Finished wiring up oid list tracking; made shutdown() work on the cher

server; added an easy mechanism to write test modules and invoke them on
the server.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@192 542714f4-19e9-0310-aa3c-eee0fc999fb1

docs/presents/notes.txt

@@ -3,8 +3,6 @@ Cher Notes -*- outline -*-
 * TODO
 Pass cause back to client somehow via FailureResponse in Client.requestFailed
 
-Finish wiring up oid list tracking.
-
 Ensure at time of OBJECT_ADDED that the object being added exists and has
 not been destroyed.
 
@@ -12,10 +10,6 @@ clientWillLogff becomes clientMayLogoff?
 
 Look into nbio waking up all sockets when any data comes in.
 
-Wire up Client.sessionDidTerminate; do session termination in general.
-
-Clear out subscriptions when we lose connection from the client.
-
 * Server-side event concentrator
 The client objects will not subscribe directly, but will subscribe through
 the concentrator so that, at least, it can create a single

src/java/com/threerings/presents/dobj/DObject.java

@@ -1,5 +1,5 @@
 //
-// $Id: DObject.java,v 1.20 2001/08/07 20:38:58 mdb Exp $
+// $Id: DObject.java,v 1.21 2001/08/08 00:28:49 mdb Exp $
 
 package com.threerings.cocktail.cher.dobj;
 
@@ -165,7 +165,7 @@ public class DObject
         // scan the lock array to see if this lock is already acquired
         int slot = -1;
         for (int i = 0; i < _locks.length; i++) {
-            if (_locks[i] == null) {
+            if (_locks[i] == null && slot == -1) {
                 // keep track of this for later
                 slot = i;
             } else if (name.equals(_locks[i])) {
@@ -343,6 +343,17 @@ public class DObject
         }
     }
 
+    /**
+     * Returns true if this object is active and registered with the
+     * distributed object system. If an object is created via
+     * <code>DObjectManager.createObject</code> it will be active until
+     * such time as it is destroyed.
+     */
+    public boolean isActive ()
+    {
+        return _mgr != null;
+    }
+
     /**
      * Don't call this function! It initializes this distributed object
      * with the supplied distributed object manager. This is called by the

src/java/com/threerings/presents/server/PresentsDObjectMgr.java

@@ -1,9 +1,9 @@
 //
-// $Id: PresentsDObjectMgr.java,v 1.11 2001/08/07 21:25:13 mdb Exp $
+// $Id: PresentsDObjectMgr.java,v 1.12 2001/08/08 00:28:49 mdb Exp $
 
 package com.threerings.cocktail.cher.server;
 
-import java.lang.reflect.Method;
+import java.lang.reflect.*;
 import java.util.HashMap;
 
