POSIX threads, or pthreads, allow multiple tasks to run concurrently within the same program. They can share a single CPU as processes do, or take advantage of multiple CPUs when available. In either case, they provide a clean way to divide the tasks of a program while sharing data. This book thoroughly covers the POSIX threads standard, which is supported by the Distributed Computer Environment (DCE), as well as Solaris, OSF/1, AIX, and several other UNIX-based operating systems. In this book you will learn not only what the pthread calls are, but when it is a good idea to use threads and how to make them efficient (which is the whole reason for using threads in the first place). The authors delves into performance issues, comparing threads to processes, contrasting kernel threads to user threads, and showing how to measure speed. He also clearly describes all the advanced features and how threads interact with the rest of the UNIX system.