Add sk_parallel_for()

samplecode/SamplePathFuzz.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleCode.h"
 #include "SkView.h"
 #include "SkCanvas.h"
@@ skipping 599 matching lines @@
         }
     }
     return true;
 }
 
 #include "SkGraphics.h"
 #include "SkSurface.h"
 #include "SkTaskGroup.h"
 #include "SkTDArray.h"
 
-struct ThreadState {
-    int fSeed;
-    const SkBitmap* fBitmap;
-};
+static void path_fuzz_stroker(SkBitmap* bitmap, int seed) {
+    sk_parallel_for(100, [&](int i) {
+        int localSeed = seed + i;
 
-static void test_fuzz(ThreadState* data) {
-    FuzzPath fuzzPath;
-    fuzzPath.setStrokeOnly();
-    fuzzPath.setSeed(data->fSeed);
-    fuzzPath.randomize();
-    const SkPath& path = fuzzPath.getPath();
-    const SkPaint& paint = fuzzPath.getPaint();
-    const SkImageInfo& info = data->fBitmap->info();
-    SkCanvas* canvas(SkCanvas::NewRasterDirect(info, data->fBitmap->getPixels(),
-            data->fBitmap->rowBytes()));
-    int w = info.width() / 4;
-    int h = info.height() / 4;
-    int x = data->fSeed / 4 % 4;
-    int y = data->fSeed % 4;
-    SkRect clipBounds = SkRect::MakeXYWH(SkIntToScalar(x) * w, SkIntToScalar(y) * h, 
-        SkIntToScalar(w), SkIntToScalar(h));
-    canvas->save();
-        canvas->clipRect(clipBounds);
-        canvas->translate(SkIntToScalar(x) * w, SkIntToScalar(y) * h);
-        canvas->drawPath(path, paint);
-    canvas->restore();
-}
-
-static void path_fuzz_stroker(SkBitmap* bitmap, int seed) {
-    ThreadState states[100];
-    for (size_t i = 0; i < SK_ARRAY_COUNT(states); i++) {
-        states[i].fSeed   = seed + (int) i;
-        states[i].fBitmap = bitmap;
-    }
-    SkTaskGroup tg;
-    tg.batch(test_fuzz, states, SK_ARRAY_COUNT(states));
+        FuzzPath fuzzPath;
+        fuzzPath.setStrokeOnly();
+        fuzzPath.setSeed(localSeed);
+        fuzzPath.randomize();
+        const SkPath& path = fuzzPath.getPath();
+        const SkPaint& paint = fuzzPath.getPaint();
+        const SkImageInfo& info = bitmap->info();
+        SkCanvas* canvas(
+            SkCanvas::NewRasterDirect(info, bitmap->getPixels(), bitmap->rowBytes()));
+        int w = info.width() / 4;
+        int h = info.height() / 4;
+        int x = localSeed / 4 % 4;
+        int y = localSeed % 4;
+        SkRect clipBounds = SkRect::MakeXYWH(SkIntToScalar(x) * w, SkIntToScalar(y) * h,
+            SkIntToScalar(w), SkIntToScalar(h));
+        canvas->save();
+            canvas->clipRect(clipBounds);
+            canvas->translate(SkIntToScalar(x) * w, SkIntToScalar(y) * h);
+            canvas->drawPath(path, paint);
+        canvas->restore();
+    });
 }
 
 class PathFuzzView : public SampleView {
 public:
     PathFuzzView()
         : fOneDraw(false)
     {
     }
 protected:
     // overrides from SkEventSink
     virtual bool onQuery(SkEvent* evt) {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "PathFuzzer");
             return true;
         }
         return this->INHERITED::onQuery(evt);
     }
 
     void onOnceBeforeDraw() override {
         fIndex = 0;
-        SkImageInfo info(SkImageInfo::MakeN32Premul(SkScalarRoundToInt(width()), 
+        SkImageInfo info(SkImageInfo::MakeN32Premul(SkScalarRoundToInt(width()),
                 SkScalarRoundToInt(height())));
         offscreen.allocPixels(info);
         path_fuzz_stroker(&offscreen, fIndex);
     }
 
     virtual void onDrawContent(SkCanvas* canvas) {
         if (fOneDraw) {
             fuzzPath.randomize();
             const SkPath& path = fuzzPath.getPath();
             const SkPaint& paint = fuzzPath.getPaint();
@@ skipping 16 matching lines @@
     SkBitmap offscreen;
     FuzzPath fuzzPath;
     bool fOneDraw;
     typedef SkView INHERITED;
 };
 
 static SkView* MyFactory() { return new PathFuzzView; }
 static SkViewRegister reg(MyFactory);