycleDetectedInComponentGraphException e )
-        {
-            throw new CycleDetectedInPluginGraphException( plugin, e );
-        }
 
             if ( validator.hasErrors() )                                                                                                                        
             {          
                 throw new InvalidPluginDescriptorException( "Invalid Plugin Descriptor for " + pluginKey, validator.getErrors() );
             }        
 
-        pluginClassLoaderCache.put( pluginKey, pluginRealm );
+            pluginDescriptor.setPlugin( plugin );
+            pluginDescriptor.setPluginArtifact( pluginArtifact );
 
-        pluginDescriptor = getPluginDescriptor( plugin );
+            pluginCache.putPluginDescriptor( plugin, localRepository, remoteRepositories, pluginDescriptor );
-        pluginDescriptor.setArtifacts( new ArrayList<Artifact>( pluginArtifacts ) );
 
             return pluginDescriptor;
+        
+        }
+        catch ( IOException e )
+        {
+            throw new PluginDescriptorParsingException( plugin, e );
+        }
+        catch ( PlexusConfigurationException e )
+        {
+            throw new PluginDescriptorParsingException( plugin, e );
+        }
+    }
+
+    private PluginDescriptor parsebuildPluginDescriptor( InputStream is )
+        throws IOException, PlexusConfigurationException
+    {
+        PluginDescriptor pluginDescriptor;
+        XmlStreamReader reader = ReaderFactory.newXmlReader( is );
+
+        InterpolationFilterReader interpolationFilterReader = new InterpolationFilterReader( new BufferedReader( reader ), container.getContext().getContextData() );
+
+        pluginDescriptor = builder.build( interpolationFilterReader );
+        return pluginDescriptor;
     }
 
     // TODO: Turn this into a component so it can be tested.
     //
-    Set<Artifact> getPluginArtifacts( Artifact pluginArtifact, Plugin pluginAsSpecifiedInPom, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
+    List<Artifact> getPluginArtifacts( Artifact pluginArtifact, Plugin pluginAsSpecifiedInPom, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws ArtifactNotFoundException, ArtifactResolutionException
     {
         AndArtifactFilter filter = new AndArtifactFilter();
@@ -284,7 +296,7 @@ public class DefaultPluginManager
 
         logger.debug( "Using the following artifacts for classpath of: " + pluginArtifact.getId() + ":\n\n" + result.getArtifacts().toString().replace( ',', '\n' ) );
 
-        return result.getArtifacts();
+        return new ArrayList<Artifact>( result.getArtifacts() );
     }
 
     // ----------------------------------------------------------------------
@@ -292,7 +304,7 @@ public class DefaultPluginManager
     // ----------------------------------------------------------------------
 
     public void executeMojo( MavenSession session, MojoExecution mojoExecution )
-        throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginExecutionException
+        throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginManagerException
     {
         MavenProject project = session.getCurrentProject();
 
@@ -308,8 +320,7 @@ public class DefaultPluginManager
             goalExecId += " {execution: " + mojoExecution.getExecutionId() + "}";
         }
 
-        // by this time, the pluginDescriptor has had the correct realm setup from getConfiguredMojo(..)
+        ClassRealm pluginRealm = getPluginRealm( session, mojoDescriptor.getPluginDescriptor() );            
-        ClassRealm pluginRealm = pluginClassLoaderCache.get( constructPluginKey( mojoDescriptor.getPluginDescriptor() ) );            
         ClassRealm oldLookupRealm = container.getLookupRealm();
         ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
 
