Turnstile Synchronization Prevents Writer Starvation in the Readers-Writers Problem

The article examines the Readers-Writers Problem, where concurrent reads are safe but writes need exclusive access. A naive solution favors readers, so a steady stream of them can keep a writer waiting indefinitely. To address this, the piece presents a design using a FIFO turnstile semaphore that queues arriving readers behind a waiting writer. Once the active readers finish, the writer proceeds without delay. The author argues this approach gives both readers and writers bounded waiting, eliminating writer starvation.