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 real trouble about women is that they must always go on trying to adapt themselves to men’s theories of women, as they always have done. When a woman is thoroughly herself, she is being what her type of man wants her to be. When a woman is hysterical it’s because she doesn’t quite know what to be, which pattern to follow, which man’s picture of woman to live up to.”
—D.H. (David Herbert)