@@ -358,6 +369,121 @@ public class DefaultPluginManager
         }
     }
 
+    /**
+     * TODO pluginDescriptor classRealm and artifacts are set as a side effect of this
+     *      call, which is not nice.
+     */
+    public synchronized ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginDescriptor ) throws PluginManagerException
+    {
+        ClassRealm pluginRealm = pluginDescriptor.getClassRealm();
+        if ( pluginRealm != null )
+        {
+            return pluginRealm;
+        }
+
+        Plugin plugin = pluginDescriptor.getPlugin();
+        ArtifactRepository localRepository = session.getLocalRepository();
+        List<ArtifactRepository> remoteRepositories = session.getCurrentProject().getPluginArtifactRepositories();
+
+        PluginCache.CacheRecord cacheRecord = pluginCache.get( plugin, localRepository, remoteRepositories );
+
+        if ( cacheRecord != null )
+        {
+            pluginDescriptor.setClassRealm( cacheRecord.realm );
+            pluginDescriptor.setArtifacts( new ArrayList<Artifact>( cacheRecord.artifacts ) );
+
+            return pluginRealm;
+        }
+
+        pluginRealm = createPluginRealm( plugin );
+
+        Artifact pluginArtifact = pluginDescriptor.getPluginArtifact();
+
+        List<Artifact> pluginArtifacts;
+
+        try
+        {
+            pluginArtifacts = getPluginArtifacts( pluginArtifact, plugin, localRepository, remoteRepositories );
+        }
+        catch ( ArtifactNotFoundException e )
+        {
+            throw new IllegalStateException( e ); // XXX
+        }
+        catch ( ArtifactResolutionException e )
+        {
+            throw new IllegalStateException( e ); // XXX
+        }
+
+        for ( Artifact a : pluginArtifacts )
+        {
+            try
+            {
+                pluginRealm.addURL( a.getFile().toURI().toURL() );
+            }
+            catch ( MalformedURLException e )
+            {
+                // Not going to happen
+            }
+        }
+
+        pluginDescriptor.setClassRealm( pluginRealm );
+        pluginDescriptor.setArtifacts( pluginArtifacts );
+        
+        try
+        {
+            for ( ComponentDescriptor componentDescriptor : pluginDescriptor.getComponents() )
+            {
+                componentDescriptor.setRealm( pluginRealm );
+                container.addComponentDescriptor( componentDescriptor );
+            }
+
+            container.discoverComponents( pluginRealm );
+        }
+        catch ( PlexusConfigurationException e )
+        {
+            throw new PluginManagerException( plugin, e.getMessage(), e );
+        }
+        catch ( CycleDetectedInComponentGraphException e )
+        {
+            throw new PluginManagerException( plugin, e.getMessage(), e );
+        }
+
+        pluginCache.put( plugin, localRepository, remoteRepositories, pluginRealm, pluginArtifacts );
+        
+        return pluginRealm;
+    }
+
+    /**
+     * Creates ClassRealm with unique id for the given plugin
+     */
+    private ClassRealm createPluginRealm( Plugin plugin ) 
+        throws PluginManagerException
+    {
+        ClassWorld world = ((MutablePlexusContainer) container).getClassWorld();
+
+        String baseRealmId = constructPluginKey( plugin );
+        String realmId = baseRealmId;
+
+        synchronized ( world )
+        {
+            for ( int i = 0; i < 100; i++ )
+            {
+                try
+                {
+                    ClassRealm pluginRealm = world.newRealm( realmId );
+                    pluginRealm.setParentRealm( container.getContainerRealm() );
+                    return pluginRealm;
+                }
+                catch ( DuplicateRealmException e )
+                {
+                    realmId = baseRealmId + "-" + i;
+                }
+            }
+        }
+
+        throw new PluginManagerException( plugin, "Could not create ClassRealm", (Throwable) null );
+    }
+
     private Mojo getConfiguredMojo( MavenSession session, MavenProject project, MojoExecution mojoExecution, ClassRealm pluginRealm )
         throws PluginConfigurationException, PluginManagerException
     {
@@ -368,11 +494,14 @@ public class DefaultPluginManager
         // We are forcing the use of the plugin realm for all lookups that might occur during
         // the lifecycle that is part of the lookup. Here we are specifically trying to keep
         // lookups that occur in contextualize calls in line with the right realm.
-        container.setLookupRealm( pluginRealm );
+        ClassRealm oldLookupRealm = container.setLookupRealm( pluginRealm );
 
         ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
         Thread.currentThread().setContextClassLoader( pluginRealm );
+        container.setLookupRealm( pluginRealm );
 
+        try
+        {
             Mojo mojo;
     
             try
@@ -419,10 +548,15 @@ public class DefaultPluginManager
     
             populatePluginFields( mojo, mojoDescriptor, pluginRealm, pomConfiguration, expressionEvaluator );
 
-        Thread.currentThread().setContextClassLoader( oldClassLoader );
-
             return mojo;
         }
+        finally
+        {
+            Thread.currentThread().setContextClassLoader( oldClassLoader );
+            container.setLookupRealm( oldLookupRealm );
+        }
+
+    }
 
     // ----------------------------------------------------------------------
     // Mojo Parameter Handling
@@ -553,118 +687,10 @@ public class DefaultPluginManager
         return "META-INF/maven/plugin.xml";
     }
 
