Coherence

Whether to share memory or to share data contained in the file, when multiple processes map a file simultaneously there can be problems with simultaneous access to data elements. Such processes can cooperate through any of the synchronization mechanisms provided in SunOS 5.0 through 5.8. Because they are very light weight, the most efficient synchronization mechanisms in SunOS 5.0 through 5.8 are those provides in the threads library. See mutex(3THR), condition(3THR), rwlock(3THR), and semaphore(3THR) in the manual pages for details on their use.