The TaskList class implements methods to build and execute a set of tasks with associated dependencies. The main functionality of the class is implemented in two member functions:
AddTask is a templated variadic function that takes the task type as a template parameter and the function and arguments that define the task as function arguments. A variety of predefined task types ship with Parthenon (defined in tasks.hpp), but applications can define new types as needed.
DoAvailable loops over the task list once, executing all tasks whose dependencies are satisfied. The function returns either TaskListStatus::complete if all tasks have been executed (and the task list is therefore empty) or TaskListStatus::running if tasks remain to be completed.
The TaskID class implements methods that allow Parthenon to keep track of tasks, their dependencies, and what remains to be completed. The main way application code will interact with this object is as a returned object from TaskList::AddTask and as an argument to subsequent calls to TaskList::AddTask as a dependency for other tasks. When used as a dependency, TaskID objects can be combined with the bitwise or operator (|) to specify multiple dependencies.