-    public ComponentSetDescriptor createComponentDescriptors( Reader componentDescriptorConfiguration, String source )
-        throws PlexusConfigurationException
-    {
-        return builder.build( componentDescriptorConfiguration, source );
-    }
-
-    public List<ComponentSetDescriptor> findComponents( Context context, ClassRealm realm )
-        throws PlexusConfigurationException
-    {
-        List<ComponentSetDescriptor> componentSetDescriptors = new ArrayList<ComponentSetDescriptor>();
-
-        Enumeration<URL> resources;
-        try
-        {
-            // We don't always want to scan parent realms. For plexus
-            // testcase, most components are in the root classloader so that needs to be scanned,
-            // but for child realms, we don't.
-            if ( realm.getParentRealm() != null )
-            {
-                resources = realm.findRealmResources( getComponentDescriptorLocation() );
-            }
-            else
-            {
-                resources = realm.findResources( getComponentDescriptorLocation() );
-            }
-        }
-        catch ( IOException e )
-        {
-            throw new PlexusConfigurationException( "Unable to retrieve resources for: " + getComponentDescriptorLocation() + " in class realm: " + realm.getId() );
-        }
-
-        for ( URL url : Collections.list( resources ) )
-        {
-            Reader reader = null;
-
-            try
-            {
-                URLConnection conn = url.openConnection();
-
-                conn.setUseCaches( false );
-
-                conn.connect();
-
-                reader = ReaderFactory.newXmlReader( conn.getInputStream() );
-
-                InterpolationFilterReader interpolationFilterReader = new InterpolationFilterReader( reader, new ContextMapAdapter( context ) );
-
-                ComponentSetDescriptor componentSetDescriptor = createComponentDescriptors( interpolationFilterReader, url.toString() );
-
-                if ( componentSetDescriptor.getComponents() != null )
-                {
-                    for ( ComponentDescriptor<?> cd : componentSetDescriptor.getComponents() )
-                    {
-                        cd.setComponentSetDescriptor( componentSetDescriptor );
-                        cd.setRealm( realm );
-                    }
-                }
-
-                componentSetDescriptors.add( componentSetDescriptor );
-            }
-            catch ( IOException ex )
-            {
-                throw new PlexusConfigurationException( "Error reading configuration " + url, ex );
-            }
-            finally
-            {
-                IOUtil.close( reader );
-            }
-        }
-
-        return componentSetDescriptors;
-    }
-
     // ----------------------------------------------------------------------
     // Component Discovery Listener
     // ----------------------------------------------------------------------
 
-    private Set pluginsInProcess = new HashSet();
-
-    public void componentDiscovered( ComponentDiscoveryEvent event )
-    {
-        ComponentSetDescriptor componentSetDescriptor = event.getComponentSetDescriptor();
-
-        if ( componentSetDescriptor instanceof PluginDescriptor )
-        {
-            PluginDescriptor pluginDescriptor = (PluginDescriptor) componentSetDescriptor;
-
-            MavenPluginValidator validator = (MavenPluginValidator) event.getData();
-            
-            validator.validate( pluginDescriptor );
-            
-            if ( validator.hasErrors() )
-            {
-                return;
-            }
-            
-            String key = constructPluginKey( pluginDescriptor );
-
-            if ( !pluginsInProcess.contains( key ) )
-            {
-                pluginsInProcess.add( key );
-
-                pluginDescriptors.put( key, pluginDescriptor );
-            }
-        }
-    }
-
-    public PluginDescriptor getPluginDescriptor( Plugin plugin )
-    {
-        return pluginDescriptors.get( constructPluginKey( plugin ) );
-    }
-
     public String constructPluginKey( Plugin plugin )
     {
         String version = ArtifactUtils.toSnapshotVersion( plugin.getVersion() );

maven-core/src/main/java/org/apache/maven/plugin/InvalidPluginDescriptorException.java

@@ -32,6 +32,11 @@ public class InvalidPluginDescriptorException
         this.errors = errors;
     }
 
+    public InvalidPluginDescriptorException( String message )
+    {
+        super( message );
+    }
+
     private static String toMessage( String message, List<String> errors )
     {
         StringBuilder buffer = new StringBuilder( 256 );

maven-core/src/main/java/org/apache/maven/plugin/PluginDescriptorParsingException.java

