Mathieu Chartier | e4a91bb | 2015-01-28 13:11:44 -0800 | [diff] [blame^] | 1 | |
| 2 | public class Main { |
| 3 | static class SuperClass { |
| 4 | protected static int getVar(int w) { |
| 5 | return w & 0xF; |
| 6 | } |
| 7 | } |
| 8 | static class SubClass extends SuperClass { |
| 9 | final int getVarDirect(int w) { |
| 10 | return w & 0xF; |
| 11 | } |
| 12 | public void testDirect(int max) { |
| 13 | for (int i = 0; i < max; ++i) { |
| 14 | getVarDirect(max); |
| 15 | } |
| 16 | } |
| 17 | public void testStatic(int max) { |
| 18 | for (int i = 0; i < max; ++i) { |
| 19 | getVar(max); |
| 20 | } |
| 21 | } |
| 22 | } |
| 23 | |
| 24 | static public void main(String[] args) throws Exception { |
| 25 | boolean timing = (args.length >= 1) && args[0].equals("--timing"); |
| 26 | run(timing); |
| 27 | } |
| 28 | |
| 29 | static int testBasis(int interations) { |
| 30 | (new SubClass()).testDirect(interations); |
| 31 | return interations; |
| 32 | } |
| 33 | |
| 34 | static int testStatic(int interations) { |
| 35 | (new SubClass()).testStatic(interations); |
| 36 | return interations; |
| 37 | } |
| 38 | |
| 39 | static public void run(boolean timing) { |
| 40 | long time0 = System.nanoTime(); |
| 41 | int count1 = testBasis(50000000); |
| 42 | long time1 = System.nanoTime(); |
| 43 | int count2 = testStatic(50000000); |
| 44 | long time2 = System.nanoTime(); |
| 45 | |
| 46 | System.out.println("basis: performed " + count1 + " iterations"); |
| 47 | System.out.println("test1: performed " + count2 + " iterations"); |
| 48 | |
| 49 | double basisMsec = (time1 - time0) / (double) count1 / 1000000; |
| 50 | double msec1 = (time2 - time1) / (double) count2 / 1000000; |
| 51 | |
| 52 | if (msec1 < basisMsec * 5) { |
| 53 | System.out.println("Timing is acceptable."); |
| 54 | } else { |
| 55 | System.out.println("Iterations are taking too long!"); |
| 56 | timing = true; |
| 57 | } |
| 58 | if (timing) { |
| 59 | System.out.printf("basis time: %.3g msec\n", basisMsec); |
| 60 | System.out.printf("test1: %.3g msec per iteration\n", msec1); |
| 61 | } |
| 62 | } |
| 63 | } |