Wait-Notify机制 矫情吗;* 2022-07-16 11:27 158阅读 0赞 http://www.ticmy.com/?p=219 Wait-Notify机制可以说是实现阻塞操作较为高效的一种方式。虽然在实际中鼓励使用类库中已有的满足条件的类,或基于类库中的类来做满足自己特殊需求的开发,并不建议直接使用如此底层的机制,但了解其原理还是很有必要的。 典型的Wait-Notify场景一般与以下内容相关: **1、状态变量(State Variable)** 当线程需要wait的时候,总是因为一些状态不满足导致的。如往BlockingQueue里加元素队列已满的时候。当状态满足的时候,程序就可以执行下去。 **2、条件断言(Condition Predicate)** 当线程确定是否进入wait或者从notify中醒来的时候是否继续往下执行,大都要测试状态条件是否满足,如往BlockingQueue里加元素队列已满,于是阻塞,后续其它线程从队列里取走了元素,就通知在等待的线程“队列不是满的了,可以往里加东西了”,这时候在等待的线程就会醒来,然后看看是不是真的队列不为满的状态,如果是,就将元素添加进去,如果不是,就继续等待。 **3、条件队列(Condition Queue)** 每个对象都有一个内置的条件队列,当一个线程在该对象是调用wait的时候,就会将该线程加入该对象的条件队列。 基于以上,接下来说说wait(以及其它两个带超时时间的wait重载版本,后文如无特别说明,wait就表示这三种操作)、notify(以及notifyAll,后文若无特别说明,notify表示这两种操作)操作。 在调用wait、notify的时候,必须先持有锁,且状态变量须由该锁保护,而内置锁对象与内置条件队列对象又是同一个对象。也就是说,**要在某个对象上执行wait,notify,先必须锁定该对象,而对应的状态变量也是由该对象锁保护的**。如果在调用wait、notify的时候没有持有锁,将会抛出以下错误: Exception in thread “main” java.lang.IllegalMonitorStateException 这很容易通过下面的代码重现: <table style="border-collapse:collapse; border-spacing:0px; width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <tbody style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <tr style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <td style="width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px!important; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">package</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> com.ticmy.concurrency;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> class</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> TestWatiNotifyMechanism { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">private</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object obj = </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">new</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> void</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> main(String[] args) </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">throws</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Exception { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//错误代码,无意义,仅测试用</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">obj.wait();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//obj.notify();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> </div> </td> </tr> </tbody> </table> 如果上述代码在obj上调用wait,而持有其他对象的锁呢? <table style="border-collapse:collapse; border-spacing:0px; width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <tbody style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <tr style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <td style="width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px!important; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">package</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> com.ticmy.concurrency;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> class</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> TestWatiNotifyMechanism { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">private</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object obj = </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">new</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> void</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> main(String[] args) </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">throws</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Exception { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//错误代码,无意义,仅测试用</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">synchronized</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">(TestWatiNotifyMechanism.</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">class</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">) { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">obj.wait();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//obj.notify();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> </div> </td> </tr> </tbody> </table> 情况和没有锁一样。只有在哪个对象上调用wait、notify,就锁定哪个对象才可以。上面的代码,只要锁定obj对象就可以了: <table style="border-collapse:collapse; border-spacing:0px; width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <tbody style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <tr style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <td style="width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px!important; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">package</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> com.ticmy.concurrency;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> class</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> TestWatiNotifyMechanism { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">private</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object obj = </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">new</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Object();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> void</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> main(String[] args) </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">throws</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Exception { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//无意义,仅测试用,勿模仿</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">synchronized</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">(obj) { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">obj.wait();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">// obj.notify();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> </div> </td> </tr> </tbody> </table> **当在obj对象上调用wait操作的时候,就会释放当前持有的锁,并将线程加入到obj所属的条件队列**,而后阻塞,直到有其它线程在该obj上调用了notify操作或阻塞线程被中断或wait超时。 当调用**Object\#notify()方法时,会去唤醒对应对象条件队列中的某个线程,至于唤醒的是哪个线程,这是不确定的,选择是任意性的**。当调用Object\#notifyAll()方法时,会唤醒条件队列中的所有线程。**当唤醒一个线程或所有线程时,这个或这些线程需要自动重新获得原先wait时释放的锁**,它(们)并不一定立马就能执行,像其它线程一样,需要等待CPU来调度,需要与其它线程竞争执行前需要获得的锁。 