@@ -20,11 +20,6 @@ package org.apache.maven.plugin;
  */
 
 import org.apache.maven.model.Plugin;
-import org.apache.maven.plugin.descriptor.PluginDescriptor;
-import org.codehaus.plexus.component.configurator.ComponentConfigurationException;
-import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
-import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
-import org.codehaus.plexus.configuration.PlexusConfigurationException;
 
 /**
  * @author Jason van Zyl
@@ -34,7 +29,7 @@ public class PluginDescriptorParsingException
 {
     private Plugin plugin;
 
-    public PluginDescriptorParsingException( Plugin plugin, PlexusConfigurationException e )
+    public PluginDescriptorParsingException( Plugin plugin, Exception e )
     {
         super( e );
         this.plugin = plugin;

maven-core/src/main/java/org/apache/maven/plugin/PluginManager.java

@@ -22,14 +22,12 @@ import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
 import org.apache.maven.plugin.descriptor.PluginDescriptor;
-import org.codehaus.plexus.component.discovery.ComponentDiscoverer;
+import org.codehaus.plexus.classworlds.realm.ClassRealm;
-import org.codehaus.plexus.component.discovery.ComponentDiscoveryListener;
 
 /**
  * @author Jason van Zyl
  */
 public interface PluginManager
-    extends ComponentDiscoverer, ComponentDiscoveryListener
 {
     // - find the plugin [extension point: any client may wish to do whatever they choose]
     // - load the plugin into a classloader [extension point: we want to take them from a repository, some may take from disk or whatever]
@@ -41,16 +39,22 @@ public interface PluginManager
     // plugin resolution exception
     // plugin configuration can't be parsed -- and this may be a result of client insertion of configuration
     // plugin component deps have a cycle -- this should be prevented for the most part but client code may inject an override component which itself has a cycle
+    // igorf: Way too many declared exceptions!
     PluginDescriptor loadPlugin( Plugin plugin, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, InvalidPluginDescriptorException;
 
+    // igorf: Way too many declared exceptions!
     MojoDescriptor getMojoDescriptor( String groupId, String artifactId, String version, String goal, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, InvalidPluginDescriptorException;
 
+    // igorf: Way too many declared exceptions!
     MojoDescriptor getMojoDescriptor( Plugin plugin, String goal, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, CycleDetectedInPluginGraphException, MojoNotFoundException, InvalidPluginDescriptorException;
 
     // Why do we have a plugin execution exception as well?
+    // igorf: Way too many declared exceptions!
     void executeMojo( MavenSession session, MojoExecution execution )
-        throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginExecutionException;
+        throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginExecutionException, PluginManagerException;
+
+    ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginDescriptor ) throws PluginManagerException;
 }

maven-core/src/main/java/org/apache/maven/project/DefaultMavenProjectCache.java

@@ -1,52 +0,0 @@
-package org.apache.maven.project;
-
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  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.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.codehaus.plexus.component.annotations.Component;
-
-@Component(role=MavenProjectCache.class)
-public class DefaultMavenProjectCache
-    implements MavenProjectCache
-{
-    private Map<String, MavenProject> projectCache = new HashMap<String, MavenProject>();
-
-    public MavenProject get( String key )
-    {
-        return projectCache.get( key );
-    }
-
-    public void put( String key, MavenProject project )
-    {
-        projectCache.put( key, project );        
-    }
-
-    public void clear()
-    {
-        projectCache.clear();
-    }
-
-    public int size()
-    {
-        return projectCache.size();
-    }
-}

maven-core/src/main/java/org/apache/maven/project/DefaultProjectBuilder.java

@@ -67,9 +67,6 @@ public class DefaultProjectBuilder
     @Requirement
     private ResolutionErrorHandler resolutionErrorHandler;
     
-    @Requirement
-    private MavenProjectCache projectCache;
-    
     private MavenProject superProject;
 
     // ----------------------------------------------------------------------
@@ -85,15 +82,6 @@ public class DefaultProjectBuilder
     private MavenProject build( File pomFile, boolean localProject, ProjectBuildingRequest configuration )
         throws ProjectBuildingException
     {
-        String cacheKey = getCacheKey( pomFile, configuration );
-
-        MavenProject project = projectCache.get( cacheKey );
-                
-        if ( project != null )
-        {
-            return project;
-        }
-        
         ModelResolver resolver =
             new RepositoryModelResolver( repositorySystem, resolutionErrorHandler, configuration.getLocalRepository(),
                                          configuration.getRemoteRepositories() );
@@ -119,7 +107,7 @@ public class DefaultProjectBuilder
         
