362ms -> 198ms. Replace shared_ptr's with raw pointers (#2)

- smart pointers? more like suck pointers

results/benchmark.txt

@@ -1,5 +1,5 @@
 ----------------------------------------------------------------------------
 Benchmark                                  Time             CPU   Iterations
 ----------------------------------------------------------------------------
-BM_NextBoard/min_time:5.000              356 ms          356 ms           20
-BM_RenderNextBoard/min_time:5.000        362 ms          362 ms           19
+BM_NextBoard/min_time:5.000              190 ms          190 ms           36
+BM_RenderNextBoard/min_time:5.000        198 ms          196 ms           35

src/board/board.h

@@ -10,5 +10,5 @@ using Cell = Uint32;
 const Cell ALIVE = SDL_MAX_UINT32;
 const Cell DEAD = 0;
 
-using Board = std::tuple<std::shared_ptr<Cell[]>, int, int>;
+using Board = std::tuple<Cell*, int, int>;
 using NeighbourPositions = std::array<int, 8>;

src/board/generate.cpp

@@ -7,7 +7,7 @@
 #include <tuple>
 
 Board randomBoard(int width, int height) {
-  auto board = std::shared_ptr<Cell[]>(new Cell[width * height]);
+  auto board = new Cell[width * height];
   for (int i = 0; i < height * width; ++i)
     board[i] = rand() % 2 ? ALIVE : DEAD;
   return {board, width, height};
@@ -25,7 +25,7 @@ Board benchmarkBoard(int width, int height) {
         "Did not meet minimum height required for the benchmark board");
 
   srand(0);
-  auto board = std::shared_ptr<Cell[]>(new Cell[width * height]);
+  auto board = new Cell[width * height];
   for (int y = 0; y < height; ++y) {
     for (int x = 0; x < width; ++x) {
       const int i = y * width + x;

src/board/next.cpp

@@ -13,7 +13,7 @@ Board nextBoard(Board board) {
   if (width == 0)
     return board;
 
-  auto output = std::shared_ptr<Cell[]>(new Cell[width*height]);
+  auto output = new Cell[width*height];
 
   for (int y = 0; y < height; y++) {
     for (int x = 0; x < width; x++) {
@@ -52,5 +52,7 @@ Board nextBoard(Board board) {
     }
   }
 
+  free(input);
+
   return {output, width, height};
 }

src/entrypoints/benchmark.cpp

@@ -13,6 +13,8 @@ static void BM_NextBoard(benchmark::State &state) {
   for (auto _ : state) {
     board = nextBoard(board);
   }
+
+  free(get<0>(board));
 }
 
 static void BM_RenderNextBoard(benchmark::State &state) {
@@ -36,6 +38,8 @@ static void BM_RenderNextBoard(benchmark::State &state) {
   SDL_DestroyRenderer(renderer);
   SDL_DestroyWindow(window);
   SDL_Quit();
+
+  free(get<0>(board));
 }
 
 BENCHMARK(BM_NextBoard)->Unit(benchmark::kMillisecond)->MinTime(5);

src/entrypoints/interactive.cpp

@@ -41,6 +41,7 @@ int main() {
       else if (event.type == SDL_KEYDOWN &&
                event.key.keysym.scancode == SDL_SCANCODE_RETURN) {
 
+        free(get<0>(board));
         board = boardForSdlWindow(window);
         int width, height;
         SDL_GetWindowSize(window, &width, &height);
@@ -59,6 +60,8 @@ int main() {
     stopProfiling(p3, "Rendered next board");
   }
 
+  free(get<0>(board));
+
   SDL_DestroyTexture(texture);
   SDL_DestroyRenderer(renderer);
   SDL_DestroyWindow(window);

src/entrypoints/test.cpp

@@ -7,7 +7,7 @@ Board generate(std::vector<std::vector<Cell>> input) {
   const auto height = (int)input.size();
   const auto width = (int)input[0].size();
 
-  auto board = std::shared_ptr<Cell[]>(new Cell[width * height]);
+  auto board = new Cell[width * height];
   for (int y = 0; y < height; ++y)
     for (int x = 0; x < width; ++x)
       board[y * width + x] = input[y][x] ? ALIVE : DEAD;