Summary

In this chapter, we introduced shared memory in GNU/Linux and the APIs that control its use. We first introduced the shared memory APIs as a quick review and then provided a more detailed view of the APIs. As shared memory segments can be shared by multiple asynchronous processes, we illustrated the protection of a shared memory segment with a semaphore. Finally, we reviewed the ipcs utility and demonstrated its use as a debugging tool, as well as the ipcrm utility for removing shared memory segments from the command line.