         Model model = result.getEffectiveModel();
 
-        project = fromModelToMavenProject( model, result.getRawModels().get( 1 ).getPomFile(), configuration, model.getPomFile() );
+        MavenProject project = fromModelToMavenProject( model, result.getRawModels().get( 1 ).getPomFile(), configuration, model.getPomFile() );
 
         project.setOriginalModel( result.getRawModel() );
      
@@ -144,19 +132,9 @@ public class DefaultProjectBuilder
         project.setFile( pomFile );
         project.setActiveProfiles( result.getActiveProfiles( result.getRawModel() ) );
                 
-        projectCache.put( cacheKey, project );
-                
         return project;
     }
 
-    private String getCacheKey( File pomFile, ProjectBuildingRequest configuration )
-    {
-        StringBuilder buffer = new StringBuilder( 256 );
-        buffer.append( pomFile.getAbsolutePath() );
-        buffer.append( '/' ).append( pomFile.lastModified() );
-        return buffer.toString();
-    }
-
     public MavenProject build( Artifact artifact, ProjectBuildingRequest configuration )
         throws ProjectBuildingException
     {

maven-core/src/main/java/org/apache/maven/project/MavenProjectCache.java

@@ -1,36 +0,0 @@
-package org.apache.maven.project;
-
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  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.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-public interface MavenProjectCache
-{
-
-    MavenProject get( String key );
-
-    void put( String key, MavenProject project );
-
-    /**
-     * Clears the cache.
-     */
-    void clear();
-
-    int size();
-
-}

maven-core/src/main/java/org/apache/maven/project/artifact/DefaultMavenMetadataCache.java

@@ -38,24 +38,26 @@ public class DefaultMavenMetadataCache
 
     public static class CacheKey 
     {
-        Artifact artifact;
+        private final Artifact artifact;
-        List<ArtifactRepository> repositories = new ArrayList<ArtifactRepository>();
+        private final List<ArtifactRepository> repositories = new ArrayList<ArtifactRepository>();
+        private final int hashCode;
 
-        CacheKey( Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
+        public CacheKey( Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         {
             this.artifact = ArtifactUtils.copyArtifact( artifact );
             this.repositories.add( localRepository );
             this.repositories.addAll( remoteRepositories );
+
+            int hash = 17;
+            hash = hash * 31 + artifactHashCode( artifact );
+            hash = hash * 31 + repositories.hashCode();
+            this.hashCode = hash;
         }
 
         @Override
         public int hashCode()
         {
-            int hash = 17;
+            return hashCode;
-            hash = hash * 31 + artifact.hashCode();
-            hash = hash * 31 + repositories.hashCode();
-
-            return hash;
         }
 
         @Override
@@ -73,18 +75,57 @@ public class DefaultMavenMetadataCache
             
             CacheKey other = (CacheKey) o;
             
-            return artifact.equals( other.artifact ) && repositories.equals( other.repositories );
+            return artifactEquals( artifact, other.artifact ) && repositories.equals( other.repositories );
         }
     }
 
+    private static int artifactHashCode( Artifact a )
+    {
+        int result = 17;
+        result = 31 * result + a.getGroupId().hashCode();
+        result = 31 * result + a.getArtifactId().hashCode();
+        result = 31 * result + a.getType().hashCode();
+        if ( a.getVersion() != null )
+        {
+            result = 31 * result + a.getVersion().hashCode();
+        }
+        result = 31 * result + ( a.getClassifier() != null ? a.getClassifier().hashCode() : 0 );
+        result = 31 * result + ( a.getScope() != null ? a.getScope().hashCode() : 0 );
+        result = 31 * result + ( a.getDependencyFilter() != null? a.getDependencyFilter().hashCode() : 0 );
+        result = 31 * result + ( a.isOptional() ? 1 : 0 );
+        return result;
+    }
+
+    private static boolean artifactEquals( Artifact a1, Artifact a2 )
+    {
+        if ( a1 == a2 )
+        {
+            return true;
+        }
+        
+        return eq( a1.getGroupId(), a2.getGroupId() )
+            && eq( a1.getArtifactId(), a2.getArtifactId() )
+            && eq( a1.getType(), a2.getType() )
+            && eq( a1.getVersion(), a2.getVersion() )
+            && eq( a1.getClassifier(), a2.getClassifier() )
+            && eq( a1.getScope(), a2.getScope() )
+            && eq( a1.getDependencyFilter(), a2.getDependencyFilter() )
+            && a1.isOptional() == a2.isOptional();
+    }
+
+    private static <T> boolean eq( T s1, T s2 )
+    {
+        return s1 != null? s1.equals( s2 ): s2 == null;
+    }
+
     public class CacheRecord
     {
-        Artifact pomArtifact;
+        private Artifact pomArtifact;
-        List<Artifact> artifacts;
+        private List<Artifact> artifacts;
-        List<ArtifactRepository> remoteRepositories;
+        private List<ArtifactRepository> remoteRepositories;
 
-        long length;
+        private long length;
-        long timestamp;
+        private long timestamp;
 
         CacheRecord(Artifact pomArtifact, Set<Artifact> artifacts, List<ArtifactRepository> remoteRepositories)
         {
@@ -106,6 +147,21 @@ public class DefaultMavenMetadataCache
             }
         }
         
+        public Artifact getArtifact()
+        {
+            return pomArtifact;
+        }
+
+        public List<Artifact> getArtifacts()
+        {
+            return artifacts;
+        }
+
+        public List<ArtifactRepository> getRemoteRepositories()
+        {
+            return remoteRepositories;
+        }
+
         public boolean isStale()
         {
             File pomFile = pomArtifact.getFile();
@@ -118,7 +174,7 @@ public class DefaultMavenMetadataCache
         }
     }
 
-    private Map<CacheKey, CacheRecord> cache = new HashMap<CacheKey, CacheRecord>();
+    protected Map<CacheKey, CacheRecord> cache = new HashMap<CacheKey, CacheRecord>();
 
     public ResolutionGroup get( Artifact artifact, ArtifactRepository localRepository,
                                 List<ArtifactRepository> remoteRepositories )
@@ -129,9 +185,9 @@ public class DefaultMavenMetadataCache
 
         if ( cacheRecord != null && !cacheRecord.isStale() )
         {
-            Artifact pomArtifact = ArtifactUtils.copyArtifact( cacheRecord.pomArtifact );
+            Artifact pomArtifact = ArtifactUtils.copyArtifact( cacheRecord.getArtifact() );
-            Set<Artifact> artifacts = new LinkedHashSet<Artifact>( copyArtifacts( cacheRecord.artifacts ) );
+            Set<Artifact> artifacts = new LinkedHashSet<Artifact>( copyArtifacts( cacheRecord.getArtifacts() ) );
-            return new ResolutionGroup( pomArtifact, artifacts , cacheRecord.remoteRepositories );
+            return new ResolutionGroup( pomArtifact, artifacts , cacheRecord.getRemoteRepositories() );
         }
 
         cache.remove( cacheKey );
@@ -158,4 +214,8 @@ public class DefaultMavenMetadataCache
         return result;
     }
 
+    public void flush()
+    {
+        cache.clear();
+    }
 }

maven-core/src/main/java/org/apache/maven/project/artifact/MavenMetadataCache.java

@@ -31,4 +31,5 @@ public interface MavenMetadataCache
     void put( Artifact artifact, ArtifactRepository localRepository,
               List<ArtifactRepository> remoteRepositories, ResolutionGroup result );
 
+    void flush();
 }

maven-core/src/main/java/org/apache/maven/project/artifact/MavenMetadataSource.java

@@ -40,8 +40,8 @@ import org.apache.maven.model.Dependency;
 import org.apache.maven.project.DefaultProjectBuildingRequest;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.ProjectBuilder;
-import org.apache.maven.project.ProjectBuildingRequest;
 import org.apache.maven.project.ProjectBuildingException;
+import org.apache.maven.project.ProjectBuildingRequest;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.annotations.Component;
 import org.codehaus.plexus.component.annotations.Requirement;
@@ -77,14 +77,12 @@ public class MavenMetadataSource
     public ResolutionGroup retrieve( Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories )
         throws ArtifactMetadataRetrievalException
     {
-        /*
         ResolutionGroup cached = cache.get( artifact, localRepository, remoteRepositories );
 
         if ( cached != null )
         {
             return cached;
         }
-        */
                 
         List<Dependency> dependencies;
 
