Return-Path: 
 <sling-commits-return-1731-apmail-incubator-sling-commits-archive=incubator.apache.org@incubator.apache.org>
Delivered-To: apmail-incubator-sling-commits-archive@locus.apache.org
Received: (qmail 48619 invoked from network); 5 Mar 2008 11:35:40 -0000
Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2)
  by minotaur.apache.org with SMTP; 5 Mar 2008 11:35:40 -0000
Received: (qmail 27991 invoked by uid 500); 5 Mar 2008 11:35:36 -0000
Delivered-To: apmail-incubator-sling-commits-archive@incubator.apache.org
Received: (qmail 27974 invoked by uid 500); 5 Mar 2008 11:35:36 -0000
Mailing-List: contact sling-commits-help@incubator.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:sling-commits-help@incubator.apache.org>
List-Unsubscribe: <mailto:sling-commits-unsubscribe@incubator.apache.org>
List-Post: <mailto:sling-commits@incubator.apache.org>
List-Id: <sling-commits.incubator.apache.org>
Reply-To: sling-dev@incubator.apache.org
Delivered-To: mailing list sling-commits@incubator.apache.org
Received: (qmail 27965 invoked by uid 99); 5 Mar 2008 11:35:36 -0000
Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Mar 2008 03:35:36 -0800
X-ASF-Spam-Status: No, hits=-2000.0 required=10.0
	tests=ALL_TRUSTED
X-Spam-Check-By: apache.org
Received: from [140.211.11.3] (HELO eris.apache.org) (140.211.11.3)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Mar 2008 11:35:08 +0000
Received: by eris.apache.org (Postfix, from userid 65534)
	id 9D8F71A9832; Wed,  5 Mar 2008 03:35:18 -0800 (PST)
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: svn commit: r633823 - in /incubator/sling/trunk/jcr/base: ./
 src/main/java/org/apache/sling/jcr/base/
 src/main/java/org/apache/sling/jcr/base/internal/
 src/main/java/org/apache/sling/jcr/base/internal/loader/
Date: Wed, 05 Mar 2008 11:35:13 -0000
To: sling-commits@incubator.apache.org
From: fmeschbe@apache.org
X-Mailer: svnmailer-1.0.8
Message-Id: <20080305113518.9D8F71A9832@eris.apache.org>
X-Virus-Checked: Checked by ClamAV on apache.org

Author: fmeschbe
Date: Wed Mar  5 03:35:06 2008
New Revision: 633823

URL: http://svn.apache.org/viewvc?rev=633823&view=rev
Log:
SLING-132 Refactor repository access based on a background thread checking
for the repository constantly and providing proper API to acquire, setup,
teardown and dispose repositories.

Modified:
    incubator/sling/trunk/jcr/base/pom.xml
    incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/AbstractSlingRepository.java
    incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/SessionPool.java
    incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/loader/Loader.java

Modified: incubator/sling/trunk/jcr/base/pom.xml
URL: http://svn.apache.org/viewvc/incubator/sling/trunk/jcr/base/pom.xml?rev=633823&r1=633822&r2=633823&view=diff
==============================================================================
--- incubator/sling/trunk/jcr/base/pom.xml (original)
+++ incubator/sling/trunk/jcr/base/pom.xml Wed Mar  5 03:35:06 2008
@@ -54,6 +54,8 @@
             <plugin>
                 <groupId>org.apache.felix</groupId>
                 <artifactId>maven-scr-plugin</artifactId>
+                <!-- require fix for FELIX-506 -->
+                <version>1.0.4-SNAPSHOT</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.felix</groupId>
@@ -95,6 +97,8 @@
         <dependency>
             <groupId>org.apache.jackrabbit</groupId>
             <artifactId>jackrabbit-jcr-rmi</artifactId>
+            <!-- require fix for JCR-1454 -->
+            <version>1.5-SNAPSHOT</version>
             <scope>compile</scope>
         </dependency>
         <!-- OSGi Libraries -->

Modified: incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/AbstractSlingRepository.java
URL: http://svn.apache.org/viewvc/incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/AbstractSlingRepository.java?rev=633823&r1=633822&r2=633823&view=diff
==============================================================================
--- incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/AbstractSlingRepository.java (original)
+++ incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/AbstractSlingRepository.java Wed Mar  5 03:35:06 2008
@@ -35,79 +35,109 @@
 import org.apache.sling.jcr.base.internal.SessionPoolFactory;
 import org.apache.sling.jcr.base.internal.SessionPoolManager;
 import org.apache.sling.jcr.base.internal.loader.Loader;
-import org.osgi.framework.Bundle;
+import org.apache.sling.jcr.base.util.RepositoryAccessor;
+import org.osgi.framework.BundleContext;
 import org.osgi.framework.BundleEvent;
+import org.osgi.framework.ServiceRegistration;
 import org.osgi.framework.SynchronousBundleListener;
 import org.osgi.service.component.ComponentContext;
 import org.osgi.service.log.LogService;
 
