enhance: use Mutex to force running SourceGit in singleton mode

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Models/IpcChannel.cs

@@ -10,7 +10,7 @@ public class IpcChannel : IDisposable
     {
         public bool IsFirstInstance
         {
-            get => _server != null;
+            get => _isFirstInstance;
         }
 
         public event Action<string> MessageReceived;
@@ -19,14 +19,19 @@ public IpcChannel()
         {
             try
             {
-                _server = new NamedPipeServerStream(
-                    "SourceGitIPCChannel", 
-                    PipeDirection.In,
-                    1,
-                    PipeTransmissionMode.Byte,
-                    PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly | PipeOptions.FirstPipeInstance);
-                _cancellationTokenSource = new CancellationTokenSource();
-                Task.Run(StartServer);
+                _singletonMutex = new Mutex(false, "SourceGit_2994509B-4906-4A48-9A45-55C1836A8208", out _isFirstInstance);
+
+                if (_isFirstInstance)
+                {
+                    _server = new NamedPipeServerStream(
+                        "SourceGitIPCChannel",
+                        PipeDirection.In,
+                        -1,
+                        PipeTransmissionMode.Byte,
+                        PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly);
+                    _cancellationTokenSource = new CancellationTokenSource();
+                    Task.Run(StartServer);
+                }
             }
             catch
             {
@@ -60,6 +65,7 @@ public void SendToFirstInstance(string cmd)
         public void Dispose()
         {
             _cancellationTokenSource?.Cancel();
+            _singletonMutex.Dispose();
         }
 
         private async void StartServer()
@@ -83,6 +89,8 @@ private async void StartServer()
             }
         }
 
+        private Mutex _singletonMutex = null;
+        private bool _isFirstInstance = false;
         private NamedPipeServerStream _server = null;
         private CancellationTokenSource _cancellationTokenSource = null;
     }