{"id":457651,"date":"2025-04-28T03:10:08","date_gmt":"2025-04-28T03:10:08","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=457651"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=457651","title":{"rendered":"\u0422\u0435\u0441\u0442\u0438\u0440\u0443\u0435\u043c JEP 491 \u0432\u043c\u0435\u0441\u0442\u0435 \u0441 \u0414\u0435\u043d\u043e\u043c \u0412\u0435\u0433\u043e\u0439<\/span>"},"content":{"rendered":"
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\u041e\u0434\u0438\u043d \u0438\u0437 \u0434\u0435\u0432\u0435\u043b\u043e\u043f\u0435\u0440 \u0430\u0434\u0432\u043e\u043a\u0430\u0442\u043e\u0432 Spring Framework, \u0414\u0435\u043d \u0412\u0435\u0433\u0430, \u043d\u0430\u00a0\u0434\u043d\u044f\u0445 \u043d\u0430\u043f\u0438\u0441\u0430\u043b \u043f\u043e\u0441\u0442 \u0432\u00a0\u043e\u0434\u043d\u0443 \u0437\u0430\u043f\u0440\u0435\u0449\u0435\u043d\u043d\u0443\u044e \u0441\u043e\u0446\u0441\u0435\u0442\u044c, \u0432\u00a0\u043a\u043e\u0442\u043e\u0440\u043e\u043c \u0438\u0437\u0443\u0447\u0430\u043b \u0440\u0430\u0431\u043e\u0442\u0443 JEP 491\u00a0\u2014 Synchronize Virtual Threads without Pinning. \u0410\u0432\u0442\u043e\u0440 \u043f\u0440\u043e\u0432\u0435\u043b \u043d\u0435\u0437\u0430\u0442\u0435\u0439\u043b\u0438\u0432\u044b\u0439 \u044d\u043a\u0441\u043f\u0435\u0440\u0438\u043c\u0435\u043d\u0442, \u043d\u043e \u044d\u0444\u0444\u0435\u043a\u0442 \u043e\u0442 JEP \u043e\u0431\u043d\u0430\u0440\u0443\u0436\u0435\u043d \u043d\u0435 \u0431\u044b\u043b. \u0420\u0435\u043f\u043e\u0437\u0438\u0442\u043e\u0440\u0438\u0439<\/em><\/a> \u0441 \u043a\u043e\u0434\u043e\u043c \u044d\u043a\u0441\u043f\u0435\u0440\u0438\u043c\u0435\u043d\u0442\u0430 \u043f\u0440\u0438\u043b\u0430\u0433\u0430\u043b\u0441\u044f. \u0410\u0432\u0442\u043e\u0440 \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0438\u043b \u0432\u044b\u044f\u0441\u043d\u0438\u0442\u044c, \u0432 \u0447\u0435\u043c \u0442\u0443\u0442 \u0434\u0435\u043b\u043e… \u0438 \u044f \u0432\u044b\u044f\u0441\u043d\u0438\u043b.<\/p>\n

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\u041d\u0430\u043f\u043e\u043c\u043d\u044e, \u0432 \u0447\u0435\u043c \u0437\u0430\u043a\u043b\u044e\u0447\u0430\u0435\u0442\u0441\u044f \u0441\u0443\u0442\u044c JEP. \u0420\u0430\u043d\u0435\u0435, synchronized<\/code> \u0431\u043b\u043e\u043a ‘\u043f\u0440\u0438\u0448\u0438\u0432\u0430\u043b’ \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0439 \u0442\u0440\u0435\u0434 \u043a \u0442\u0440\u0435\u0434\u0443 \u043d\u043e\u0441\u0438\u0442\u0435\u043b\u044e. \u0418\u043d\u043e\u0433\u0434\u0430, \u044d\u0442\u043e \u043f\u0440\u0438\u0432\u043e\u0434\u0438\u043b\u043e \u043a \u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u043e \u043d\u0435\u043e\u0431\u044b\u0447\u043d\u044b\u043c \u044d\u0444\u0444\u0435\u043a\u0442\u0430\u043c, \u0432 \u0447\u0430\u0441\u0442\u043d\u043e\u0441\u0442\u0438, \u043f\u0440\u043e \u044d\u0442\u043e \u0431\u044b\u043b \u043e\u0434\u0438\u043d \u0438\u0437 \u043f\u0435\u0440\u0435\u0432\u043e\u0434\u043e\u0432<\/a> \u0432 \u043d\u0430\u0448\u0435\u043c \u0431\u043b\u043e\u0433\u0435. \u041d\u0430\u0447\u0438\u043d\u0430\u044f \u0441 Java 24 \u0442\u0430\u043a\u043e\u0433\u043e \u043f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u044f \u043d\u0435\u0442 \u0438 synchronized<\/code> \u043c\u043e\u0436\u043d\u043e \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u044c \u0441 \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u043c\u0438 \u0442\u0440\u0435\u0434\u0430\u043c\u0438 \u0431\u0435\u0437 \u043e\u043f\u0430\u0441\u0435\u043d\u0438\u0439.<\/p>\n

