Revert "Improvements in engine process exit and termination (#145)" (#…

…146)

This reverts commit 0743675.

source/nanoFramework.Tools.DebugLibrary.Shared/PortSerial/SerialPort.cs

@@ -43,10 +43,6 @@ public partial class SerialPort : PortBase, IPort
         /// </summary>
         private List<NanoDeviceBase> _tentativeNanoFrameworkDevices = new List<NanoDeviceBase>();
 
-        DataWriter outputStreamWriter = null;
-        DataReader inputStreamReader = null;
-
-
         /// <summary>
         /// Creates an Serial debug client
         /// </summary>
@@ -665,17 +661,16 @@ public async Task<uint> SendBufferAsync(byte[] buffer, TimeSpan waiTimeout, Canc
             // device must be connected
             if (EventHandlerForSerialDevice.Current.IsDeviceConnected && !cancellationToken.IsCancellationRequested)
             {
+                DataWriter outputStreamWriter = new DataWriter(EventHandlerForSerialDevice.Current.Device.OutputStream);
 
                 try
                 {
-                    outputStreamWriter = new DataWriter(EventHandlerForSerialDevice.Current.Device.OutputStream);
-
                     // write buffer to device
                     outputStreamWriter.WriteBytes(buffer);
 
-                    cancellationToken.ThrowIfCancellationRequested();
+                    Task<UInt32> storeAsyncTask = outputStreamWriter.StoreAsync().AsTask(cancellationToken.AddTimeout(waiTimeout));
 
-                    return await outputStreamWriter.StoreAsync().AsTask(cancellationToken.AddTimeout(waiTimeout));
+                    return await storeAsyncTask;
                 }
                 catch (TaskCanceledException)
                 {
@@ -706,12 +701,10 @@ public async Task<byte[]> ReadBufferAsync(uint bytesToRead, TimeSpan waiTimeout,
             // device must be connected
             if (EventHandlerForSerialDevice.Current.IsDeviceConnected && !cancellationToken.IsCancellationRequested)
             {
+                DataReader inputStreamReader = new DataReader(EventHandlerForSerialDevice.Current.Device.InputStream);
+
                 try
                 {
-                    inputStreamReader = new DataReader(EventHandlerForSerialDevice.Current.Device.InputStream);
-
-                    cancellationToken.ThrowIfCancellationRequested();
-
                     Task<UInt32> loadAsyncTask = inputStreamReader.LoadAsync(bytesToRead).AsTask(cancellationToken.AddTimeout(waiTimeout));
 
                     UInt32 bytesRead = await loadAsyncTask;

source/nanoFramework.Tools.DebugLibrary.Shared/PortUSB/UsbPort.cs

@@ -531,7 +531,8 @@ public async Task<uint> SendBufferAsync(byte[] buffer, TimeSpan waiTimeout, Canc
             }
             else
             {
-                throw new DeviceNotConnectedException();
+                // FIXME 
+                // NotifyDeviceNotConnected
             }
 
             return bytesWritten;
@@ -624,7 +625,8 @@ public async Task<byte[]> ReadBufferAsync(uint bytesToRead, TimeSpan waiTimeout,
             }
             else
             {
-                throw new DeviceNotConnectedException();
+                // FIXME 
+                // NotifyDeviceNotConnected
             }
 
             // return empty byte array

source/nanoFramework.Tools.DebugLibrary.Shared/WireProtocol/Controller.cs

@@ -38,11 +38,6 @@ public Converter CreateConverter()
             return new Converter(Capabilities);
         }
 
-        private void ProcessExit()
-        {
-            App.ProcessExited();
-        }
-
         public async Task<bool> SendAsync(MessageRaw raw, CancellationToken cancellationToken)
         {
             _sendSemaphore.WaitOne();
@@ -100,10 +95,6 @@ public async Task<bool> SendAsync(MessageRaw raw, CancellationToken cancellation
             {
                 // don't do anything here, as this is expected
             }
-            catch(DeviceNotConnectedException)
-            {
-                App.ProcessExited();
-            }
             finally
             {
                 _sendSemaphore.Release();
@@ -175,13 +166,8 @@ internal async Task<int> ReadBufferAsync(byte[] buffer, int offset, int bytesToR
             {
                 // don't do anything here, as this is expected
             }
-            catch (DeviceNotConnectedException)
-            {
-                App.ProcessExited();
-            }
 
             return bytesToReadRequested - bytesToRead;
         }
-
     }
 }

source/nanoFramework.Tools.DebugLibrary.Shared/WireProtocol/Engine.cs

@@ -60,6 +60,8 @@ public partial class Engine : IDisposable, IControllerHostLocal
         ManualResetEvent m_evtShutdown;
         ManualResetEvent m_evtPing;
         TypeSysLookup m_typeSysLookup;
+        EngineState _state;
+        //bool m_fProcessExited;
 
         private Task _backgroundProcessor;
 
