Thread Independent Services

Digital UNIX supports Thread Independent Services (TIS) routines, which are provided to enable application writers to write thread-safe code for non-threaded libraries and applications. In the presence of threads, these routines provide the indicated thread-safe functionality. In the absence of threads, these routines impose the minimum possible overhead on their caller. Note that the TIS routines are used by the C runtime library to provide support for both single and multithreaded applications.