Cross-process read-write synchronization primative in .NET?

Question

Is there a read/write locking mechanism that works across processes (similar to Mutex, but read/write instead exclusive locking)? I would like to allow concurrent read access,

Answer 1

Windows does not include a cross process Reader-Writer lock. A combination of Semaphore and Mutex could be used to construct ones (the Mutex is held by a writer for exclusive access or by a Reader which then uses the Semaphore to release other readers—i.e. writers would wait on just the mutex and readers for either).

However, if contention is expected to be low (i.e. no thread holds a lock for long) then mutual exclusion may still be faster: the additional complexity of the reader-writer lock overwhelms any benefit of allowing multiple readers in. (A reader-writer lock will only be faster if there are many more readers and locks are held for significant time—but only your profiling can confirm this.)