Ewald Cress explains thread-local storage and its relationship with SQL Server workers:
So far, this is all rather abstract, and we’re just seeing numbers which may or may not be pointers, pointing to heaven knows what. Let me finish off by illuminating one trail to something we can relate to.
Out of the five local storage slots which contain something, the first one here points to 00000000`3b656040. As it turns out, this is an instance of the CCompExecCtxtBasic class, and you’ll just have to take my word for it today. Anyway, we’re hunting it for its meat, rather than for its name. Have some:
Click through for details, including a graphic.