 import com.samskivert.util.Queue;
@@ -172,9 +172,191 @@ public class CherDObjectMgr implements DObjectManager
      */
     public void objectDestroyed (DEvent event, DObject target)
     {
+        int oid = target.getOid();
+
 //          Log.info("Removing destroyed object from table " +
-        // "[oid=" + target.getOid() + "].");
-        _objects.remove(target.getOid());
+//                   "[oid=" + oid + "].");
+
+        // remove the object from the table
+        _objects.remove(oid);
+
+        // inactivate the object
+        target.setManager(null);
+
+        // deal with any remaining oid lists that reference this object
+        Reference[] refs = (Reference[])_refs.remove(oid);
+        if (refs != null) {
+            for (int i = 0; i < refs.length; i++) {
+                // skip empty spots
+                if (refs[i] == null) {
+                    continue;
+                }
+
+                Reference ref = refs[i];
+                DObject reffer = (DObject)_objects.get(ref.reffingOid);
+
+                // ensure that the referencing object is still around
+                if (reffer != null) {
+                    // post an object removed event to clear the reference
+                    postEvent(new ObjectRemovedEvent(
+                        ref.reffingOid, ref.field, oid));
+//                      Log.info("Forcing removal " + ref + ".");
+
+                } else {
+                    Log.info("Dangling reference from inactive object " +
+                             ref + ".");
+                }
+            }
+        }
+
+        // if this object has any oid list fields that are still
+        // referencing other objects, we need to clear out those
+        // references
+        Class oclass = target.getClass();
+        Field[] fields = oclass.getFields();
+        for (int f = 0; f < fields.length; f++) {
+            Field field = fields[f];
+
+            // ignore static and non-public fields
+            int mods = field.getModifiers();
+            if ((mods & Modifier.STATIC) != 0 ||
+                (mods & Modifier.PUBLIC) == 0) {
+                continue;
+            }
+
+            // ignore non-oidlist fields
+            if (!OidList.class.isAssignableFrom(field.getType())) {
+                continue;
+            }
+
+            try {
+                OidList list = (OidList)field.get(target);
+                for (int i = 0; i < list.size(); i++) {
+                    clearReference(target, field.getName(), list.get(i));
+                }
+
+            } catch (Exception e) {
+                Log.warning("Unable to clean up after oid list field " +
+                            "[target=" + target + ", field=" + field + "].");
+            }
+        }
+    }
+
+    /**
+     * Called by <code>objectDestroyed</code>; clears out the tracking
+     * info for a reference by the supplied object to the specified oid
+     * via the specified field.
+     */
+    protected void clearReference (
+        DObject reffer, String field, int reffedOid)
+    {
+        // look up the reference vector for the referenced object
+        Reference[] refs = (Reference[])_refs.get(reffedOid);
+        Reference ref = null;
+
+        if (refs != null) {
+            for (int i = 0; i < refs.length; i++) {
+                if (refs[i].equals(reffer.getOid(), field)) {
+                    ref = refs[i];
+                    refs[i] = null;
+                    break;
+                }
+            }
+        }
+
+        if (ref == null) {
+            Log.warning("Requested to clear out non-existent reference " +
+                        "[refferOid=" + reffer.getOid() +
+                        ", field=" + field +
+                        ", reffedOid=" + reffedOid + "].");
+
+//          } else {
+//              Log.info("Cleared out reference " + ref + ".");
+        }
+    }
+
+    /**
+     * Called as a helper for <code>ObjectAddedEvent</code> events. It
+     * updates the object/oid list tracking structures.
+     */
+    public void objectAdded (DEvent event, DObject target)
+    {
+        ObjectAddedEvent oae = (ObjectAddedEvent)event;
+        int oid = oae.getOid();
+        Reference ref = new Reference(target.getOid(), oae.getName(), oid);
+
+        // get the reference vector for the referenced object. we use bare
+        // arrays rather than something like an array list to conserve
+        // memory. there will be many objects and references
+        Reference[] refs = (Reference[])_refs.get(oid);
+        if (refs == null) {
+            refs = new Reference[DEFREFVEC_SIZE];
+            _refs.put(oid, refs);
+        }
+
+        // determine where to add the reference
+        int rpos = -1;
+        for (int i = 0; i < refs.length; i++) {
+            if (ref.equals(refs[i])) {
+                Log.warning("Ignoring request to track existing " +
+                            "reference " + ref + ".");
+                return;
+            } else if (refs[i] == null && rpos == -1) {
+                rpos = i;
+            }
+        }
+
+        // expand the refvec if necessary
+        if (rpos == -1) {
+            Reference[] nrefs = new Reference[refs.length*2];
+            System.arraycopy(refs, 0, nrefs, 0, refs.length);
+            rpos = refs.length;
+            _refs.put(oid, refs = nrefs);
+        }
+
+        // finally add the reference
+        refs[rpos] = ref;
+
+//          Log.info("Tracked reference " + ref + ".");
+    }
+
+    /**
+     * Called as a helper for <code>ObjectRemovedEvent</code> events. It
+     * updates the object/oid list tracking structures.
+     */
+    public void objectRemoved (DEvent event, DObject target)
+    {
+        ObjectRemovedEvent ore = (ObjectRemovedEvent)event;
+        String field = ore.getName();
+        int toid = target.getOid();
+        int oid = ore.getOid();
+
+        // get the reference vector for the referenced object
+        Reference[] refs = (Reference[])_refs.get(oid);
+        if (refs == null) {
+            // this can happen normally when an object is destroyed. it
+            // will remove itself from the reference system and then
+            // generate object removed events for all of its referencees.
+            // so we opt not to log anything in this case
+
+//              Log.warning("Object removed without reference to track it " +
+//                          "[toid=" + toid + ", field=" + field +
+//                          ", oid=" + oid + "].");
+            return;
+        }
+
+        // look for the matching reference
+        for (int i = 0; i < refs.length; i++) {
+            if (refs[i].equals(toid, field)) {
+//                  Log.info("Removed reference " + refs[i] + ".");
+                refs[i] = null;
+                return;
+            }
+        }
+
+        Log.warning("Unable to locate reference for removal " +
+                    "[reffingOid=" + toid + ", field=" + field +
+                    ", reffedOid=" + oid + "].");
     }
 
     protected synchronized boolean isRunning ()
@@ -351,17 +533,74 @@ public class CherDObjectMgr implements DObjectManager
             method = omgrcl.getMethod("objectDestroyed", ptypes);
             _helpers.put(ObjectDestroyedEvent.class, method);
 
