java.lang.Thread.activeCount()方法的使用及代码示例

x33g5p2x  于2022-01-16 转载在 其他  
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本文整理了Java中java.lang.Thread.activeCount()方法的一些代码示例，展示了Thread.activeCount()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Thread.activeCount()方法的具体详情如下：
包路径：java.lang.Thread
类名称：Thread
方法名：activeCount

Thread.activeCount介绍

[英]Returns an estimate of the number of active threads in the current thread's java.lang.ThreadGroup and its subgroups. Recursively iterates over all subgroups in the current thread's thread group.

The value returned is only an estimate because the number of threads may change dynamically while this method traverses internal data structures, and might be affected by the presence of certain system threads. This method is intended primarily for debugging and monitoring purposes.
[中]返回当前线程的java中活动线程数的估计值。lang.ThreadGroup及其子组。递归迭代当前线程的线程组中的所有子组。
返回的值只是一个估计值，因为当此方法遍历内部数据结构时，线程的数量可能会动态变化，并且可能会受到某些系统线程的影响。此方法主要用于调试和监视目的。

代码示例

代码示例来源：origin: brianfrankcooper/YCSB

/**
 * Measure the estimated active thread count in the current thread group.
 * Since this calls {@link Thread.activeCount} it should be called from the
 * main thread or one started by the main thread. Threads included in the
 * count can be in any state.
 * For a more accurate count we could use {@link Thread.getAllStackTraces().size()}
 * but that freezes the JVM and incurs a high overhead.
 * @return An estimated thread count, good for showing the thread count
 * over time.
 */
public static int getActiveThreadCount() {
 return Thread.activeCount();
}

代码示例来源：origin: apache/ignite

/**
 * @param threadId Thread ID.
 * @return Thread name if found.
 */
public static String threadName(long threadId) {
  Thread[] threads = new Thread[Thread.activeCount()];
  int cnt = Thread.enumerate(threads);
  for (int i = 0; i < cnt; i++)
    if (threads[i].getId() == threadId)
      return threads[i].getName();
  return "<failed to find active thread " + threadId + '>';
}

代码示例来源：origin: objectbox/objectbox-java

/** dump thread stacks if pool does not terminate promptly. */
private void checkThreadTermination() {
  try {
    if (!threadPool.awaitTermination(1, TimeUnit.SECONDS)) {
      int activeCount = Thread.activeCount();
      System.err.println("Thread pool not terminated in time; printing stack traces...");
      Thread[] threads = new Thread[activeCount + 2];
      int count = Thread.enumerate(threads);
      for (int i = 0; i < count; i++) {
        System.err.println("Thread: " + threads[i].getName());
        Thread.dumpStack();
      }
    }
  } catch (InterruptedException e) {
    e.printStackTrace();
  }
}

代码示例来源：origin: loklak/loklak_server

public static JSONObject getSystemConfig(Runtime runtime) throws Exception {
  JSONObject system = new JSONObject();
  String xmx = DAO.getConfig("Xmx", "");
  system.put("assigned_memory", runtime.maxMemory());
  system.put("used_memory", runtime.totalMemory() - runtime.freeMemory());
  system.put("available_memory", runtime.maxMemory() - runtime.totalMemory() + runtime.freeMemory());
  system.put("cores", runtime.availableProcessors());
  system.put("threads", Thread.activeCount());
  system.put("runtime", System.currentTimeMillis() - Caretaker.startupTime);
  system.put("time_to_restart", Caretaker.upgradeTime - System.currentTimeMillis());
  system.put("load_system_average", OS.getSystemLoadAverage());
  Double systemCpuLoad = OS.getSystemCpuLoad();
  system.put("load_system_cpu", systemCpuLoad.isNaN() || systemCpuLoad.isInfinite() ? 0 : systemCpuLoad.doubleValue());
  system.put("load_process_cpu", systemCpuLoad.isNaN() || systemCpuLoad.isInfinite() ? 0 : systemCpuLoad);
  system.put("server_threads", LoklakServer.getServerThreads());
  system.put("server_uri", LoklakServer.getServerURI());
  system.put("Xmx", xmx);
  return system;
}

代码示例来源：origin: jphp-group/jphp

@Signature
public static Memory getActiveCount(Environment env, Memory... args){
  return LongMemory.valueOf(Thread.activeCount());
}

代码示例来源：origin: plantuml/plantuml

public static Collection<String> interestingValues() {
  final List<String> strings = new ArrayList<String>();
  if (withIp() == false) {
    strings.add("Machine: " + getHostName());
  }
  strings.add("PLANTUML_LIMIT_SIZE: " + GraphvizUtils.getenvImageLimit());
  strings.add("Processors: " + Runtime.getRuntime().availableProcessors());
  final long freeMemory = Runtime.getRuntime().freeMemory();
  final long maxMemory = Runtime.getRuntime().maxMemory();
  final long totalMemory = Runtime.getRuntime().totalMemory();
  final long usedMemory = totalMemory - freeMemory;
  final int threadActiveCount = Thread.activeCount();
  strings.add("Max Memory: " + format(maxMemory));
  strings.add("Total Memory: " + format(totalMemory));
  strings.add("Free Memory: " + format(freeMemory));
  strings.add("Used Memory: " + format(usedMemory));
  strings.add("Thread Active Count: " + threadActiveCount);
  return Collections.unmodifiableCollection(strings);
}

