Re: Ada.Execution_Time

[anon@att.net]

In <iemhm8$4up$1@news.eternal-september.org>, BrianG <briang000@gmail.com> writes:
>anon@att.net wrote:
>> In <iejsu9$lct$1@news.eternal-september.org>, BrianG <briang000@gmail.com> writes:
>>> anon@att.net wrote:
>>>> In <ie91co$cko$1@news.eternal-september.org>, BrianG <briang000@gmail.com> writes:
>>>>> Georg Bauhaus wrote:
>>>>>> On 12/12/10 10:59 PM, BrianG wrote:
>>> ....
>> 
>> Kind of funny you cutting down "TOP" which can be found on most Linux 
>> boxes  Which allow anyone with the CPU options turn on to see both the 
>> Real_Time and CPU_Time.
>Please provide any comment I made for/against "top".  Since my original 
>question was based on Windows and I've stated that my (current) Linux 
>doesn't support this package, that seems unlikely (even if I didn't 
>trust my memory).
>> 
>....
>> Note: Not sure of the name for the Windows version of Linux's top.
>There is (that I know of) no real equiv to "top" - as in a command-line 
>program.  The equiv to GNOME's "System Monitor" (for example - a gui 
>program) would be Task Manager (and I made no comment about that either).
>> 
>....
>> 
>> How to you think these or any other web hosting company could measure the 
>> complete system resources without measuring the CPU Execution Time on a 
>> given user or application! In Ada, the routines can now use the package 
>> called "Ada.CPU_Execution_Time".
>> 
>I have no problem with what Execution_Time does (as evidenced by the 
>fact that I asked a question about its use) - it measures exactly what I 
>want, an estimate of the CPU time used by a task.  My problem is with 
>the way it is defined - it provides, by itself, no "value" of that that 
>a using program can make use of to print or calculate (i.e. you also 
>need Real_Time for that, which is silly - and I disagree that that is 
>necessarily required in any case - my program didn't need it otherwise).
>> 
>--BrianG
There has been many third party versions of this package over the years 
and most of them included a Linux version. The Windows is specific to GNAT. 
And it just like GNAT the Windows version is not complete either.

For Execution_Time there are three package. GNAT has 
  Ada.Execution_Time                    for both Linux-MaRTE and Windows
  Ada.Execution_Time.Timers             only for Linux-MaRTE
  Ada.Execution_Time.Group_Budgets      Unimplemented Yet



In using the Linux-MaRTE version ( 2 packages ) 
  Ada.Execution_Time 
  Ada.Execution_Time.Timers 

Of course in this example you could use ( Note: they are fully implemented )
  Ada.Real_Time
  Ada.Real_Time.Timing_Events


An algorithm comparison program might look like:

with Ada.Execution_Time ;
with Ada.Execution_Time.Timers ;

procedure Compare_Algorithm is

    task type Algorithm_1 is
      use Ada.Execution_Time.Timers ;
    begin
      begin
        Set_Handler ( ... ) ; -- start timer
        Algorithm_1 ;
        Time_Remaining ( ... ) ; -- sample timer
      end ;
      Cancel_Handler ( ... ) ; release timer
    end ;    

    task type Algorithm_2 is
      use Ada.Execution_Time.Timers ;
    begin
      begin
        Set_Handler ( ... ) ; -- start timer
        Algorithm_2 ;
        Time_Remaining ( ... ) ; -- sample timer
      end ;
      Cancel_Handler ( ... ) ; release timer
    end ;    

  use Ada.Execution_Time ;

begin
  -- Start tasks
  -- wait until all tasks finish
  -- compare times using Execution_Time
  -- Print summary of comparison
end ;