Fixed issue #4 where outbound messages were being timestamped with

System.nanoTime() even if that was not the time basis used in the object update notifications. Fixing this required threading a server-side TimeSource from EtherealHost down through to StateWriter. In the process, TimeSource was refactored to just be a TimeSource. A new SynchedTimeSource extends it to provide the drift-related methods... mostly in case clients care to monitor those values for some reason. RemoteTimeSource now implements SynchedTimeSource.
Simsilica · Nov 17, 2018 · c6272ff · c6272ff
1 parent c2e6993
commit c6272ff
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diff --git a/build.gradle b/build.gradle
@@ -14,10 +14,10 @@ buildscript {
 apply plugin: 'java'
 apply plugin: 'maven'
 
-version='1.2.2-SNAPSHOT'
+version='1.3.0-SNAPSHOT'
 group='com.simsilica'
 
-ext.jmeVersion = "3.1.0-alpha4" 
+ext.jmeVersion = "3.1.0-stable" 
 
 // Version meta-data
 ext {
@@ -34,7 +34,9 @@ ext {
     issueTrackerUrl = 'https://github.com/Simsilica/SimEthereal/issues'
 }
 
+sourceCompatibility = 1.7
 compileJava {
+    options.encoding = 'UTF-8'
     options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
 }
 
@@ -53,7 +55,7 @@ dependencies {
     compile "org.jmonkeyengine:jme3-networking:$jmeVersion" 
 
     // Uses SimMath for bit streaming utilities and transition buffers
-    compile "com.simsilica:sim-math:1.1.2-SNAPSHOT"
+    compile "com.simsilica:sim-math:1.2.0-SNAPSHOT"
 
     // Base logging   
     compile 'org.slf4j:slf4j-api:1.7.15'    

diff --git a/release-notes.md b/release-notes.md
@@ -1,12 +1,19 @@
-Version 1.2.2 (unreleased)
+Version 1.3.0 (unreleased)
 --------------
 * Fixed a bug where the newer state messages would fail if the game hadn't
     already registered Vec3d as a serializable class.
 * Fixed NetworkStateListener to properly pay attention to zone extents.
 * Fixed EtherealHost to pass the specified client zone extents on to the 
     NetworkStateListener.
 * Added additional trace logging to NetworkStateListener.
-* Upgraded to sim-math 1.1.1   
+* Fixed an issue where raw nanoTime() was being used to timestamp messages.
+    Now applications can specify their own TimeSource on the server.
+    See issue #4.
+* Refactored the TimeSource interface to be just a time provider and added
+    a SynchedTimeSource interface to provide the extra drift/offset methods
+    that it previously had.  RemoteTimeSource now implements SynchedTimeSource.
+* Upgraded to sim-math 1.2.0
+* Set sourceCompatibility to 1.7   
 
 
 Version 1.2.1

diff --git a/src/main/java/com/simsilica/ethereal/EtherealHost.java b/src/main/java/com/simsilica/ethereal/EtherealHost.java
@@ -73,6 +73,15 @@ public class EtherealHost extends AbstractHostedConnectionService {
 
     private SessionDataDelegator delegator;
 
+    /**
+     *  This is the time source that will be used for timestamping outbound
+     *  object state messages.  This time source should be compatible with whatever
+     *  is providing time to the object update messages.  Otherwise, clients will
+     *  see a wide difference between what they see from RemoteTimeSource and
+     *  the timestamps in the object updates.
+     */
+    private TimeSource timeSource = new NanoTimeSource();
+
     public EtherealHost() {
         this(new ObjectStateProtocol(8, 64, new Vec3Bits(-10, 42, 16), new QuatBits(12)),
              new ZoneGrid(32), new Vec3i(1, 1, 1));
@@ -93,6 +102,23 @@ public EtherealHost( ObjectStateProtocol objectProtocol, ZoneGrid grid, Vec3i cl
         Serializer.registerClass(Vec3d.class, new FieldSerializer());        
     }
 
