Revert "GC unused SessionHandler"

6 files changed, 674 insertions, 13 deletions

diff --git a/jrt/src/com/yahoo/jrt/Connection.java b/jrt/src/com/yahoo/jrt/Connection.java
index 00aceb7e352..c4f906f5e35 100644
--- a/jrt/src/com/yahoo/jrt/Connection.java
+++ b/jrt/src/com/yahoo/jrt/Connection.java
@@ -40,6 +40,7 @@ class Connection extends Target {
     private final boolean tcpNoDelay;
     private final Map<Integer, ReplyHandler> replyMap = new HashMap<>();
     private final Map<TargetWatcher, TargetWatcher> watchers = new IdentityHashMap<>();
+    private int activeReqs = 0;
     private int writeWork  = 0;
     private boolean pendingHandshakeWork = false;
     private final TransportThread parent;
@@ -59,9 +60,11 @@ class Connection extends Target {
         }
         boolean live = (state == CONNECTED);
         boolean down = (state == CLOSED);
+        boolean fini;
         boolean pendingWrite;
         synchronized (this) {
             this.state = state;
+            fini = down && (activeReqs == 0);
             pendingWrite = (writeWork > 0);
         }
         if (live) {
@@ -71,6 +74,7 @@ class Connection extends Target {
             } else {
                 disableWrite();
             }
+            owner.sessionLive(this);
         }
         if (down) {
             for (ReplyHandler rh : replyMap.values()) {
@@ -79,6 +83,10 @@ class Connection extends Target {
             for (TargetWatcher watcher : watchers.values()) {
                 watcher.notifyTargetInvalid(this);
             }
+            owner.sessionDown(this);
+        }
+        if (fini) {
+            owner.sessionFini(this);
         }
     }
 
@@ -94,6 +102,7 @@ class Connection extends Target {
         maxOutputSize = owner.getMaxOutputBufferSize();
         dropEmptyBuffers = owner.getDropEmptyBuffers();
         server = true;
+        owner.sessionInit(this);
     }
 
     public Connection(TransportThread parent, Supervisor owner, Spec spec, Object context, boolean tcpNoDelay) {
@@ -106,6 +115,7 @@ class Connection extends Target {
         maxOutputSize = owner.getMaxOutputBufferSize();
         dropEmptyBuffers = owner.getDropEmptyBuffers();
         server = false;
+        owner.sessionInit(this);
     }
 
     public TransportThread transportThread() {
@@ -115,7 +125,8 @@ class Connection extends Target {
     public int allocateKey() {
         long v = requestId.getAndIncrement();
         v = v*2 + (server ? 1 : 0);
-        return (int)(v & 0x7fffffff);
+        int i = (int)(v & 0x7fffffff);
+        return i;
     }
 
     public synchronized boolean cancelReply(ReplyHandler handler) {
@@ -267,7 +278,7 @@ class Connection extends Target {
             try {
                 packet = info.decodePacket(rb);
             } catch (RuntimeException e) {
-                log.log(Level.WARNING, "got garbage; closing connection: " + this);
+                log.log(Level.WARNING, "got garbage; closing connection: " + toString());
                 throw new IOException("jrt: decode error", e);
             }
             ReplyHandler handler;
@@ -385,10 +396,6 @@ class Connection extends Target {
         return (state == CLOSED);
     }
 
-    public synchronized boolean isConnected() {
-        return (state == CONNECTED);
-    }
-
     public boolean hasSocket() {
         return ((socket != null) && (socket.channel() != null));
     }
@@ -410,16 +417,25 @@ class Connection extends Target {
     }
 
     public TieBreaker startRequest() {
+        synchronized (this) {
+            activeReqs++;
+        }
         return new TieBreaker();
     }
 
     public boolean completeRequest(TieBreaker done) {
+        boolean signalFini = false;
         synchronized (this) {
             if (!done.first()) {
                 return false;
             }
+            if (--activeReqs == 0 && state == CLOSED) {
+                signalFini = true;
+            }
+        }
+        if (signalFini) {
+            owner.sessionFini(this);
         }
-
         return true;
     }
 
