Added GlobalClock.Suspend() to stop time when needed.

src/mindtouch.dream/mindtouch.dream.csproj

@@ -134,6 +134,7 @@
     <Compile Include="dream\RegistrationInspector.cs" />
     <Compile Include="Extensions\ReflectionEx.cs" />
     <Compile Include="Numeric.cs" />
+    <Compile Include="system\DisposeCallback.cs" />
     <Compile Include="system\GitBranchAttribute.cs" />
     <Compile Include="system\GitRevisionAttribute.cs" />
     <Compile Include="system\GitUriAttribute.cs" />

src/mindtouch.dream/system/DisposeCallback.cs

@@ -0,0 +1,50 @@
+/*
+ * MindTouch Dream - a distributed REST framework 
+ * Copyright (C) 2006-2014 MindTouch, Inc.
+ * www.mindtouch.com  oss@mindtouch.com
+ *
+ * For community documentation and downloads visit mindtouch.com;
+ * please review the licensing section.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace System {
+
+    /// <summary>
+    /// Class to trigger a callback when Dispose() is called.
+    /// </summary>
+    public class DisposeCallback : IDisposable {
+
+        //--- Fields ---
+        private readonly Action _callback;
+        private bool _disposed;
+
+        //--- Constructors ---
+        public DisposeCallback(Action callback) {
+            if(callback == null) {
+                throw new ArgumentNullException("callback");
+            }
+            _callback = callback;
+        }
+
+        //--- Methods ---
+        public void Dispose() {
+            if(_disposed) {
+                throw new ObjectDisposedException("DisposeCallback");
+            }
+            _disposed = true;
+            _callback();
+        }
+    }
+}

src/mindtouch.dream/system/GlobalClock.cs

@@ -46,6 +46,7 @@ public static class GlobalClock {
         private static readonly ManualResetEvent _stopped = new ManualResetEvent(false);
         private static NamedClockCallback[] _callbacks = new NamedClockCallback[INITIAL_CALLBACK_CAPACITY];
         private static readonly int _intervalMilliseconds;
+        private static object _suspendedTime;
         private static int _timeOffset;
 
         //--- Class Constructor ---
@@ -62,7 +63,7 @@ public static class GlobalClock {
         }
 
         //--- Class Properties ---
-        public static DateTime UtcNow { get { return DateTime.UtcNow + TimeSpan.FromMilliseconds(_timeOffset); } }
+        public static DateTime UtcNow { get { return (((DateTime?)_suspendedTime) ?? DateTime.UtcNow) + TimeSpan.FromMilliseconds(_timeOffset); } }
 
         //--- Class Methods ---
 
@@ -146,6 +147,20 @@ public static class GlobalClock {
             }
         }
 
+        /// <summary>
+        /// Suspend the global clock from progressing.
+        /// </summary>
+        /// <returns>Object that when disposed resumes the global clock.</returns>
+        /// <remarks>DO NOT USE FOR PRODUCTION CODE!!!</remarks>
+        public static IDisposable Suspend() {
+            Monitor.Enter(_syncRoot);
+            var suspendedTime = Interlocked.Exchange(ref _suspendedTime, UtcNow);
+            return new DisposeCallback(() => {
+                Interlocked.Exchange(ref _suspendedTime, suspendedTime);
+                Monitor.Exit(_syncRoot);
+            });
+        }
+
         internal static bool Shutdown(TimeSpan timeout) {
 
             // stop the thread timer