@@ -169,7 +167,7 @@ public class MavenMetadataSource
 
         ResolutionGroup result = new ResolutionGroup( pomArtifact, artifacts, remoteRepositories );
 
-        //cache.put( artifact, localRepository, remoteRepositories, result );
+        cache.put( artifact, localRepository, remoteRepositories, result );
 
         return result;
     }

maven-core/src/test/java/org/apache/maven/AbstractCoreMavenComponentTestCase.java

@@ -2,10 +2,13 @@ package org.apache.maven;
 
 import java.io.File;
 import java.util.Arrays;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.ArtifactUtils;
 import org.apache.maven.artifact.InvalidRepositoryException;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.execution.DefaultMavenExecutionRequest;
@@ -21,6 +24,7 @@ import org.apache.maven.plugin.PluginManager;
 import org.apache.maven.project.DefaultProjectBuildingRequest;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.ProjectBuildingRequest;
+import org.apache.maven.repository.DelegatingLocalArtifactRepository;
 import org.apache.maven.repository.RepositorySystem;
 import org.codehaus.plexus.ContainerConfiguration;
 import org.codehaus.plexus.PlexusTestCase;
@@ -77,8 +81,8 @@ public abstract class AbstractCoreMavenComponentTestCase
      */
     protected void customizeContainerConfiguration( ContainerConfiguration containerConfiguration )
     {
-        containerConfiguration.addComponentDiscoverer( PluginManager.class );
+//        containerConfiguration.addComponentDiscoverer( PluginManager.class );
-        containerConfiguration.addComponentDiscoveryListener( PluginManager.class );
+//        containerConfiguration.addComponentDiscoveryListener( PluginManager.class );
     }
 
     protected MavenExecutionRequest createMavenExecutionRequest( File pom )
@@ -151,6 +155,22 @@ public abstract class AbstractCoreMavenComponentTestCase
         return repositorySystem.createDefaultLocalRepository();        
     }
 
+    protected ArtifactRepository getReactorRepository( MavenProject... projects ) 
+        throws InvalidRepositoryException
+    {
+        Map<String, MavenProject> projectsMap = new LinkedHashMap<String, MavenProject>();
+
+        for ( MavenProject project : projects )
+        {
+            projectsMap.put( ArtifactUtils.key( project.getGroupId(), project.getArtifactId(), project.getVersion() ), project );
+        }
+
+        DelegatingLocalArtifactRepository delegatingLocalArtifactRepository = new DelegatingLocalArtifactRepository( getLocalRepository() );
+        delegatingLocalArtifactRepository.setBuildReactor( new ReactorArtifactRepository( projectsMap ) );
+        
+        return delegatingLocalArtifactRepository;
+    }
+    
     protected class ProjectBuilder
     {
         private MavenProject project;

maven-core/src/test/java/org/apache/maven/plugin/PluginManagerTest.java

@@ -1,11 +1,9 @@
 package org.apache.maven.plugin;
 
-import java.util.Set;
+import java.util.List;
 
 import org.apache.maven.AbstractCoreMavenComponentTestCase;
 import org.apache.maven.artifact.Artifact;
-import org.apache.maven.artifact.resolver.ArtifactResolutionRequest;
-import org.apache.maven.artifact.resolver.ArtifactResolutionResult;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
@@ -66,7 +64,8 @@ public class PluginManagerTest
         MojoDescriptor mojoDescriptor = pluginManager.getMojoDescriptor( plugin, goal, session.getLocalRepository(), session.getCurrentProject().getRemoteArtifactRepositories() );        
         assertNotNull( mojoDescriptor );
         assertEquals( "generate-metadata", mojoDescriptor.getGoal() );
-        assertNotNull( mojoDescriptor.getRealm() );
+        // igorf: plugin realm comes later
+        // assertNotNull( mojoDescriptor.getRealm() );
         
         PluginDescriptor pluginDescriptor = mojoDescriptor.getPluginDescriptor();
         assertNotNull( pluginDescriptor );
@@ -226,7 +225,7 @@ public class PluginManagerTest
         ArtifactResolutionResult result = repositorySystem.resolve( request );
         */
         
