Question

I have a shared Map data structure that needs to be thread-safe. Is synchronized the most efficient way to read or add to the Map?

Thanks!

Edit: The data structure is a non-updatable cache, i.e. once it fills up it does not update the cache. So lots of writes initially with some reads then it is mostly reads

Answer 1

“Most efficient” is relative, of course, and depends on your specific situation. But consider something like ConcurrentHashMap if you expect there to be many threads working with the map simultaneously; it’s thread safe but still allows concurrent access, unlike Hashtable or Collections.synchronizedMap().