As its name suggests, a single instance of ThreadLocal can store different values for each thread independently. Therefore, the value stored in a ThreadLocal instance is specific (local) to the current running thread. Any other code logic running on the same thread will see the same value, but not the values set on the same instance by other threads. There are exceptions, though, like InhertiableThreadLocal, which inherits parent threads’ values by default.

On January 3, 2018, the Meltdown and Spectre CPU architecture flaws were announced to the world. Due to early leaks, the announcement was made roughly a week earlier than planned. These bugs are easily the largest vulnerabilities announced in the last decade and require a complete reassessment of microprocessor architectures, and how software and hardware interact.