state, e.g. assuming that there is single flow of operations, and nothing gets swapped out (logically). This breaks with co-operative scheduling systems - e.g.

state, e.g. assuming that there is single flow of operations, and nothing gets swapped out (logically). This breaks with co-operative scheduling systems - e.g. task thread while waiting on I/O (for example) gets reused for some other task, hence they get to see the same thread_local, and somewhere someone assumed "thread_local" == "task_local" of sorts (but not).