Operating Systems: Concurrent and Distributed Software Design

25.4. Sockets and file subsystem integrated IPC

In Section 25.3 we showed how SVr4 UNIX introduced a number of IPC abstractions for communication between processes. These represent a departure from the traditional I/O mechanisms that UNIX has provided in that they each use separate system call interfaces rather than being expressed in terms of operations on file descriptors. Alternative UNIX designs introduced a further set of IPC mechanisms which, in contrast, are integrated with the file subsystem and are generally accessed by performing ordinary read and write system calls. This increases the transparency with which they can be used by applications although, of course, it is important to remember the practical limits to this transparency and ...