[LTP] [PATCH 5/6] [WIP,RFC] tst_run.sh: Run setup() only once

[Cyril Hrubis]

Hi!
> > NOTE: this is still not working on iterations (-i2), because
> > static int iterations is from tst_test.c is not propagated to
> > tst_run_shell.c. I wonder if I should set the value as environment
> > variable or add it into struct context.
> 
> Passing the current iteration as env variable is feasible.
> 
> Since LTP export an similar variable 'TST_ITERATIONS' in tst_test.sh,
> maybe define another env var for current loop, e.g. TST_ITERATION
> (or TST_CURRENT_LOOP), pass to tst_run.sh?
> 
> Something like:
> 
> 1. Create tst_get_cur_iteration(void) function in LTP core API
> 
> 2. Export current loop in tst_run_shell.c before running run_shell_tcnt()
> 
>   static void run_shell_tcnt(unsigned int n)
>   {
>     ...
>     char iter_buf[32];
>     
>     snprintf(iter_buf, sizeof(iter_buf), "%u", tst_get_cur_iteration());
>     
>     if (setenv("TST_ITERATION", iter_buf, 1))
>     	tst_brk(TBROK | TERRNO, "setenv(TST_ITERATION) failed");
>     
>     tst_run_script(shell_filename, params);
>   }
> 
> 3. Reuse it in tst_run.sh to run setup once globally
> 
>   [ "$1" == "1" ] && [ "${TST_ITERATION:-1}" == "1" ] && $TST_SETUP

It's a bit more complicated we do not have only iterations but also
duration and timeout per iteration. So we would need a function that
would return if the script should continue or not and also call the
heartbeat() function. Something as:

int tst_next_shell_iteration(void)
{
	int cont = 0;
	static int iteration = 0;

	if (iteration < iterations)
		cont = 1;

	if (stop_time && get_time_ms() < stop_time())
		cont = 1;

	if (!cont)
		return 0;

	heartbeat();
	return ++iteration;
}

The shell helper would call this and we would use it in tst_run.sh and
loop the tst_test() until we are said to stop.

-- 
Cyril Hrubis
chrubis@suse.cz