-
 /**
- * The <code>AbstractSlingRepository</code> is an abstract implementation of the
- * {@link SlingRepository} interface which provides core support for session
+ * The <code>AbstractSlingRepository</code> is an abstract implementation of
+ * the {@link SlingRepository} interface which provides core support for session
  * pooling. Implementations of the <code>SlingRepository</code> interface may
  * wish to extend this class to benefit from a default implementation.
  * <p>
  * Extensions of this class will have to declare the following
  * <code>scr.property</code> tags to have them declared automatically in the
  * respective component and metatype definitions by the maven-sling-plugin:
- *
- * <pre>
- *  scr.property value=&quot;&quot; name=&quot;defaultWorkspace&quot;
- *  scr.property value=&quot;anonymous&quot; name=&quot;anonymous.name&quot;
- *  scr.property value=&quot;anonymous&quot; name=&quot;anonymous.password&quot;
- *  scr.property value=&quot;admin&quot; name=&quot;admin.name&quot;
- *  scr.property value=&quot;admin&quot; name=&quot;admin.password&quot;
- *  scr.property value=&quot;10&quot; type=&quot;Integer&quot; name=&quot;pool.maxActive&quot;
- *  scr.property value=&quot;10&quot; type=&quot;Integer&quot; name=&quot;pool.maxIdle&quot;
- *  scr.property value=&quot;256&quot; type=&quot;Integer&quot; name=&quot;pool.maxActiveWait&quot;
- * </pre>
+ * 
  * @scr.component
  */
-public abstract class AbstractSlingRepository
-    implements SlingRepository, SynchronousBundleListener {
+public abstract class AbstractSlingRepository implements SlingRepository,
+        SynchronousBundleListener, Runnable {
 
+    /** @scr.property value="" */
     public static final String PROPERTY_DEFAULT_WORKSPACE = "defaultWorkspace";
 
+    /** @scr.property valueRef="DEFAULT_ANONYMOUS_USER" */
     public static final String PROPERTY_ANONYMOUS_USER = "anonymous.name";
 
+    /** @scr.property valueRef="DEFAULT_ANONYMOUS_PASS" */
     public static final String PROPERTY_ANONYMOUS_PASS = "anonymous.password";
 
+    /** @scr.property valueRef="DEFAULT_ADMIN_USER" */
     public static final String PROPERTY_ADMIN_USER = "admin.name";
 
+    /** @scr.property valueRef="DEFAULT_ADMIN_PASS" */
     public static final String PROPERTY_ADMIN_PASS = "admin.password";
-
-    public static final String DEFAULT_WORKSPACE = "default";
-
-    public static final String DEFAULT_ANONYMOUS_USER = "anonymous";
-
-    public static final String DEFAULT_ANONYMOUS_PASS = "anonymous";
-
-    public static final String DEFAULT_ADMIN_USER = "admin";
-
-    public static final String DEFAULT_ADMIN_PASS = "admin";
+    
+    /** @scr.property valueRef="DEFAULT_POLL_ACTIVE"  */
+    public static final String PROPERTY_POLL_ACTIVE = "poll.active";
+    
+    /** @scr.property valueRef="DEFAULT_POLL_INACTIVE" */
+    public static final String PROPERTY_POLL_INACTIVE = "poll.inactive";
 
     /**
      * The name of the configuration parameter containing the maximum number of
      * seconds to wait for the number of currently active sessions to drop be
      * low the upper limit before giving up (value is "pool.maxActiveWait").
+     * 
+     * @scr.property value="1" type="Integer"
      */
-    public static final String PARAM_MAX_ACTIVE_SESSIONS_WAIT = "pool.maxActiveWait";
+    public static final String PROPERTY_MAX_ACTIVE_SESSIONS_WAIT = "pool.maxActiveWait";
 
     /**
      * The name of the configuration parameter containing the upper limit of the
      * simultaneously active sessions (value is "pool.maxActive").
+     * 
+     * @scr.property value="-1" type="Integer"
      */
-    public static final String PARAM_MAX_ACTIVE_SESSIONS = "pool.maxActive";
+    public static final String PROPERTY_MAX_ACTIVE_SESSIONS = "pool.maxActive";
 
     /**
      * The name of the configuration parameter containing the upper limit of the
      * currently idle sessions to keep in the pool (value is "pool.maxIdle").
+     * 
+     * @scr.property value="10" type="Integer"
      */
-    public static final String PARAM_MAX_IDLE_SESSIONS = "pool.maxIdle";
+    public static final String PROPERTY_MAX_IDLE_SESSIONS = "pool.maxIdle";
+
+    public static final String DEFAULT_WORKSPACE = "default";
+
+    public static final String DEFAULT_ANONYMOUS_USER = "anonymous";
 
