Question

我有一席之地,需要放弃,以便它能够继续发表带有其他价值的发言。这样做的最佳方式是什么? 例如:

if (data.startsWith("tcp") ) 
{
   /* main.strings should have a value but it may take a while */
   main.start("i generate some encoding/decoding, i take uncertain time...");

   int i = 0;
   while(main.strings != null) 
   {
     /* Maximum 20 time waiting is accepted, else not */
     if (i > 20 ) break; 
     Thread.sleep(1000);
     i++;
   }

   /* It crash, if main.start() is not creating the main.strings  
    * so there is a uncertain specific time, for this but we however can t wait long
    */
   main.NowUDPSend(main.strings); 
   ...
}

这是在休息期间处理实时问题的最佳途径,这样一来,在20倍的时间里,我就能够离开。

Answer 1

for (int i = 0; main.strings != null && i <= 20; ++i) {
  Thread.sleep(1000);
}

将使用main.wait (0), , 并且有下列内容:main.strings ,docs/api/java/article/contentr=#28%。

见。 a. 接受良好教学。

往往必须协调它们的行动。最常见的协调部分是守卫区。投票开始后,投票必须满足条件,才能进入投票区。为了正确做到这一点,采取了一些步骤。

例如,<代码>受保障监督的Joy是一种方法,在另一条路面确定共同可变的喜悦之前不得继续使用。从理论上讲,这种方法只能停留在满足条件之前,但这种做法是浪费的,因为它在等待时不断执行。
public void guardedJoy() {
  //Simple loop guard. Wastes processor time. Don t do this!
  while(!joy) {}
  System.out.println("Joy has been achieved!");
}
A more efficient guard invokes Object.wait to suspend the current thread. The invocation of wait does not return until another thread has issued a notification that some special event may have occurred — though not necessarily the event this thread is waiting for:
public synchronized guardedJoy() {
    //This guard only loops once for each special event, which may not
    //be the event we re waiting for.
    while(!joy) {
        try {
            wait();
        } catch (InterruptedException e) {}
    }
    System.out.println("Joy and efficiency have been achieved!");
}
......

当援引<条码>wait时,便可24小时释放并暂停执行。在今后某个时候,另一条之行将获得同一锁,并援引<条码>。 All , informing all threadsimmer at that lock that some important has dated:
public synchronized notifyJoy() {
    joy = true;
    notifyAll();
}

Answer 2

等待/说明所有这一切都将奏效,在“java.util”一揽子计划下,在JDK实施了一些锁和障碍,而目前一揽子计划的使用和使用比像等待这样的基本条件更容易。

For this, check out CountdownLatch. It does exactly what you want.

友情链接