Move `getTicks()` from OSystem to TimerManager.

- This allows OSystem dependency to be removed in a few places (WIP).
- It more properly belongs in TimerManager, which has other functionality related to std::chrono.
- Historically this was a virtual method in OSystem, since different ports implemented it differently.  Now that we use proper C++11 code, it doesn't need to be there anymore.
- Changed from a virtual call to a static call, so it's probably even a little faster.

src/common/TimerManager.hxx

@@ -119,6 +119,22 @@ class TimerManager
     // Returns lazily initialized singleton
     static TimerManager& global();
 
+    /**
+      This method returns number of ticks in microseconds since some
+      pre-defined time in the past.  *NOTE*: it is necessary that this
+      pre-defined time exists between runs of the application, and must
+      be (relatively) unique.  For example, the time since the system
+      started running is not a good choice, since it can be duplicated.
+      The current implementation uses time since the UNIX epoch.
+
+      @return Current time in microseconds.
+    */
+    static uInt64 getTicks() {
+      using namespace std::chrono;
+      return duration_cast<duration<uInt64, std::ratio<1, 1000000> > >
+        (system_clock::now().time_since_epoch()).count();
+    }
+
   private:
     using Lock = std::mutex;
     using ScopedLock = std::unique_lock<Lock>;

src/debugger/DebuggerParser.cxx

@@ -34,6 +34,7 @@
 #include "RomWidget.hxx"
 #include "ProgressDialog.hxx"
 #include "PackedBitArray.hxx"
+#include "TimerManager.hxx"
 #include "Vec.hxx"
 
 #include "Base.hxx"
@@ -1066,7 +1067,8 @@ void DebuggerParser::executeDump()
     }
     else
     {
-      file << std::hex << std::setw(8) << std::setfill('0') << uInt32(debugger.myOSystem.getTicks() / 1000);
+      file << std::hex << std::setw(8) << std::setfill('0')
+           << uInt32(TimerManager::getTicks() / 1000);
     }
     file << ".dump";
     FilesystemNode node(file.str());
@@ -1161,7 +1163,8 @@ void DebuggerParser::executeExec()
   }
   else {
     ostringstream prefix;
-    prefix << std::hex << std::setw(8) << std::setfill('0') << uInt32(debugger.myOSystem.getTicks()/1000);
+    prefix << std::hex << std::setw(8) << std::setfill('0')
+           << uInt32(TimerManager::getTicks()/1000);
     execPrefix = prefix.str();
   }
   ++execDepth;

src/debugger/gui/TiaOutputWidget.cxx

@@ -30,6 +30,7 @@
 #include "TIADebug.hxx"
 #include "TIASurface.hxx"
 #include "TIA.hxx"
+#include "TimerManager.hxx"
 
 #include "TiaOutputWidget.hxx"
 
@@ -70,7 +71,8 @@ void TiaOutputWidget::saveSnapshot(int execDepth, const string& execPrefix)
   if (execDepth > 0 && !execPrefix.empty()) {
     sspath << execPrefix << "_";
   }
-  sspath << std::hex << std::setw(8) << std::setfill('0') << uInt32(instance().getTicks()/1000) << ".png";
+  sspath << std::hex << std::setw(8) << std::setfill('0')
+         << uInt32(TimerManager::getTicks()/1000) << ".png";
 
   const uInt32 width  = instance().console().tia().width(),
                height = instance().console().tia().height();

src/emucore/Cart.hxx

@@ -216,7 +216,7 @@ class Cartridge : public Device
     /**
       Setter for injecting OSystem.
     */
-    virtual void setOSystem(OSystem* osystem) {};
+    virtual void setOSystem(OSystem* osystem) {}
 
   protected:
     /**

src/emucore/CartCTY.cxx

@@ -18,6 +18,7 @@
 #include "OSystem.hxx"
 #include "Serializer.hxx"
 #include "System.hxx"
+#include "TimerManager.hxx"
 #include "CartCTY.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -381,7 +382,7 @@ uInt8 CartridgeCTY::ramReadWrite()
         if(index < 7)
         {
           // Add 0.5 s delay for read
-          myRamAccessTimeout = myOSystem->getTicks() + 500000;
+          myRamAccessTimeout = TimerManager::getTicks() + 500000;
           loadTune(index);
         }
         break;
@@ -389,7 +390,7 @@ uInt8 CartridgeCTY::ramReadWrite()
         if(index < 4)
         {
           // Add 0.5 s delay for read
-          myRamAccessTimeout = myOSystem->getTicks() + 500000;
+          myRamAccessTimeout = TimerManager::getTicks() + 500000;
           loadScore(index);
         }
         break;
@@ -397,13 +398,13 @@ uInt8 CartridgeCTY::ramReadWrite()
         if(index < 4)
         {
           // Add 1 s delay for write
-          myRamAccessTimeout = myOSystem->getTicks() + 1000000;
+          myRamAccessTimeout = TimerManager::getTicks() + 1000000;
           saveScore(index);
         }
         break;
       case 4:  // Wipe all score tables
         // Add 1 s delay for write
-        myRamAccessTimeout = myOSystem->getTicks() + 1000000;
+        myRamAccessTimeout = TimerManager::getTicks() + 1000000;
         wipeAllScores();
         break;
     }
@@ -413,7 +414,7 @@ uInt8 CartridgeCTY::ramReadWrite()
   else
   {
     // Have we reached the timeout value yet?
-    if(myOSystem->getTicks() >= myRamAccessTimeout)
+    if(TimerManager::getTicks() >= myRamAccessTimeout)
     {
       myRamAccessTimeout = 0;  // Turn off timer
       myRAM[0] = 0;            // Successful operation

