他是說以前一定要寫 finally 去回溯/移除 自己放在 ThreadLocal 的變數，因為 Thread 多半有 pool，是大家共用的。
之後用 virtual thread 就沒人在共用了，所以 ThreadLocal 不用怕碰到別人塞的值，也不用 finally 去處理。
而你講的 sharing 是該 thread 被用的當下，很多人都想塞變數，這個的確沒變，要靠 Scope Variable 的結構減少忘記互蓋的問題。
比較在意 ThreadLocal 關聯的應用場景..
var oldValue = myTL.get();
myTL.set(newValue);
try {
...
} finally {
myTL.set(oldValue);
}
Without this imposed structure, when a thread is shared among multiple tasks, one task’s TL values might leak into another. Virtual threads solve that problem by being lightweight enough to not require sharing.
沒看懂，為何 lightweight 就不用 sharing.
Even basic control flow, like loops and try/catch, need to be reconstructed in “reactive” DSLs, some sporting classes with hundreds of methods.
RxJava 就是你
一個 class 有上百個 method 就是錯錯錯，沒什麼好說的
能夠寫正常的程式的話，誰要寫 reactive，誰要寫 async/await
Project Loom 走在正確的道路上，成功後就會換其他平台來學
virtual thread 真是讓人興奮
所以 jdbc driver 都不用改自動就會變 virtual thread ?
web request ->
socket virtual thread -> (virtually blocking)
business logic ->
jdbc request ->
driver socket virtual thread -> (virtually blocking)
然後在兩次的 virtual block 中，背後 OS thread 可能已經換過，或是沒變這樣？
It's like putting another I/O specific cache layer that supports plenty operations including batch between the kernel space and the user space, so that the transitions between the kernel mode and the user mode can be largely reduced. Relying on a bunch of magic, it increases the throughput of I/O operations.
最近發現 Kotlin 的設計商 JetBrains 自己有做了一個教學系統叫做 JetBrains Academy ，透過線上教學文件和自動審核程式的機制來讓你一步一步學習 Kotlin ，我覺得還蠻不錯的，只是每次 Submit 上去都要等蠻久的就是了 XD""""
目前支援 Java, Kotlin, Python 三種語言。