From f7c27a1afaf87876573930a82686d7e34388dafa Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@threerings.net>
Date: Thu, 28 Nov 2002 22:51:52 +0000
Subject: [PATCH] Added a mechanism to check that we are running on (or not on)
 the distributed object event dispatch thread.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@2005 542714f4-19e9-0310-aa3c-eee0fc999fb1
---
 .../presents/server/PresentsDObjectMgr.java   | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/java/com/threerings/presents/server/PresentsDObjectMgr.java b/src/java/com/threerings/presents/server/PresentsDObjectMgr.java
index e93e95ffc..568ef7aef 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 1.26 2002/11/05 02:17:56 mdb Exp $
+// $Id: PresentsDObjectMgr.java,v 1.27 2002/11/28 22:51:52 mdb Exp $
 
 package com.threerings.presents.server;
 
@@ -129,6 +129,17 @@ public class PresentsDObjectMgr
         return (DObject)_objects.get(oid);
     }
 
+    /**
+     * Returns true if the thread invoking this method is the same thread
+     * that is doing distributed object event dispatch. Code that wishes
+     * to enforce that it is either always or never called on the event
+     * dispatch thread will want to make use of this method.
+     */
+    public synchronized boolean isEventDispatchThread ()
+    {
+        return Thread.currentThread() == _dobjThread;
+    }
+
     /**
      * Runs the dobjmgr event loop until it is requested to exit. This
      * should be called from the main application thread.
@@ -137,6 +148,11 @@ public class PresentsDObjectMgr
     {
         Log.info("DOMGR running.");
 
+        // make a note of the thread that's processing events
+        synchronized (this) {
+            _dobjThread = Thread.currentThread();
+        }
+
         while (isRunning()) {
             // pop the next unit off the queue
             Object unit = _evqueue.get();
@@ -760,6 +776,11 @@ public class PresentsDObjectMgr
      * objects. */
     protected AccessController _defaultController;
 
+    /** We keep track of which thread is executing the event loop so that
+     * other services can enforce restrictions on code that should or
+     * should not be called from the event dispatch thread. */
+    protected Thread _dobjThread;
+
     /** Check whether we should generate a report every 100 events. */
     protected static final long REPORT_CHECK_PERIOD = 100;