add a new module for file locking

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1550396 13f79535-47bb-0310-9956-ffa450edef68

14 files changed, 789 insertions, 35 deletions

diff --git a/archiva-modules/archiva-base/archiva-configuration/pom.xml b/archiva-modules/archiva-base/archiva-configuration/pom.xml
index 94d3fa219..577e3a884 100644
--- a/archiva-modules/archiva-base/archiva-configuration/pom.xml
+++ b/archiva-modules/archiva-base/archiva-configuration/pom.xml
@@ -40,6 +40,16 @@
       </exclusions>
     </dependency>
     <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-context</artifactId>
+      <exclusions>
+        <exclusion>
+          <groupId>commons-logging</groupId>
+          <artifactId>commons-logging</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+    <dependency>
       <groupId>org.apache.archiva.redback.components.registry</groupId>
       <artifactId>spring-registry-commons</artifactId>
       <exclusions>
@@ -52,41 +62,41 @@
     <dependency>
       <groupId>commons-configuration</groupId>
       <artifactId>commons-configuration</artifactId>
-        <exclusions>
-          <exclusion>
-            <groupId>commons-beanutils</groupId>
-            <artifactId>commons-beanutils-core</artifactId>
-          </exclusion>
-          <!-- targeting JDK 1.4, xml parser/apis not needed -->
-          <exclusion>
-            <groupId>xerces</groupId>
-            <artifactId>xerces</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>xerces</groupId>
-            <artifactId>xercesImpl</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>xalan</groupId>
-            <artifactId>xalan</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>xml-apis</groupId>
-            <artifactId>xml-apis</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>servletapi</groupId>
-            <artifactId>servletapi</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>commons-logging</groupId>
-            <artifactId>commons-logging</artifactId>
-          </exclusion>
-          <exclusion>
-            <groupId>ant</groupId>
-            <artifactId>ant-optional</artifactId>
-          </exclusion>
-        </exclusions>
+      <exclusions>
+        <exclusion>
+          <groupId>commons-beanutils</groupId>
+          <artifactId>commons-beanutils-core</artifactId>
+        </exclusion>
+        <!-- targeting JDK 1.4, xml parser/apis not needed -->
+        <exclusion>
+          <groupId>xerces</groupId>
+          <artifactId>xerces</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>xerces</groupId>
+          <artifactId>xercesImpl</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>xalan</groupId>
+          <artifactId>xalan</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>xml-apis</groupId>
+          <artifactId>xml-apis</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>servletapi</groupId>
+          <artifactId>servletapi</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>commons-logging</groupId>
+          <artifactId>commons-logging</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>ant</groupId>
+          <artifactId>ant-optional</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
     <dependency>
       <groupId>org.apache.ant</groupId>
diff --git a/archiva-modules/archiva-base/archiva-filelock/pom.xml b/archiva-modules/archiva-base/archiva-filelock/pom.xml
new file mode 100644
index 000000000..d8ab67df0
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/pom.xml
@@ -0,0 +1,134 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <parent>
+    <groupId>org.apache.archiva</groupId>
+    <artifactId>archiva-base</artifactId>
+    <version>2.0.0-SNAPSHOT</version>
+  </parent>
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>archiva-filelock</artifactId>
+  <packaging>bundle</packaging>
+  <name>Archiva Base :: FileLock</name>
+  <dependencies>
+
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-context</artifactId>
+      <exclusions>
+        <exclusion>
+          <groupId>commons-logging</groupId>
+          <artifactId>commons-logging</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+
+    <dependency>
+      <groupId>javax.inject</groupId>
+      <artifactId>javax.inject</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-jcl</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>com.googlecode.multithreadedtc</groupId>
+      <artifactId>multithreadedtc</artifactId>
+      <version>1.01</version>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>commons-io</groupId>
+      <artifactId>commons-io</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <configuration>
+          <instructions>
+            <Bundle-SymbolicName>org.apache.archiva.common</Bundle-SymbolicName>
+            <Bundle-Version>${project.version}</Bundle-Version>
+            <Export-Package>
+              org.apache.archiva.common*;version=${project.version}
+            </Export-Package>
+            <Import-Package>
+
+            </Import-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <configuration>
