| /** | |
| * @author Jerry Lee | |
| */ | |
| public class Testee { | |
| static long countTimeIn500ms = 0; | |
| public static void main(String[] args) throws Exception { | |
| countTimeIn500ms = guessCountTimeIn500ms(); | |
| Thread runAndSleepTask = new Thread(new RunAndSleepTask(), "RunAndSleepTask"); | |
| Thread runAndWaitTask = new Thread(new RunAndWaitTask(), "RunAndWaitTask"); | |
| Thread runAndLongSleepTask = new Thread(new RunAndLongSleepTask(), "RunAndLongSleepTask"); | |
| runAndSleepTask.start(); | |
| runAndWaitTask.start(); | |
| runAndLongSleepTask.start(); | |
| System.out.println("Tasks started!"); | |
| Thread.sleep(Long.MAX_VALUE); | |
| } | |
| public static class RunAndSleepTask implements Runnable { | |
| @Override | |
| public void run() { | |
| String name = this.getClass().getSimpleName(); | |
| while (true) { | |
| for (long i = 0; i < countTimeIn500ms; i++) { | |
| } | |
| System.out.println(name + ": " + new Date()); | |
| try { | |
| Thread.sleep(500); | |
| } catch (InterruptedException e) { | |
| e.printStackTrace(); | |
| } | |
| } | |
| } | |
| } | |
| public static class RunAndWaitTask implements Runnable { | |
| @Override | |
| public void run() { | |
| String name = this.getClass().getSimpleName(); | |
| while (true) { | |
| for (long i = 0; i < countTimeIn500ms; i++) { | |
| } | |
| try { | |
| System.out.println(name + ": " + new Date()); | |
| synchronized (this) { | |
| this.wait(500); | |
| } | |
| } catch (InterruptedException e) { | |
| e.printStackTrace(); | |
| } | |
| } | |
| } | |
| } | |
| public static class RunAndLongSleepTask implements Runnable { | |
| @Override | |
| public void run() { | |
| String name = this.getClass().getSimpleName(); | |
| while (true) { | |
| for (long i = 0; i < countTimeIn500ms; i++) { | |
| } | |
| System.out.println(name + ": " + new Date()); | |
| try { | |
| Thread.sleep(5000); | |
| } catch (InterruptedException e) { | |
| e.printStackTrace(); | |
| } | |
| } | |
| } | |
| } | |
| /** | |
| * @return 100ms可以做{@code long}的计数次数。 | |
| */ | |
| static long guessCountTimeIn500ms() { | |
| System.out.println("start guess."); | |
| long count = 1000L * 1000 * 1000; | |
| // simple warm-up | |
| for (long i = 0; i < count; i++) { | |
| // nothing! | |
| } | |
| long tick = System.currentTimeMillis(); | |
| for (long i = 0; i < count; i++) { | |
| // nothing! | |
| } | |
| long duration = System.currentTimeMillis() - tick; | |
| System.out.printf("1G times count take %d ms.\n", duration); | |
| return count * 500 / duration; | |
| } | |
| } |