Please, open developer's console to view program's output
+ +
+public final class AsyncProgram {
+ private static long start = System.currentTimeMillis();
+
+ private AsyncProgram() {
+ }
+
+ public static void main(String[] args) throws InterruptedException {
+ report(Arrays.toString(args));
+ findPrimes();
+ withoutAsync();
+ report("");
+ withAsync();
+
+ report("");
+ final Object lock = new Object();
+ Thread t = new Thread(new Runnable() {
+ @Override
+ public void run() {
+ try {
+ doRun(lock);
+ } catch (InterruptedException ex) {
+ report("Exception caught: " + ex.getMessage());
+ }
+ }
+
+ }, "Test Thread");
+ t.start();
+
+ Thread t2 = new Thread(new Runnable() {
+ @Override
+ public void run() {
+ try {
+ doRun(lock);
+ } catch (InterruptedException ex) {
+ report("Exception caught: " + ex.getMessage());
+ }
+ }
+ }, "Test Thread 2");
+ t2.start();
+
+ report("Should be main");
+ report("Now trying wait...");
+
+ synchronized (lock) {
+ report("Lock acquired");
+ lock.wait(20000);
+ }
+ report("Finished main thread");
+ }
+
+ private static void findPrimes() {
+ report("Finding primes");
+ boolean[] prime = new boolean[1000];
+ prime[2] = true;
+ prime[3] = true;
+ nextPrime: for (int i = 5; i < prime.length; i += 2) {
+ int maxPrime = (int)Math.sqrt(i);
+ for (int j = 3; j <= maxPrime; j += 2) {
+ Thread.yield();
+ if (prime[j] && i % j == 0) {
+ continue nextPrime;
+ }
+ }
+ prime[i] = true;
+ }
+ StringBuilder sb = new StringBuilder();
+ for (int i = 0; i < 1000; ++i) {
+ if (prime[i]) {
+ sb.append(i).append(' ');
+ }
+ }
+ report(sb.toString());
+ }
+
+ private static void report(String message) {
+ long current = System.currentTimeMillis() - start;
+ System.out.println("[" + Thread.currentThread().getName() + "]/" + current + ": " + message);
+ }
+
+ private static void doRun(Object lock) throws InterruptedException {
+ report("Executing timer task");
+ Thread.sleep(2000);
+ report("Calling lock.notify()");
+ synchronized (lock) {
+ lock.notify();
+ }
+ report("Finished calling lock.notify()");
+ report("Waiting 5 seconds");
+ Thread.sleep(5000);
+ report("Finished another 5 second sleep");
+
+ synchronized (lock) {
+ report("Sleep inside locked section");
+ Thread.sleep(2000);
+ report("Finished locked section");
+ }
+ }
+
+ private static void withoutAsync() {
+ report("Start sync");
+ for (int i = 0; i < 20; ++i) {
+ StringBuilder sb = new StringBuilder();
+ for (int j = 0; j <= i; ++j) {
+ sb.append(j);
+ sb.append(' ');
+ }
+ report(sb.toString());
+ }
+ report("Complete sync");
+ }
+
+ private static void withAsync() throws InterruptedException {
+ report("Start async");
+ for (int i = 0; i < 20; ++i) {
+ StringBuilder sb = new StringBuilder();
+ for (int j = 0; j <= i; ++j) {
+ sb.append(j);
+ sb.append(' ');
+ }
+ report(sb.toString());
+ if (i % 3 == 0) {
+ report("Suspend for a second");
+ Thread.sleep(1000);
+ }
+ }
+ report("2nd Thread.sleep in same method");
+ Thread.sleep(1000);
+
+ report("Throwing exception");
+ try {
+ throwException();
+ } catch (IllegalStateException e) {
+ report("Exception caught");
+ }
+ report("Complete async");
+ }
+
+ private static void throwException() {
+ Thread.yield();
+ report("Thread.yield called");
+ throw new IllegalStateException();
+ }
+}
+
+
+