+    public static final String DEFAULT_ANONYMOUS_PASS = "anonymous";
+
+    public static final String DEFAULT_ADMIN_USER = "admin";
+
+    public static final String DEFAULT_ADMIN_PASS = "admin";
+    
+    /**
+     * The default value for the number of seconds to wait between two
+     * consecutive checks while the repository is active (value is 10).
+     */
+    public static final int DEFAULT_POLL_ACTIVE = 10;
+    
+    /**
+     * The default value for the number of seconds to wait between two
+     * consecutive checks while the repository is not active (value is 10).
+     */
+    public static final int DEFAULT_POLL_INACTIVE = 10;
+    
+    /** The minimum number of seconds allowed for any of the two poll times */
+    public static final int MIN_POLL = 2;
+
+    /** @scr.reference bind="bindLog" unbind="unbindLog" */
+    private LogService log;
+    
     private ComponentContext componentContext;
 
+    private Repository repository;
+
+    private ServiceRegistration repositoryService;
+
     private String defaultWorkspace;
 
     private String anonUser;
@@ -122,60 +152,28 @@
 
     private Loader loader;
 
-    protected AbstractSlingRepository() {
-    }
-
-    protected abstract Repository getDelegatee() throws RepositoryException;
-
-    protected final SessionPoolManager getPoolManager()
-            throws RepositoryException {
-        if (this.poolManager == null) {
-            this.poolManager = new SessionPoolManager(this.getDelegatee(), this.loader,
-                this.getSessionPoolFactory());
-        }
+    // the poll interval used while the repository is not active
+    private long pollTimeInActive;
 
-        return this.poolManager;
-    }
+    // the poll interval used while the repository is active
+    private long pollTimeActive;
 
-    /**
-     * @return
-     */
-    protected SessionPoolFactory getSessionPoolFactory() {
-        @SuppressWarnings("unchecked")
-        Dictionary<String, Object> properties = this.componentContext.getProperties();
-        final int maxActiveSessions = this.getIntProperty(properties,
-            PARAM_MAX_ACTIVE_SESSIONS);
-        final int maxIdleSessions = this.getIntProperty(properties,
-            PARAM_MAX_IDLE_SESSIONS);
-        final int maxActiveSessionsWait = this.getIntProperty(properties,
-            PARAM_MAX_ACTIVE_SESSIONS_WAIT);
-        return new SessionPoolFactory() {
+    // whether the repository checker task should be active. this field
+    // is managed by the startRepositoryPinger and stopRepositoryPinger methods
+    private boolean running;
 
-            public SessionPool createPool(final SessionPoolManager mgr, final SimpleCredentials credentials) {
-                // create and configure the new pool
-                final SessionPool pool = createSessionPool(mgr, credentials);
-                pool.setMaxActiveSessions(maxActiveSessions);
-                pool.setMaxActiveSessionsWait(maxActiveSessionsWait);
-                pool.setMaxIdleSessions(maxIdleSessions);
-                return pool;
-            }
-        };
-    }
+    // the background thread constantly checking the repository
+    private Thread repositoryPinger;
 
-    protected SessionPool createSessionPool(final SessionPoolManager mgr, final SimpleCredentials credentials) {
-        final SessionPool pool = new SessionPool(mgr, credentials);
-        return pool;
+    protected AbstractSlingRepository() {
     }
 
     /**
-     * @see org.apache.sling.jcr.api.SlingRepository#getDefaultWorkspace()
-     * Declared final to make sure the SLING-256 rule is enforced.
+     * Returns the default workspace, which may be <code>null</code> meaning
+     * to use the repository provided default workspace.
      */
     public final String getDefaultWorkspace() {
-        if(defaultWorkspace == null || defaultWorkspace.trim().length() == 0) {
-            // SLING-256
-            return null;
-        }
+        // Declared final to make sure the SLING-256 rule is enforced.
         return this.defaultWorkspace;
     }
 
@@ -187,49 +185,29 @@
         return this.login(null, null);
     }
 
-    /*
-     * (non-Javadoc)
-     *
-     * @see org.apache.sling.core.jcr.SessionProvider#getAdministrationSession()
-     */
     public Session loginAdministrative(String workspace)
             throws RepositoryException {
-        SimpleCredentials sc = new SimpleCredentials(this.adminUser, this.adminPass);
+        SimpleCredentials sc = new SimpleCredentials(this.adminUser,
+            this.adminPass);
         return this.login(sc, workspace);
     }
 
-    /*
-     * (non-Javadoc)
-     *
-     * @see javax.jcr.Repository#login(javax.jcr.Credentials)
-     */
     public Session login(Credentials credentials) throws LoginException,
             RepositoryException {
         return this.login(credentials, null);
     }
 
-    /*
-     * (non-Javadoc)
-     *
-     * @see javax.jcr.Repository#login(java.lang.String)
-     */
     public Session login(String workspace) throws LoginException,
             NoSuchWorkspaceException, RepositoryException {
         return this.login(null, workspace);
     }
 
