Remove busy waiting.

src/emucore/OSystem.cxx

@@ -686,8 +686,6 @@ double OSystem::dispatchEmulation(EmulationWorker& emulationWorker)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void OSystem::mainLoop()
 {
-  // Sleep-based wait: good for CPU, bad for graphical sync
-  bool busyWait = mySettings->getString("timing") != "sleep";
   // 6507 time
   time_point<high_resolution_clock> virtualTime = high_resolution_clock::now();
   // The emulation worker
@@ -726,10 +724,7 @@ void OSystem::mainLoop()
       virtualTime = now;
     else if (virtualTime > now) {
       // Wait until we have caught up with 6507 time
-      if (busyWait && myEventHandler->state() == EventHandlerState::EMULATION) {
+      std::this_thread::sleep_until(virtualTime);
-        while (high_resolution_clock::now() < virtualTime);
-      }
-      else std::this_thread::sleep_until(virtualTime);
     }
   }
 

src/emucore/Settings.cxx

@@ -40,7 +40,6 @@ Settings::Settings(OSystem& osystem)
   setInternal("fullscreen", "false");
   setInternal("center", "false");
   setInternal("palette", "standard");
-  setInternal("timing", "sleep");
   setInternal("uimessages", "true");
 
   // TIA specific options
@@ -308,9 +307,6 @@ void Settings::validate()
   f = getFloat("speed");
   if (f <= 0) setInternal("speed", "1.0");
 
-  s = getString("timing");
-  if(s != "sleep" && s != "busy")  setInternal("timing", "sleep");
-
   i = getInt("tia.aspectn");
   if(i < 80 || i > 120)  setInternal("tia.aspectn", "90");
   i = getInt("tia.aspectp");

src/gui/VideoDialog.cxx

@@ -215,11 +215,6 @@ VideoDialog::VideoDialog(OSystem& osystem, DialogContainer& parent,
   wid.push_back(myCenter);
   ypos += (lineHeight + VGAP) * 2;
 
-  // Timing to use between frames
-  myFrameTiming = new CheckboxWidget(myTab, font, xpos, ypos + 1, "Idle between frames (*)");
-  wid.push_back(myFrameTiming);
-  ypos += lineHeight + VGAP;
-
   // Use multi-threading
   myUseThreads = new CheckboxWidget(myTab, font, xpos, ypos + 1, "Multi-threading");
   wid.push_back(myUseThreads);
@@ -359,9 +354,6 @@ void VideoDialog::loadConfig()
   // TIA interpolation
   myTIAInterpolate->setState(instance().settings().getBool("tia.inter"));
 
-  // Wait between frames
-  myFrameTiming->setState(instance().settings().getString("timing") == "sleep");
-
   // Aspect ratio setting (NTSC and PAL)
   myNAspectRatio->setValue(instance().settings().getInt("tia.aspectn"));
   myPAspectRatio->setValue(instance().settings().getInt("tia.aspectp"));
@@ -431,9 +423,6 @@ void VideoDialog::saveConfig()
   instance().settings().setValue("palette",
     myTIAPalette->getSelectedTag().toString());
 
-  // Wait between frames
-  instance().settings().setValue("timing", myFrameTiming->getState() ? "sleep" : "busy");
-
   // TIA interpolation
   instance().settings().setValue("tia.inter", myTIAInterpolate->getState());
 
@@ -514,7 +503,6 @@ void VideoDialog::setDefaults()
       myRenderer->setSelectedIndex(0);
       myTIAZoom->setSelected("3", "");
       myTIAPalette->setSelected("standard", "");
-      myFrameTiming->setState(true);
       myTIAInterpolate->setState(false);
       myNAspectRatio->setValue(91);
       myPAspectRatio->setValue(109);

src/gui/VideoDialog.hxx

@@ -54,7 +54,6 @@ class VideoDialog : public Dialog
     PopUpWidget*      myRenderer;
     PopUpWidget*      myTIAZoom; // TODO: SliderWidget
     PopUpWidget*      myTIAPalette;
-    CheckboxWidget*   myFrameTiming;
     CheckboxWidget*   myTIAInterpolate;
     SliderWidget*     myNAspectRatio;
     SliderWidget*     myPAspectRatio;