InheritableThreadLocal retrieves the threadLocal value of the parent thread.

Nov 22, 202362

AI Translation

This post is translated from Chinese into English through AI.View Original

AI-generated summary

The text discusses the get() and set() methods in InheritableThreadLocal and ThreadLocal. It explains that both methods use the getMap() method to obtain the ThreadLocalMap object. It also compares the getMap() method in InheritableThreadLocal and ThreadLocal, noting that InheritableThreadLocal retrieves inheritableThreadLocals while ThreadLocal retrieves threadLocals. The inheritableThreadLocals can be inherited by child threads, allowing them to access the threadLocal values of the parent thread.

1. get() and set() methods

get()
set()

Here we can see that both methods use the getMap method to obtain the ThreadLocalMap object. Therefore, we can infer that this method is probably what allows InheritableThreadLocal to access values from the parent thread.

2. getMap() method

Next, let's compare the getMap() method in InheritableThreadLocal and ThreadLocal.

InheritableThreadLocal
ThreadLocal

We can see that one obtains inheritableThreadLocals, while the other obtains threadLocals. The inheritableThreadLocals will be inherited by the child thread, allowing the child thread to access the threadLocal values of the parent thread (acting as a shared variable between threads).