-- PERFORMANCE MEASUREMENT : opening files

with Text_Io;
use Text_Io;
with Remote_Global;
use Remote_Global; -- control optimization
with Iteration; -- obtain stable measurement
with Piwg_Io; -- output results

procedure G000007 is  -- main procedure to execute
    Cpu_Time : Duration; -- CPU time for one feature execution
    Wall_Time : Duration; -- WALL time for one feature execution
    Check_Times : constant := 10; -- inside loop count and check
    Iteration_Count : Integer; -- set and varied by ITERATION package
    Stable : Boolean; -- true when measurement stable
    Scratch : File_Type;

begin

    Create (Scratch, Out_File, "SCRATCH7");
    Put_Line (Scratch, " just stuff ");
    Close (Scratch);

    Iteration.Start_Control;  -- dummy to bring in pages on some machines

    delay 0.5;  -- wait for stable enviornment on some machines

    Iteration.Initialize (Iteration_Count);

    loop  -- until stable measurement, ITERATION_COUNT increases each time

--
-- Control loop
--
        Iteration.Start_Control;
        for J in 1 .. Iteration_Count loop
            Global := 0;
            for Inside_Loop in 1 .. Check_Times loop
                Global := Global + A_One;
                Remote;  
            end loop;
        end loop;
        Iteration.Stop_Control (Global, Check_Times);

--
-- Test loop
--
-- establish the time to open a file

        Iteration.Start_Test;
        for J in 1 .. Iteration_Count loop
            Global := 0;
            for Inside_Loop in 1 .. Check_Times loop
                Global := Global + A_One;
                Remote;
                Open (Scratch, In_File, "SCRATCH7");
                Close (Scratch);
            end loop;
        end loop;
        Iteration.Stop_Test (Global, Check_Times);
        Iteration.Test_Stable (Iteration_Count, Stable);
        exit when Stable;
    end loop;
--
    Iteration.Feature_Times (Cpu_Time, Wall_Time);

--
-- Printout
--
    Piwg_Io.Piwg_Output
       ("G000007", "Input/Output", Cpu_Time, Wall_Time, Iteration_Count,
        " Open and close an existing file, time measurement",
        " A scratch file is created and closed ",
        " The scratch file is opened IN_FILE and closed in a loop");

end G000007;