Shulou(Shulou.com)05/31 Report--

This article is to share with you about the thread class Thread method is what, the editor feels very practical, so share with you to learn, I hope you can get something after reading this article, say no more, follow the editor to have a look.

1) currentThread (): public static Thread currentThread () description: returns a reference to the currently executing thread object, that is, the thread object that calls the current code.

2) join (): public final void join (long millis) throws InterruptedException parameter: the waiting time is optional. If left empty, the default is 0. Note: 1 > force the thread that calls the join method to run. Within milliseconds after the thread starts, other threads cannot run. 2 > if the value of millis is 0, it means that other threads cannot run while the thread is running and must wait until the thread ends before other threads can run. 3 > the join (long) method is the wait effect achieved by internally calling the wait (long) method. 3) setDaemon (): public final void setDaemon (boolean on) description: Mark the thread as a background thread. This method must be called before the thread (start () method) is started, otherwise an IllegalThreadStateException exception is reported. Add: background thread: run in the background, the task is to provide services for other threads. Also known as "daemon thread" or "sprite thread". Garbage collection in JVM is a typical background thread. Features: 1 > if all the foreground threads die, the background threads die automatically. 2 > the thread created by the foreground thread is the foreground thread by default. IsDaemon (): public final boolean isDaemon () description: determine whether it is a background thread: 4) sleep (): public static void sleep (long millis) throws InterruptedException description: let the currently executing thread sleep (pause) the specified number of milliseconds Comparison of entering blocking state: both Thread.sleep () and Object.wait () can pause the current thread and release control of CPU. The main difference is that Object.wait () releases the object lock held while releasing CPU. 5) yield (): public static void yield () description: pause the currently executing thread object and execute other threads, that is, thread comity. Note: pausing the current thread does not block the thread, but puts it into the ready state. So it's entirely possible: after a thread calls yield (), the thread scheduler dispatches it for re-execution. 6) interrupt (): description: 1) each thread has an interrupt flag of boolean type. When a thread calls the interrupt () method, the interrupt flag of the thread will be set to true, and the thread is in the interrupted state. 2) calling the thread's interrupt () method simply sets the thread's interrupt flag to true and does not interrupt a running thread. 3) if the thread's interrupt flag is not detected in the program, the thread will run as usual even if the thread's interrupt flag is set to true. Application: 1) when a thread calls methods such as Thread.sleep (), Thread.join (), object.wait (), etc., it will put the current thread into a blocking state. 2) if (the thread is in the blocking state) calls the interrupt () method to interrupt the thread, the thread in the blocking state will throw an exception and clear the interrupted state of the thread, so that the thread can exit the blocking state. 3) the implementation of Thread.sleep (), Thread.join (), object.wait () and other methods all include the detection of thread interrupt identification: if the interrupt flag is true, an exception is thrown and the interrupt flag bit is set to false. IsInterrupted (): public boolean isInterrupted () states that the test thread has been interrupted without clearing the interrupted state of the thread. Eg:thread.isInterrupted (); determines whether the thread object pointed to by thread is in an interrupted state. Interrupted (): public static boolean interrupted () description: test whether the current thread has been interrupted, and set the interrupt ID of the thread to false. Eg:thread.interrupted (); determines whether the thread that calls the thread.interrupted (); statement (that is, the current thread) is in an interrupted state. 7) stop (): [@ Deprecated] (https://my.oschina.net/jianhuaw) public final void stop () description: terminate the thread, stop the thread immediately, and release the lock held by the thread! As a result, the data can not be synchronized, and the problem of data inconsistency may occur. Add: other ways to stop the thread; 1 > manually throw an exception to stop the thread (recommended): advantage: in the catch block, the caught exception can be thrown up, so that the thread stop event can be propagated upward. 2 > use return to stop threads: use the interrupt () method in combination with return to achieve the function of stopping threads. Eg: in the run method: if (this.isInterrupt ()) {return;} 8) suspend (): [@ Deprecated] (https://my.oschina.net/jianhuaw) public final void suspend () description: 1 > suspend the thread into the "blocking" state until the resume () method is called. 2 > monopolize public synchronization objects, making it impossible for other threads to access public synchronization objects. 3 > this method is prone to deadlocks: when suspend () is called, the target thread stops, but still holds the lock acquired before. If other threads want to restore the target thread through the resume () method, and must use the resources locked by the target thread, it will cause a deadlock. Example: when the program in a thread's run () method executes and enters the interior of a synchronized method, if the thread calls the suspend () method is suspended, then the synchronized method will be in a "paused" state until the call to resume () method is awakened, and the lock has not been released, and other threads cannot call this method. 9) resume (): [@ Deprecated] (https://my.oschina.net/jianhuaw) public final void resume () description: resume threads, resume threads suspended by suspend method Note: suspend () and resume () can easily lead to deadlocks, so the mechanism of calling wait () and notify () by lock objects should be used instead of suspend () and resume () to control threads. 10) getName () / setName (): description: get / set the name of the thread Note: the default name of the first child thread: Thread-0 is the method in the thread class Thread. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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