java - Compare 在 AtomicInteger.incrementAndGet() 的 CompareAndSwap 中比较什么？

Question

我知道CompareAndSwap是在java并发中的AtomicInteger.incrementAndGet()等方法的底层使用的，它的工作原理就像无限循环，直到成功并阻塞它的线程

It compares the contents of a memory location with a given value and, only if they are the same, modifies the contents of that memory location to a new given value. This is done as a single atomic operation. The atomicity guarantees that the new value is calculated based on up-to-date information; if the value had been updated by another thread in the meantime, the write would fail. The result of the operation must indicate whether it performed the substitution; this can be done either with a simple boolean response (this variant is often called compare-and-set), or by returning the value read from the memory location (not the value written to it).

那么incrementAndGet()中的给定值和内存位置的内容是什么？

Answer 1

当一个线程看到当前值(例如 1)时，会将其递增到 2 作为给定值，并比较 2 为当前时刻内存中的实际值。

如果成功，将返回2。

否则，它将检索最新值，假设为 x，并递增到 x + 1 作为给定值。

...

此过程将持续到比较成功为止。