+    /**
+     *  Returns the aurhoritative time source on the server.  This should match the timestamps
+     *  that are being supplied in object update notifications.
+     */
+    public TimeSource getTimeSource() {
+        return timeSource;
+    }
+
+    /**
+     *  Returns the aurhoritative time source on the server.  This should match the timestamps
+     *  that are being supplied in object update notifications.  Applications should set their
+     *  own timesource if they are using a different time tracking basis than System.nanoTime().
+     */
+    public void setTimeSource( TimeSource timeSource ) {
+        this.timeSource = timeSource == null ? new NanoTimeSource() : timeSource;
+    }
+
     public ZoneManager getZones() {
         return zones;
     }

diff --git a/src/main/java/com/simsilica/ethereal/NanoTimeSource.java b/src/main/java/com/simsilica/ethereal/NanoTimeSource.java
@@ -38,42 +38,19 @@
 
 
 /**
- *  Provides local or networked time as needed with certain
- *  implied constraints (like time always moves forward, ie:
- *  never backwards, etc.)
+ *  A TimeSource that directly returns System.nanoTime() as the time.
  *
  *  @author    Paul Speed
  */
 public class NanoTimeSource implements TimeSource {
 
-    private long offset;
-
     public NanoTimeSource() {
     }
 
-    public NanoTimeSource( long offset ) {
-        this.offset = offset;
-    }
-
-    public void setOffset( long offset ) {
-        this.offset = offset;
-    }
-
-    public long getOffset() {
-        return offset;
-    }
-
     /**
      *  Returns the current time in nanoseconds.
      */
     public long getTime() {
-        return System.nanoTime() + offset;
-    }
-
-    /**
-     *  Returns 0.
-     */   
-    public long getDrift() {
-        return 0;
+        return System.nanoTime();
     }
 }
diff --git a/src/main/java/com/simsilica/ethereal/NetworkStateListener.java b/src/main/java/com/simsilica/ethereal/NetworkStateListener.java
@@ -120,7 +120,7 @@ public NetworkStateListener( EtherealHost host, HostedConnection conn, LocalZone
         this.zoneIndex = zoneIndex;
         this.idIndex = idIndex;
         this.space = new SharedObjectSpace(host.getObjectProtocol());
-        this.stateWriter = new StateWriter(conn, host.getObjectProtocol(), stats);        
+        this.stateWriter = new StateWriter(conn, host.getObjectProtocol(), host.getTimeSource(), stats);        
     }
 
     public void setSelf( Long self, Vec3d startingPosition ) {

diff --git a/src/main/java/com/simsilica/ethereal/SynchedTimeSource.java b/src/main/java/com/simsilica/ethereal/SynchedTimeSource.java
@@ -0,0 +1,70 @@
+/*
+ * $Id$
+ * 
+ * Copyright (c) 2018, Simsilica, LLC
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions 
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in 
+ *    the documentation and/or other materials provided with the 
+ *    distribution.
+ * 
+ * 3. Neither the name of the copyright holder nor the names of its 
+ *    contributors may be used to endorse or promote products derived 
+ *    from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package com.simsilica.ethereal;
+
+
+/**
+ *  A time source that represents time that has been synched with
+ *  another time source relative to local system time.  It has
+ *  methods that indicate the amount of drift, offset, etc. that
+ *  maps local system time to TimeSource time.
+ *
+ *  @author    Paul Speed
+ */
+public interface SynchedTimeSource extends TimeSource {
+
+    /**
+     *  Returns the current drift if there is one.  In a remote
+     *  time source, the drift is the offset from current time
+     *  and is related in a loose way to both the ping time of the
+     *  server and the general time difference of the server.
+     */   
+    public long getDrift();
+
+    /**
+     *  Sets a time that will be automatically added into the
+     *  normally returned time.  This allows getTime() to return
+     *  time in the past for interpolating object state buffers.
+     */   
+    public void setOffset( long offset );
+
+    /**
+     *  Returns the current time offset for this TimeSource.
+     */   
+    public long getOffset();
+
+}
diff --git a/src/main/java/com/simsilica/ethereal/TimeSource.java b/src/main/java/com/simsilica/ethereal/TimeSource.java
@@ -50,25 +50,4 @@ public interface TimeSource {
      *  Returns the current time in nanoseconds.
      */
     public long getTime();
-
-    /**
-     *  Returns the current drift if there is one.  In a remote
-     *  time source, the drift is the offset from current time
-     *  and is related in a loose way to both the ping time of the
-     *  server and the general time difference of the server.
-     */   
-    public long getDrift();
-
-    /**
-     *  Sets a time that will be automatically added into the
-     *  normally returned time.  This allows getTime() to return
-     *  time in the past for interpolating object state buffers.
-     */   
-    public void setOffset( long offset );
-
-    /**
-     *  Returns the current time offset for this TimeSource.
-     */   
-    public long getOffset();
-
 }
diff --git a/src/main/java/com/simsilica/ethereal/net/RemoteTimeSource.java b/src/main/java/com/simsilica/ethereal/net/RemoteTimeSource.java
@@ -39,7 +39,7 @@
 import com.simsilica.ethereal.DebugUtils;
 import com.simsilica.ethereal.Statistics;
 import com.simsilica.ethereal.Statistics.Sequence;
-import com.simsilica.ethereal.TimeSource;
+import com.simsilica.ethereal.SynchedTimeSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -52,7 +52,7 @@
  *
  *  @author    Paul Speed
  */
-public class RemoteTimeSource implements TimeSource {
+public class RemoteTimeSource implements SynchedTimeSource {
 
