Added 'threads' commandline argument, to enable/disable multi-threading.

- Still TODO is expose this in the UI, but the infrastructure is there
- For now, this defaults to off

Changes.txt

@@ -24,6 +24,9 @@
     this, further optimized the TIA rendering code.  Thanks to Thomas
     Jentzsch for the bulk of the work in this area.
 
+  * Added 'threads' commandline argument and associated UI item to
+    enable/disable multi-threading.
+
   * Updated CDF scheme to latest version from Spiceware.  In addition,
     this scheme now supports versioning, so older and newer ROMs will
     continue to work.

src/common/tv_filters/AtariNTSC.cxx

@@ -35,22 +35,6 @@ void AtariNTSC::initialize(const Setup& setup, const uInt8* palette)
 {
   init(myImpl, setup);
   initializePalette(palette);
-
-  uInt32 systemThreads = std::thread::hardware_concurrency();
-  if(systemThreads <= 1)
-  {
-    myWorkerThreads = 0;
-    myTotalThreads  = 1;
-  }
-  else
-  {
-    systemThreads = std::min(4u, systemThreads);
-
-    myWorkerThreads = systemThreads - 1;
-    myTotalThreads  = systemThreads;
-
-    myThreads = make_unique<std::thread[]>(myWorkerThreads);
-  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -82,6 +66,26 @@ void AtariNTSC::initializePalette(const uInt8* palette)
   }
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void AtariNTSC::enableThreading(bool enable)
+{
+  uInt32 systemThreads = enable ? std::thread::hardware_concurrency() : 0;
+  if(systemThreads <= 1)
+  {
+    myWorkerThreads = 0;
+    myTotalThreads  = 1;
+  }
+  else
+  {
+    systemThreads = std::min(4u, systemThreads);
+
+    myWorkerThreads = systemThreads - 1;
+    myTotalThreads  = systemThreads;
+
+    myThreads = make_unique<std::thread[]>(myWorkerThreads);
+  }
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void AtariNTSC::render(const uInt8* atari_in, const uInt32 in_width, const uInt32 in_height,
   void* rgb_out, const uInt32 out_pitch, uInt32* rgb_in)

src/common/tv_filters/AtariNTSC.hxx

@@ -51,6 +51,9 @@ class AtariNTSC
       entry_size = 2 * 14,
     };
 
+    // By default, threading is turned off
+    AtariNTSC() { enableThreading(false); }
+
     // Image parameters, ranging from -1.0 to 1.0. Actual internal values shown
     // in parenthesis and should remain fairly stable in future versions.
     struct Setup
@@ -80,6 +83,9 @@ class AtariNTSC
     void initialize(const Setup& setup, const uInt8* palette);
     void initializePalette(const uInt8* palette);
 
+    // Set up threading
+    void enableThreading(bool enable);
+
     // Set phosphor palette, for use in Blargg + phosphor mode
     void setPhosphorPalette(uInt8 palette[256][256]) {
       memcpy(myPhosphorPalette, palette, 256 * 256);

src/common/tv_filters/NTSCFilter.hxx

@@ -120,6 +120,12 @@ class NTSCFilter
       myNTSC.render(src_buf, src_width, src_height, dest_buf, dest_pitch, prev_buf);
     }
 
+    // Enable threading for the NTSC rendering
+    inline void enableThreading(bool enable)
+    {
+      myNTSC.enableThreading(enable);
+    }
+
   private:
     // Convert from atari_ntsc_setup_t values to equivalent adjustables
     void convertToAdjustable(Adjustable& adjustable,

src/emucore/Settings.cxx

@@ -139,6 +139,7 @@ Settings::Settings(OSystem& osystem)
   setInternal("avoxport", "");
   setInternal("stats", "false");
   setInternal("fastscbios", "true");
+  setInternal("threads", "false");
   setExternal("romloadcount", "0");
   setExternal("maxres", "");
 
@@ -424,6 +425,7 @@ void Settings::usage() const
     << "  -autoslot     <1|0>          Automatically switch to next save slot when state saving\n"
     << "  -stats        <1|0>          Overlay console info during emulation\n"
     << "  -fastscbios   <1|0>          Disable Supercharger BIOS progress loading bars\n"
+    << "  -threads      <1|0>          Whether to using multi-threading during emulation\n"
     << "  -snapsavedir  <path>         The directory to save snapshot files to\n"
     << "  -snaploaddir  <path>         The directory to load snapshot files from\n"
     << "  -snapname     <int|rom>      Name snapshots according to internal database or ROM\n"

src/emucore/TIASurface.cxx

@@ -56,6 +56,9 @@ TIASurface::TIASurface(OSystem& system)
   myBaseTiaSurface = myFB.allocateSurface(kTIAW*2, kTIAH);
 
   memset(myRGBFramebuffer, 0, AtariNTSC::outWidth(kTIAW) * kTIAH);
+
+  // Enable/disable threading in the NTSC TV effects renderer
+  myNTSCFilter.enableThreading(myOSystem.settings().getBool("threads"));
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -