1. A multiprocessing system, comprising: a hardware multithreading microprocessor, comprising: a plurality of thread contexts (TCs), each having a program counter and a general purpose register set; and a multiprocessor operating system (OS), said OS comprising a data structure having an entry for each of said plurality of TCs, each said entry configured to store a first item of information describing capabilities of at least one hardware resource shared by said plurality of TCs and a second item of information associated with a corresponding one of said plurality of TCs such that a value of said first item of said data structure corresponding to one of said plurality of TCs is the same as a value of said first item of said data structure corresponding to each other of said plurality of TCs while a value of said second item of said data structure corresponding to said one of said plurality of TCs is different from a value of said second item of said data structure corresponding to said each other of said plurality of TCs, wherein said second item of information comprises a TC identifier field for identifying said corresponding one of said plurality of TCs, wherein said OS is further configured to populate said TC identifier field for each said entry.