Priorities

The default scheduler knows two priorities, TaskPriority::Normal and ::High. High work is always taken before normal work.

Choosing a priority

• AddTask and Schedule take a priority. TaskPriority::Default inherits the calling task's priority, or Normal when the caller is not a task.
• Inside a task, SetTaskPriority changes the priority of the calling task.

What High is for

Give High to the tasks on the critical path — the serial stage of a pipeline that everything else waits for, the task that hands out work to the others. Normal tasks then fill the remaining time. In the showcases built on ConcurrentTasks, raising the serial stages to High is one of the simplest and most effective steps.

Yielding to high priority

A long-running normal task can let waiting high-priority work through with YieldTask(YieldFlags::HigherPriority); it returns at once if no high-priority work is waiting. See Yielding.

TaskSwap

The TaskSwap scheduler ignores priorities.

See also

• Task graphs
• TaskPriority, SetTaskPriority