(I am interested in design of implementation NOT a readymade construct that will do it all.)

Suppose we have a class HashTable (not hash-map implemented as a tree but hash-table) and say there are eight threads. Suppose read to write ratio is about 100:1 or even better 1000:1. Case A) Only one thread is a writer and others including writer can read from HashTable(they may simply iterate over entire hash table) Case B) All threads are identical and all could read/write.

Can someone suggest best strategy to make the class thread safe with following consideration 1. Top priority to least lock contention 2. Second priority to least number of locks

My understanding so far is thus : One BIG reader-writer lock(semaphore). Specialize the semaphore so that there could be eight instances writer-resource for case B, where each each writer resource locks one row(or range for that matter). (so i guess 1+8 mutexes)

Please let me know if I am thinking on the correct line, and how could we improve on this solution.