From d76d4e89ff3e3dc94444c06dae7ec800c60e8a02 Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@threerings.net>
Date: Thu, 22 May 2003 17:23:53 +0000
Subject: [PATCH] Make it possible to have a distributed object destroyed when
 its last subscriber is removed.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@2602 542714f4-19e9-0310-aa3c-eee0fc999fb1
---
 .../presents/client/ClientDObjectMgr.java       |  4 ++--
 .../com/threerings/presents/dobj/DObject.java   | 17 +++++++++++++++--
 .../presents/dobj/DObjectManager.java           |  4 ++--
 .../presents/server/PresentsDObjectMgr.java     |  9 ++++++---
 4 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/src/java/com/threerings/presents/client/ClientDObjectMgr.java b/src/java/com/threerings/presents/client/ClientDObjectMgr.java
index ea10b5b8c..e94040e00 100644
--- a/src/java/com/threerings/presents/client/ClientDObjectMgr.java
+++ b/src/java/com/threerings/presents/client/ClientDObjectMgr.java
@@ -1,5 +1,5 @@
 //
-// $Id: ClientDObjectMgr.java,v 1.23 2003/04/10 17:48:42 mdb Exp $
+// $Id: ClientDObjectMgr.java,v 1.24 2003/05/22 17:23:53 mdb Exp $
 
 package com.threerings.presents.client;
 
@@ -106,7 +106,7 @@ public class ClientDObjectMgr
     }
 
     // inherit documentation from the interface
-    public void removedLastSubscriber (DObject obj)
+    public void removedLastSubscriber (DObject obj, boolean deathWish)
     {
         // if this object has a registered flush delay, don't can it just
         // yet, just slip it onto the flush queue
diff --git a/src/java/com/threerings/presents/dobj/DObject.java b/src/java/com/threerings/presents/dobj/DObject.java
index 55823435e..58df1fc53 100644
--- a/src/java/com/threerings/presents/dobj/DObject.java
+++ b/src/java/com/threerings/presents/dobj/DObject.java
@@ -1,5 +1,5 @@
 //
-// $Id: DObject.java,v 1.63 2003/04/30 22:32:04 mdb Exp $
+// $Id: DObject.java,v 1.64 2003/05/22 17:23:53 mdb Exp $
 
 package com.threerings.presents.dobj;
 
@@ -151,11 +151,20 @@ public class DObject implements Streamable
             // that we're still active otherwise there's no need to notify
             // our objmgr because we don't have one
             if (--_scount == 0 && _omgr != null) {
-                _omgr.removedLastSubscriber(this);
+                _omgr.removedLastSubscriber(this, _deathWish);
             }
         }
     }
 
+    /**
+     * Instructs this object to request to have a fork stuck in it when
+     * its last subscriber is removed.
+     */
+    public void setDestroyOnLastSubscriberRemoved (boolean deathWish)
+    {
+        _deathWish = deathWish;
+    }
+
     /**
      * Adds an event listener to this object. The listener will be
      * notified when any events are dispatched on this object that match
@@ -872,4 +881,8 @@ public class DObject implements Streamable
 
     /** Whether or not our nested transaction has been cancelled. */
     protected transient boolean _tcancelled;
+
+    /** Indicates whether we want to be destroyed when our last subscriber
+     * is removed. */
+    protected transient boolean _deathWish = false;
 }
diff --git a/src/java/com/threerings/presents/dobj/DObjectManager.java b/src/java/com/threerings/presents/dobj/DObjectManager.java
index 87136b1d3..de36b9edd 100644
--- a/src/java/com/threerings/presents/dobj/DObjectManager.java
+++ b/src/java/com/threerings/presents/dobj/DObjectManager.java
@@ -1,5 +1,5 @@
 //
-// $Id: DObjectManager.java,v 1.11 2003/03/10 18:29:54 mdb Exp $
+// $Id: DObjectManager.java,v 1.12 2003/05/22 17:23:53 mdb Exp $
 
 package com.threerings.presents.dobj;
 
@@ -95,5 +95,5 @@ public interface DObjectManager
      * then choose to flush this object from the system or unregister from
      * some upstream manager whose object it was proxying, for example.
      */
-    public void removedLastSubscriber (DObject obj);
+    public void removedLastSubscriber (DObject obj, boolean deathWish);
 }
diff --git a/src/java/com/threerings/presents/server/PresentsDObjectMgr.java b/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
index cd98b2946..42b879bcc 100644
--- a/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
+++ b/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
@@ -1,5 +1,5 @@
 //
-// $Id: PresentsDObjectMgr.java,v 1.31 2003/04/10 17:48:42 mdb Exp $
+// $Id: PresentsDObjectMgr.java,v 1.32 2003/05/22 17:23:53 mdb Exp $
 
 package com.threerings.presents.server;
 
@@ -105,9 +105,12 @@ public class PresentsDObjectMgr
     }
 
     // inherit documentation from the interface
-    public void removedLastSubscriber (DObject obj)
+    public void removedLastSubscriber (DObject obj, boolean deathWish)
     {
-        // nothing to do here, our objects live forever!
+        // destroy the object if it so desires
+        if (deathWish) {
+            destroyObject(obj.getOid());
+        }
     }
 
     /**