diff --git a/jrt/src/com/yahoo/jrt/SessionHandler.java b/jrt/src/com/yahoo/jrt/SessionHandler.java
new file mode 100644
index 00000000000..82355d73a93
--- /dev/null
+++ b/jrt/src/com/yahoo/jrt/SessionHandler.java
@@ -0,0 +1,66 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jrt;
+
+
+/**
+ * Interface used to handle the lifetime of a {@link Target}. The word
+ * session is used to denote all the RPC activity across a single
+ * {@link Target} during its lifetime. This interface gives the
+ * application information about when different {@link Target} objects
+ * enter different stages in their lifetime. Combined with the ability
+ * to bind application specific data to a {@link Target} with the
+ * {@link Target#setContext} method, this enables method invocations
+ * in the same session to share state information. Usage of this
+ * interface is optional. It is typically useful for server
+ * applications needing state to be shared between RPC method
+ * invocation on a session. Each {@link Supervisor} can only have a
+ * single session handler. Use the {@link Supervisor#setSessionHandler
+ * Supervisor.setSessionHandler} method to set the session
+ * handler. The different callbacks may be called from several
+ * different threads, but for a single target there will be no
+ * overlapping of session callbacks, and the order will always be the
+ * same; init, live (not always called), down, fini.
+ **/
+public interface SessionHandler {
+
+    /**
+     * Invoked when a new {@link Target} is created. This is a nice
+     * place to initialize and attach application context to the
+     * {@link Target}.
+     *
+     * @param target the target
+     **/
+    public void handleSessionInit(Target target);
+
+    /**
+     * Invoked when a connection is established with the peer. Note
+     * that if a connection could not be established with the peer,
+     * this method is never invoked.
+     *
+     * @param target the target
+     **/
+    public void handleSessionLive(Target target);
+
+    /**
+     * Invoked when the target becomes invalid. This is typically
+     * caused by the network connection with the peer going down. Note
+     * that this method is invoked also when a connection with the
+     * peer could not be established at all.
+     *
+     * @param target the target
+     **/
+    public void handleSessionDown(Target target);
+
+    /**
+     * Invoked when the target is invalid and no more RPC invocations
+     * are active on our side of this target (invoked from the other
+     * side; we being the server). If you need to perform cleanup
+     * related to the application data associated with the target, you
+     * should wait until this method is invoked, to avoid cleaning up
+     * the {@link Target} application context under the feet of active
+     * invocations.
+     *
+     * @param target the target
+     **/
+    public void handleSessionFini(Target target);
+}
diff --git a/jrt/src/com/yahoo/jrt/Supervisor.java b/jrt/src/com/yahoo/jrt/Supervisor.java
index 48dd2d8bd3d..e8dc6219768 100644
--- a/jrt/src/com/yahoo/jrt/Supervisor.java
+++ b/jrt/src/com/yahoo/jrt/Supervisor.java
@@ -15,7 +15,10 @@ import java.util.concurrent.atomic.AtomicReference;
  **/
 public class Supervisor {
 
+    private static final int SMALL_INPUT_BUFFER_SIZE = 20 * 1024;  // Large enough too hold the typical application buffersize of 17k.
+    private static final int SMALL_OUTPUT_BUFFER_SIZE = 8 *1024;   // Suitable small buffer usage with many connections and little traffic.
     private final Transport         transport;
+    private SessionHandler          sessionHandler = null;
     private final Object            methodMapLock = new Object();
     private final AtomicReference<HashMap<String, Method>> methodMap = new AtomicReference<>(new HashMap<>());
     private int                     maxInputBufferSize  = 64*1024;
@@ -95,6 +98,15 @@ public class Supervisor {
     }
 
     /**
+     * Set the session handler for this Supervisor
+     *
+     * @param handler the session handler
+     **/
+    public void setSessionHandler(SessionHandler handler) {
+        sessionHandler = handler;
+    }
+
+    /**
      * Add a method to the set of methods held by this Supervisor
      *
      * @param method the method to add
@@ -161,6 +173,73 @@ public class Supervisor {
     }
 
