refactor: GDB start and wait

Signed-off-by: Maximilien Noal <noal.maximilien@gmail.com>

src/Spice86.Core/Emulator/Gdb/GdbServer.cs

@@ -12,7 +12,6 @@
 /// </summary>
 public sealed class GdbServer : IDisposable {
     private readonly ILoggerService _loggerService;
-    private EventWaitHandle? _waitFirstConnectionHandle;
     private readonly Configuration _configuration;
     private bool _disposed;
     private bool _isRunning = true;
@@ -26,7 +25,6 @@ public sealed class GdbServer : IDisposable {
     private readonly ExecutionFlowRecorder _executionFlowRecorder;
     private readonly FunctionHandler _functionHandler;
     private readonly EmulatorBreakpointsManager _emulatorBreakpointsManager;
-    private GdbCommandHandler? _gdbCommandHandler;
 
     /// <summary>
     /// Creates a new instance of the GdbServer class with the specified parameters.
@@ -71,9 +69,6 @@ private void Dispose(bool disposing) {
                 // Prevent it from restarting when the connection is killed
                 _isRunning = false;
                 _gdbIo?.Dispose();
-                // Release lock if called before the first connection to gdb server has been done
-                _waitFirstConnectionHandle?.Set();
-                _waitFirstConnectionHandle?.Dispose();
                 _gdbServerThread?.Join();
                 _isRunning = false;
             }
@@ -95,7 +90,6 @@ private void AcceptOneConnection(GdbIo gdbIo) {
             _configuration);
         gdbCommandHandler.PauseEmulator();
         OnConnect();
-        _gdbCommandHandler = gdbCommandHandler;
         while (gdbCommandHandler.IsConnected && gdbIo.IsClientConnected) {
             string command = gdbIo.ReadCommand();
             if (!string.IsNullOrWhiteSpace(command)) {
@@ -144,41 +138,27 @@ private void RunServer() {
     }
 
     /// <summary>
-    /// Starts the GDB server thread and waits for the initial connection to be made.
+    /// Starts the GDB server thread.
     /// </summary>
-    public void StartServerAndWait() {
+    public void StartServer() {
         if (_configuration.GdbPort is not null) {
             StartServerThread();
         }
     }
 
-    /// <summary>
-    /// Starts the GDB server thread and waits for the initial connection to be made.
-    /// </summary>
     private void StartServerThread() {
-        _waitFirstConnectionHandle = new AutoResetEvent(false);
         _gdbServerThread = new(RunServer) {
             Name = "GdbServer"
         };
         _gdbServerThread?.Start();
         // wait for thread to start and the initial connection to be made
-        _waitFirstConnectionHandle.WaitOne();
-        // Remove the handle so that no wait
-        _waitFirstConnectionHandle.Dispose();
-        _waitFirstConnectionHandle = null;
+       _pauseHandler.WaitIfPaused();
     }
 
     /// <summary>
     /// Sets the auto-reset event for the initial connection.
     /// </summary>
     private void OnConnect() {
-        _waitFirstConnectionHandle?.Set();
-    }
-
-    /// <summary>
-    /// Executes a single CPU instruction.
-    /// </summary>
-    public void StepInstruction() {
-        _gdbCommandHandler?.Step();
+        _pauseHandler.Resume();
     }
 }

src/Spice86.Core/Emulator/ProgramExecutor.cs

@@ -31,7 +31,6 @@
 public sealed class ProgramExecutor : IDisposable {
     private bool _disposed;
     private readonly ILoggerService _loggerService;
-    private readonly IPauseHandler _pauseHandler;
     private readonly Configuration _configuration;
     private readonly GdbServer? _gdbServer;
     private readonly EmulationLoop _emulationLoop;
@@ -63,7 +62,6 @@ public ProgramExecutor(Configuration configuration,
         _configuration = configuration;
         _loggerService = loggerService;
         _emulatorStateSerializer = emulatorStateSerializer;
-        _pauseHandler = pauseHandler;
         _emulationLoop = new EmulationLoop(_loggerService, functionHandler, cpu, state, timer,
             emulatorBreakpointsManager, pauseHandler);
         if (configuration.GdbPort.HasValue) {
@@ -88,12 +86,8 @@ public ProgramExecutor(Configuration configuration,
     /// Starts the loaded program.
     /// </summary>
     public void Run() {
-        if (_gdbServer is not null) {
-            _gdbServer?.StartServerAndWait();
-        } else if (_configuration.Debug) {
-            _pauseHandler.RequestPause("Starting the emulated program paused was requested");
-        }
-        _emulationLoop.Run();
+        _gdbServer?.StartServer();
+        _emulationLoop.Run(_gdbServer is not null || _configuration.Debug);
 
         if (_configuration.DumpDataOnExit is not false) {
             _emulatorStateSerializer.SerializeEmulatorStateToDirectory(_configuration.RecordedDataDirectory);

src/Spice86.Core/Emulator/VM/EmulationLoop.cs

@@ -57,9 +57,9 @@ public EmulationLoop(ILoggerService loggerService, FunctionHandler functionHandl
     /// Starts and waits for the end of the emulation loop.
     /// </summary>
     /// <exception cref="InvalidVMOperationException">When an unhandled exception occurs. This can occur if the target program is not supported (yet).</exception>
-    public void Run() {
+    internal void Run(bool startPaused) {
         try {
-            StartRunLoop(_functionHandler);
+            StartRunLoop(startPaused, _functionHandler);
         } catch (HaltRequestedException) {
             // Actually a signal generated code requested Exit
             return;
@@ -80,13 +80,16 @@ internal void Exit() {
         IsPaused = false;
     }
 
-    private void StartRunLoop(FunctionHandler functionHandler) {
+    private void StartRunLoop(bool startPaused, FunctionHandler functionHandler) {
         // Entry could be overridden and could throw exceptions
         functionHandler.Call(CallType.MACHINE, _cpuState.CS, _cpuState.IP, null, null, "entry", false);
-        RunLoop();
+        RunLoop(startPaused);
     }
 
-    private void RunLoop() {
+    private void RunLoop(bool startPaused) {
+        if(startPaused) {
+            _pauseHandler.RequestPause("Starting the emulated program paused was requested by the user.");
+        }
         _stopwatch.Start();
         if (_cpu is CfgCpu cfgCpu) {
             cfgCpu.SignalEntry();