-        Set<Artifact> artifacts = pluginManager.getPluginArtifacts( pluginArtifact, plugin, getLocalRepository(), getRemoteRepositories() );   
+        List<Artifact> artifacts = pluginManager.getPluginArtifacts( pluginArtifact, plugin, getLocalRepository(), getRemoteRepositories() );   
         assertEquals( 4, artifacts.size() );
         
         for ( Artifact a : artifacts )

maven-embedder/src/main/java/org/apache/maven/cli/MavenCli.java

@@ -166,6 +166,15 @@ public class MavenCli
 
         MavenExecutionResult result = mavenEmbedder.execute( request );
 
+        try
+        {
+            mavenEmbedder.stop();
+        }
+        catch ( MavenEmbedderException e )
+        {
+            result.addException( e );
+        }
+
         // The exception handling should be handled in Maven itself.
         
         if ( result.hasExceptions() )

maven-embedder/src/main/java/org/apache/maven/embedder/MavenEmbedder.java

@@ -37,7 +37,6 @@ import org.apache.maven.execution.MavenExecutionResult;
 import org.apache.maven.model.Model;
 import org.apache.maven.model.io.ModelReader;
 import org.apache.maven.model.io.ModelWriter;
-import org.apache.maven.plugin.PluginManager;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.MavenProjectBuildingResult;
 import org.apache.maven.project.ProjectBuilder;
@@ -355,8 +354,6 @@ public class MavenEmbedder
         try
         {
             ContainerConfiguration cc = new DefaultContainerConfiguration()
-                .addComponentDiscoverer( PluginManager.class )
-                .addComponentDiscoveryListener( PluginManager.class )
                 .setClassWorld( classWorld )
                 .setName( "embedder" );
 

maven-embedder/src/test/java/org/apache/maven/embedder/MavenEmbedderTest.java

@@ -39,7 +39,6 @@ import org.apache.maven.model.Build;
 import org.apache.maven.model.Model;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.project.MavenProject;
-import org.apache.maven.project.MavenProjectCache;
 import org.apache.maven.settings.Profile;
 import org.apache.maven.settings.Repository;
 import org.apache.maven.settings.Settings;
@@ -244,9 +243,6 @@ public class MavenEmbedderTest
 
         assertNull( p0.getProperties().getProperty( "occupation" ) );
 
-        // NOTE: The default cache does not consider profiles so clear it to ensure the project is properly rebuild
-        mavenEmbedder.getPlexusContainer().lookup( MavenProjectCache.class ).clear();
-
         // Check with profile activated
 
         MavenExecutionRequest request = new DefaultMavenExecutionRequest()

maven-model-builder/src/main/java/org/apache/maven/model/ModelUtils.java

@@ -64,7 +64,7 @@ import org.apache.maven.model.Scm;
 import org.apache.maven.model.Site;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 
-final class ModelUtils
+public final class ModelUtils
 {
 
     // TODO: Replace this with MODELLO-191

maven-plugin-api/src/main/java/org/apache/maven/plugin/descriptor/PluginDescriptor.java

@@ -27,6 +27,7 @@ import java.util.Set;
 
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.artifact.ArtifactUtils;
+import org.apache.maven.model.Plugin;
 import org.codehaus.plexus.classworlds.realm.ClassRealm;
 import org.codehaus.plexus.component.repository.ComponentSetDescriptor;
 
@@ -61,6 +62,8 @@ public class PluginDescriptor
 
     private String description;
 
+    private Plugin plugin;
+
     private Artifact pluginArtifact;
 
     // ----------------------------------------------------------------------
@@ -307,6 +310,16 @@ public class PluginDescriptor
         return description;
     }
 
+    public void setPlugin( Plugin plugin )
+    {
+        this.plugin = plugin;
+    }
+    
+    public Plugin getPlugin()
+    {
+        return plugin;
+    }
+
     public Artifact getPluginArtifact()
     {
         return pluginArtifact;

pom.xml

@@ -54,7 +54,7 @@ under the License.
     <plexusVersion>1.0-beta-3.0.8-SNAPSHOT</plexusVersion>
     <plexusInterpolationVersion>1.8.1</plexusInterpolationVersion>
     <plexusPluginManagerVersion>1.0-alpha-1</plexusPluginManagerVersion>
-    <plexusUtilsVersion>1.5.8</plexusUtilsVersion>
+    <plexusUtilsVersion>1.5.13-SNAPSHOT</plexusUtilsVersion>
     <plexusJetty6Version>1.6</plexusJetty6Version>
     <plexusWebdavVersion>1.0</plexusWebdavVersion>
     <wagonVersion>1.0-beta-5</wagonVersion>