--- a/Implab/Parallels/ArrayTraits.cs	Tue Oct 14 09:30:45 2014 +0400
+++ b/Implab/Parallels/ArrayTraits.cs	Wed Oct 22 18:37:56 2014 +0400
@@ -12,7 +12,7 @@
             readonly Action<TSrc> m_action;
             readonly TSrc[] m_source;
             readonly Promise<int> m_promise = new Promise<int>();
-            readonly TraceContext m_traceContext;
+            readonly LogicalOperation m_logicalOperation;
 
             int m_pending;
             int m_next;
@@ -23,7 +23,7 @@
                 Debug.Assert(source != null);
                 Debug.Assert(action != null);
 
-                m_traceContext = TraceContext.Snapshot();
+                m_logicalOperation = TraceContext.Instance.CurrentOperation;
                 m_next = 0;
                 m_source = source;
                 m_pending = source.Length;
@@ -41,8 +41,12 @@
             }
 
             protected override void Worker() {
-                TraceContext.Fork(m_traceContext);
-                base.Worker();
+                TraceContext.Instance.EnterLogicalOperation(m_logicalOperation, false);
+                try {
+                    base.Worker();
+                } finally {
+                    TraceContext.Instance.Leave();
+                }
             }
 
             protected override bool TryDequeue(out int unit) {
@@ -67,7 +71,7 @@
             readonly TSrc[] m_source;
             readonly TDst[] m_dest;
             readonly Promise<TDst[]> m_promise = new Promise<TDst[]>();
-            readonly TraceContext m_traceContext;
+            readonly LogicalOperation m_logicalOperation;
 
             int m_pending;
             int m_next;
@@ -83,7 +87,7 @@
                 m_dest = new TDst[source.Length];
                 m_pending = source.Length;
                 m_transform = transform;
-                m_traceContext = TraceContext.Snapshot();
+                m_logicalOperation = TraceContext.Instance.CurrentOperation;
 
                 m_promise.Anyway(Dispose);
 
@@ -97,13 +101,17 @@
             }
 
             protected override void Worker() {
-                TraceContext.Fork(m_traceContext);
-                base.Worker();
+                TraceContext.Instance.EnterLogicalOperation(m_logicalOperation,false);
+                try {
+                    base.Worker();
+                } finally {
+                    TraceContext.Instance.Leave();
+                }
             }
 
             protected override bool TryDequeue(out int unit) {
                 unit = Interlocked.Increment(ref m_next) - 1;
-                return unit >= m_source.Length ? false : true;
+                return unit < m_source.Length;
             }
 
             protected override void InvokeUnit(int unit) {