线程的wait操作的典型代码结构如下: <table style="border-collapse:collapse; border-spacing:0px; width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <tbody style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <tr style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <td style="width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px!important; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">void</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> op() </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">throws</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> InterruptedException { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">synchronized</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">(obj) { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">while</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">(条件不满足) { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">obj.wait();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> </div> </td> </tr> </tbody> </table> **为什么要在循环中wait**?有以下几个原因。 1、一个对象锁可能用于保护多个状态变量,当它们都需要wait-notify操作时,如果不将wait放到while中就有问题。例如,某对象锁obj保护两种状态变量a和b,当a的条件断言不成立时发生了wait操作,当b的条件断言不成立时也发生了wait操作,两个线程被加入到obj对应的条件队列中,现在若改变状态变量a的某操作发生,在obj上调用了notifyAll操作,obj对应的条件队列里的所有线程均被唤醒,之前等待a的某个或几个线程去判断a的条件断言可能成立了,但b对应的条件断言肯定仍不成立,而此时等待b的线程也被唤醒了,所以需要循环判断b的条件断言是否满足,如果不满足,继续wait。 2、多个线程wait的同一个状态的条件断言。如BlockingQueue场景下,当前队列是空的,多个线程要从里面取元素,于是都wait了。此时另一个线程往里面添加了一个元素,调用了notifyAll操作,唤醒了所有线程,但只有一个线程能拿到那个新加进来的元素,继续走下去,其它的仍需等待。 3、虚假唤醒。在没有被通知、中断或超时的情况下,线程自动苏醒了。虽然这种情况在实践中很少发生,但是必须通过循环检测条件是否满足的方式来防止其发生,如果不满足该条件,则继续等待。 notify操作有两个方法可用,nofity和notifyAll,顾名思义,前者每次唤醒一个线程,后者唤醒所有线程。当唤醒所有线程的时候,会增加上下文切换、锁竞争。但很多时候,使用notify是有风险的,多个线程在同一个条件队列里等待不同的条件断言成立,极可能本该唤醒的线程没唤醒。那么什么时候才能用notify呢?牛人们已经总结好了,需要满足以下两个条件: 1、该对象的条件队列只关联了一个条件断言,且线程被唤醒后执行的代码逻辑是相同的; 2、单进单出。一次notify(这里不是指notify方法)能唤醒的线程至多一个。 对于第一点,在为什么要循环中wait以及为什么notify方法有风险时已经说过了。对于第二点,比如要实现一个类似开/关锁存器(在构造CountDownLatch的时候传入1)的功能,所有线程调用await()操作,最终某一线程调用countDown()操作,该countDown()操作就需要唤醒所有wait的线程。在这种场景下,第二条是不满足的——使用notify方法,其它线程将无法唤醒。 上面说到的都是内置锁,内置条件队列,与之对应的,有显式锁(Lock),显式条件队列(Lock\#newCondition()) Lock\#newCondition()返回一个Condition对象,该对象上对应于操作条件队列的wait和notify方法为:await、signal。与内置锁一样,要调用Condition的await、signal,需要锁定创建该Condition的Lock。如下代码形式: <table style="border-collapse:collapse; border-spacing:0px; width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <tbody style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <tr style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <td style="width:1022px; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px!important; background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important"> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">package</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> com.ticmy.concurrency;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">import</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> java.util.concurrent.locks.Condition;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">import</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> java.util.concurrent.locks.Lock;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">import</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> java.util.concurrent.locks.ReentrantLock;</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> class</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> TestWatiNotifyMechanism { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">private</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Lock lock = </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">new</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> ReentrantLock();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">private</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Condition condition = lock.newCondition();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">public</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> static</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important"> void</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> main(String[] args) </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">throws</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> Exception { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(63,95,191)!important">//无意义,仅测试用,勿模仿</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">lock.lock();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">try</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">condition.await();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">} </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-weight:bold!important; font-size:1em!important; direction:ltr!important; display:inline!important; color:rgb(127,0,85)!important">finally</code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> { </code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">lock.unlock();</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important"> </code> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0em!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; direction:ltr!important; white-space:pre!important"> <code style="background:none!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,"Bitstream Vera Sans Mono","Courier New",Courier,monospace!important; font-size:1em!important; direction:ltr!important; display:inline!important">}</code> </div> </div> </td> </tr> </tbody> </table> 除了这个对应关系不一样,其他诸如需要在循环中await,以及使用signal()还是signalAll()等原理与前面一致,不再赘述。需要说到的是,它与内置锁、内置条件队列的区别。 1、内置锁对象只有一个条件队列,而显式锁可以通过newCondition方法创建多个条件队列,这样就可以避免不同的条件断言关联同一个条件队列造成的问题。 2、如同Lock比内置锁更灵活一样,显式的条件队列也提供了更多的方法供调用(如等待的时候不可被中断的awaitUninterruptibly方法),更多方法参见java.util.concurrent.locks.Condition的JAVA API。 3、Condition也有wait、notify方法,它们从Object类继承而来,一般实际中不会调用这些方法(要调用这些方法必须持有Condition对象的锁,而不是Lock的锁定)以避免混淆。 4、Condition可以继承Lock的公平策略。如new ReentrantLock的时候传入的公平策略参数。当公平策略为true的时候,signal的时候,Condition中的线程唤醒顺序是FIFO的。 至于是选择显式的条件队列还是内置的,如同**[内置锁和Lock][Lock]**一样,取决于应用是否需要使用内置条件队列无法提供而显式条件队列提供了的特性。如果已使用了Lock,那么使用Condition是自然而然的事情。 [Lock]: http://www.ticmy.com/?p=192
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