并发测试 JavaDemo

https://github.com/oldratlee/fucking-java-concurrency




             



 



/**



 * @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;



 }



}