Question

我正在学习Android Studio中的工具，获取线程转储，如下所示：

我注意到像这样的每个线程的不同状态，

我可以看到有runnable，sleeping，waiting。我深入到线程堆栈，大多数线程堆栈都是这样，

"<61> RxComputationScheduler-3@830064517520" daemon prio=5 waiting
    java.lang.Thread.State: WAITING
        at java.lang.Object.wait(Object.java:-1)
        at java.lang.Thread.parkFor(Thread.java:1205)
        at sun.misc.Unsafe.park(Unsafe.java:325)
        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:157)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2017)
        at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1050)
        at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:778)
        at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1035)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1097)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
        at java.lang.Thread.run(Thread.java:841)

我很困惑他们都在Object.wait暂停了，但线程的状态可以是runnable，sleeping，waiting？

这是另一个状态线程的堆栈。

RUNNABLE

<53> RxSchedulerPurge-1@830057651944" daemon prio=5 runnable
  java.lang.Thread.State: RUNNABLE
      at java.lang.Object.wait(Object.java:-1)
      at java.lang.Thread.parkFor(Thread.java:1205)
      at sun.misc.Unsafe.park(Unsafe.java:325)
      at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:197)
      at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2056)
      at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1062)
      at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:778)
      at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1035)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1097)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
      at java.lang.Thread.run(Thread.java:841)</code>

TIMED_WAITING

<58> RxScheduledExecutorPool-2@830064740632" daemon prio=5 sleeping
  java.lang.Thread.State: TIMED_WAITING
      at java.lang.Object.wait(Object.java:-1)
      at java.lang.Thread.parkFor(Thread.java:1205)
      at sun.misc.Unsafe.park(Unsafe.java:325)
      at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:197)
      at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2056)
      at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1062)
      at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:778)
      at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1035)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1097)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
      at java.lang.Thread.run(Thread.java:841)

Answer 1

新表示如果您创建Thread类的实例但在调用start()方法之前线程处于新状态：

Thread t = new Thread(...); // t is New

Runnable 表示调用start()方法后线程处于可运行状态。基本上是：

t.start(); // t is Runnable

运行是 Runnable 的“子状态”：如果线程调度程序选择了线程，则线程处于运行状态。您无法明确地执行任何操作，这意味着您调用start()然后等待。

就绪是 Runnable 的另一个“子状态”：该线程有资格运行并等待线程调度程序选择它。

已阻止表示线程仍处于活动状态但当前无法运行的状态。例如，当一个线程遇到synchronized块时，会发生这种情况，该块由另一个线程处理。在这种情况下，第一个帖子变为被阻止。

等待是您的帖子既不是被阻止也不是准备好的状态。当您在某个主题上调用wait()或join()时，通常会发生这种情况。

Thread t1 = new Thread(); // t1 is New
Thread t2 = new Thread(); // t2 is New
t1.start(); // t1 becomes Runnable
t2.start(); // t2 becomes Runnable
t1.join(); // t2 becomes Waiting, because t1 is processed until it terminates

还有一个名为定时等待的状态，这几乎是一样的，但是由调用sleep()引起。如果您致电wait(timeout)或join(timeout)，该主题也会获得定时等待状态。

Thread t = new Thread(); // t is New
t.start(); // t is Runnable
t.sleep(4000); // t get state of Timed Waiting for 4 seconds

终止是处于run()方法退出时处于已终止或处于停止状态的线程。

我想我已经涵盖了所有内容:)这是一张图片，可以帮助您更清楚地理解它：

正如JoxTraex所要求的，这是我在发布之前阅读的资料：

https://docs.oracle.com/javase/7/docs/api/java/lang/Thread.State.html
javarush.ru
http://www.uml-diagrams.org/examples/java-6-thread-state-machine-diagram-example.html
http://www.journaldev.com/1044/thread-life-cycle-in-java-thread-states-in-java

这只是一个很好的谷歌搜索技巧，真的......

Answer 2

localStorage

线程状态。线程可以处于以下状态之一：

public static enum Thread.State
extends Enum<Thread.State>

线程在给定时间点只能处于一种状态。这些状态是虚拟机状态，不反映任何操作系统线程状态。

请参阅oracle's api以获取更多信息。

java线程的状态究竟意味着什么？

2 个答案: