Question

我得到一个IllegalMonitorStateException，我觉得我不能读更多，所以我问是否有人知道我做错了什么。我在程序运行结束时，在计数器（Gate类中的线程之间的共享资源）卡在等待之后得到此错误。告诉线程结束我从main方法中断它们。

Counter类有其他几个关键部分的方法。

            private int currentValue; /* to keep score of people passing */

            /* critical section */
    public synchronized boolean isFull() {
        if(busy) {  /* lock */
            try {
                wait();
            } catch (InterruptedException e) {
                System.out.println("isFull was interrupted waiting");
            }
        }
        busy=true;
                    /* is not full notify threads waiting to resume work*/
        if(currentValue < maxValue) {
            notify();
            busy=false; /* unlock */
            return false;
        }
                    /* do not notify threads */
        return true;
    }

            /* critical section */
    public synchronized void addPersons() {
        if(busy) {
            try {
                wait();
            } catch (InterruptedException e) {
                System.out.println("addPersons was interrupted waiting");
            }   
        }
        busy=true;
        currentValue += nr_p;
        notify();
        busy=false;
    }

            public synchronized int getValue() {
        return currentValue;
    }

类Gate中的run方法（也有线程）：

            public void run() {
        while(!blocked) {
            int waitTime = (r.nextInt(5) + 1) * 1000; /* random seconds */
            if(counter.isFull(gatenr))
                try {
                       t.wait(); /* here is where the IllegalMonitorStateException occurs. */   
                } catch (InterruptedException e) {
                    System.out.println("Shutting gate off from waiting");
                }
            if(t.isInterrupted()) { /* check if thread is interrupted */
                System.out.println("breaking");
                break;
            }
            counter.addPersons(1);
            nrOfPassengers++;
            try {
                Thread.sleep(waitTime);
            } catch (InterruptedException e) {
                System.out.println("Shutting gate off from sleep");
            }
        }
    }

        /* used by main to interrupt threads from wait statement and close gate */
    public synchronized void close() {
        t.interrupt();
        blocked = true;
    }

主要方法有以下几行：

            while(counter.getValue() < MAX) { 
                Thread.sleep(3000);
            }
            System.out.println("Announcement: Ship is full!");


            /* wait for child threads to finish */
            for(Gate g: gates) {
                g.close(); /* interrupts thread in gate object */
                System.out.println(g.getNoOfPassangers() + " passed through gate nr " + g.getId());
            }
           }

这让我发疯，我已经阅读了有关显示器错误的所有信息。

Answer 1

t.wait();应该在synchronized(t)块中。

但是我在代码中看不到任何t.notifyAll()，所以看起来你可以永远等待。另请注意，标准习惯是在循环中等待机智虚假唤醒。

中断线程时出现IllegalMonitorStateException

1 个答案: