Each task has to implement the task interface which inherits annotation to subclasses.
Annotations provide the possibility to express runtime information about the behavior of a task to the scheduling and execution layer. Such information include
- the priority a task should run with,
- the target (a specific worker id, a resource that needs synchronized access,
localoranywhere) the task should execute on, - and the resource a task is accessing that could be load from memory into cache before the task executes.
Upon start, MxTasking will launch one worker thread on each (specified) logical hardware thread. The worker will fetch tasks from the task pool and executes them.
Every worker has its own task pool which has different backend-queues (a queue for normal priority and local dispatches, a queue for normal priority and remote dispatches from the same numa region, a queue for normal priority and dispatches from remote numa regions, a queue for low priority ...). Tasks will be fetched from the task pool and stored in a buffer before executed.
The task buffer is a buffer for a specific amount of tasks (i.e., 64 tasks).
Whenever the buffer becomes empty, the worker will contact the task pool and fill up the buffer with tasks from the pool.
The main reason for using a buffer is to get a precise view of future-tasks.
Tasks in the pool are stored in linked lists which are very costly to iterate whereas the buffer can be accessed like an array.
This is important to prefetch tasks that will be executed in the near future.
The task stack is used to persist the state of a task before executing the task optimistically. Executing a task optimistically may fail and the state of the task has to be reset to the state before executing (to execute again at a later time).
The scheduler dispatches tasks to task pools on different worker threads.
The configuration is specified by a config file.
max_cores: Specifies the maximal number of cores the tasking will spawn worker threads on.task_size: The size that will be allocated for every task.task_buffer_size: The size allocated in the worker-local task buffer which is filled by the task pools.is_use_task_counter: If enabled, MxTasking will collect information about the number of executed and disptached tasks. Should be disabled for measurements.is_collect_task_traces: If enabled, MxTasking will collect information about which task executed at what times at which worker thread. Should be disabled for measurements.memory_reclamation: Specifies if reclamation should be done periodically, after every task execution, or never.worker_mode: When running inPowerSavemode, every worker will sleep for a small amount of time to reduce power. Should bePerformancefor measurements.