@@ -79,9 +81,13 @@ internal Engine(NanoDeviceBase device)
             // default to false
             IsCRC32EnabledForWireProtocol = false;
 
+            _state.SetValue(EngineState.Value.Starting, true);
+
             // start task to process background messages
             _backgroundProcessor = Task.Factory.StartNew(() => IncomingMessagesListenerAsync(), _backgroundProcessorCancellation.Token, TaskCreationOptions.LongRunning, TaskScheduler.Current);
 
+            _state.SetValue(EngineState.Value.Started, false);
+
             _pendingRequestsTimer = new Timer(ClearPendingRequests, null, 1000, 1000);
         }
 
@@ -98,6 +104,8 @@ private void Initialize()
 
             m_notifyNoise = new FifoBuffer();
             m_typeSysLookup = new TypeSysLookup();
+            _state = new EngineState(this);
+            //m_fProcessExited = false;
 
             //default capabilities, used until clr can be queried.
             Capabilities = new CLRCapabilities();
@@ -112,7 +120,7 @@ private void InitializeLocal(NanoDeviceBase device)
             _controlller = new Controller(this);
 
             Device = (INanoDevice)device;
-            
+
             Initialize();
         }
 
@@ -147,11 +155,6 @@ public async Task<bool> ConnectAsync(int timeout, bool force = false, Connection
                 // connect to device 
                 if (await Device.ConnectAsync())
                 {
-                    if (_backgroundProcessor.Status != TaskStatus.Running)
-                    {
-                        // background processor is not running, start it
-                        ResumeProcessing();
-                    }
 
                     Commands.Monitor_Ping cmd = new Commands.Monitor_Ping();
 
@@ -259,28 +262,48 @@ public async Task IncomingMessagesListenerAsync()
         {
             var reassembler = new MessageReassembler(_controlller);
 
-            while (!_backgroundProcessorCancellation.IsCancellationRequested)
+            while (!_backgroundProcessorCancellation.IsCancellationRequested && _state.IsRunning)
             {
-                try
-                {
-                    await reassembler.ProcessAsync(_backgroundProcessorCancellation.Token);
-                }
-                catch (DeviceNotConnectedException)
-                {
-                    ProcessExited();
-                }
-                catch (Exception ex)
+                if (await Device.ConnectAsync())
                 {
-                    // look for I/O exception
-                    // 0x800703E3
-                    if (ex.HResult == -2147023901)
+                    try
                     {
-                        ProcessExited();
+                        await reassembler.ProcessAsync(_backgroundProcessorCancellation.Token);
                     }
-
-                    if (_backgroundProcessorCancellation.IsCancellationRequested)
+                    catch (DeviceNotConnectedException)
                     {
-                        break;
+                        if (_backgroundProcessorCancellation.IsCancellationRequested || !_state.IsRunning)
+                        {
+                            return;
+                        }
+                        else
+                        {
+                            await Task.Delay(1000);
+                            await Device.ConnectAsync();
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        if (_backgroundProcessorCancellation.IsCancellationRequested || !_state.IsRunning)
+                        {
+                            return;
+                        }
+                        else
+                        {
+
+                            if (ex.GetType().Equals(typeof(AggregateException)))
+                            {
+                                if (ex.GetBaseException().GetType().Name == typeof(DeviceNotConnectedException).Name)
+                                {
+                                    await Task.Delay(1000);
+                                    await Device.ConnectAsync();
+                                }
+                            }
+                            else if (ex.HResult == 0x80070006)
+                            {
+                                return;
+                            }
+                        }
                     }
                 }
             }
@@ -621,9 +644,7 @@ public void SpuriousCharacters(byte[] buf, int offset, int count)
 
         public void ProcessExited()
         {
-            Stop();
-
-            _eventProcessExit?.Invoke(this, null);
+            throw new NotImplementedException();
         }
 
         public async Task<byte[]> ReadBufferAsync(uint bytesToRead, TimeSpan waitTimeout, CancellationToken cancellationToken)
@@ -638,6 +659,8 @@ private OutgoingMessage CreateMessage(uint cmd, uint flags, object payload)
 
         public void StopProcessing()
         {
+            _state.SetValue(EngineState.Value.Stopping, false);
+
             m_evtShutdown.Set();
 
             if (_backgroundProcessor != null)
@@ -650,14 +673,18 @@ public void StopProcessing()
                     Task.WaitAll(_backgroundProcessor);
                 }
                 catch { }
+
+                _backgroundProcessor = null;
             }
         }
 
         public void ResumeProcessing()
         {
             m_evtShutdown.Reset();
 