-    /*
-     * (non-Javadoc)
-     *
-     * @see org.apache.sling.core.jcr.SlingRepository#login(javax.jcr.Credentials,
-     *      java.lang.String)
-     */
     public Session login(Credentials credentials, String workspace)
             throws LoginException, NoSuchWorkspaceException,
             RepositoryException {
 
         // if already stopped, don't retrieve a session
-        if (this.componentContext == null || this.getDelegatee() == null) {
+        if (this.componentContext == null || this.getRepository() == null) {
             throw new RepositoryException("Sling Repository not ready");
         }
 
@@ -243,13 +221,14 @@
         }
 
         try {
-            getLog().log(LogService.LOG_DEBUG,
-                    "Logging in to workspace '" + workspace + "'");
+            log(LogService.LOG_DEBUG, "login: Logging in to workspace '"
+                + workspace + "'");
             return this.getPoolManager().login(credentials, workspace);
         } catch (NoSuchWorkspaceException nswe) {
             // if the desired workspace is the default workspace, try to create
             // (but not if using the repository-supplied default workspace)
-            if (workspace!=null && workspace.equals(this.getDefaultWorkspace())
+            if (workspace != null
+                && workspace.equals(this.getDefaultWorkspace())
                 && this.createWorkspace(workspace)) {
                 return this.getPoolManager().login(credentials, workspace);
             }
@@ -262,46 +241,284 @@
 
     /*
      * (non-Javadoc)
-     *
+     * 
      * @see javax.jcr.Repository#getDescriptor(java.lang.String)
      */
     public String getDescriptor(String name) {
-        try {
-            return this.getDelegatee().getDescriptor(name);
-        } catch (RepositoryException re) {
-            this.log(LogService.LOG_ERROR, "Repository not available", re);
+        Repository repo = getRepository();
+        if (repo != null) {
+            return repo.getDescriptor(name);
         }
 
+        log(LogService.LOG_ERROR, "getDescriptor: Repository not available");
         return null;
     }
 
     /*
      * (non-Javadoc)
-     *
+     * 
      * @see javax.jcr.Repository#getDescriptorKeys()
      */
     public String[] getDescriptorKeys() {
-        try {
-            return this.getDelegatee().getDescriptorKeys();
-        } catch (RepositoryException re) {
-            this.log(LogService.LOG_ERROR, "Repository not available", re);
+        Repository repo = getRepository();
+        if (repo != null) {
+            return repo.getDescriptorKeys();
         }
 
+        log(LogService.LOG_ERROR, "getDescriptorKeys: Repository not available");
         return new String[0];
     }
 
-    // ---------- logging ------------------------------------------------------
+    //---------- Session Pool support -----------------------------------------
+    
+    protected final SessionPoolManager getPoolManager() {
+        if (this.poolManager == null) {
+            this.poolManager = new SessionPoolManager(this.getRepository(),
+                this.loader, this.getSessionPoolFactory());
+        }
 
-    protected abstract LogService getLog();
+        return this.poolManager;
+    }
+
+    /**
+     * @return
+     */
+    protected SessionPoolFactory getSessionPoolFactory() {
+        @SuppressWarnings("unchecked")
+        Dictionary<String, Object> properties = this.componentContext.getProperties();
+        final int maxActiveSessions = this.getIntProperty(properties,
+            PROPERTY_MAX_ACTIVE_SESSIONS);
+        final int maxIdleSessions = this.getIntProperty(properties,
+            PROPERTY_MAX_IDLE_SESSIONS);
+        final int maxActiveSessionsWait = this.getIntProperty(properties,
+            PROPERTY_MAX_ACTIVE_SESSIONS_WAIT);
+        return new SessionPoolFactory() {
+
+            public SessionPool createPool(final SessionPoolManager mgr,
+                    final SimpleCredentials credentials) {
+                // create and configure the new pool
+                final SessionPool pool = createSessionPool(mgr, credentials);
+                pool.setMaxActiveSessions(maxActiveSessions);
+                pool.setMaxActiveSessionsWait(maxActiveSessionsWait);
+                pool.setMaxIdleSessions(maxIdleSessions);
+                return pool;
+            }
+        };
+    }
+
+    protected SessionPool createSessionPool(final SessionPoolManager mgr,
+            final SimpleCredentials credentials) {
+        final SessionPool pool = new SessionPool(mgr, credentials);
+        return pool;
+    }
+    
+    // ---------- logging ------------------------------------------------------
 
     protected void log(int level, String message) {
         this.log(level, message, null);
     }
 
