* Shutdown:

- Kill the global app context
    - Recognize multi-router case
    - Fix RandomIterator, YKGenerator, DHBuilder, NTCPConnection
      hanging on to old context -
      probably other offenders not yet found
    - Fix DHBuilder thread not stopping

router/java/src/net/i2p/data/i2np/I2NPMessageHandler.java

@@ -22,8 +22,8 @@ import net.i2p.util.Log;
  *
  */
 public class I2NPMessageHandler {
-    private Log _log;
-    private I2PAppContext _context;
+    private final Log _log;
+    private final I2PAppContext _context;
     private long _lastReadBegin;
     private long _lastReadEnd;
     private int _lastSize;

router/java/src/net/i2p/data/i2np/I2NPMessageImpl.java

@@ -28,8 +28,8 @@ import net.i2p.util.SimpleByteCache;
  * @author jrandom
  */
 public abstract class I2NPMessageImpl extends DataStructureImpl implements I2NPMessage {
-    private Log _log;
-    protected I2PAppContext _context;
+    private final Log _log;
+    protected final I2PAppContext _context;
     private long _expiration;
     private long _uniqueId;
     

router/java/src/net/i2p/router/Router.java

@@ -980,19 +980,23 @@ public class Router {
         try { _context.inNetMessagePool().shutdown(); } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting down the inbound net pool", t); }
         //try { _sessionKeyPersistenceHelper.shutdown(); } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting down the session key manager", t); }
         _context.deleteTempDir();
-        RouterContext.listContexts().remove(_context);
+        List<RouterContext> contexts = RouterContext.getContexts();
+        contexts.remove(_context);
 
         // shut down I2PAppContext tasks here
 
-        // TODO if there are multiple routers in the JVM, we don't want to do this
+        // If there are multiple routers in the JVM, we don't want to do this
         // to the DH or YK tasks, as they are singletons.
-        // Have MultiRouter set a property or something.
-        try {
-            DHSessionKeyBuilder.shutdown();
-        } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting DH", t); }
-        try {
-            _context.elGamalEngine().shutdown();
-        } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting elGamal", t); }
+        if (contexts.isEmpty()) {
+            try {
+                DHSessionKeyBuilder.shutdown();
+            } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting DH", t); }
+            try {
+                _context.elGamalEngine().shutdown();
+            } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting elGamal", t); }
+        } else {
+            _log.logAlways(Log.WARN, "Warning - " + contexts.size() + " routers remaining in this JVM, not releasing all resources");
+        }
         try {
             ((FortunaRandomSource)_context.random()).shutdown();
         } catch (Throwable t) { _log.log(Log.CRIT, "Error shutting random()", t); }
@@ -1020,6 +1024,8 @@ public class Router {
 
         File f = getPingFile();
         f.delete();
+        if (RouterContext.getContexts().isEmpty())
+            RouterContext.killGlobalContext();
         if (_killVMOnEnd) {
             try { Thread.sleep(1000); } catch (InterruptedException ie) {}
             Runtime.getRuntime().halt(exitCode);

router/java/src/net/i2p/router/RouterContext.java

@@ -1,6 +1,7 @@
 package net.i2p.router;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Properties;
 
@@ -67,6 +68,8 @@ public class RouterContext extends I2PAppContext {
         // to init everything. Caller MUST call initAll() afterwards.
         // Sorry, this breaks some main() unit tests out there.
         //initAll();
+        if (!_contexts.isEmpty())
+            System.out.println("Warning - More than one router in this JVM");
         _contexts.add(this);
     }
 
@@ -165,11 +168,37 @@ public class RouterContext extends I2PAppContext {
     /**
      * Retrieve the list of router contexts currently instantiated in this JVM.  
      * This will always contain only one item (except when a simulation per the
-     * MultiRouter is going on), and the list should only be modified when a new
+     * MultiRouter is going on).
+     *
+     * @return an unmodifiable list (as of 0.8.8). May be null or empty.
+     */
+    public static List<RouterContext> listContexts() {
+        return Collections.unmodifiableList(_contexts);
+    }
+    
+    /**
+     * Same as listContexts() but package private and modifiable.
+     * The list should only be modified when a new
      * context is created or a router is shut down.
      *
+     * @since 0.8.8
      */
-    public static List<RouterContext> listContexts() { return _contexts; }
+    static List<RouterContext> getContexts() {
+        return _contexts;
+    }
+    
+    /**
+     * Kill the global I2PAppContext, so it isn't still around
+     * when we restart in the same JVM (Android).
+     * Only do this if there are no other routers in the JVM.
+     *
+     * @since 0.8.8
+     */
+    static void killGlobalContext() {
+        synchronized (I2PAppContext.class) {
+            _globalAppContext = null;
+        }
+    }
     
     /** what router is this context working for? */
     public Router router() { return _router; }

router/java/src/net/i2p/router/transport/ntcp/NTCPConnection.java

@@ -1089,6 +1089,10 @@ class NTCPConnection implements FIFOBandwidthLimiter.CompleteListener {
     }
     
     private static final int MAX_HANDLERS = 4;
+
+    /**
+     *  FIXME static queue mixes handlers from different contexts in multirouter JVM
+     */
     private final static LinkedBlockingQueue<I2NPMessageHandler> _i2npHandlers = new LinkedBlockingQueue(MAX_HANDLERS);
 
     private final static I2NPMessageHandler acquireHandler(RouterContext ctx) {
@@ -1129,6 +1133,15 @@ class NTCPConnection implements FIFOBandwidthLimiter.CompleteListener {
         _dataReadBufs.offer(buf);
     }
 
+    /** @since 0.8.8 */
+    static void releaseResources() {
+        _i2npHandlers.clear();
+        _dataReadBufs.clear();
+        synchronized(_bufs) {
+            _bufs.clear();
+        }
+    }
+
     /**
      * sizeof(data)+data+pad+crc.
      *

router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java

@@ -702,6 +702,7 @@ public class NTCPTransport extends TransportImpl {
             NTCPConnection con = (NTCPConnection)iter.next();
             con.close();
         }
+        NTCPConnection.releaseResources();
         // will this work?
         replaceAddress(null);
     }

router/java/src/net/i2p/router/util/RandomIterator.java

@@ -84,7 +84,7 @@ public class RandomIterator<E> implements Iterator<E> {
     * <a href="http://www.qbrundage.com/michaelb/pubs/essays/random_number_generation" title="http://www.qbrundage.com/michaelb/pubs/essays/random_number_generation" target="_blank">http://www.qbrundage.com/michaelb/pubs/e&#8230;</a>
     * for some implementations, which are faster than java.util.Random.
     */
-    private static final Random rand = RandomSource.getInstance();
+    private final Random rand = RandomSource.getInstance();
 
     /** Used to narrow the range to take random indexes from */
     private int lower, upper;