+          <systemPropertyVariables>
+            <buildDirectory>${project.build.directory}</buildDirectory>
+            <java.io.tmpdir>${project.build.directory}</java.io.tmpdir>
+          </systemPropertyVariables>
+        </configuration>
+      </plugin>
+    </plugins>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.rat</groupId>
+          <artifactId>apache-rat-plugin</artifactId>
+          <configuration>
+            <excludes>
+            </excludes>
+          </configuration>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+</project>
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/DefaultFileLockManager.java b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/DefaultFileLockManager.java
new file mode 100644
index 000000000..795760672
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/DefaultFileLockManager.java
@@ -0,0 +1,177 @@
+package org.apache.archiva.common.filelock;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.io.File;
+import java.io.IOException;
+
+import java.nio.channels.OverlappingFileLockException;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * @author Olivier Lamy
+ */
+@Service("fileLockManager#default")
+public class DefaultFileLockManager
+    implements FileLockManager
+{
+    private static final ConcurrentMap<File, Lock> lockFiles = new ConcurrentHashMap<File, Lock>( 64 );
+
+    private boolean skipLocking = false;
+
+    private Logger log = LoggerFactory.getLogger( getClass() );
+
+    @Override
+    public Lock readFileLock( File file )
+        throws FileLockException
+    {
+        if ( skipLocking )
+        {
+            try
+            {
+                return new Lock( file, false );
+            }
+            catch ( IOException e )
+            {
+                throw new FileLockException( e.getMessage(), e );
+            }
+        }
+        Lock lock = lockFiles.get( file );
+        if ( lock == null )
+        {
+            try
+            {
+                lock = new Lock( file, false );
+                Lock current = lockFiles.putIfAbsent( file, lock );
+                if ( current != null )
+                {
+                    lock = current;
+                }
+                return lock;
+            }
+            catch ( IOException e )
+            {
+                throw new FileLockException( e.getMessage(), e );
+            }
+            catch ( OverlappingFileLockException e )
+            {
+                log.debug( "OverlappingFileLockException: {}", e.getMessage() );
+                if ( lock == null )
+                {
+                    lock = lockFiles.get( file );
+                }
+            }
+        }
+        // FIXME add a timeout on getting that!!!
+        while ( true )
+        {
+            log.debug( "wait read lock" );
+            synchronized ( lock )
+            {
+                if ( lock.getFileLock().isShared() || !lock.getFileLock().isValid() )
+                {
+                    lock.addFileClient( Thread.currentThread() );
+                    return lock;
+                }
+            }
+        }
+        //return lock;
+    }
+
+    @Override
+    public Lock writeFileLock( File file )
+        throws FileLockException
+    {
+        try
+        {
+            if ( skipLocking )
+            {
+                return new Lock( file, true );
+            }
+
+            // FIXME add a timeout on getting that!!!
+            while ( true )
+            {
+                Lock lock = lockFiles.get( file );
+                log.debug( "wait write lock" );
+                if ( lock != null )
+                {
+                    synchronized ( lock )
+                    {
+                        if ( lock.getFileLock().isValid() || lock.getFileClients().size() > 0 )
+                        {
+                            continue;
+                        }
+                        return lock;
+                    }
+                }
+                else
+                {
+                    try
+                    {
+                        lock = new Lock( file, true );
+                    }
+                    catch ( OverlappingFileLockException e )
+                    {
+                        log.debug( "OverlappingFileLockException: {}", e.getMessage() );
+                        if ( lock == null )
+                        {
+                            lock = lockFiles.get( file );
+                        }
+
+                        lock = lockFiles.get( file );
+                        log.debug( "OverlappingFileLockException get: {}", lock );
+                    }
+                    Lock current = lockFiles.putIfAbsent( file, lock );
+                    if ( current != null )
+                    {
+                        lock = current;
+                    }
+                    return lock;
+                }
+            }
+
+        }
+        catch ( IOException e )
+        {