     protected void log(int level, String message, Throwable t) {
-        LogService log = this.getLog();
+        LogService log = this.log;
         if (log != null) {
-            log.log(this.componentContext.getServiceReference(), level, message, t);
+            log.log(this.componentContext.getServiceReference(), level,
+                message, t);
+        }
+    }
+
+    // ---------- Repository Access -------------------------------------------
+
+    /**
+     * Acquires the repository by calling the
+     * {@link org.apache.sling.jcr.base.util.RepositoryAccessor#getRepositoryFromURL(String)}
+     * with the value of the
+     * {@link org.apache.sling.jcr.base.util.RepositoryAccessor#REPOSITORY_URL_OVERRIDE_PROPERTY}
+     * framework or configuration property. If the property exists and a
+     * repository can be accessed using this property, that repository is
+     * returned. Otherwise <code>null</code> is returned.
+     * <p>
+     * Extensions of this class may overwrite this method with implementation
+     * specific acquisition semantics and may call this base class method or not
+     * as the implementation sees fit.
+     * <p>
+     * This method does not throw any <code>Throwable</code> but instead just
+     * returns <code>null</code> if not repository is available. Any problems
+     * trying to acquire the repository must be caught and logged as
+     * appropriate.
+     * 
+     * @return The acquired JCR <code>Repository</code> or <code>null</code>
+     *         if not repository can be acquired.
+     */
+    protected Repository acquireRepository() {
+        // if the environment provides a repository override URL, other settings
+        // are ignored
+        String overrideUrl = (String) componentContext.getProperties().get(
+            RepositoryAccessor.REPOSITORY_URL_OVERRIDE_PROPERTY);
+        if (overrideUrl == null) {
+            overrideUrl = componentContext.getBundleContext().getProperty(
+                RepositoryAccessor.REPOSITORY_URL_OVERRIDE_PROPERTY);
+        }
+
+        if (overrideUrl != null && overrideUrl.length() > 0) {
+            log(LogService.LOG_INFO,
+                "acquireRepository: Will not use embedded repository due to property "
+                    + RepositoryAccessor.REPOSITORY_URL_OVERRIDE_PROPERTY + "="
+                    + overrideUrl + ", acquiring repository using that URL");
+            return new RepositoryAccessor().getRepositoryFromURL(overrideUrl);
+        }
+
+        log(LogService.LOG_DEBUG,
+            "acquireRepository: No existing repository to access");
+        return null;
+    }
+
+    /**
+     * This method is called after a repository has been acquired by
+     * {@link #acquireRepository()} but before the repository is registered as a
+     * service.
+     * <p>
+     * Implementations may overwrite this method but MUST call this base class
+     * implementation first.
+     * 
+     * @param repository The JCR <code>Repository</code> to setup.
+     */
+    protected void setupRepository(Repository repository) {
+        BundleContext bundleContext = componentContext.getBundleContext();
+        this.loader = new Loader(this, bundleContext.getBundles());
+    }
+
+    /**
+     * Registers this component as an OSGi service with type
+     * <code>javax.jcr.Repository</code> and
+     * <code>org.apache.sling.jcr.api.SlingRepository</code> using the
+     * component properties as service registration properties.
+     * <p>
+     * This method may be overwritten to register the component with different
+     * types.
+     * 
+     * @return The OSGi <code>ServiceRegistration</code> object representing
+     *         the registered service.
+     */
+    protected ServiceRegistration registerService() {
+        @SuppressWarnings("unchecked")
+        Dictionary<String, Object> props = componentContext.getProperties();
+        String[] interfaces = new String[] { SlingRepository.class.getName(),
+            Repository.class.getName() };
+
+        return componentContext.getBundleContext().registerService(interfaces,
+            this, props);
+    }
+
+    /**
+     * Returns the repository underlying this instance or <code>null</code> if
+     * no repository is currently being available.
+     */
+    protected Repository getRepository() {
+        return repository;
+    }
+
+    /**
+     * Checks that the given <code>repository</code> is still available. This
+     * implementation tries to get the <code>Repository.SPEC_NAME_DESC</code>
+     * descriptor from the repository and returns <code>true</code> if the
+     * returned value is not <code>null</code>.
+     * <p>
+     * Extensions of this class may overwrite this method to implement different
+     * access checks. The contract of this method must be obeyed, though in a
+     * sense, the <code>true</code> must only be returned if
+     * <code>repository</code> is actually usable.
+     * 
+     * @param repository The JCR <code>Repository</code> to check for
+     *            availability.
+     * @return <code>true</code> if <code>repository</code> is not
+     *         <code>null</code> and accessible.
+     */
+    protected boolean pingRepository(Repository repository) {
+        if (repository != null) {
+            try {
+                return repository.getDescriptor(Repository.SPEC_NAME_DESC) != null;
+            } catch (Throwable t) {
+                log(LogService.LOG_DEBUG, "pingRepository: Repository "
+                    + repository + " does not seem to be available any more", t);
+            }
+        }
+
+        // fall back to unavailable
+        return false;
+    }
+
+    /**
+     * Unregisters the service represented by the
+     * <code>serviceRegistration</code>.
+     * <p>
+     * This method may be overwritten by extensions of this class as long as it
+     * is made sure, the given service registration is unregistered.
+     */
+    protected void unregisterService(ServiceRegistration serviceRegistration) {
+        serviceRegistration.unregister();
+    }
+
+    /**
+     * Performs any cleanups before the repository is actually disposed off by
+     * the {@link #disposeRepository(Repository)} method.
+     * <p>
+     * This method is meant for cleanup tasks before the repository is actually
+     * disposed off. Extensions of this class may overwrite but must call this
+     * base class implementation.
+     * 
+     * @param repository
+     */
+    protected void tearDown(Repository repository) {
+
+        if (this.poolManager != null) {
+            this.poolManager.dispose();
+            this.poolManager = null;
+        }
+
+        if (this.loader != null) {
+            this.loader.dispose();
+            this.loader = null;
+        }
+    }
+
+    /**
+     * Disposes off the given <code>repository</code>. This base class
+     * implementation does nothing. Extensions should overwrite if any special
+     * disposal operation is required.
+     * 
+     * @param repository
+     */
+    protected void disposeRepository(Repository repository) {
+        // nothing to do here ...
+    }
+
+    //---------- SynchronousBundleListener ------------------------------------
+    
+    /**
+     * Loads and unloads any components provided by the bundle whose state
+     * changed. If the bundle has been started, the components are loaded. If
+     * the bundle is about to stop, the components are unloaded.
+     * 
+     * @param event The <code>BundleEvent</code> representing the bundle state
+     *            change.
+     */
+    public void bundleChanged(BundleEvent event) {
+        // Take care: This is synchronous - take care to not block the system !!
+        Loader theLoader = this.loader;
+        if (theLoader != null) {
+            switch (event.getType()) {
+                case BundleEvent.INSTALLED:
+                    // register types when the bundle gets installed
+                    theLoader.registerBundle(event.getBundle());
+                    break;
+    
+                case BundleEvent.UNINSTALLED:
+                    theLoader.unregisterBundle(event.getBundle());
+                    break;
+                    
+                case BundleEvent.UPDATED:
+                    theLoader.updateBundle(event.getBundle());
+            }
         }
     }
 
@@ -313,6 +530,7 @@
 
     /**
      * This method must be called if overwritten by implementations !!
+     * 
      * @throws nothing, but allow derived classes to throw any Exception
      */
     protected void activate(ComponentContext componentContext) throws Exception {
@@ -320,8 +538,14 @@
 
         @SuppressWarnings("unchecked")
         Dictionary<String, Object> properties = componentContext.getProperties();
-        this.defaultWorkspace = this.getProperty(properties, PROPERTY_DEFAULT_WORKSPACE,
-            DEFAULT_WORKSPACE);
+
+        // ensure the default workspace is not null and not empty
+        this.defaultWorkspace = this.getProperty(properties,
+            PROPERTY_DEFAULT_WORKSPACE, DEFAULT_WORKSPACE);
+        if (this.defaultWorkspace != null
+            && this.defaultWorkspace.length() == 0) {
+            this.defaultWorkspace = null;
+        }
 
         this.anonUser = this.getProperty(properties, PROPERTY_ANONYMOUS_USER,
             DEFAULT_ANONYMOUS_USER);
@@ -333,77 +557,48 @@
         this.adminPass = this.getProperty(properties, PROPERTY_ADMIN_PASS,
             DEFAULT_ADMIN_PASS).toCharArray();
 
-        this.loader = new Loader(this);
-
+        setPollTimeActive(getIntProperty(properties, PROPERTY_POLL_ACTIVE));
+        setPollTimeInActive(getIntProperty(properties, PROPERTY_POLL_INACTIVE));
+        
         componentContext.getBundleContext().addBundleListener(this);
 
-        // TODO: Consider running this in the background !!
-        // FIXME: Commented while SLING-132 is still unfixed
-        Bundle[] bundles = componentContext.getBundleContext().getBundles();
-        for (int i = 0; i < bundles.length; i++) {
-            if ((bundles[i].getState() & (Bundle.INSTALLED | Bundle.UNINSTALLED)) == 0) {
-                // load content for bundles which are neither INSTALLED nor
-                // UNINSTALLED
-                this.loader.registerBundle(bundles[i]);
-            }
-        }
+        startRepositoryPinger();
     }
 
     /**
      * This method must be called if overwritten by implementations !!
-     *
+     * 
      * @param componentContext
      */
     protected void deactivate(ComponentContext componentContext) {
 
         componentContext.getBundleContext().removeBundleListener(this);
 
