When there are concurrent requests for a resource, it is necessary to synchronize access.
Therefore:
Implement a scheduler that selects which request will be allowed to execute next.
Scheduling policies may be first-come/first-served, priority-based, or otherwise.
Using the StrategyPattern, one can customize the behavior of the scheduler for particular configurations or applications.
Consider the CommandPattern for representation of queued requests.
Other Related Patterns: LockPattern, ReadWriteLock, MediatorPattern, InterruptibleCommand, ReactorPattern
CategoryPattern | CategoryConcurrencyPatterns