如何为 Parallel.Async 后台任务设置更高的任务优先级？

Question

我需要为Parallel.Async 后台任务分配更高的任务优先级。由于 OmniThreadLibrary 有 SetPriority：如何为这个 Parallel.Async 任务设置特定的优先级？

uses
  CodeSiteLogging,
  OtlParallel, OtlTaskControl, OtlTask;

procedure TForm2.btnParallelAsyncClick(Sender: TObject);
begin
  CodeSite.Send('btnParallelAsyncClick 1');

  Parallel.Async(
    procedure(const task: IOmniTask)
    var
      a: Integer;
    begin
      // executed in background thread:
      a := 1 + 1;
      Sleep(2000);
      CodeSite.Send('Executed in Async Thread', a);

      task.Invoke( // used to execute code in main thread
        procedure
        begin
          CodeSite.Send('task.Invoke executed in main thread', a);
        end);

      Sleep(2000);
      CodeSite.Send('Again executed in Async Thread', a);
    end,
    Parallel.TaskConfig.OnTerminated(
    procedure(const task: IOmniTaskControl)
    begin
      // executed in main thread:
      CodeSite.Send('After background thread termination: Executed in Main Thread');
    end
    )
    );

  CodeSite.Send('btnParallelAsyncClick 2');
end;

Answer 1

替换

Parallel.TaskConfig.OnTerminated(...

例如

Parallel.TaskConfig.SetPriority(tpAboveNormal).OnTerminated(...

优先级的可能值是

tpIdle, tpLowest, tpBelowNormal, tpNormal, tpAboveNormal, tpHighest

请注意，这只会影响进程中线程的优先级，不会赋予进程本身更高的优先级。有关详细信息，请参阅 SetThreadPriority 函数的文档。