In computer programming, the scheduler pattern is a software design pattern. It is a concurrency pattern used to explicitly control when threads may execute single-threaded code, like write operation to a file.
The scheduler pattern uses an object that explicitly sequences waiting threads. It provides a mechanism to implement a scheduling policy, but is independent of any specific scheduling policy — the policy is encapsulated in its own class and is reusable.
The read/write lock pattern is usually implemented using the scheduler pattern to ensure fairness in scheduling.
Note that the scheduler pattern adds significant overhead beyond that required to call a synchronized method.
The scheduler pattern is not quite the same as the scheduled-task pattern used for real-time systems.
Famous quotes containing the word pattern:
“The kind of relatedness to the world may be noble or trivial, but even being related to the basest kind of pattern is immensely preferable to being alone.”
—Erich Fromm (1900–1980)