Limiting the Number of Requests

Bounding requests processed concurrently

This is easily accomplished using a channel with a buffer, whose capacity is the maximum number of concurrent requests. The following program does nothing useful, but contains the technique to bound the requests. No more than MAXREQS requests will be handled and processed simultaneously because, when the buffer of the channel sem is full, the function handle blocks and no other requests can start until a request is removed from sem. The sem acts like a semaphore that is a technical term for a flag variable in a program that signals a certain condition.