+            throw new FileLockException( e.getMessage(), e );
+        }
+    }
+
+    @Override
+    public void release( Lock lock )
+        throws FileLockException
+    {
+        if ( lock == null )
+        {
+            log.debug( "skip releasing null" );
+            return;
+        }
+        if ( skipLocking )
+        {
+            return;
+        }
+        try
+        {
+            if ( lock.isWrite().get() )
+            {
+                lock.getFileLock().release();
+            }
+            synchronized ( lock )
+            {
+                lock.close();
+                if ( lock.getFileClients().size() < 1 )
+                {
+                    lockFiles.remove( lock.getFile() );
+                }
+            }
+        }
+        catch ( IOException e )
+        {
+            throw new FileLockException( e.getMessage(), e );
+        }
+    }
+}
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockException.java b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockException.java
new file mode 100644
index 000000000..2d14859c0
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockException.java
@@ -0,0 +1,13 @@
+package org.apache.archiva.common.filelock;
+
+/**
+ * @author Olivier Lamy
+ */
+public class FileLockException
+    extends Exception
+{
+    public FileLockException( String s, Throwable throwable )
+    {
+        super( s, throwable );
+    }
+}
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockManager.java b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockManager.java
new file mode 100644
index 000000000..5f3832634
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/FileLockManager.java
@@ -0,0 +1,18 @@
+package org.apache.archiva.common.filelock;
+
+import java.io.File;
+
+/**
+ * @author Olivier Lamy
+ */
+public interface FileLockManager
+{
+    Lock writeFileLock( File file )
+        throws FileLockException;
+
+    Lock readFileLock( File file )
+        throws FileLockException;
+
+    void release( Lock lock )
+        throws FileLockException;
+}
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/Lock.java b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/Lock.java
new file mode 100644
index 000000000..6baabbc05
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/main/java/org/apache/archiva/common/filelock/Lock.java
@@ -0,0 +1,105 @@
+package org.apache.archiva.common.filelock;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.channels.FileLock;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * @author Olivier Lamy
+ */
+public class Lock
+{
+    private File file;
+
+    private AtomicBoolean write;
+
+    private final Map<Thread, AtomicInteger> fileClients = new HashMap<Thread, AtomicInteger>();
+
+    private FileLock fileLock;
+
+    public Lock( File file, boolean write )
+        throws FileNotFoundException, IOException
+    {
+        this.file = file;
+        this.write = new AtomicBoolean( write );
+        this.openLock( write );
+    }
+
+    public File getFile()
+    {
+        return file;
+    }
+
+    public AtomicBoolean isWrite()
+    {
+        return write;
+    }
+
+    public void setFile( File file )
+    {
+        this.file = file;
+    }
+
+    public void setWrite( boolean write )
+    {
+        this.write.set( write );
+    }
+
+    public FileLock getFileLock()
+    {
+        return fileLock;
+    }
+
+    public void setFileLock( FileLock fileLock )
+    {
+        this.fileLock = fileLock;
+    }
+
+    public Map<Thread, AtomicInteger> getFileClients()
+    {
+        return fileClients;
+    }
+
+    public void addFileClient( Thread thread )
+    {
+        this.fileClients.put( thread, new AtomicInteger( 1 ) );
+    }
+
+    public boolean removeFileClient( Thread thread )
+    {
+        return this.fileClients.remove( thread ) != null;
+    }
+
+    protected void close()
+        throws IOException
+    {
+        if ( this.write.get() )
+        {
+            this.fileLock.release();
+            fileClients.remove( Thread.currentThread() );
+        }
+    }
+
+    public void openLock( boolean write )
+        throws IOException
+    {
+        fileClients.put( Thread.currentThread(), new AtomicInteger( 1 ) );
+        RandomAccessFile raf = new RandomAccessFile( file, write ? "rw" : "r" );
+        this.fileLock = raf.getChannel().lock( 1, 1, !write );
+    }
+
+    @Override
+    public String toString()
+    {
+        final StringBuilder sb = new StringBuilder( "Lock{" );
+        sb.append( "file=" ).append( file );
+        sb.append( '}' );
+        return sb.toString();
+    }
+}
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/main/resources/META-INF/spring-context.xml b/archiva-modules/archiva-base/archiva-filelock/src/main/resources/META-INF/spring-context.xml
new file mode 100644
index 000000000..944c8d606
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/main/resources/META-INF/spring-context.xml
@@ -0,0 +1,34 @@
+<?xml version="1.0"?>
+
+<!--
+  ~ 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.