     /**
+     * Convenience method for connecting to a peer, invoking a method
+     * and disconnecting.
+     *
+     * @param spec the address to connect to
+     * @param req the invocation request
+     * @param timeout request timeout in seconds
+     **/
+    public void invokeBatch(Spec spec, Request req, double timeout) {
+        Target target = connect(spec);
+        try {
+            target.invokeSync(req, timeout);
+        } finally {
+            target.close();
+        }
+    }
+
+    /**
+     * This method is invoked when a new target is created
+     *
+     * @param target the target
+     **/
+    void sessionInit(Target target) {
+        SessionHandler handler = sessionHandler;
+        if (handler != null) {
+            handler.handleSessionInit(target);
+        }
+    }
+
+    /**
+     * This method is invoked when a target establishes a connection
+     * with its peer
+     *
+     * @param target the target
+     **/
+    void sessionLive(Target target) {
+        SessionHandler handler = sessionHandler;
+        if (handler != null) {
+            handler.handleSessionLive(target);
+        }
+    }
+
+    /**
+     * This method is invoked when a target becomes invalid
+     *
+     * @param target the target
+     **/
+    void sessionDown(Target target) {
+        SessionHandler handler = sessionHandler;
+        if (handler != null) {
+            handler.handleSessionDown(target);
+        }
+    }
+
+    /**
+     * This method is invoked when a target is invalid and no more
+     * invocations are active
+     *
+     * @param target the target
+     **/
+    void sessionFini(Target target) {
+        SessionHandler handler = sessionHandler;
+        if (handler != null) {
+            handler.handleSessionFini(target);
+        }
+    }
+
+    /**
      * This method is invoked each time we write a packet. This method
      * is empty and only used for testing through sub-classing.
      *
diff --git a/jrt/tests/com/yahoo/jrt/ConnectTest.java b/jrt/tests/com/yahoo/jrt/ConnectTest.java
index 6ad7198f310..31bb713595c 100644
--- a/jrt/tests/com/yahoo/jrt/ConnectTest.java
+++ b/jrt/tests/com/yahoo/jrt/ConnectTest.java
@@ -1,7 +1,6 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.jrt;
 
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 public class ConnectTest {
@@ -12,25 +11,32 @@ public class ConnectTest {
         Test.Orb client   = new Test.Orb(new Transport());
         Acceptor acceptor = server.listen(new Spec(0));
 
-        Connection target = (Connection) client.connect(new Spec("localhost", acceptor.port()));
+        assertTrue(server.checkLifeCounts(0, 0));
+        assertTrue(client.checkLifeCounts(0, 0));
+
+        Target target = client.connect(new Spec("localhost", acceptor.port()));
 
         for (int i = 0; i < 100; i++) {
-            if (target.isConnected()) {
+            if (client.initCount == 1 && server.initCount == 1) {
                 break;
             }
             try { Thread.sleep(100); } catch (InterruptedException e) {}
         }
-        assertTrue(target.isConnected());
+
+        assertTrue(server.checkLifeCounts(1, 0));
+        assertTrue(client.checkLifeCounts(1, 0));
 
         target.close();
 
         for (int i = 0; i < 100; i++) {
-            if (!target.isClosed()) {
+            if (client.finiCount == 1 && server.finiCount == 1) {
                 break;
             }
             try { Thread.sleep(100); } catch (InterruptedException e) {}
         }
-        assertFalse(target.isClosed());
+
+        assertTrue(server.checkLifeCounts(1, 1));
+        assertTrue(client.checkLifeCounts(1, 1));
 
