Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Workflow.ComponentModel/AuthoringOM/Trace.cs

@@ -0,0 +1,99 @@
+namespace System.Workflow.Runtime
+{
+    using System;
+    using System.Diagnostics;
+
+    /// <summary>
+    /// Holds trace sources for the runtime and associated modules
+    /// </summary>
+    internal static class WorkflowTrace
+    {
+        static TraceSource runtime;
+        static TraceSource tracking;
+        static TraceSource host;
+
+        /// <summary>
+        /// Tracesource for the core runtime
+        /// </summary>
+        internal static TraceSource Runtime
+        {
+            get { return runtime; }
+        }
+
+        /// <summary>
+        /// Tracesource for tracking
+        /// </summary>
+        internal static TraceSource Tracking
+        {
+            get { return tracking; }
+        }
+
+        /// <summary>
+        /// Tracesource for the host
+        /// </summary>
+        internal static TraceSource Host
+        {
+            get { return host; }
+        }
+
+        /// <summary>
+        /// Statically set up trace sources
+        /// 
+        /// To enable logging to a file, add lines like the following to your app config file.
+        /*
+            <system.diagnostics>
+                <switches>
+                    <add name="System.Workflow LogToFile" value="1" />
+                </switches>
+            </system.diagnostics>
+        */
+        /// To enable tracing to default trace listeners, add lines like the following
+        /*
+            <system.diagnostics>
+                <switches>
+                    <add name="System.Workflow LogToTraceListener" value="1" />
+                </switches>
+            </system.diagnostics>
+        */
+        /// </summary>
+        static WorkflowTrace()
+        {
+            runtime = new TraceSource("System.Workflow.Runtime");
+            runtime.Switch = new SourceSwitch("System.Workflow.Runtime", SourceLevels.Off.ToString());
+            // we'll use ID of 1 for the scheduler, 0 for rest of runtime
+
+            tracking = new TraceSource("System.Workflow.Runtime.Tracking");
+            tracking.Switch = new SourceSwitch("System.Workflow.Runtime.Tracking", SourceLevels.Off.ToString());
+
+            host = new TraceSource("System.Workflow.Runtime.Hosting");
+            host.Switch = new SourceSwitch("System.Workflow.Runtime.Hosting", SourceLevels.Off.ToString());
+
+
+
+            BooleanSwitch logToFile = new BooleanSwitch("System.Workflow LogToFile", "Log traces to file");
+            if (logToFile.Enabled)
+            {
+                TextWriterTraceListener fileLog = new TextWriterTraceListener("WorkflowTrace.log");
+                // add to global Listeners list
+                Trace.Listeners.Add(fileLog);
+                // don't add to tracking (which probably has its own log)
+                runtime.Listeners.Add(fileLog);
+                host.Listeners.Add(fileLog);
+            }
+
+            BooleanSwitch traceToDefault = new BooleanSwitch("System.Workflow LogToTraceListeners", "Trace to listeners in Trace.Listeners", "0");
+            if (traceToDefault.Enabled)
+            {
+                foreach (TraceListener listener in Trace.Listeners)
+                {
+                    if (!(listener is DefaultTraceListener))
+                    {
+                        runtime.Listeners.Add(listener);
+                        tracking.Listeners.Add(listener);
+                        host.Listeners.Add(listener);
+                    }
+                }
+            }
+        }
+    }
+}