深入浅析java中volatile与lock的原理-创新互联

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深入浅析java 中volatile与lock的原理？针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。

java 中volatile和lock原理分析

volatile和lock是Java中用于线程协同同步的两种机制。

Volatile

volatile是Java中的一个关键字，它的作用有

• 保证变量的可见性
• 防止重排序
• 保证64位变量(long，double)的原子性读写
   

volatile在Java语言规范中规定的是

The Java programming language allows threads to access shared variables (§17.1). As a rule, to ensure 
that shared variables are consistently and reliably updated, a thread should ensure that it
 has exclusive use of such variables by obtaining a lock that, conventionally, enforces mutual 
exclusion for those shared variables.
The Java programming language provides a second mechanism, volatile fields, that is more convenient 
than locking for some purposes.
A field may be declared volatile, in which case the Java Memory Model ensures that all threads 
see a consistent value for the variable .
It is a compile-time error if a final variable is also declared volatile.