Qt/Unix: Implement signal handler

Source/Core/DolphinQt2/CMakeLists.txt

@@ -95,6 +95,7 @@ add_executable(dolphin-emu
   QtUtils/DoubleClickEventFilter.cpp
   QtUtils/ElidedButton.cpp
   QtUtils/ImageConverter.cpp
+  QtUtils/SignalDaemon.cpp
   QtUtils/WindowActivationEventFilter.cpp
   QtUtils/WinIconHelper.cpp
   QtUtils/WrapInScrollArea.cpp

Source/Core/DolphinQt2/MainWindow.cpp

@@ -1,4 +1,3 @@
-
 // Copyright 2015 Dolphin Emulator Project
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
@@ -20,6 +19,12 @@
 #include <future>
 #include <optional>
 
+#if defined(__unix__) || defined(__unix) || defined(__APPLE__)
+#include <signal.h>
+
+#include "QtUtils/SignalDaemon.h"
+#endif
+
 #include "Common/Version.h"
 
 #include "Core/Boot/Boot.h"
@@ -86,6 +91,23 @@
 #include "UICommon/X11Utils.h"
 #endif
 
+#if defined(__unix__) || defined(__unix) || defined(__APPLE__)
+void MainWindow::OnSignal()
+{
+  close();
+}
+
+static void InstallSignalHandler()
+{
+  struct sigaction sa;
+  sa.sa_handler = &SignalDaemon::HandleInterrupt;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = SA_RESETHAND;
+  sigaction(SIGINT, &sa, nullptr);
+  sigaction(SIGTERM, &sa, nullptr);
+}
+#endif
+
 MainWindow::MainWindow(std::unique_ptr<BootParameters> boot_parameters) : QMainWindow(nullptr)
 {
   setWindowTitle(QString::fromStdString(Common::scm_rev_str));
@@ -109,6 +131,14 @@ MainWindow::MainWindow(std::unique_ptr<BootParameters> boot_parameters) : QMainW
 
   NetPlayInit();
 
+#if defined(__unix__) || defined(__unix) || defined(__APPLE__)
+  auto* daemon = new SignalDaemon(this);
+
+  connect(daemon, &SignalDaemon::InterruptReceived, this, &MainWindow::OnSignal);
+
+  InstallSignalHandler();
+#endif
+
   if (boot_parameters)
     m_pending_boot = std::move(boot_parameters);
 

Source/Core/DolphinQt2/MainWindow.h

@@ -138,6 +138,7 @@ private:
   void OnBootGameCubeIPL(DiscIO::Region region);
   void OnImportNANDBackup();
   void OnConnectWiiRemote(int id);
+  void OnSignal();
 
   void OnUpdateProgressDialog(QString label, int progress, int total);
 

Source/Core/DolphinQt2/QtUtils/SignalDaemon.cpp

@@ -0,0 +1,55 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DolphinQt2/QtUtils/SignalDaemon.h"
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <QSocketNotifier>
+
+int SignalDaemon::s_sigterm_fd[2];
+
+static constexpr char message[] =
+    "\nA signal was received. A second signal will force Dolphin to stop.\n";
+
+SignalDaemon::SignalDaemon(QObject* parent) : QObject(parent)
+{
+  if (socketpair(AF_UNIX, SOCK_STREAM, 0, s_sigterm_fd))
+    qFatal("Couldn't create TERM socketpair");
+
+  m_term = new QSocketNotifier(s_sigterm_fd[1], QSocketNotifier::Read, this);
+  connect(m_term, &QSocketNotifier::activated, this, &SignalDaemon::OnNotifierActivated);
+}
+
+SignalDaemon::~SignalDaemon()
+{
+  close(s_sigterm_fd[0]);
+  close(s_sigterm_fd[1]);
+}
+
+void SignalDaemon::OnNotifierActivated()
+{
+  m_term->setEnabled(false);
+
+  char tmp;
+  if (read(s_sigterm_fd[1], &tmp, sizeof(char)))
+  {
+  }
+
+  m_term->setEnabled(true);
+
+  emit InterruptReceived();
+}
+
+void SignalDaemon::HandleInterrupt(int)
+{
+  write(STDERR_FILENO, message, sizeof(message));
+
+  char a = 1;
+  if (write(s_sigterm_fd[0], &a, sizeof(a)))
+  {
+  }
+}

Source/Core/DolphinQt2/QtUtils/SignalDaemon.h

@@ -0,0 +1,31 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <QObject>
+
+class QSocketNotifier;
+
+// Loosely based on https://doc.qt.io/qt-5.9/unix-signals.html
+class SignalDaemon : public QObject
+{
+  Q_OBJECT
+
+public:
+  explicit SignalDaemon(QObject* parent);
+  ~SignalDaemon();
+
+  static void HandleInterrupt(int);
+
+signals:
+  void InterruptReceived();
+
+private:
+  void OnNotifierActivated();
+
+  static int s_sigterm_fd[2];
+
+  QSocketNotifier* m_term;
+};