Efficient C++ Performance Programming Techniques

Partial Sharing

We have previously encountered the two opposite extremes of resource sharing: the publicly shared resource pool and the thread-private instance of a resource. Between these two extremes lie the sharing middleground of the partial-sharing resource pool.

When each thread requires a single instance of a resource, you can easily eliminate contention by making it thread-private. If the required number of instances cannot be determined in advance, you need to use a resource pool that is shared among all threads. Such shared resources often become a contention hot spot among threads, which severely degrades performance and scalability. Threads spend significant cycles spinning idle. Partial-sharing of resource pools offers a way out ...