Threads—a sequential flow of control—have been around for a long while now; only, they went under the name of processes (reports put this at the time of the Berkeley Timesharing System, 1965). Then, by the early 1970s, along came Unix, which cemented the process as the combination of a VAS and a sequential flow of control. As mentioned earlier, this is now called the single threaded model, as of course only a single thread of control—the main function—existed.
Then, in May 1993, Sun Solaris 2.2 came out with UI threads, and a thread library called libthread, which exposed the UI API set; in effect, modern threads. Competing Unix vendors quickly came up with their own proprietary multithreaded solutions (with ...
