/** Test that MT is faster then ST. Assumes we always run on a MT box */ public void _testMTFaster() { // TODO: this test does not always works so removing for now int size1 = 800; int size2 = 800; byte state1 = Grid.INSIDE; byte state2 = Grid.INSIDE; Grid grid1 = new ArrayGridByte(size1, size1, size1, 0.001, 0.001); Grid grid2 = new ArrayGridByte(size2, size2, size2, 0.002, 0.002); Grid grid3 = new ArrayGridByte(size2, size2, size2, 0.002, 0.002); for (int y = 0; y < grid1.getHeight(); y++) { for (int x = 0; x < grid1.getWidth(); x++) { for (int z = 0; z < grid1.getDepth(); z++) { grid1.setState(x, y, z, state1); } } } for (int y = 0; y < grid2.getHeight(); y++) { for (int x = 0; x < grid2.getWidth(); x++) { for (int z = 0; z < grid2.getDepth(); z++) { grid2.setState(x, y, z, state1); } } } int WARMUP = 3; long st_time = 0; for (int i = 0; i < WARMUP; i++) { long t0 = System.currentTimeMillis(); // get the subtraction of grid1 from grid2 SubtractOpMT op = new SubtractOpMT(grid1, Runtime.getRuntime().availableProcessors()); Grid subtrGridMT = op.execute(grid2); long mt_time = System.currentTimeMillis() - t0; t0 = System.currentTimeMillis(); SubtractOp op2 = new SubtractOp(grid1, 0, 0, 0, 1); Grid subtrGridST = op2.execute(grid2); st_time = System.currentTimeMillis() - t0; // printf("MT time: %6d ST time: %6d SpeedUp: %6.2f\n",mt_time,st_time,(float)st_time / // mt_time); } int TIMES = 1; int cores = Runtime.getRuntime().availableProcessors(); cores = Math.min(cores, 16); // We expect linear scaling to stop by this time float expected_speedup = 0.5f * cores; for (int i = 0; i < TIMES; i++) { long t0 = System.currentTimeMillis(); // get the subtraction of grid1 from grid2 SubtractOpMT op = new SubtractOpMT(grid1, Runtime.getRuntime().availableProcessors()); op.setThreadCount(cores); op.setSliceSize(2); Grid subtrGridMT = op.execute(grid2); if (subtrGridMT.getWidth() > 10000) { System.out.println("no optimize away"); } ; long mt_time = System.currentTimeMillis() - t0; float speedup = (float) st_time / mt_time; printf("MT time: %6d ST time: %6d SpeedUp: %6.2f\n", mt_time, st_time, speedup); assertTrue("Speedup factor > " + expected_speedup, speedup >= expected_speedup); } }