-        if (this.poolManager != null) {
-            this.poolManager.dispose();
-            this.poolManager = null;
-        }
-        if ( this.loader != null ) {
-            this.loader.dispose();
-            this.loader = null;
-        }
+        stopRepositoryPinger();
 
         this.componentContext = null;
     }
-
-    /**
-     * Loads and unloads any components provided by the bundle whose state
-     * changed. If the bundle has been started, the components are loaded. If
-     * the bundle is about to stop, the components are unloaded.
-     *
-     * @param event The <code>BundleEvent</code> representing the bundle state
-     *            change.
-     */
-    public void bundleChanged(BundleEvent event) {
-        // TODO: This is synchronous - take care to not block the system !!
-        switch (event.getType()) {
-            case BundleEvent.INSTALLED:
-                // register content and types when the bundle content is
-                // available
-                this.loader.registerBundle(event.getBundle());
-                break;
-
-            case BundleEvent.UNINSTALLED:
-                this.loader.unregisterBundle(event.getBundle());
-                break;
-            case BundleEvent.UPDATED:
-                this.loader.updateBundle(event.getBundle());
+    
+    protected void bindLog(LogService log) {
+        this.log = log;
+    }
+    
+    protected void unbindLog(LogService log) {
+        if (this.log == log) {
+            log = null;
         }
     }
 
     // ---------- internal -----------------------------------------------------
 
-    private String getProperty(Dictionary<String, Object> properties, String name,
-            String defaultValue) {
+    private String getProperty(Dictionary<String, Object> properties,
+            String name, String defaultValue) {
         Object prop = properties.get(name);
         return (prop instanceof String) ? (String) prop : defaultValue;
     }
 
-    private int getIntProperty(Dictionary<String, Object> properties, String name) {
+    private int getIntProperty(Dictionary<String, Object> properties,
+            String name) {
         Object prop = properties.get(name);
         if (prop instanceof Number) {
             return ((Number) prop).intValue();
@@ -419,13 +614,14 @@
     }
 
     private boolean createWorkspace(String workspace) {
-        this.log(LogService.LOG_INFO, "login: Requested workspace " + workspace
-            + " does not exist, trying to create");
+        this.log(LogService.LOG_INFO, "createWorkspace: Requested workspace "
+            + workspace + " does not exist, trying to create");
 
         Session tmpSession = null;
         try {
-            SimpleCredentials sc = new SimpleCredentials(this.adminUser, this.adminPass);
-            tmpSession = this.getDelegatee().login(sc);
+            SimpleCredentials sc = new SimpleCredentials(this.adminUser,
+                this.adminPass);
+            tmpSession = this.getRepository().login(sc);
             Workspace defaultWs = tmpSession.getWorkspace();
             if (defaultWs instanceof JackrabbitWorkspace) {
                 ((JackrabbitWorkspace) defaultWs).createWorkspace(workspace);
@@ -433,11 +629,13 @@
             }
 
