在操作系统中，解决进程间的(1)两种基本关系，往往运用对信号量进行(2)的(3)。例如，为保证系统数据库的完整性，可以把信号量定义为某个库文件(或记录)的锁，初值为1，任何进程存取该库文件(或记录)之前先对它作一个(4)，存取之后对它作一个(5)，从而做到对该文件(或记录)任一时刻只有一个进程可存取，但要注意使用不当引起的死锁。

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When we announced Java 2 Micro Edition(J2ME)a few years ago, we believed that Java had an important role to play in hand held devices. Some were(71)that Java would be small enough for such limited devices.

 But no(72), Java for the small device is a success. J2ME has emerged strongly in the wireless market. Java's portability and extensibility have brought about rapid(73)in this market.

 The success of Java beyond desktop computers is significant(74)developers. Java literacy is now more important than ever, as Java is used more and more to(75)a whole range of new computing devices--not only wireless handsets but also personal digital assistants, cameras, automobiles, home control, and so on.

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