         acceptor.shutdown().join();
         client.transport().shutdown().join();
diff --git a/jrt/tests/com/yahoo/jrt/SessionTest.java b/jrt/tests/com/yahoo/jrt/SessionTest.java
new file mode 100644
index 00000000000..61db0438959
--- /dev/null
+++ b/jrt/tests/com/yahoo/jrt/SessionTest.java
@@ -0,0 +1,466 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jrt;
+
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+import static com.yahoo.jrt.CryptoUtils.createTestTlsContext;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(Parameterized.class)
+public class SessionTest implements SessionHandler {
+
+    @Parameter public CryptoEngine crypto;
+    @Parameters(name = "{0}") public static Object[] engines() {
+        return new Object[] { new NullCryptoEngine(), new XorCryptoEngine(), new TlsCryptoEngine(createTestTlsContext()) };
+    }
+
+    private static class Session {
+        private static volatile int cnt = 0;
+        private static boolean error = false;
+
+        private int     value   = 0;
+        private boolean gotInit = false;
+        private boolean gotLive = false;
+        private boolean gotDown = false;
+        private boolean gotFini = false;
+
+        private static synchronized void add() {
+            cnt++;
+        }
+
+        private static synchronized void sub() {
+            cnt--;
+        }
+
+        public Session() {
+            add();
+        }
+
+        public void init() {
+            if (gotInit || gotLive || gotDown || gotFini) {
+                setError();
+            }
+            gotInit = true;
+        }
+
+        public void live() {
+            if (!gotInit || gotLive || gotDown || gotFini) {
+                setError();
+            }
+            gotLive = true;
+        }
+
+        public void touch() {
+            if (!gotInit || gotFini) {
+                setError();
+            }
+        }
+
+        public int value() {
+            if (!gotInit || gotFini) {
+                setError();
+            }
+            return value;
+        }
+
+        public void value(int value) {
+            if (!gotInit || gotFini) {
+                setError();
+            }
+            this.value = value;
+        }
+
+        public void down() {
+            if (!gotInit || gotDown || gotFini) {
+                setError();
+            }
+            gotDown = true;
+        }
+
+        public void fini() {
+            if (!gotInit || !gotDown || gotFini) {
+                setError();
+            }
+            gotFini = true;
+            sub();
+        }
+
+        public static int cnt() {
+            return cnt;
+        }
+
+        public static void setError() {
+            error = true;
+            Throwable e = new RuntimeException("ERROR TRACE");
+            e.printStackTrace();
+        }
+
+        public static boolean getError() {
+            return error;
+        }
+
+        public static void reset() {
+            error = false;
+            cnt = 0;
+        }
+    }
+
+    Test.Orb      server;
+    Acceptor      acceptor;
+    Test.Orb      client;
+    Target        target;
+    Test.Receptor receptor;
+
+    @Before
+    public void setUp() throws ListenFailedException {
+        Session.reset();
+        server   = new Test.Orb(new Transport("server", crypto, 1));
+        server.setSessionHandler(this);
+        client   = new Test.Orb(new Transport("client", crypto, 1));
+        client.setSessionHandler(this);
+        acceptor = server.listen(new Spec(0));
+        target   = client.connect(new Spec("localhost", acceptor.port()), new Session());
+
+        server.addMethod(new Method("set", "i", "", this::rpc_set));
+        server.addMethod(new Method("get", "", "i", this::rpc_get));
+        server.addMethod(new Method("call_detach", "", "", this::rpc_call_detach));
+        client.addMethod(new Method("detach", "", "", this::rpc_detach));
+        receptor = new Test.Receptor();
+    }
+
+    @After
+    public void tearDown() {
+        target.close();
+        acceptor.shutdown().join();
+        client.transport().shutdown().join();
+        server.transport().shutdown().join();
+    }
+
+    public void handleSessionInit(Target t) {
+        Object ctx = t.getContext();
+        if (t.isClient()) {
+            if (ctx == null) {
+                Session.setError();
+            }
+        }
+        if (t.isServer()) {
+            if (ctx != null) {
+                Session.setError();
+            }
+            t.setContext(new Session());
+        }
+        Session s = (Session) t.getContext();
+        if (s == null) {
+            Session.setError();
+        } else {
+            s.init();
+        }
+    }
+
+    public void handleSessionLive(Target t) {
+        Session s = (Session) t.getContext();
+        if (s == null) {
+            Session.setError();