代码示例来源：origin: AsyncHttpClient/async-http-client

private static Thread[] getThreads() {
 int count = Thread.activeCount() + 1;
 for (; ; ) {
  Thread[] threads = new Thread[count];
  int filled = Thread.enumerate(threads);
  if (filled < threads.length) {
   return Arrays.copyOf(threads, filled);
  }
  count *= 2;
 }
}

代码示例来源：origin: SonarSource/sonarqube

@Test
public void constructor_does_not_start_a_new_Thread() throws IOException {
 int activeCount = Thread.activeCount();
 newCeServer();
 assertThat(Thread.activeCount()).isSameAs(activeCount);
}

代码示例来源：origin: apache/pulsar

@SuppressWarnings("deprecation")
public void sleepServer(final int seconds, final CountDownLatch l) throws InterruptedException, IOException {
  Thread[] allthreads = new Thread[Thread.activeCount()];
  Thread.enumerate(allthreads);
  for (final Thread t : allthreads) {
    if (t.getName().contains("SyncThread:0")) {
      Thread sleeper = new Thread() {
        public void run() {
          try {
            t.suspend();
            l.countDown();
            Thread.sleep(seconds * 1000);
            t.resume();
          } catch (Exception e) {
            LOG.error("Error suspending thread", e);
          }
        }
      };
      sleeper.start();
      return;
    }
  }
  throw new IOException("ZooKeeper thread not found");
}

代码示例来源：origin: SonarSource/sonarqube

@Test
public void start_starts_a_new_Thread() throws IOException {
 int activeCount = Thread.activeCount();
 newCeServer().start();
 assertThat(Thread.activeCount()).isSameAs(activeCount + 1);
}

代码示例来源：origin: apache/kafka

@Test
public void testHeartbeatThreadClose() throws Exception {
  ConsumerCoordinator coordinator = prepareCoordinatorForCloseTest(true, true, true);
  coordinator.ensureActiveGroup();
  time.sleep(heartbeatIntervalMs + 100);
  Thread.yield(); // Give heartbeat thread a chance to attempt heartbeat
  closeVerifyTimeout(coordinator, Long.MAX_VALUE, requestTimeoutMs, requestTimeoutMs);
  Thread[] threads = new Thread[Thread.activeCount()];
  int threadCount = Thread.enumerate(threads);
  for (int i = 0; i < threadCount; i++)
    assertFalse("Heartbeat thread active after close", threads[i].getName().contains(groupId));
}

代码示例来源：origin: reactor/reactor-core

@Test
public void testCustomRequestTaskThreadName() {
  String expectedName = "topicProcessorRequestTaskCreate";
  //NOTE: the below single executor should not be used usually as requestTask assumes it immediately gets executed
  ExecutorService customTaskExecutor = Executors.newSingleThreadExecutor(r -> new Thread(r, expectedName));
  TopicProcessor<Object> processor = TopicProcessor.builder()
      .executor(Executors.newCachedThreadPool())
      .requestTaskExecutor(customTaskExecutor)
      .bufferSize(8)
      .waitStrategy(WaitStrategy.liteBlocking())
      .autoCancel(true)
      .build();
  processor.requestTask(Operators.cancelledSubscription());
  Thread[] threads = new Thread[Thread.activeCount()];
  Thread.enumerate(threads);
  //cleanup to avoid visibility in other tests
  customTaskExecutor.shutdownNow();
  processor.forceShutdown();
  Condition<Thread> customRequestTaskThread = new Condition<>(
      thread -> thread != null && expectedName.equals(thread.getName()),
      "a thread named \"%s\"", expectedName);
  Assertions.assertThat(threads)
       .haveExactly(1, customRequestTaskThread);
}

代码示例来源：origin: reactor/reactor-core

@Test
public void testDefaultRequestTaskThreadName() {
  String mainName = "topicProcessorRequestTask";
  String expectedName = mainName + "[request-task]";
  TopicProcessor<Object> processor = TopicProcessor.builder().name(mainName).bufferSize(8).build();
  processor.requestTask(Operators.cancelledSubscription());
  Thread[] threads = new Thread[Thread.activeCount()];
  Thread.enumerate(threads);
  //cleanup to avoid visibility in other tests
  processor.forceShutdown();
  Condition<Thread> defaultRequestTaskThread = new Condition<>(
      thread -> thread != null && expectedName.equals(thread.getName()),
      "a thread named \"%s\"", expectedName);
  Assertions.assertThat(threads)
       .haveExactly(1, defaultRequestTaskThread);
}