-            if (_backgroundProcessor == null || _backgroundProcessor.IsCompleted)
+            _state.SetValue(EngineState.Value.Resume, false);
+
+            if (_backgroundProcessor == null)
             {
                 _backgroundProcessor = Task.Factory.StartNew(() => IncomingMessagesListenerAsync(), _backgroundProcessorCancellation.Token, TaskCreationOptions.LongRunning, TaskScheduler.Current);
             }
@@ -670,9 +697,19 @@ public void Stop()
                 m_evtShutdown.Set();
             }
 
-            StopProcessing();
+            if (_state.SetValue(EngineState.Value.Stopping, false))
+            {
+                StopProcessing();
+
+                //((IController)this).ClosePort();
+
+                _state.SetValue(EngineState.Value.Stopped, false);
+            }
         }
 
+        public bool IsRunning => _state.IsRunning;
+
+
         #region RPC Support
 
         // comment from original code REVIEW: Can this be refactored out of here to a separate class dedicated to RPC?
@@ -974,7 +1011,10 @@ private void RpcReceiveSendDispatch(object obj)
         {
             EndPointRegistration.InboundRequest ir = (EndPointRegistration.InboundRequest)obj;
 
-            ir.Owner.m_ep.DispatchMessage(ir.m_msg);
+            if (IsRunning)
+            {
+                ir.Owner.m_ep.DispatchMessage(ir.m_msg);
+            }
         }
 
         internal bool RpcReply(Commands.Debugging_Messaging_Address addr, byte[] data)
@@ -1041,7 +1081,11 @@ internal async Task<WireProtocolRequest> RequestAsync(OutgoingMessage message, i
         {
             using (CancellationTokenSource cts = new CancellationTokenSource())
             {
-                if(_backgroundProcessor.Status != TaskStatus.Running)
+                //Checking whether IsRunning and adding the request to m_requests
+                //needs to be atomic to avoid adding a request after the Engine
+                //has been stopped.
+
+                if (!IsRunning)
                 {
                     throw new ApplicationException("Engine is not running or process has exited.");
                 }

source/nanoFramework.Tools.DebugLibrary.Shared/WireProtocol/EngineState.cs

@@ -0,0 +1,80 @@
+//
+// Copyright (c) 2017 The nanoFramework project contributors
+// Portions Copyright (c) Microsoft Corporation.  All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+
+using System;
+
+namespace nanoFramework.Tools.Debugger
+{
+    internal class EngineState
+    {
+        public enum Value
+        {
+            NotStarted,
+            Starting,
+            Started,
+            Stopping,
+            Resume,
+            Stopped,
+            Disposing,
+            Disposed
+        }
+
+        private Value _value;
+        public object SyncObject { get; private set; }
+
+        public EngineState(object syncObject)
+        {
+            _value = Value.NotStarted;
+            SyncObject = syncObject;
+        }
+
+        public Value GetValue()
+        {
+            return _value;
+        }
+
+        public bool SetValue(Value value)
+        {
+            return SetValue(value, false);
+        }
+
+        public bool SetValue(Value value, bool fThrow)
+        {
+            lock (SyncObject)
+            {
+                if (_value == Value.Stopping && value == Value.Resume)
+                {
+                    _value = Value.Started;
+                    return true;
+                }
+                else if (_value < value)
+                {
+                    _value = value;
+                    return true;
+                }
+                else
+                {
+                    if (fThrow)
+                    {
+                        throw new Exception(string.Format("Cannot set State to {0}", value));
+                    }
+
+                    return false;
+                }
+            }
+        }
+
+        public bool IsRunning
+        {
+            get
+            {
+                Value val = _value;
+
+                return val == Value.Starting || val == Value.Started;
+            }
+        }
+    }
+}

source/nanoFramework.Tools.DebugLibrary.Shared/nanoFramework.Tools.DebugLibrary.Net.projitems

@@ -92,6 +92,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\Converter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\DeploymentBlock.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\Engine.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\EngineState.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\FifoBuffer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\DeploymentSector.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)WireProtocol\IControllerRemote.cs" />