+        } else {
+            s.live();
+        }
+    }
+
+    public void handleSessionDown(Target t) {
+        Session s = (Session) t.getContext();
+        if (s == null) {
+            Session.setError();
+        } else {
+            s.down();
+        }
+    }
+
+    public void handleSessionFini(Target t) {
+        Session s = (Session) t.getContext();
+        if (s == null) {
+            Session.setError();
+        } else {
+            s.fini();
+        }
+    }
+
+    private void rpc_set(Request req) {
+        Session s = (Session) req.target().getContext();
+        s.value(req.parameters().get(0).asInt32());
+    }
+
+    private void rpc_get(Request req) {
+        Session s = (Session) req.target().getContext();
+        req.returnValues().add(new Int32Value(s.value()));
+    }
+
+    private void rpc_call_detach(Request req) {
+        Session s = (Session) req.target().getContext();
+        s.touch();
+        req.target().invokeVoid(new Request("detach"));
+    }
+
+    private void rpc_detach(Request req) {
+        Session s = (Session) req.target().getContext();
+        if (s == null) {
+            Session.setError();
+        } else {
+            s.touch();
+        }
+        req.detach();
+        receptor.put(req);
+    }
+
+    public void waitState(int sessionCount,
+                          int serverInitCount,
+                          int serverLiveCount,
+                          int serverDownCount,
+                          int serverFiniCount,
+                          int clientInitCount,
+                          int clientLiveCount,
+                          int clientDownCount,
+                          int clientFiniCount) {
+        server.transport().sync().sync();
+        client.transport().sync().sync();
+        for (int i = 0; i < 12000; i++) {
+            if ((sessionCount    == Session.cnt()    || sessionCount    < 0) &&
+                (serverInitCount == server.initCount || serverInitCount < 0) &&
+                (serverLiveCount == server.liveCount || serverLiveCount < 0) &&
+                (serverDownCount == server.downCount || serverDownCount < 0) &&
+                (serverFiniCount == server.finiCount || serverFiniCount < 0) &&
+                (clientInitCount == client.initCount || clientInitCount < 0) &&
+                (clientLiveCount == client.liveCount || clientLiveCount < 0) &&
+                (clientDownCount == client.downCount || clientDownCount < 0) &&
+                (clientFiniCount == client.finiCount || clientFiniCount < 0)) {
+                break;
+            }
+            try { Thread.sleep(10); } catch (InterruptedException e) {}
+        }
+        server.transport().sync().sync();
+        client.transport().sync().sync();
+    }
+
+    @org.junit.Test
+    public void testConnDownLast() {
+        waitState(2, 1, 1, 0, 0, 1, 1, 0, 0);
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        Request req = new Request("get");
+        target.invokeSync(req, 5.0);
+        assertEquals(0, req.returnValues().get(0).asInt32());
+
+        req = new Request("set");
+        req.parameters().add(new Int32Value(42));
+        target.invokeSync(req, 5.0);
+        assertTrue(!req.isError());
+
+        req = new Request("get");
+        target.invokeSync(req, 5.0);
+        assertEquals(42, req.returnValues().get(0).asInt32());
+
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        target.close();
+        waitState(0, 1, 1, 1, 1, 1, 1, 1, 1);
+        assertEquals(0, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(1, client.downCount);
+        assertEquals(1, client.finiCount);
+        assertFalse(Session.getError());
+    }
+
+    @org.junit.Test
+    public void testReqDoneLast() {
+        waitState(2, 1, 1, 0, 0, 1, 1, 0, 0);
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        Request req = new Request("get");
+        target.invokeSync(req, 5.0);
+        assertEquals(0, req.returnValues().get(0).asInt32());
+
+        req = new Request("set");
+        req.parameters().add(new Int32Value(42));
+        target.invokeSync(req, 5.0);
+        assertTrue(!req.isError());
+
+        req = new Request("get");
+        target.invokeSync(req, 5.0);
+        assertEquals(42, req.returnValues().get(0).asInt32());
+
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        req = new Request("call_detach");
+        target.invokeSync(req, 5.0);
+        assertTrue(!req.isError());
+        Request detached = (Request) receptor.get();
+
+        target.close();
+        waitState(1, 1, 1, 1, 1, 1, 1, 1, 0);
+        assertEquals(1, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(1, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        detached.returnRequest();
+        waitState(0, 1, 1, 1, 1, 1, 1, 1, 1);
