Problem Statement

Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute. Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could include time used by other processes on the computer. This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.

Let's start with the solution:

integer
identity(integer x)
{
    x;
}


integer
sum(integer c)
{
    integer s;

    s = 0;
    while (c) {
	s += c;
	c -= 1;
    }

    s;
}


real
time_f(integer (*fp)(integer), integer fa)
{
    date f, s;
    time t;

    s.now;

    fp(fa);

    f.now;

    t.ddiff(f, s);

    t.microsecond / 1000000r;
}


integer
main(void)
{
    o_real(6, time_f(identity, 1));
    o_text(" seconds\n");
    o_real(6, time_f(sum, 1000000));
    o_text(" seconds\n");

    0;
}