+  -->
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:context="http://www.springframework.org/schema/context"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans
+           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
+           http://www.springframework.org/schema/context 
+           http://www.springframework.org/schema/context/spring-context-3.0.xsd"
+       default-lazy-init="true">
+
+  <context:annotation-config/>
+  <context:component-scan base-package="org.apache.archiva.common.filelock"/>
+
+
+</beans>
\ No newline at end of file
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/test/cassandra-all-2.0.3.jar b/archiva-modules/archiva-base/archiva-filelock/src/test/cassandra-all-2.0.3.jar
new file mode 100644
index 000000000..0a4b1c542
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/test/cassandra-all-2.0.3.jar
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/test/java/org/apache/archiva/common/filelock/DefaultFileLockManagerTest.java b/archiva-modules/archiva-base/archiva-filelock/src/test/java/org/apache/archiva/common/filelock/DefaultFileLockManagerTest.java
new file mode 100644
index 000000000..86fb24dd3
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/test/java/org/apache/archiva/common/filelock/DefaultFileLockManagerTest.java
@@ -0,0 +1,208 @@
+package org.apache.archiva.common.filelock;
+
+import edu.umd.cs.mtc.MultithreadedTestCase;
+import edu.umd.cs.mtc.TestFramework;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+/**
+ * @author Olivier Lamy
+ */
+@RunWith( SpringJUnit4ClassRunner.class )
+@ContextConfiguration( locations = { "classpath*:/META-INF/spring-context.xml" } )
+public class DefaultFileLockManagerTest
+{
+
+    final Logger logger = LoggerFactory.getLogger( getClass() );
+
+    @Inject
+    @Named( value = "fileLockManager#default" )
+    FileLockManager fileLockManager;
+
+    class ConcurentFileWrite
+        extends MultithreadedTestCase
+    {
+
+        FileLockManager fileLockManager;
+
+        File file = new File( System.getProperty( "buildDirectory" ), "foo.txt" );
+
+        File largeJar = new File( System.getProperty( "basedir" ), "src/test/cassandra-all-2.0.3.jar" );
+
+        ConcurentFileWrite( FileLockManager fileLockManager )
+            throws IOException
+        {
+            this.fileLockManager = fileLockManager;
+            file.createNewFile();
+
+        }
+
+        @Override
+        public void initialize()
+        {
+
+        }
+
+        public void thread1()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread1" );
+            Lock lock = fileLockManager.writeFileLock( this.file );
+            try
+            {
+                lock.getFile().delete();
+                FileUtils.copyFile( largeJar, lock.getFile() );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread1 ok" );
+        }
+
+        public void thread2()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread2" );
+            Lock lock = fileLockManager.writeFileLock( this.file );
+            try
+            {
+                lock.getFile().delete();
+                FileUtils.copyFile( largeJar, lock.getFile() );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread2 ok" );
+        }
+
+        public void thread3()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread3" );
+            Lock lock = fileLockManager.readFileLock( this.file );
+            try
+            {
+                IOUtils.copy( new FileInputStream( lock.getFile() ),
+                              new FileOutputStream( File.createTempFile( "foo", ".jar" ) ) );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread3 ok" );
+        }
+
+        public void thread4()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread4" );
+            Lock lock = fileLockManager.writeFileLock( this.file );
+            try
+            {
+                lock.getFile().delete();
+                FileUtils.copyFile( largeJar, lock.getFile() );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread4 ok" );
+        }
+
+        public void thread5()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread5" );
+            Lock lock = fileLockManager.writeFileLock( this.file );
+            try
+            {
+                lock.getFile().delete();
+                FileUtils.copyFile( largeJar, lock.getFile() );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread5 ok" );
+        }
+
+        public void thread6()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread6" );
+            Lock lock = fileLockManager.readFileLock( this.file );
+            try
+            {
+                IOUtils.copy( new FileInputStream( lock.getFile() ),
+                              new FileOutputStream( File.createTempFile( "foo", ".jar" ) ) );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread6 ok" );
+        }
+
+        public void thread7()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread7" );
+            Lock lock = fileLockManager.writeFileLock( this.file );
+            try
+            {
+                lock.getFile().delete();
+                FileUtils.copyFile( largeJar, lock.getFile() );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread7 ok" );
+        }
+
+        public void thread8()
+            throws FileLockException, IOException
+        {
+            logger.info( "thread8" );
+            Lock lock = fileLockManager.readFileLock( this.file );
+            try
+            {
+                IOUtils.copy( new FileInputStream( lock.getFile() ),
+                              new FileOutputStream( File.createTempFile( "foo", ".jar" ) ) );
+            }
+            finally
+            {
+                fileLockManager.release( lock );
+            }
+            logger.info( "thread8 ok" );
+        }
+
+
+
+    }
+
+    @Test
+    public void testWrite()
+        throws Throwable
+    {
+        ConcurentFileWrite concurentFileWrite = new ConcurentFileWrite( fileLockManager );
+        //concurentFileWrite.setTrace( true );
+        TestFramework.runOnce( concurentFileWrite );
+    }
+
+}
diff --git a/archiva-modules/archiva-base/archiva-filelock/src/test/resources/log4j2-test.xml b/archiva-modules/archiva-base/archiva-filelock/src/test/resources/log4j2-test.xml
new file mode 100644
index 000000000..93e519df7
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-filelock/src/test/resources/log4j2-test.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+  ~ 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.
