/* ====================================================================
* Loom Software License, version 1.1
*
* Copyright (c) 2003, Loom Group. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. Neither the name of the Loom Group nor the name "Loom" nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
*
* Loom includes code from the Apache Software Foundation
*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 1997-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software
* itself, if and wherever such third-party acknowledgments
* normally appear.
*
* 4. The names "Jakarta", "Avalon", and "Apache Software Foundation"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
package org.codehaus.loom.components.kernel;
import java.io.File;
import java.util.HashMap;
import org.apache.avalon.framework.container.ContainerUtil;
import org.apache.excalibur.instrument.InstrumentManager;
import org.codehaus.loom.components.application.DefaultApplication;
import org.codehaus.loom.components.util.profile.PartitionProfile;
import org.codehaus.loom.interfaces.Application;
import org.codehaus.loom.interfaces.ApplicationContext;
import org.codehaus.loom.interfaces.ConfigurationInterceptor;
import org.codehaus.loom.interfaces.ConfigurationValidator;
import org.codehaus.loom.interfaces.Kernel;
import org.codehaus.loom.interfaces.LoomException;
import org.codehaus.loom.interfaces.SystemManager;
import org.codehaus.spice.loggerstore.LoggerStore;
import org.codehaus.spice.salt.i18n.ResourceManager;
import org.codehaus.spice.salt.i18n.Resources;
import org.codehaus.dna.AbstractLogEnabled;
import org.codehaus.dna.Active;
import org.codehaus.dna.Composable;
import org.codehaus.dna.Configurable;
import org.codehaus.dna.Configuration;
import org.codehaus.dna.ConfigurationException;
import org.codehaus.dna.Logger;
import org.codehaus.dna.MissingResourceException;
import org.codehaus.dna.ResourceLocator;
import org.codehaus.dna.impl.DefaultResourceLocator;
/**
* The ServerKernel is the core of the container system. The kernel is
* responsible for orchestrating low level services such as loading, configuring
* and destroying blocks. It also gives access to basic facilities such as
* scheduling sub-systems, protected execution contexts, naming and directory
* services etc.
*
* Note that no facilities are available until after the Kernel has been
* configured and initialized.
*
* @author Peter Donald
* @author Leo Simons
* @dna.component
* @mx.component
*/
public class DefaultKernel
extends AbstractLogEnabled
implements Kernel, Active, Composable, Configurable
{
private static final Resources REZ =
ResourceManager.getPackageResources( DefaultKernel.class );
///SystemManager provided by Embeddor
private SystemManager m_systemManager;
private SystemManager m_applicationManager;
///Configuration Repository
private ConfigurationInterceptor m_repository;
//Configuration Validator
private ConfigurationValidator m_validator;
//Instrument Manager
private InstrumentManager m_instrumentManager;
private final HashMap m_entries = new HashMap();
//Allow applications that fail to startup to remain in the kernel in a stopped state?
private boolean m_addInvalidApplications;
//Counter to provide simple locking. when the count is 0, the kernel is unlocked
private int m_lockCount;
//List of applications to return when the kernel is locked
private String[] m_lockedApplications;
/**
* @dna.dependency type="InstrumentManager"
* @dna.dependency type="SystemManager"
* @dna.dependency type="ConfigurationInterceptor"
* @dna.dependency type="ConfigurationValidator"
*/
public void compose( final ResourceLocator locator )
throws MissingResourceException
{
m_systemManager = (SystemManager)locator.
lookup( SystemManager.class.getName() );
m_repository = (ConfigurationInterceptor)locator.
lookup( ConfigurationInterceptor.class.getName() );
m_validator = (ConfigurationValidator)locator.
lookup( ConfigurationValidator.class.getName() );
m_instrumentManager = (InstrumentManager)locator.
lookup( InstrumentManager.class.getName() );
}
public void configure( final Configuration configuration )
throws ConfigurationException
{
m_addInvalidApplications =
configuration.getChild( "add-invalid-applications" ).getValueAsBoolean(
false );
}
public void initialize()
throws Exception
{
m_applicationManager =
m_systemManager.getSubContext( null, "application" );
}
public void dispose()
{
final String[] names = getApplicationNames();
for( int i = 0; i < names.length; i++ )
{
try
{
final SarEntry entry = (SarEntry)m_entries.get( names[ i ] );
shutdown( entry );
}
catch( final Exception e )
{
final String message = REZ.format(
"kernel.error.entry.dispose", names[ i ] );
getLogger().warn( message, e );
}
}
}
/**
* Lock the kernel, temporarily preserving the list of applications running
* in the container
*/
public void lock()
{
synchronized( this )
{
m_lockedApplications = getApplicationNames();
m_lockCount++;
if( getLogger().isDebugEnabled() )
{
getLogger().debug( "Kernel locked [count:" + m_lockCount + "]" );
}
}
}
/**
* Unlock the kernel, restoring the list of applications to be the current
* active list
*/
public void unlock()
{
synchronized( this )
{
m_lockCount--;
if( m_lockCount < 0 )
{
throw new IllegalStateException(
REZ.getString( "kernel.error.negativelock" ) );
}
if( getLogger().isDebugEnabled() )
{
getLogger().debug(
"Kernel unlocked [count:" + m_lockCount + "]" );
}
}
}
/**
* @mx.attribute description="the list of applications running in the
* container"
*/
public String[] getApplicationNames()
{
if( isLocked() )
{
return m_lockedApplications;
}
else
{
return (String[])m_entries.keySet().toArray( new String[ 0 ] );
}
}
private boolean isLocked()
{
return m_lockCount > 0;
}
public Application getApplication( final String name )
{
final SarEntry entry = (SarEntry)m_entries.get( name );
if( null == entry )
{
return null;
}
else
{
return entry.getApplication();
}
}
/**
* Create and initialize the application instance if it is not already
* initialized.