\u0414\u0435\u043d \u0412\u0435\u0433\u0430 \u043f\u043e\u043f\u0440\u043e\u0431\u043e\u0432\u0430\u043b \u043f\u0440\u043e\u0442\u0435\u0441\u0442\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u044d\u0442\u043e \u043f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u0435 \u043d\u0430 \u043f\u0440\u0430\u043a\u0442\u0438\u043a\u0435, \u0437\u0430\u043a\u043e\u043d\u043e\u043c\u0435\u0440\u043d\u043e \u043f\u0440\u0435\u0434\u043f\u043e\u043b\u0430\u0433\u0430\u044f, \u0447\u0442\u043e \u0442\u0435\u043f\u0435\u0440\u044c synchronized<\/code> \u0432\u043d\u0443\u0442\u0440\u0438 \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0445 \u0442\u0440\u0435\u0434\u043e\u0432 \u043d\u0435 \u0432\u044b\u0437\u043e\u0432\u0435\u0442 \u0438\u0441\u0442\u043e\u0449\u0435\u043d\u0438\u0435 \u043f\u0443\u043b\u0430 \u0442\u0440\u0435\u0434\u043e\u0432-\u043d\u043e\u0441\u0438\u0442\u0435\u043b\u0435\u0439. \u041a\u043e\u0434 \u043f\u0440\u043e\u0441\u0442, \u043a\u0430\u043a \u0442\u0440\u0438 \u043a\u043e\u043f\u0435\u0439\u043a\u0438. \u0412 \u0446\u0438\u043a\u043b\u0435 \u043c\u043d\u043e\u0433\u043e\u043a\u0440\u0430\u0442\u043d\u043e \u0441\u043e\u0437\u0434\u0430\u044e\u0442\u0441\u044f \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u044b\u0435 \u043f\u043e\u0442\u043e\u043a\u0438, \u043a\u043e\u0442\u043e\u0440\u044b\u0435: <\/p>\n

1. \u0412\u044b\u043f\u043e\u043b\u043d\u044f\u044e\u0442 \u043d\u0435\u043a\u043e\u0442\u043e\u0440\u0443\u044e \u0432\u044b\u0447\u0438\u0441\u043b\u0438\u0442\u0435\u043b\u044c\u043d\u0443\u044e \u0440\u0430\u0431\u043e\u0442\u0443
2. \u0414\u0435\u043b\u0430\u044e\u0442 Thread.sleep()<\/code> \u0432\u043d\u0443\u0442\u0440\u0438 synchronized<\/code> \u0431\u043b\u043e\u043a\u0430.<\/p>\n

\n\u041a\u043e\u0434 \u044d\u043a\u0441\u043f\u0435\u0440\u0438\u043c\u0435\u043d\u0442\u0430<\/summary>\n
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package dev.danvega;  import java.time.Duration; import java.time.Instant; import java.util.concurrent.Executors; import java.util.concurrent.ThreadFactory; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger;  public class Application {     private static final int NUM_THREADS = 5000; \/\/ Increased threads    private static final long BLOCKING_TIME_MS = 5; \/\/ Shorter sleep inside lock    private static final int CPU_WORK_ITERATIONS = 10000; \/\/ Work *outside* lock     private static final Object lock = new Object();    private static final AtomicInteger completedTasks = new AtomicInteger(0);    private static volatile double busyWorkSink = 0; \/\/ To prevent dead code elimination     \/\/ Simple CPU-bound work    private static void doCpuWork() {       double result = 0;       for (int i = 0; i < CPU_WORK_ITERATIONS; i++) {          result += Math.sin(i) * Math.cos(i);       }       \/\/ Use the result to prevent optimization       busyWorkSink += result;    }     public static void main(String[] args) throws InterruptedException {       System.out.println(\"Running with Java version: \" + System.getProperty(\"java.version\"));       System.out.printf(\"Launching %,d virtual threads...\\n\", NUM_THREADS);       System.out.printf(\"Each thread does CPU work (%,d iterations), then acquires lock and blocks for %d ms.\\n\",               CPU_WORK_ITERATIONS, BLOCKING_TIME_MS);        ThreadFactory factory = Thread.ofVirtual().factory();       try (var executor = Executors.newThreadPerTaskExecutor(factory)) {           Instant start = Instant.now();           for (int i = 0; i < NUM_THREADS; i++) {             executor.submit(() -> {                try {                   \/\/ This work can run concurrently if carrier threads are available.                   doCpuWork();                   synchronized (lock) {                      \/\/ Short sleep *inside* the lock                      \/\/ JDK 21: Pins carrier, making it unavailable for others' doCpuWork()                      \/\/ JDK 24: Unmounts carrier, allowing it to run others' doCpuWork()                      Thread.sleep(Duration.ofMillis(BLOCKING_TIME_MS));                   }                   completedTasks.incrementAndGet();                } catch (InterruptedException e) {                   Thread.currentThread().interrupt();                   System.err.println(\"Thread interrupted: \" + e.getMessage());                } catch (Exception e) {                   System.err.println(\"Error in task: \" + e.getMessage());                   e.printStackTrace(); \/\/ Print stack trace for unexpected errors                }             });          }           executor.shutdown();          boolean finished = executor.awaitTermination(5, TimeUnit.MINUTES);           Instant end = Instant.now();          Duration duration = Duration.between(start, end);           if (finished) {             System.out.printf(\"All %,d tasks completed.\\n\", completedTasks.get());             System.out.printf(\"Total execution time: %.3f seconds\\n\", duration.toMillis() \/ 1000.0);          } else {             System.err.printf(\"Executor timed out after 5 minutes. Tasks completed: %,d\\n\", completedTasks.get());          }       }       System.out.println(\"----------------------------------------\");       \/\/ Print sink value to ensure work wasn't optimized away       \/\/ System.out.println(\"Sink value (ignore): \" + busyWorkSink);    } }<\/code><\/pre>\n<\/div>\n<\/details>\n
\u0427\u0442\u043e \u043e\u0436\u0438\u0434\u0430\u0435\u043c<\/h2>\n
\u0410\u0432\u0442\u043e\u0440 \u043e\u043f\u0438\u0441\u0430\u043b \u0441\u0432\u043e\u0438 \u043e\u0436\u0438\u0434\u0430\u043d\u0438\u044f \u043a\u0430\u043a \u0440\u0430\u0437 \u0432\u043d\u0443\u0442\u0440\u0438 synchronized<\/code> \u0431\u043b\u043e\u043a\u0430.<\/p>\n
synchronized (lock) {     \/\/ Short sleep *inside* the lock     \/\/ JDK 21: Pins carrier, making it unavailable for others' doCpuWork()     \/\/ JDK 24: Unmounts carrier, allowing it to run others' doCpuWork()     Thread.sleep(Duration.ofMillis(BLOCKING_TIME_MS)); }<\/code><\/pre>\n