A question about the interruption when JAVA uses Condition?

problem description

when using Condition to suspend and wake up threads, I often see the following methods
Thread1 calling the Await () method to wait for Thread2"s Signal to wake up. In order to avoid a long wait and add a timeout limit, Thread1 is usually written as Condition.await (long,TimeUnit). But is it true that Condition will return after the timeout?

the environmental background of the problems and what methods you have tried

I looked through the relevant source code and found that this is not the case. You can detect

with the following code

related codes

/ / Please paste the code text below (do not replace the code with pictures)

public class TestConditionAwait {

    private static ReentrantLock lock = new ReentrantLock();

    private static Logger Log = LoggerFactory.getLogger(TestConditionAwait.class);

    public static void main(String[] args) throws InterruptedException {
        final Condition condition = lock.newCondition();
        final Thread thread1 = new Thread(new Runnable() {
            @Override
            public void run() {
                lock.lock();
                try {
                    Thread.currentThread().setName("ConditionAwait-Thread-");
                    Log.error(Thread.currentThread().getName() + " beforeAwaitTime:" + System.currentTimeMillis());
                    condition.await(5000, TimeUnit.MILLISECONDS);
                } catch (InterruptedException e) {
                    Log.error(Thread.currentThread().getName() + " finishAwaitTime:" + System.currentTimeMillis());
                }finally {
                    lock.unlock();
                    Log.error(Thread.currentThread().getName() + " unlockTime:" + System.currentTimeMillis());
                }

            }
        });

        Thread thread2 = new Thread(new Runnable() {
            @Override
            public void run() {
                Thread.currentThread().setName("ConditionSignal-Thread-");
                try{
                    Log.error(Thread.currentThread().getName() + " getLockTime:" + System.currentTimeMillis());
                    thread1.interrupt();
                    lock.lock();
                    long currentTime = System.currentTimeMillis();
                    while (System.currentTimeMillis() - currentTime < 8000){

                    }
                    condition.signal();
                    Log.error(Thread.currentThread().getName() + " signalTime:" + System.currentTimeMillis());
                }catch (Exception e){

                }finally {
                    lock.unlock();
                    Log.error(Thread.currentThread().getName() + " unlockTime:" + System.currentTimeMillis());
                }
            }
        });
        thread1.start();
        Thread.sleep(50);
        thread2.start();
    }
}

what result do you expect? What is the error message actually seen?

Dec.22,2021

the result of your code is like this: thread1 gives up the lock after await, thread2 acquires the lock and starts the loop. After 5000ms, thread1 is awakened from the condition variable waiting queue. At this time, thread1 has to regain the lock to continue execution, but the lock is occupied by thread2, so it has to wait until thread2 releases the lock, that is, after 8000ms.

thread1 is awakened by a timeout from the conditional variable waiting queue and then enters the lock waiting queue.

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b409dc-348da.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b409dc-348da.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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