+            method = omgrcl.getMethod("objectAdded", ptypes);
+            _helpers.put(ObjectAddedEvent.class, method);
+
+            method = omgrcl.getMethod("objectRemoved", ptypes);
+            _helpers.put(ObjectRemovedEvent.class, method);
+
         } catch (Exception e) {
             Log.warning("Unable to register event helpers " +
                         "[error=" + e + "].");
         }
     }
 
+    /**
+     * Used to track references of objects in oid lists.
+     */
+    protected static class Reference
+    {
+        public int reffingOid;
+        public String field;
+        public int reffedOid;
+
+        public Reference (int reffingOid, String field, int reffedOid)
+        {
+            this.reffingOid = reffingOid;
+            this.field = field;
+            this.reffedOid = reffedOid;
+        }
+
+        public boolean equals (Reference other)
+        {
+            if (other == null) {
+                return false;
+            } else {
+                return (reffingOid == other.reffingOid &&
+                        field.equals(other.field));
+            }
+        }
+
+        public boolean equals (int reffingOid, String field)
+        {
+            return (this.reffingOid == reffingOid && this.field.equals(field));
+        }
+
+        public String toString ()
+        {
+            return "[reffingOid=" + reffingOid + ", field=" + field +
+                ", reffedOid=" + reffedOid + "]";
+        }
+    }
+
+    /** A flag indicating that the event dispatcher is still running. */
     protected boolean _running = true;
+
+    /** The event queue via which all events are processed. */
     protected Queue _evqueue = new Queue();
+
+    /** The managed distributed objects table. */
     protected IntMap _objects = new IntMap();
+
+    /** Used to assign a unique oid to each distributed object. */
     protected int _nextOid = 0;
 
+    /** Used to track oid list references of distributed objects. */
+    protected IntMap _refs = new IntMap();
+
+    /** The default size of an oid list refs vector. */
+    protected static final int DEFREFVEC_SIZE = 4;
+
     /**
      * This table maps event classes to helper methods that perform some
      * additional processing for particular events.

src/java/com/threerings/presents/server/PresentsServer.java

@@ -1,5 +1,5 @@
 //
-// $Id: PresentsServer.java,v 1.9 2001/07/19 21:29:01 mdb Exp $
+// $Id: PresentsServer.java,v 1.10 2001/08/08 00:28:49 mdb Exp $
 
 package com.threerings.cocktail.cher.server;
 
@@ -132,15 +132,49 @@ public class CherServer
         // start up the connection manager
         conmgr.start();
         // invoke the dobjmgr event loop
-        ((CherDObjectMgr)omgr).run();
+        omgr.run();
+    }
+
+    /**
+     * Requests that the server shut down.
+     */
+    public static void shutdown ()
+    {
+        // shut down our managers
+        authmgr.shutdown();
+        conmgr.shutdown();
+        omgr.shutdown();
     }
 
     public static void main (String[] args)
     {
+        Log.info("Cher server starting...");
+
         CherServer server = new CherServer();
         try {
+            // initialize the server
             server.init();
+
+            // check to see if we should load and invoke a test module
+            // before running the server
+            String testmod = System.getProperty("test_module");
+            if (testmod != null) {
+                try {
+                    Log.info("Invoking test module [mod=" + testmod + "].");
+                    Class tmclass = Class.forName(testmod);
+                    Runnable trun = (Runnable)tmclass.newInstance();
+                    trun.run();
+                } catch (Exception e) {
+                    Log.warning("Unable to invoke test module " +
+                                "[mod=" + testmod + "].");
+                    Log.logStackTrace(e);
+                }
+            }
+
+            // start the server to running (this method call won't return
+            // until the server is shut down)
             server.run();
+
         } catch (Exception e) {
             Log.warning("Unable to initialize server.");
             Log.logStackTrace(e);

src/java/com/threerings/presents/server/net/AuthManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: AuthManager.java,v 1.3 2001/06/01 22:12:03 mdb Exp $
+// $Id: AuthManager.java,v 1.4 2001/08/08 00:28:49 mdb Exp $
 
 package com.threerings.cocktail.cher.server.net;
 
@@ -55,8 +55,16 @@ public class AuthManager extends LoopingThread
     protected void iterate ()
     {
         // grab the next authing connection from the queue
-        AuthingConnection aconn = (AuthingConnection)_authq.get();
+        Object item = _authq.get();
 
+        // if we're being kicked and requested to exit, we'll just post
+        // some bogus item on the queue to wake up the auth manager and
+        // get him the hell out of dodge
+        if (!(item instanceof AuthingConnection)) {
+            return;
+        }
+
+        AuthingConnection aconn = (AuthingConnection)item;
         try {
             // instruct the authenticator to process the auth request
             AuthResponse rsp = _author.process(aconn.getAuthRequest());
@@ -74,6 +82,12 @@ public class AuthManager extends LoopingThread
         }
     }
 
+    protected void kick ()
+    {
+        // we post something bogus to the queue to wake up the authmgr
+        _authq.append(new Integer(0));
+    }
+
     protected Authenticator _author;
     protected ConnectionManager _conmgr;
     protected Queue _authq = new Queue();

tests/src/java/com/threerings/presents/server/RefTest.java

@@ -0,0 +1,73 @@
+//
+// $Id: RefTest.java,v 1.1 2001/08/08 00:28:49 mdb Exp $
+
+package com.threerings.cocktail.cher.server.test;
+
+import com.threerings.cocktail.cher.Log;
+import com.threerings.cocktail.cher.dobj.*;
+import com.threerings.cocktail.cher.server.CherServer;
+
+/**
+ * Tests the oid list reference tracking code.
+ */
+public class RefTest
+    implements Runnable, Subscriber
+{
+    public void run ()
+    {
+        // create two test objects
+        CherServer.omgr.createObject(TestObject.class, this, true);
+        CherServer.omgr.createObject(TestObject.class, this, true);
+    }
+
+    public void objectAvailable (DObject object)
+    {
+        // keep references to our test objects
+        if (_objone == null) {
+            _objone = (TestObject)object;
+
+        } else {
+            _objtwo = (TestObject)object;
+
+            // now that we have both objects, set up the references
+            _objone.addToList(_objtwo.getOid());
+            _objtwo.addToList(_objone.getOid());
+        }
+    }
+
+    public void requestFailed (int oid, ObjectAccessException cause)
+    {
+        Log.warning("Ack. Unable to create object [cause=" + cause + "].");
+    }
+
+    public boolean handleEvent (DEvent event, DObject target)
+    {
+        // Log.info("Got event: " + event);
+
+        // once we receive the second object added we can destroy the
+        // target object to see if the reference is cleaned up
+        if (event instanceof ObjectAddedEvent && target == _objtwo) {
+            Log.info("Destroying object two " + _objtwo + ".");
+            _objtwo.destroy();
+
+        } else if (event instanceof ObjectDestroyedEvent) {
+            if (target == _objtwo) {
+                Log.info("List won't yet be empty: " + _objone.list);
+            } else {
+                Log.info("Other object destroyed.");
+                // go bye bye
+                CherServer.shutdown();
+            }
+
+        } else if (event instanceof ObjectRemovedEvent) {
+            Log.info("List should be empty: " + _objone.list);
+            // finally destroy the other object to complete the circle
+            _objone.destroy();
+        }
+
+        return true;
+    }
+
+    protected TestObject _objone;
+    protected TestObject _objtwo;
+}

tests/src/java/com/threerings/presents/server/TestObject.dobj

@@ -1,5 +1,5 @@
 //
-// $Id: TestObject.dobj,v 1.2 2001/07/19 05:56:20 mdb Exp $
+// $Id: TestObject.dobj,v 1.3 2001/08/08 00:28:49 mdb Exp $
 
 package com.threerings.cocktail.cher.server.test;
 
@@ -12,12 +12,12 @@ import com.threerings.cocktail.cher.dobj.*;
 public class TestObject extends DObject
 {
     public static final String FOO = "foo";
+    public static final String BAR = "bar";
+    public static final String LIST = "list";
 
     public int foo;
-
-    public static final String BAR = "bar";
-
     public String bar;
+    public OidList list = new OidList();
 
     public void setFoo (int foo)
     {
@@ -29,8 +29,29 @@ public class TestObject extends DObject
         requestAttributeChange(BAR, bar);
     }
 
-    public String toString ()
+    /**
+     * Requests that the specified oid be added to the
+     * <code>list</code> oid list.
+     */
+    public void addToList (int oid)
     {
-        return "[foo=" + foo + ", bar=" + bar + "]";
+        requestOidAdd(LIST, oid);
+    }
+
+    /**
+     * Requests that the specified oid be removed from the
+     * <code>list</code> oid list.
+     */
+    public void removeFromList (int oid)
+    {
+        requestOidRemove(LIST, oid);
+    }
+
+    protected void toString (StringBuffer buf)
+    {
+        super.toString(buf);
+        buf.append(", foo=").append(foo);
+        buf.append(", bar=").append(bar);
+        buf.append(", list=").append(list);
     }
 }