代码示例来源：origin: reactor/reactor-core

@Test
public void testDefaultRequestTaskThreadName() {
  String mainName = "workQueueProcessorRequestTask";
  String expectedName = mainName + "[request-task]";
  WorkQueueProcessor<Object> processor = WorkQueueProcessor.builder().name(mainName).bufferSize(8).build();
  processor.requestTask(Operators.cancelledSubscription());
  Thread[] threads = new Thread[Thread.activeCount()];
  Thread.enumerate(threads);
  //cleanup to avoid visibility in other tests
  processor.forceShutdown();
  Condition<Thread> defaultRequestTaskThread = new Condition<>(
      thread -> thread != null && expectedName.equals(thread.getName()),
      "a thread named \"%s\"", expectedName);
  Assertions.assertThat(threads)
       .haveExactly(1, defaultRequestTaskThread);
}

代码示例来源：origin: reactor/reactor-core

@Test
public void testCustomRequestTaskThreadShare() {
  String expectedName = "topicProcessorRequestTaskShare";
  //NOTE: the below single executor should not be used usually as requestTask assumes it immediately gets executed
  ExecutorService customTaskExecutor = Executors.newSingleThreadExecutor(r -> new Thread(r, expectedName));
  TopicProcessor<Object> processor = TopicProcessor.builder().share(true)
      .executor(Executors.newCachedThreadPool())
      .requestTaskExecutor(customTaskExecutor)
      .bufferSize(8)
      .waitStrategy(WaitStrategy.liteBlocking())
      .autoCancel(true)
      .build();
  processor.requestTask(Operators.cancelledSubscription());
  Thread[] threads = new Thread[Thread.activeCount()];
  Thread.enumerate(threads);
  //cleanup to avoid visibility in other tests
  customTaskExecutor.shutdownNow();
  processor.forceShutdown();
  Condition<Thread> customRequestTaskThread = new Condition<>(
      thread -> thread != null && expectedName.equals(thread.getName()),
      "a thread named \"%s\"", expectedName);
  Assertions.assertThat(threads)
       .haveExactly(1, customRequestTaskThread);
}

代码示例来源：origin: reactor/reactor-core

@Test
public void testCustomRequestTaskThreadNameCreate() {
  String expectedName = "workQueueProcessorRequestTaskCreate";
  //NOTE: the below single executor should not be used usually as requestTask assumes it immediately gets executed
  ExecutorService customTaskExecutor = Executors.newSingleThreadExecutor(r -> new Thread(r, expectedName));
  WorkQueueProcessor<Object> processor = WorkQueueProcessor.builder()
      .executor(Executors.newCachedThreadPool())
      .requestTaskExecutor(customTaskExecutor)
      .bufferSize(8)
      .waitStrategy(WaitStrategy.liteBlocking())
      .autoCancel(true)
      .build();
  processor.requestTask(Operators.cancelledSubscription());
  processor.subscribe();
  Thread[] threads = new Thread[Thread.activeCount()];
  Thread.enumerate(threads);
  //cleanup to avoid visibility in other tests
  customTaskExecutor.shutdownNow();
  processor.forceShutdown();
  Condition<Thread> customRequestTaskThread = new Condition<>(
      thread -> thread != null && expectedName.equals(thread.getName()),
      "a thread named \"%s\"", expectedName);
  Assertions.assertThat(threads)
       .haveExactly(1, customRequestTaskThread);
}

代码示例来源：origin: reactor/reactor-core

@Test(timeout = 15000L)
public void cancelDoesNotHang() throws Exception {
  WorkQueueProcessor<String> wq = WorkQueueProcessor.create();
  Disposable d = wq.subscribe();
  Assert.assertTrue(wq.downstreamCount() == 1);
  d.dispose();
  while (wq.downstreamCount() != 0 && Thread.activeCount() > 2) {
  }
}

代码示例来源：origin: reactor/reactor-core

@Test(timeout = 15000L)
public void completeDoesNotHang() throws Exception {
  WorkQueueProcessor<String> wq = WorkQueueProcessor.create();
  wq.subscribe();
  Assert.assertTrue(wq.downstreamCount() == 1);
  wq.onComplete();
  while (wq.downstreamCount() != 0 && Thread.activeCount() > 2) {
  }
}

代码示例来源：origin: reactor/reactor-core

@Test()
public void retryNoThreadLeak() throws Exception {
  WorkQueueProcessor<Integer> wq = WorkQueueProcessor.<Integer>builder().autoCancel(false).build();
  wq.handle((integer, sink) -> sink.error(new RuntimeException()))
   .retry(10)
   .subscribe();
  wq.onNext(1);
  wq.onNext(2);
  wq.onNext(3);
  wq.onComplete();
  while (wq.downstreamCount() != 0 && Thread.activeCount() > 1) {
  }
}

代码示例来源：origin: reactor/reactor-core

@Test(timeout = 15000L)
public void disposeSubscribeNoThreadLeak() throws Exception {
  WorkQueueProcessor<String> wq = WorkQueueProcessor.<String>builder().autoCancel(false).build();
  Disposable d = wq.subscribe();
  d.dispose();
  d = wq.subscribe();
  d.dispose();
  d = wq.subscribe();
  d.dispose();
  while (wq.downstreamCount() != 0 && Thread.activeCount() > 2) {
  }
}

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