零散任务将在特定时间运行

Question

我有个零星的任务要打印一些东西。我想在指定的时间，即下午4:40运行这个任务。

我有一个创建循环任务的想法，它检查时间，当时间等于我指定的时间时，这个循环任务实现了零星任务的障碍。但是，如何检查我指定的时间(表示为Unix时间戳或字符串)现在是否等于时间？如何根据Ravenscar配置文件将我指定的时间转换为Ada.Real_Time.Time？

我怎样才能在Ada实现这一点？

这是我的代码：

sprinkler.ads

pragma Profile(Ravenscar);
with GNATCOLL.Ravenscar.Simple_Cyclic_Task;
with GNATCOLL.Ravenscar.Simple_Sporadic_Task;

package Sprinkler is

    Counter : Integer := 0;
    MyTime : String := "4:45";

    procedure My_Cyclic_Operation;
    package My_Cyclic_Task is new GNATCOLL.Ravenscar.Simple_Cyclic_Task
     (Task_Priority => 10,
      Phase => 0,
      Period => 1000,
      Cyclic_Operation => My_Cyclic_Operation);


    procedure My_Sporadic_Operation;
    package My_Sporadic_Task is new GNATCOLL.Ravenscar.Simple_Sporadic_Task
        (Task_Priority => 10,
        Minimum_Interelease_Time => 1_000,
        Protocol_Ceiling => 15,
        Sporadic_Operation => My_Sporadic_Operation);

end Sprinkler;

sprinkler.adb

pragma Profile(Ravenscar);
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Real_Time; use Ada.Real_Time;

package body Sprinkler is

    procedure My_Cyclic_Operation is
    begin 
        -- Here I want to run My_Sporadic_Operation when time at now is equal to my specified time
        null;
    end My_Cyclic_Operation;

    procedure My_Sporadic_Operation is
    begin
        Put_Line("Sporadic at specified time!");
    end;

end Sprinkler;

Answer 1

GNATCOLL.Ravenscar包遵守Ravenscar配置文件的限制，但是可以将它们编译到具有无限制配置文件的分区中。因此，除非您正在为一个只支持Ravenscar的系统进行编译，否则您可以(因为调用时间有限而导致一个小错误)。

• 将您的下午4:40转换为Ada.Calendar.Time
• 减去Ada.Calendar.Clock以获得Duration
• 使用Ada.Real_Time.To_Time_Span转换为Time_Span