     static Logger log = LoggerFactory.getLogger(RemoteTimeSource.class);
 
@@ -102,7 +102,7 @@ public long getOffset() {
     }
 
     protected void updateDrift( long serverTime ) {
-        
+
         syncTime.add(serverTime);
 
         this.lastServerTime = serverTime;

diff --git a/src/main/java/com/simsilica/ethereal/net/StateWriter.java b/src/main/java/com/simsilica/ethereal/net/StateWriter.java
@@ -36,16 +36,21 @@
 
 package com.simsilica.ethereal.net;
 
-import com.jme3.network.HostedConnection;
-import com.simsilica.ethereal.ConnectionStats;
-import com.simsilica.ethereal.zone.ZoneKey;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.Set;
 import java.util.TreeSet;
 
+import org.slf4j.*;
+
+import com.jme3.network.HostedConnection;
+
+import com.simsilica.ethereal.ConnectionStats;
+import com.simsilica.ethereal.TimeSource;
+import com.simsilica.ethereal.zone.ZoneKey;
+
 
 /**
  *  Buffers the state information, flushing it to real messages
@@ -55,6 +60,8 @@
  */
 public class StateWriter {
 
+    static Logger log = LoggerFactory.getLogger(StateWriter.class);
+
     /**
      *  The connection to send state through.
      */
@@ -91,12 +98,18 @@ public class StateWriter {
     private int nextMessageId = 0;
     private int headerBits;
     private int estimatedSize;
+
+    // Time source we will use for timestamping outbound messages.
+    // This time should be compatible with the times provided by the 
+    // frame updates or things will get weird.
+    private TimeSource timeSource;
 
     private ConnectionStats stats;
 
-    public StateWriter( HostedConnection conn, ObjectStateProtocol objectProtocol, ConnectionStats stats ) {
+    public StateWriter( HostedConnection conn, ObjectStateProtocol objectProtocol, TimeSource timeSource, ConnectionStats stats ) {
         this.conn = conn;
         this.objectProtocol = objectProtocol;
+        this.timeSource = timeSource;
         this.stats = stats;   
     }
 
@@ -187,6 +200,15 @@ public SentState ackSentState( int messageId ) {
     }
 
     public void startFrame( long time, ZoneKey centerZone ) throws IOException {
+
+        // Watchdog to check for mismatched time sources.
+        long delta = Math.abs(time - timeSource.getTime()); 
+        if( delta > 1000000000 ) {
+            // more then a second difference means they are waaaaaay off.
+            // Even a ms difference would be large.
+            log.warn("Mismatched time sources.  Delta:" + (delta/1000000000.0) + " seconds");
+        }
+
         // End any previous frame that we might be in the middle of    
         endFrame();
 
@@ -409,7 +431,8 @@ protected void endFrame() throws IOException {
 
     protected void endMessage() throws IOException {
 
-        long timestamp = System.nanoTime();
+        //long timestamp = System.nanoTime();
+        long timestamp = timeSource.getTime();
         int id = nextMessageId++;    
 
         ObjectStateMessage msg = new ObjectStateMessage(id, timestamp, null);