+        assertEquals(0, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(1, client.downCount);
+        assertEquals(1, client.finiCount);
+        assertFalse(Session.getError());
+    }
+
+    @org.junit.Test
+    public void testNeverLive() {
+        waitState(2, 1, 1, 0, 0, 1, 1, 0, 0);
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        target.close();
+        waitState(0, 1, 1, 1, 1, 1, 1, 1, 1);
+        assertEquals(0, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(1, client.downCount);
+        assertEquals(1, client.finiCount);
+
+        Target bogus = client.connect(new Spec("bogus"),
+                                          new Session());
+        waitState(0, 1, 1, 1, 1, 2, 1, 2, 2);
+        assertEquals(0, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(2, client.initCount);
+        assertEquals(1, client.liveCount); // <--- NB
+        assertEquals(2, client.downCount);
+        assertEquals(2, client.finiCount);
+        assertFalse(Session.getError());
+    }
+
+    @org.junit.Test
+    public void testTransportDown() {
+        waitState(2, 1, 1, 0, 0, 1, 1, 0, 0);
+        assertEquals(2, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(0, server.downCount);
+        assertEquals(0, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(0, client.downCount);
+        assertEquals(0, client.finiCount);
+
+        server.transport().shutdown().join();
+
+        waitState(0, 1, 1, 1, 1, 1, 1, 1, 1);
+        assertEquals(0, Session.cnt());
+        assertEquals(1, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(1, server.downCount);
+        assertEquals(1, server.finiCount);
+        assertEquals(1, client.initCount);
+        assertEquals(1, client.liveCount);
+        assertEquals(1, client.downCount);
+        assertEquals(1, client.finiCount);
+
+        target = client.connect(new Spec("localhost", acceptor.port()),
+                                new Session());
+
+        waitState(0, 2, 1, 2, 2, 2, -1, 2, 2);
+        assertEquals(0, Session.cnt());
+        assertEquals(2, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(2, server.downCount);
+        assertEquals(2, server.finiCount);
+        assertEquals(2, client.initCount);
+        int oldClientLive = client.liveCount;
+        assertEquals(2, client.downCount);
+        assertEquals(2, client.finiCount);
+
+        client.transport().shutdown().join();
+
+        target = client.connect(new Spec("localhost", acceptor.port()),
+                                new Session());
+
+        waitState(0, 2, 1, 2, 2, 3, oldClientLive, 3, 3);
+        assertEquals(0, Session.cnt());
+        assertEquals(2, server.initCount);
+        assertEquals(1, server.liveCount);
+        assertEquals(2, server.downCount);
+        assertEquals(2, server.finiCount);
+        assertEquals(3, client.initCount);
+        assertEquals(oldClientLive, client.liveCount);
+        assertEquals(3, client.downCount);
+        assertEquals(3, client.finiCount);
+        assertFalse(Session.getError());
+    }
+
+}
diff --git a/jrt/tests/com/yahoo/jrt/Test.java b/jrt/tests/com/yahoo/jrt/Test.java
index ed2566a7ec2..59edd31ecea 100644
--- a/jrt/tests/com/yahoo/jrt/Test.java
+++ b/jrt/tests/com/yahoo/jrt/Test.java
@@ -13,6 +13,8 @@ public class Test {
      * testing.
      **/
     public static class Orb extends Supervisor {
+        public volatile int  initCount         = 0;
+        public volatile int  liveCount         = 0;
         public volatile int  readRequestCount  = 0;
         public volatile int  readReplyCount    = 0;
         public volatile int  readErrorCount    = 0;
@@ -21,6 +23,8 @@ public class Test {
         public volatile int  writeReplyCount   = 0;
         public volatile int  writeErrorCount   = 0;
         public volatile long writeBytes        = 0;
+        public volatile int  downCount         = 0;
+        public volatile int  finiCount         = 0;
 
         public Orb(Transport t) {
             super(t);
@@ -38,6 +42,30 @@ public class Test {
                     error == writeErrorCount);
         }
 
+        public boolean checkLifeCounts(int init, int fini) {
+            return (init == initCount && fini == finiCount);
+        }
+
+        public void sessionInit(Target target) {
+            initCount++;
+            super.sessionInit(target);
+        }
+
+        public void sessionLive(Target target) {
+            liveCount++;
+            super.sessionLive(target);
+        }
+
+        public void sessionDown(Target target) {
+            downCount++;
+            super.sessionDown(target);
+        }
+
+        public void sessionFini(Target target) {
+            finiCount++;
+            super.sessionFini(target);
+        }
+
         public void readPacket(PacketInfo info) {
             if (info.packetCode() == Packet.PCODE_REQUEST) {
                 readRequestCount++;