+  -->
+
+
+<configuration status="debug">
+
+
+
+  <appenders>
+    <Console name="console" target="SYSTEM_OUT">
+      <!--PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/-->
+      <PatternLayout pattern="%highlight{%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n}" />
+    </Console>
+
+  </appenders>
+  <loggers>
+
+
+    <logger name="org.apache.archiva.common.filelock" level="debug"/>
+
+    <root level="info" includeLocation="true">
+      <appender-ref ref="console"/>
+    </root>
+  </loggers>
+</configuration>
+
+
diff --git a/archiva-modules/archiva-base/archiva-proxy/src/main/java/org/apache/archiva/proxy/DefaultRepositoryProxyConnectors.java b/archiva-modules/archiva-base/archiva-proxy/src/main/java/org/apache/archiva/proxy/DefaultRepositoryProxyConnectors.java
index 9b78010e6..72eb22e8e 100644
--- a/archiva-modules/archiva-base/archiva-proxy/src/main/java/org/apache/archiva/proxy/DefaultRepositoryProxyConnectors.java
+++ b/archiva-modules/archiva-base/archiva-proxy/src/main/java/org/apache/archiva/proxy/DefaultRepositoryProxyConnectors.java
@@ -83,6 +83,7 @@ import javax.inject.Inject;
 import javax.inject.Named;
 import java.io.File;
 import java.io.IOException;
+import java.io.RandomAccessFile;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -1091,6 +1092,9 @@ public class DefaultRepositoryProxyConnectors
         }
 
         target.getParentFile().mkdirs();
+        // TODO file lock library
+        RandomAccessFile raf;
+
         if ( !temp.renameTo( target ) )
         {
             log.warn( "Unable to rename tmp file to its final name... resorting to copy command." );
diff --git a/archiva-modules/archiva-base/pom.xml b/archiva-modules/archiva-base/pom.xml
index d8d8d7748..429ee5257 100644
--- a/archiva-modules/archiva-base/pom.xml
+++ b/archiva-modules/archiva-base/pom.xml
@@ -32,6 +32,7 @@
   <modules>
     <module>archiva-test-utils</module>
     <module>archiva-common</module>
+    <module>archiva-filelock</module>
     <module>archiva-model</module>
     <module>archiva-configuration</module>
     <module>archiva-checksum</module>
diff --git a/archiva-modules/archiva-web/archiva-webdav/src/main/java/org/apache/archiva/webdav/ArchivaDavResource.java b/archiva-modules/archiva-web/archiva-webdav/src/main/java/org/apache/archiva/webdav/ArchivaDavResource.java
index e7de17e84..5b76c7cfb 100644
--- a/archiva-modules/archiva-web/archiva-webdav/src/main/java/org/apache/archiva/webdav/ArchivaDavResource.java
+++ b/archiva-modules/archiva-web/archiva-webdav/src/main/java/org/apache/archiva/webdav/ArchivaDavResource.java
@@ -201,6 +201,7 @@ public class ArchivaDavResource
             FileInputStream is = null;
             try
             {
+                // TODO file lock library
                 // Write content to stream
                 is = new FileInputStream( localResource );
                 IOUtils.copy( is, outputContext.getOutputStream() );
diff --git a/pom.xml b/pom.xml
index 2d1f6448a..0c28cbbfc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -262,6 +262,11 @@
       </dependency>
       <dependency>
         <groupId>org.apache.archiva</groupId>
+        <artifactId>archiva-filelock</artifactId>
+        <version>${project.version}</version>
+      </dependency>
+      <dependency>
+        <groupId>org.apache.archiva</groupId>
         <artifactId>archiva-configuration</artifactId>
         <version>${project.version}</version>
       </dependency>