src/emucore/CartCTY.hxx

@@ -116,7 +116,7 @@ class CartridgeCTY : public Cartridge
       @param image     Pointer to the ROM image
       @param size      The size of the ROM image
       @param md5       The md5sum of the ROM image
-      @param osystem   A reference to the OSystem currently in use
+      @param settings  A reference to the settings object
     */
     CartridgeCTY(const BytePtr& image, uInt32 size, const string& md5,
                  const Settings& settings);

src/emucore/CartFA2.cxx

@@ -18,6 +18,7 @@
 #include "OSystem.hxx"
 #include "Serializer.hxx"
 #include "System.hxx"
+#include "TimerManager.hxx"
 #include "CartFA2.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -333,7 +334,7 @@ uInt8 CartridgeFA2::ramReadWrite()
   if(myRamAccessTimeout == 0)
   {
     // Remember when the first access was made
-    myRamAccessTimeout = myOSystem->getTicks();
+    myRamAccessTimeout = TimerManager::getTicks();
 
     // We go ahead and do the access now, and only return when a sufficient
     // amount of time has passed
@@ -372,7 +373,7 @@ uInt8 CartridgeFA2::ramReadWrite()
   else
   {
     // Have we reached the timeout value yet?
-    if(myOSystem->getTicks() >= myRamAccessTimeout)
+    if(TimerManager::getTicks() >= myRamAccessTimeout)
     {
       myRamAccessTimeout = 0;  // Turn off timer
       myRAM[255] = 0;          // Successful operation

src/emucore/CartFA2.hxx

@@ -56,7 +56,7 @@ class CartridgeFA2 : public Cartridge
       @param image     Pointer to the ROM image
       @param size      The size of the ROM image
       @param md5       The md5sum of the ROM image
-      @param osystem   A reference to the OSystem currently in use
+      @param settings  A reference to the settings object
     */
     CartridgeFA2(const BytePtr& image, uInt32 size, const string& md5,
                  const Settings& settings);

src/emucore/OSystem.cxx

@@ -158,7 +158,7 @@ bool OSystem::create()
   mySerialPort = MediaFactory::createSerialPort();
 
   // Create random number generator
-  myRandom = make_unique<Random>(uInt32(getTicks()));
+  myRandom = make_unique<Random>(uInt32(TimerManager::getTicks()));
 
   // Create PNG handler
   myPNGLib = make_unique<PNGLibrary>(*this);
@@ -595,12 +595,6 @@ string OSystem::getROMInfo(const Console& console)
   return buf.str();
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt64 OSystem::getTicks() const
-{
-  return duration_cast<duration<uInt64, std::ratio<1, 1000000> > >(system_clock::now().time_since_epoch()).count();
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 float OSystem::frameRate() const
 {
@@ -692,7 +686,7 @@ void OSystem::mainLoop()
   {
     bool wasEmulation = myEventHandler->state() == EventHandlerState::EMULATION;
 
-    myEventHandler->poll(getTicks());
+    myEventHandler->poll(TimerManager::getTicks());
     if(myQuitLoop) break;  // Exit if the user wants to quit
 
     if (!wasEmulation && myEventHandler->state() == EventHandlerState::EMULATION) {

src/emucore/OSystem.hxx

@@ -392,6 +392,8 @@ class OSystem
     */
     void resetFps();
 
+    float frameRate() const;
+
     /**
       Attempt to override the base directory that will be used by derived
       classes, and use this one instead.  Note that this is only a hint;
@@ -410,20 +412,6 @@ class OSystem
     // The following methods are system-specific and can be overrided in
     // derived classes.  Otherwise, the base methods will be used.
     //////////////////////////////////////////////////////////////////////
-    /**
-      This method returns number of ticks in microseconds since some
-      pre-defined time in the past.  *NOTE*: it is necessary that this
-      pre-defined time exists between runs of the application, and must
-      be (relatively) unique.  For example, the time since the system
-      started running is not a good choice, since it can be duplicated.
-      The current implementation uses time since the UNIX epoch.
-
-      @return Current time in microseconds.
-    */
-    virtual uInt64 getTicks() const;
-
-    float frameRate() const;
-
     /**
       This method runs the main loop.  Since different platforms
       may use different timing methods and/or algorithms, this method can

src/emucore/System.cxx

@@ -23,6 +23,7 @@
 #include "M6532.hxx"
 #include "TIA.hxx"
 #include "Cart.hxx"
+#include "TimerManager.hxx"
 #include "System.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -39,7 +40,7 @@ System::System(const OSystem& osystem, M6502& m6502, M6532& m6532,
     mySystemInAutodetect(false)
 {
   // Re-initialize random generator
-  randGenerator().initSeed(uInt32(myOSystem.getTicks()));
+  randGenerator().initSeed(uInt32(TimerManager::getTicks()));
 
   // Initialize page access table
   PageAccess access(&myNullDevice, System::PA_READ);

src/gui/ListWidget.cxx

@@ -24,8 +24,8 @@
 #include "Dialog.hxx"
 #include "FrameBuffer.hxx"
 #include "StellaKeys.hxx"
+#include "TimerManager.hxx"
 #include "ListWidget.hxx"
-#include "bspf.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 ListWidget::ListWidget(GuiObject* boss, const GUI::Font& font,
@@ -256,7 +256,7 @@ bool ListWidget::handleText(char text)
     // Only works in a useful fashion if the list entries are sorted.
     // TODO: Maybe this should be off by default, and instead we add a
     // method "enableQuickSelect()" or so ?
-    uInt64 time = instance().getTicks() / 1000;
+    uInt64 time = TimerManager::getTicks() / 1000;
     if (_quickSelectTime < time)
       _quickSelectStr = text;
     else