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