*
* @param entry the entry for application
* @throws Exception if an error occurs
*/
private void startup( final SarEntry entry )
throws Exception
{
//lock for application startup and shutdown
synchronized( entry )
{
final String name = entry.getProfile().getMetaData().getName();
Application application = entry.getApplication();
if( null == application )
{
try
{
final Application newApp = new DefaultApplication();
final Logger childLogger =
getLogger().getChildLogger( name );
org.codehaus.dna.impl.ContainerUtil.enableLogging(
newApp, childLogger );
final ApplicationContext context =
createApplicationContext( entry );
newApp.setApplicationContext( context );
org.codehaus.dna.impl.ContainerUtil.initialize( newApp );
application = newApp;
}
catch( final Throwable t )
{
//Initialization failed so clean entry
//so invalid instance is not used
entry.setApplication( null );
final String message =
REZ.format( "kernel.error.entry.initialize",
entry.getProfile().getMetaData().getName() );
throw new LoomException( message, t );
}
try
{
ContainerUtil.start( application );
}
catch( final Throwable t )
{
final String message =
REZ.format( "kernel.error.entry.start",
entry.getProfile().getMetaData().getName() );
if( m_addInvalidApplications )
{
getLogger().warn( message, t );
}
else
{
//Initialization failed so clean entry
//so invalid instance is not used
entry.setApplication( null );
throw new LoomException( message, t );
}
}
entry.setApplication( application );
// manage application
try
{
m_applicationManager.register( name, application );
}
catch( final Throwable t )
{
final String message =
REZ.format( "kernel.error.entry.manage", name );
throw new LoomException( message, t );
}
}
}
}
private void shutdown( final SarEntry entry )
throws Exception
{
//lock for application startup and shutdown
synchronized( entry )
{
final Application application = entry.getApplication();
if( null != application )
{
entry.setApplication( null );
ContainerUtil.stop( application );
org.codehaus.dna.impl.ContainerUtil.dispose( application );
}
else
{
final String message =
REZ.format( "kernel.error.entry.nostop",
entry.getProfile().getMetaData().getName() );
getLogger().warn( message );
}
}
}
public void addApplication( final PartitionProfile profile,
final File homeDirectory,
final File workDirectory,
final ClassLoader classLoader,
final LoggerStore store )
throws Exception
{
final String name = profile.getMetaData().getName();
final SarEntry entry =
new SarEntry( profile, homeDirectory,
workDirectory, classLoader,
store );
m_entries.put( name, entry );
try
{
startup( entry );
}
catch( final Exception e )
{
final String message =
REZ.format( "kernel.error.entry.start", name );
getLogger().warn( message, e );
throw e;
}
}
private ApplicationContext createApplicationContext( final SarEntry entry )
throws Exception
{
final String name = entry.getProfile().getMetaData().getName();
final DefaultApplicationContext context =
new DefaultApplicationContext( entry.getProfile(),
entry.getHomeDirectory(),
entry.getWorkDirectory(),
entry.getClassLoader(),
entry.getLoggerStore() );
org.codehaus.dna.impl.ContainerUtil.
enableLogging( context, createContextLogger( name ) );
org.codehaus.dna.impl.ContainerUtil.
compose( context, createResourceLocator() );
org.codehaus.dna.impl.ContainerUtil.initialize( context );
return context;
}
/**
* Create a logger for specified ApplicationContext.
*
* @param name the name of application name
* @return the Logger for context
*/
private Logger createContextLogger( final String name )
{
final String loggerName = name + ".frame";
final Logger childLogger =
getLogger().getChildLogger( loggerName );
return childLogger;
}
private ResourceLocator createResourceLocator()
{
final DefaultResourceLocator serviceManager = new DefaultResourceLocator();
serviceManager.put( SystemManager.class.getName(), m_systemManager );
serviceManager.put( ConfigurationInterceptor.class.getName(),
m_repository );
serviceManager.put( ConfigurationValidator.class.getName(),
m_validator );
serviceManager.put( InstrumentManager.class.getName(),
m_instrumentManager );
serviceManager.put( Kernel.class.getName(), this );
serviceManager.makeReadOnly();
return serviceManager;
}
/**
* @mx.operation description="Removes the application from the container"
* @mx.parameter name="name" description="the name of application to
* remove"
*/
public void removeApplication( final String name )
throws Exception
{
final SarEntry entry = (SarEntry)m_entries.remove( name );
if( null == entry )
{
final String message =
REZ.format( "kernel.error.entry.initialize", name );
throw new Exception( message );
}
else
{
// un-manage application
try
{
m_applicationManager.unregister( name );
}
catch( final Throwable t )
{
final String message =
REZ.format( "kernel.error.entry.unmanage", name );
throw new LoomException( message, t );
}
shutdown( entry );
}
}
}