             // not Jackrabbit
-            this.log(LogService.LOG_ERROR, "login: Cannot create requested workspace "
-                + workspace + ": Jackrabbit is required");
+            this.log(LogService.LOG_ERROR,
+                "createWorkspace: Cannot create requested workspace "
+                    + workspace + ": Jackrabbit is required");
         } catch (Throwable t) {
-            this.log(LogService.LOG_ERROR, "login: Cannot create requested workspace "
-                + workspace, t);
+            this.log(LogService.LOG_ERROR,
+                "createWorkspace: Cannot create requested workspace "
+                    + workspace, t);
         } finally {
             if (tmpSession != null) {
                 tmpSession.logout();
@@ -447,4 +645,186 @@
         // fall back to failure
         return false;
     }
+
+    // ---------- Background operation checking repository availability --------
+
+    private void setPollTimeActive(int seconds) {
+        if (seconds < MIN_POLL) {
+            seconds = DEFAULT_POLL_ACTIVE;
+        }
+        pollTimeActive = 1000L * seconds;
+    }
+
+    private void setPollTimeInActive(int seconds) {
+        if (seconds < MIN_POLL) {
+            seconds = DEFAULT_POLL_INACTIVE;
+        }
+        pollTimeInActive = 1000L * seconds;
+    }
+    
+    private void startRepositoryPinger() {
+        if (repositoryPinger != null) {
+            // make sure the ping will be running
+            running = true;
+            
+            // create and start the thread
+            repositoryPinger = new Thread(this, "Repository Pinger");
+            repositoryPinger.start();
+        }
+    }
+
+    private void stopRepositoryPinger() {
+        
+        // make sure the thread is terminating
+        running = false;
+
+        // nothing to do if the thread is not running at all
+        Thread rpThread = repositoryPinger;
+        if (rpThread == null) {
+            return;
+        }
+        
+        // clear the repositoryPinger thread field
+        repositoryPinger = null;
+        
+        // notify the thread for it to be able to shut down
+        synchronized (rpThread) {
+            rpThread.notifyAll();
+        }
+
+        // wait at most 10 seconds for the thread to terminate
+        try {
+            rpThread.join(10000L);
+        } catch (InterruptedException ie) {
+            // don't care here
+        }
+
+        // consider it an error if the thread is still running !!
+        if (rpThread.isAlive()) {
+            log(LogService.LOG_ERROR,
+                "stopRepositoryPinger: Timed waiting for thread "
+                    + rpThread + " to terminate");
+        }
+        
+    }
+
+    private boolean startRepository() {
+        try {
+            Repository newRepo = acquireRepository();
+            if (newRepo != null) {
+                
+                // ensure we really have the repository
+                if (pingRepository(newRepo)) {
+                    repository = newRepo;
+    
+                    setupRepository(newRepo);
+                    repositoryService = registerService();
+    
+                    return true;
+                }
+                
+                // otherwise let go off the repository and fail startup
+                log(LogService.LOG_INFO, "startRepository: Acquired Repository is not responsive, failing");
+                disposeRepository(repository);
+            }
+        } catch (Throwable t) {
+            // consider an uncaught problem an error
+            log(
+                LogService.LOG_ERROR,
+                "startRepository: Uncaught problem trying to provide repository access",
+                t);
+
+            // repository might be partially start, stop anything left
+            stopRepository();
+        }
+
+        return false;
+    }
+
+    private void stopRepository() {
+        if (repositoryService != null) {
+            try {
+                unregisterService(repositoryService);
+            } catch (Throwable t) {
+                log(
+                    LogService.LOG_INFO,
+                    "stopRepository: Uncaught problem unregistering the repository service",
+                    t);
+            }
+            repositoryService = null;
+        }
+
+        if (repository != null) {
+            Repository oldRepo = repository;
+            repository = null;
+
+            try {
+                tearDown(oldRepo);
+            } catch (Throwable t) {
+                log(
+                    LogService.LOG_INFO,
+                    "stopRepository: Uncaught problem tearing down the repository",
+                    t);
+            }
+
+            try {
+                disposeRepository(oldRepo);
+            } catch (Throwable t) {
+                log(
+                    LogService.LOG_INFO,
+                    "stopRepository: Uncaught problem disposing the repository",
+                    t);
+            }
+        }
+    }
+
+    public void run() {
+        long pollTime = pollTimeInActive;
+        Object waitLock = repositoryPinger;
+        
+        try {
+
+            while (running) {
+
+                Repository repo = repository;
+                if (repo == null && running) {
+
+                    if (startRepository()) {
+                        pollTime = pollTimeActive;
+                    }
+
+                } else if (!pingRepository(repo)) {
+
+                    log(LogService.LOG_INFO,
+                        "run: Repository not accessible any more, unregistering service");
+                    stopRepository();
+                    pollTime = pollTimeInActive;
+                    
+                } else {
+
+                    log(LogService.LOG_DEBUG,
+                        "run: Repository available, checking again in "
+                            + pollTime + "ms");
+                }
+
+
+                // only wait if still running
+                synchronized (waitLock) {
+                    if (running) {
+                        try {
+                            waitLock.wait(pollTime);
+                        } catch (InterruptedException ie) {
+                            // don't care, go ahead
+                        }
+                    }
+                }
+            }
+
+        } finally {
+            // whatever goes on, make sure the repository is disposed off
+            // at the end of the thread....
+            stopRepository();
+        }
+    }
+
 }

Modified: incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/SessionPool.java
URL: http://svn.apache.org/viewvc/incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/SessionPool.java?rev=633823&r1=633822&r2=633823&view=diff
==============================================================================
--- incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/SessionPool.java (original)
+++ incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/SessionPool.java Wed Mar  5 03:35:06 2008
@@ -117,7 +117,7 @@
      * sessions from this pool to drop below the configured number of maximum
      * active sessions.
      *
-     * @see #PARAM_MAX_ACTIVE_SESSIONS_WAIT
+     * @see #PROPERTY_MAX_ACTIVE_SESSIONS_WAIT
      * @see #DEFAULT_MAX_ACTIVE_SESSIONS_WAIT
      * @see #getMaxActiveSessionsWait()
      * @see #setMaxActiveSessionsWait(long)

Modified: incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/loader/Loader.java
URL: http://svn.apache.org/viewvc/incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/loader/Loader.java?rev=633823&r1=633822&r2=633823&view=diff
==============================================================================
--- incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/loader/Loader.java (original)
+++ incubator/sling/trunk/jcr/base/src/main/java/org/apache/sling/jcr/base/internal/loader/Loader.java Wed Mar  5 03:35:06 2008
@@ -61,9 +61,19 @@
     /** Namespace prefix table. */
     private final Map<Long, NamespaceEntry[]> namespaceTable = new HashMap<Long, NamespaceEntry[]>();
 
-    public Loader(AbstractSlingRepository repository) {
+    public Loader(AbstractSlingRepository repository, Bundle[] existingBundles) {
         this.slingRepository = repository;
         this.delayedBundles = new LinkedList<Bundle>();
+
+        // scan existing bundles
+        for (Bundle bundle : existingBundles) {
+            if ((bundle.getState() & (Bundle.INSTALLED | Bundle.UNINSTALLED)) == 0) {
+                // load content for bundles which are neither INSTALLED nor
+                // UNINSTALLED
+                registerBundle(bundle);
+            }
+        }
+
     }
 
     public void dispose() {