Constant RMR solutions to reader writer synchronization
Vibhor Bhatt, Prasad Jayanti · 2010
We study Reader-Writer Exclusion [1], a well-known variant of the Mutual Exclusion problem [2] where processes are divided into two classes - readers and writers - and multiple readers can be in the Critical Section (CS) at the same time, although no process may be in the CS at the same time as a writer. Since readers don't conflict with each other, they should not obstruct each other. Specifically, the concurrent entering property must be satisfied: if all writers are in the Remainder section, each reader should be able to enter the CS in a bounded number of its own steps. Three versions of the Reader-Writer Exclusion problem are commonly studied - one where writers have priority over readers, another where readers have priority, and the last where neither class has priority over the other and no process may starve.